JPH03234536A - Printhead, printhead substrate, and inkjet printing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to copying machines, facsimile machines, word processors,
Generates thermal energy used as energy for recording, especially regarding recording heads of recording devices used in printers as output terminals of host combinations, video output printers, etc., substrates for the heads, and inkjet recording devices. The present invention relates to a recording head in which an electrothermal transducer element and a recording functional element are formed on the same substrate, a substrate for the head, and an inkjet recording apparatus.

[Prior Art] Conventionally, the configuration of a recording head is to form an electrothermal transducer array on a single-crystal silicon substrate, and to use an electrothermal transducer such as a transistor array or diode array outside the silicon substrate as a drive circuit for the electrothermal transducer. Functional elements for driving the elements were arranged, and connections between the electrothermal conversion elements and the functional elements such as the transistor array were made using flexible cables, wire bonding, or the like.

Simplification of the structure considered for the above-mentioned head configuration,
Alternatively, electrothermal transducer elements and functional elements such as those proposed in Japanese Patent Application Laid-Open No. 57-72867 have been developed for the purpose of reducing defects occurring in the manufacturing process, making the characteristics of each element uniform, and improving reproducibility. An inkjet recording head is known in which both are provided on the same substrate.

FIG. 9 is a schematic cross-sectional view showing a portion of the recording head having the above-described configuration. 901 is a semiconductor substrate made of single crystal silicon. 902 is a collector region of an N-type semiconductor, 903 is an ohmic contact region of a highly impurity-concentrated N-type semiconductor, 904 is a base region of a P-type semiconductor, 90
Reference numeral 5 denotes an emitter region of a highly impurity-concentrated N-type semiconductor, which forms a bipolar transistor 920.

906 is a silicon oxide layer as a heat storage layer and an insulating layer;
907 is octunium boride (HfB) as a heating resistor layer.
2) Layer 908 is an aluminum (1) electrode, 909 and a silicon oxide layer as a protective layer, forming a base 930 for the recording head. Here, 940 is a heat generating part. The top plate 910 cooperates with the base 930 to open the liquid path 95.
0 is defined.

[Problem to be solved by the invention] By the way, although the structure described above is superior,
There is still room for improvement in order to satisfy the requirements of high speed driving, energy saving, high integration, low cost, and high reliability that have been strongly demanded of recording devices in recent years.

First of all, in order to achieve commercial success, a high performance recording head must be provided at a low cost. For that purpose,
It is necessary to integrate functional elements at a high density, reduce the area of a chip serving as a substrate of the recording head, and construct a lower cost recording head.

To this end, it is conceivable to reduce the size of functional elements such as diode transistors.

However, in the case of an inkjet recording head, in order to efficiently drive the electrothermal conversion elements disposed therein, it is necessary to
Do not allow a current of 200 to 400 mA to flow through it.As diodes, etc. become smaller, (1) the current will concentrate locally, and the current density in a certain area will abnormally increase, potentially destroying the junction. .

(2) High voltage is required to secure current for driving, and the entire system must be changed.

(3) If the current density flowing through the junction exceeds a certain value, the current may become saturated and the desired current may not be obtained.

Such problems arise.

An object of the present invention is to solve the above-mentioned technical problems and provide a recording head, a recording head substrate, and an inkjet recording apparatus capable of high-speed recording and high-resolution recording.

Another object of the present invention is to provide a highly integrated and highly reliable recording head and a recording head substrate at a low cost, thereby contributing to lower prices of inkjet recording apparatuses.

[Means for Solving the Problems] The present invention aims to solve these problems, and for this purpose, the present invention provides a liquid ejection section having an ejection port for ejecting ink, and a liquid ejection section having an ejection port for ejecting ink. a base body provided with an electrothermal conversion element for generating thermal energy used for ejecting the ink supplied to the base body, and a functional element electrically connected to the electrothermal conversion element. In the recording head, the junction area between the anode electrode and the cathode electrode of the functional element is 5 X 10-' cm2 or more when the driving current is 200 mA or more and less than 300 mA, and I X 10-' when the driving current is 300 mA or more and less than 400 IIIA. It is characterized by being larger than cm2.

The present invention also provides a recording head substrate in which an electrothermal transducer for generating thermal energy and a functional element electrically connected to the electrothermal transducer are provided on the same substrate. The junction area between the anode electrode and the cathode electrode of the element is 5 x 10 cm2 or more when the drive current is 200 mA or more and less than 300 mA, and is 1X10 cm2 or more when the drive current is 300 mA or more and less than 400 mA. do.

Furthermore, the inkjet recording apparatus of the present invention is characterized by comprising the recording head described above, means for supplying ink to the recording head, and means for conveying a recording medium to a recording position by the recording head.

[Function] In the present invention, by designing the bonding area to be larger than a set value, the area of the entire functional element can be reduced, and the above-mentioned problems that occur when attempting to reduce costs can be solved. That is, a small drive current with no variation can be obtained without changing the conventional drive voltage. As a result, a liquid jet recording head having a built-in single-function electrothermal transducer element that is inexpensive and highly reliable can be obtained.

[Examples] Hereinafter, the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following examples,
Any material may be used as long as the object of the present invention can be achieved.

(Example 1) First, the connection between an electrothermal conversion element and a diode as a driving functional element, and the driving of the electrothermal conversion element will be described.

FIG. 1(a) is a cross-sectional view schematically showing the wiring part of the board according to this embodiment, and FIG. 1(b) is an equivalent diagram of one block including a predetermined number of electrothermal conversion elements and functional elements. It is a circuit diagram. In this embodiment, the collector/base common electrode 12 corresponds to the anode of the diode, as will be described later with reference to FIG. 2(b).

The emitter electrode 13 corresponds to the cathode of the diode. When driving the electrothermal transducer (RHI, RH2), by applying a positive potential bias (V, , ) to the electrothermal transducer connected to the collector-base common electrode 12, the NPN transistor in the cell is activated. is turned on, and the bias current flows out from the emitter electrode 13 as a collector current and a base current.

As a result of short-circuiting the base and collector as in this example, the rise and fall characteristics of the heat of the electrothermal transducer are good, and the occurrence of film boiling phenomenon and the accompanying growth and contraction of bubbles are better controlled ( This is because in an inkjet recording head that uses thermal energy, the characteristics of the transistor are closely related to the characteristics of film boiling, and the switching characteristics are low due to the small accumulation of minority carriers in the transistor. This is thought to have a large influence on the prediction due to the fact that the rise time is faster and the rise characteristics are better.Also, there are relatively few parasitic effects (there is no variation between elements, and a stable drive current can be obtained. Furthermore, in the embodiment, by grounding the isolation electrode 14, it is possible to prevent charges from flowing into other adjacent cells, and the problem of malfunction of other elements can be prevented. .

In such a semiconductor device, the concentration of the N-type collector buried region 2 is set to Ix10"co+-" or more, and the concentration of the base region 5 is set to 5x10'4 to 5xlO? c.
It is desirable to set the bonding surface to m-' and further to make the area of the bonding surface between the high concentration base region 8 and the electrode as small as possible. In this way, the GN
It is possible to prevent the leakage current that occurs at point D from occurring.

The method for driving the recording head will be described in more detail. Although only two semiconductor functional elements (cells) are shown in FIG. 1(a), in reality, such elements are arranged in equal numbers corresponding to, for example, 128 electrothermal conversion elements. They are electrically connected in a matrix so that they can be driven in blocks (see FIG. 1(b)).

Here, driving of the electrothermal resistance elements RHI and RH2 as two segments in the same group will be explained.

In order to drive the electrothermal transducer RHI, first a group is selected by switch G1, and then switch S is selected.
1, the electrothermal converter RHI is selected and the positive voltage VHI
is applied. Then, the diode cell SHI having a transistor configuration is positively biased and a current flows out from the emitter electrode 13. Thus, the electrothermal converter RHI generates heat, and this thermal energy causes a state change in the liquid to generate bubbles and discharge the liquid from the discharge port.

Similarly, when driving the electrothermal converter RH2, the switch Gl and the switch S2 are selectively turned on to drive the diode cell SH2 and supply current to the electrothermal converter.

At this time, the substrate 1 is grounded via the isolation regions 3, 4.6. By grounding the isolation regions 3, 4.6 of each semiconductor element (cell) in this way, malfunctions due to electrical interference between the elements are prevented.

FIG. 2(a) shows a recording head generally constructed as described above. As shown in the figure, this head includes a plurality of ejection ports 500, a liquid path wall member 501 made of photosensitive resin or the like to form a liquid path communicating with the ejection ports, a top plate 502, and an ink supply port 503. have

Note that the liquid path wall member 501 and the top plate 502 can be integrated by using a resin molding material.

Next, the board and its wiring section will be described in more detail.

FIG. 2(b) is a schematic cross-sectional view of the recording head substrate and its wiring portion according to this embodiment, that is, a cross-sectional view taken along the line EE' in FIG. 2(a).

In the figure, 1 is a P-type silicon substrate, 2 is an N-type collector buried region for configuring functional elements, 3 is a P-type isolation buried region for separating functional elements, 4 is an N-type epitaxial region, and 5 is an N-type buried region. P-type base region for configuring functional elements; 6 is a P-type isolation region for element isolation;
7 is an N-type collector region for forming a functional element, 8 is a high concentration P-type base region for forming an element, 9 is a high concentration P-type isolation region for element isolation, and lO is for forming an element. 11 is a highly doped N-type collector region for forming the element, I2 is a collector-base common electrode, 13 is an emitter electrode, and 14 is an isolating electrode. Here, an NPN transistor is formed, with collector regions 2, 4, 7.11 completely surrounding the emitter region 10 and the base region 5.8. Further, as element isolation regions, each cell is surrounded and electrically isolated by a P-type isolation buried region, a P-type isolation region 7, and a high concentration P-type isolation region.

In the recording head 100 of this embodiment, a Si film 101 formed by thermal oxidation is formed on a substrate having the above-mentioned driving section, and a heat storage layer 102 formed of an oxidized SL film formed by CVD or sputtering is formed by sputtering. FIFB
A heat generating resistance layer 103 such as T and an electrode 1 such as Aβ formed by vapor deposition.
04 is provided.

A heating resistance layer 103 such as HfB2 is connected to a collector/base common electrode 12, an emitter electrode 13, and a wiring 20 such as Aβ.
2 and 201.

In addition, P t + Ta +
Z r B z *Ti-1f, Ni-Cr,
Ta-AA, Ta-3t, Ta-Mo,
Ta-11゜Ta-Cu, Ta-Ni, Ta-N
i-AA2, Ta-Mo-1114, Ta-W-N
i.

Ta-5i-AA2, Ta-W-AA2-Ni,
Ti-5i, W, Ti, Ti-N.

There are Mo, Mo-3i, W-SL, etc. Furthermore, on the heat generating part 110 of the electric force converting element, 5iO is applied by CVD method.
A protective film 105 such as Z and a protective film 106 such as Ta are provided.

Here, the SiO□ film forming the heat storage layer 102 is used for the lowermost wiring 12.14 of the driving section and the intermediate wiring 201 and 202.
It is provided integrally with the glabella insulating film between.

Similarly, regarding the protective layer 105, the wirings 201 and 20
It is integrated with the glabella insulating film between 2 and 2.

Next, the manufacturing process of the recording head according to this embodiment will be explained using FIGS. 3(a) to 3(k).

■P with an impurity concentration of about lX10''~10111013
A silicon oxide film of approximately 5,000 to 20,000 layers was formed on the surface of the mold silicon substrate 1.

The silicon oxide film in the portion where the collector buried region 2 of each cell was to be formed was removed by a photophosphorography process.

After forming the silicon oxide film, N-type impurities such as
N-type collector buried region 2 with an impurity concentration of I x 10"cm-3 or higher by ion implantation of P, As, etc. by thermal diffusion.
was formed to a thickness of 10 to 20 μm. The sheet resistance at this time is 3
It was designed to have a low resistance of 0Ω/mouth or less.

Next, the oxide film in the region where the P-type isolation buried region 3 is to be formed is removed, and after forming an oxide film of about 100 to 3000 layers, P-type impurities such as B are ion-implanted and heated. Due to diffusion, the impurity concentration lXl0''~lO1
A P-type isolation buried region 3 with a cm arch was formed.(See Figure 3(a)) ■After removing the oxide film on the entire surface,
1xlO+! N with an impurity concentration of ~10'cm-''
A mold epitaxial region 4 was epitaxially grown to a thickness of about 5 to 20 μm.

(See Figure 3(b)) Next, 100 to 300
Form a silicon oxide film the size of a human, apply resist,
Patterning was performed, and P-type impurity ions were implanted only into the region where the low concentration base region 5 was to be formed. After removing the resist, the impurity concentration is reduced to 5 x 10” to 5 by thermal diffusion.
x 10"cm-" low concentration P-type base region 5 from 5 to 1
A thickness of 0 μm was formed.

The oxide film is completely removed again, and further 1000~1ooo.

After forming a silicon oxide film as thick as a human being, the oxide film in the area where the P-type isolation region 6 is to be formed is removed, and the BS
A G film is deposited on the entire surface using the CVD method, and by thermal diffusion, a P-type isolation region 6 with an impurity concentration of 1xlo18 to 10"cm-" is formed to about 1101L so as to reach the P-type isolation buried region 3. Formed. (See FIG. 3(C) above) Here, it is also possible to form BBri as a diffusion source.

■After removing the BSG film, a silicon oxide film of about 1,000 to 10,000 layers is formed, and then an N-type collector region 7 is formed.
After removing the oxide film only in the region where the oxide film is to be formed, ions are implanted by forming PSG, and the N-type collector region 7 is formed by thermal diffusion to reach the collector buried region 5. The sheet resistance was set to be as low as 1007 or less.The thickness of the region was approximately 10 μm, and the impurity concentration was 1X10'' to 10''cm-''.

Subsequently, after removing the oxide film in the cell region, a silicon oxide film of 100 to 300 layers is formed, resist patterning is performed, and P is applied only to the regions where the high concentration base region 8 and the high concentration isolation region 9 are to be formed. Type impurity ion implantation was performed. After removing the resist, the oxide film in the area where the N-type emitter region 10 and the high-concentration N-type collector region 11 are to be formed is removed, a PSG film is formed on the entire surface, No is implanted, and high-concentration P is formed by thermal diffusion. type base region 8, high concentration P type isolating region 9, N type emitter region 10.
A highly doped N-type collector region 11 was formed at the same time. In addition,
The thickness of each region was 1.0 .mu.m or less, and the impurity concentration was 1X10'g to 10"cm.sup.-".

(The above is shown in Figure 3(d)) ■Furthermore, after forming the silicon oxide film 101, the silicon oxide film at the connection points of the electrodes was removed, Aβ etc. were deposited on the entire surface, and 1 etc. other than the electrode area was removed. .

(The above is shown in Figure 3(d)). Then, by sputtering, a layer of 0.4 to 1.0 μm is deposited on the SiO
Formed to some extent. This SiO□ film may be formed by the CVD method.

Next, the emitter area and base area are connected to make electrical connections.
A part CH of the insulating film 102 above the collector region was opened by photolithography. (The above is shown in FIG. 3(f)). Next, HfB as the heating resistance layer 103 is replaced with SiO
□ 1 on the top of the film 10 and the electrode on the top of the emitter region and the electrode on the top of the base/collector region for electrical connection
About 1,000 layers were deposited and patterned. (See Figure 3 (g) above) ■ On top of that, a layer of l material is deposited as a pair of electrodes 104 of the electrothermal transducer, the cathode electrode wiring 201 of the diode, and the anode electrode wiring 202, and patterned. The conversion element and other wiring were formed simultaneously.

(Fig. 3 (h)) ② In this way, a layer made of the same material as the heating resistor layer 103 was interposed between the semiconductor region and the A° C. electrode to obtain electrical connection.

Thereafter, a SiO□ film 10 was formed by sputtering as a protective layer of the electrothermal conversion element and an insulating layer between layer A°C wiring.
5 was deposited. (Fig. 3(i)) [Phase] Then, about 2000 Ta is deposited as a protective layer 106 for anti-cavitation 3 on the upper part of the heat generating part of the electrothermal converter, and on other parts, a protective layer 107 is deposited. A photosensitive polyimide was formed.

(FIG. 3(j)) A liquid path wall member and a top plate 502 for forming an ink ejection portion are provided on the base body having the electrothermal transducer element and the semiconductor element created as described above. , a recording head with an ink liquid path formed therein was manufactured. (Figure 3 (
k)) In this case, HfBz was interposed between the emitter and a part of the base-collector common electrode, but short circuits in the shallowly formed emitter part are particularly problematic, so at least a heat generating resistor layer is provided in this part. Any structure may be used as long as a layer of the same material is interposed therebetween.

Regarding such a recording head, recording and operation tests were performed by block driving the electrothermal transducer elements.

In the operation test, eight semiconductor diodes were connected to one segment and a current of 300 mA (total 2.4 A) was passed through each, but the other semiconductor diodes did not malfunction and could perform good discharge.

It goes without saying that the present invention can also be applied to a transistor having a PNP junction structure.

(Experimental Example) In the present invention, a plurality of samples of an inkjet recording head made by the above-described manufacturing process and a thermal head using a diode made by the above-described manufacturing process were made.

The emitter junction area is 5 x 10-', 5 x 10
-'8 X 10-' I X 10-' 2 X
10"' 3 X 10-'5 X 10-'
7 X 10-' 8 X 10-'' 9 X 10
-'I X 10-' 2 X 10-' 3 X
10-' 5 x 10-' were used to prepare 8 samples each of an inkjet recording head with 64 ejection ports and a thermal head with 64 heating elements.
Each pixel was prepared individually, and inkjet recording and thermal recording were performed continuously for a period of time to evaluate the dispersion of recorded dots for each pixel. The results are shown in the table below.

Note that the emitter junction area is the area of the X portion with the emitter junction length Y (the shaded area )
, and if you add the area of the two parts (side part), it becomes 10% larger. In Table 1, "I/J" indicates an inkjet recording head, and "thermal" indicates a thermal head.

The evaluation method is to select the most widely spaced dots from among all the dots ejected from one ejection port attached to the recording paper, and those whose values are within the desired standard value pass, and those that are outside the standard value. Reject something.

0 if all the ejection ports among the 8 heads passed, 0 if there were 2 or less heads with at least one ejection port failing.
A case where there were 14 or less pieces was graded Δ, and a case where there were 6 or more pieces was graded ×. Basically, with a thermal head, color is generated by contact between the thermal recording paper and the head, so no variation in dots was observed. Here, ×I indicates an abnormality such as no color development. Here, by comparison with a thermal head, it can be seen that in I/J, the recorded image is not simply deteriorated due to damage to the diode, but the ink ejection characteristics are affected.

(Example of apparatus to which the recording head is applied) Figures 4 to 8
The figure shows an inkjet unit IJU, an inkjet head IJH, an ink tank IT, and an inkjet cartridge IJC in which the recording head having the above configuration is implemented or applied.

Inkjet recording device main body IJRA, carriage HC
FIG. The configuration of each part will be explained below using these drawings.

As is clear from the perspective view of FIG. 5, the inkjet cartridge IJC in this example has a large ink storage ratio, and the tip of the inkjet unit IJU is slightly larger than the front surface of the ink tank IT. It has a prominent shape. This inkjet cartridge IJ
C is fixedly supported by a positioning means and electrical contacts (described later) of a carriage HC (FIG. 8) mounted on the inkjet recording apparatus main body IJRA, and
It is a disposable type that can be attached to and detached from the carriage HC. 4 to 8 of this example have configurations to which numerous inventions made at the stage of establishment of the present invention are applied, so while briefly explaining these configurations,
I will explain the whole thing.

(i) Inkjet unit IJU configuration description The inkjet unit IJU is a bubble jet unit that performs recording using an electrothermal transducer that generates thermal energy to cause film boiling in ink in response to electrical signals. be.

In FIG. 4, reference numeral 100 consists of electrothermal converters (discharge heaters) arranged in a plurality of rows on the SL substrate, and electrical wiring such as A2 for supplying electric power to the converters, which are formed by film-forming technology. This is a heater board having the above configuration. Reference numeral 1200 denotes a wiring board for the heater board 100, which includes wiring corresponding to the wiring of the heater board 100 (for example, connected by wire bonding), and a pad 1201 located at the end of this wiring and receiving electrical signals from the main device. have.

1300 is a grooved top plate provided with partition walls and a common liquid chamber for dividing a plurality of ink flow paths, and an ink receiver that receives ink supplied from an ink tank and introduces it into the common liquid chamber has an opening 1500. , an orifice plate 400 having a plurality of discharge ports is integrally molded. Although polysulfone is preferable as the material for integrally molding these, other resin materials for molding may also be used.

Reference numeral 300 denotes a support made of metal, for example, which supports the back surface of the wiring board 1200 on a flat surface, and serves as a bottom plate of the inkjet unit. Reference numeral 500 denotes a pressing spring, which has an M-shape and presses the common liquid chamber at the center of the M-shape, and also presses a part of the liquid path with linear pressure at the front sagging portion 501. The feet of the springs that press the heater board 100 and the top plate 1300 fit into the holes 312 of the support body 300.
1 to the back side of the support body 300 to engage the two in a state where they are sandwiched between them. Crimp and fix. Further, the support body 300 has two positioning protrusions 1012 of the ink tank IT and a protrusion 18 for positioning and heat-sealing retention.
0 (positioning hole 312.19 that engages with 1,1801
00.2000, and a projection 2500.2600 for positioning the device main body IJRA with respect to the carriage HC.
It has on the back side. In addition, the support 300 has an ink supply pipe 220 that allows ink to be supplied from an ink tank.
It also has a hole 320 that allows it to pass through. The wiring board 200 is attached to the support body 300 by adhering it with an adhesive or the like. Note that the recess 24 of the support body 300
00.2400 are the positioning protrusions 2500.
2600, and in the assembled inkjet cartridge IJC (Fig. 5), the three sides of the inkjet cartridge IJC are located at the extension point of the head tip region formed by a plurality of parallel grooves 3000 and 3001, and the dust is removed. The protrusions 2500 and 2600 are located in such a way that unnecessary substances such as oil and ink do not reach the protrusions 2500 and 2600. This parallel groove 3000 is formed. As can be seen in FIG. 4, the lid member 800 forms the outer wall of the inkjet cartridge IJC and also forms a space in which the inkjet unit IJU is accommodated. In addition, the ink supply member 600 in which the parallel grooves 3001 are formed has an ink conduit 1600 continuous to the ink supply pipe 2200 described above formed as a cantilever with the supply pipe 2200 side fixed, so that the fixed side of the ink conduit and the ink A sealing bottle 602 is inserted to ensure capillarity with the supply tube 2200. In addition, 601 is ink tank I
A gasket for sealing the connection between the T and the supply pipe 2200, 7
00 is a filter provided at the tank side end of the supply pipe.

Since this ink supply member 600 is molded, it is inexpensive and has high positional accuracy (no deterioration in precision during manufacturing), and the cantilevered conduit 1600 allows the conduit to be easily used during mass production. The above-mentioned ink receiver 1600 can be in stable pressure contact with the opening 1500. In this example, by simply pouring the sealing adhesive from the ink supply member side under this pressure contact state, a complete communication state can be reliably obtained. The support body 30 of the ink supply member 600
0 is fixed by holes 1901 and 190 in the support 300.
This can easily be done by projecting the back side bottle (not shown) of the ink supply member 600 for the support 300 through the holes 1901 and 1902 of the support 300, and heat-sealing the protruding part to the back side of the support 300. be exposed. Incidentally, since the slight protruding area of this heat-sealed back surface portion is accommodated in a recess (not shown) in the side wall surface of the inkjet unit IJU mounting surface of the ink tank IT, an accurate positioning surface for the unit IJU can be obtained.

(ii) Ink tank IT configuration description The ink tank is constructed by inserting the cartridge body 1000, the ink absorber 900, and the ink absorber 900 from the side of the cartridge body 1000 opposite to the unit IJU mounting surface, and then sealing the ink tank. and a lid member 1100 that stops.

Reference numeral 900 denotes an absorber for impregnating ink, and is disposed within the cartridge body 1000.

1220 is a unit I consisting of the above-mentioned parts 100 to 600.
It is a supply port for supplying ink to the JU, and also connects the unit to part 1 of the cartridge body 1000.
It is also an injection port for impregnating the absorber 900 with ink by injecting ink from the supply port 1220 in a step before disposing it in the absorber 900 .

In this example, the parts that can supply ink are the atmosphere communication port and this supply port, but the ribs 2300 in the main body 1000 and the lid member 1100 are used to ensure good ink supply from the ink absorber. The air existing area in the tank formed by the ribs 2500 and 2400 is connected to the atmosphere communication port 14.
Since the ink is formed continuously from the 01 side and extends over the farthest corner area from the ink supply port 1200, relatively good and uniform ink supply to the absorber can be achieved from the supply port 1200 side. It is important that This method is extremely effective in practice. This rib 1000 has four ribs parallel to the carriage movement direction on the rear surface of the main body 1000 of the ink tank, and prevents the absorber from coming into close contact with the rear surface. In addition, the partial rib 24
00 and 2500 are similarly provided on the inner surface of the lid member 1100 on the corresponding extension to the rib 1000, but unlike the rib 1000, they are in a divided state and the space in which air exists is more concentrated than the former. It is increasing.

It should be noted that the partial ribs 2500 and 2400 are distributed over half or less of the total area of the lid member 1000. These ribs allow the tank supply port 1200 of the ink absorber to
The ink in the corner region farthest from the ink could be more stably guided to the supply 01200 side by capillary force. Reference numeral 1401 denotes an atmosphere communication port provided in the lid member to communicate the inside of the cartridge with the atmosphere. Reference numeral 1400 denotes a liquid-repellent material disposed inside the atmosphere communication port 1401, which prevents ink from leaking from the atmosphere communication port 1400.

The ink storage space of the ink tank IT described above has a rectangular shape with its long sides on the sides, so the arrangement of the ribs described above is particularly effective. In the case of a case or a cube, the ink supply from the ink absorber 900 can be stabilized by providing ribs on the entire lid member 1100.

Further, the configuration of the mounting surface of the unit IJU of the ink tank IT is shown in FIG. If a straight line is drawn passing approximately through the center of the protruding opening of the orifice plate 400 and parallel to the mounting reference plane on the bottom surface of the tank IT or the surface of the carriage, then two positioning protrusions that engage with the holes 312 of the support body 300 are drawn. The origin 1012 is on this straight line.

The height of this protrusion 1012 is slightly lower than the thickness of the support 300, and positions the support 300. In this drawing, on the extension of the straight line L1, there is a claw 2 that is engaged with a 90° engagement surface 4002 of a carriage positioning hook 4001.
100 is located, and the positioning force for the carriage is configured to act in a plane region parallel to the reference plane including this straight line L1. As will be described later with reference to FIG. 4, these relationships are effective because the positioning accuracy of only the ink tank is equivalent to the positioning accuracy of the ejection ports of the head.

In addition, the fixing hole 1 on the side surface of the ink tank of the support body 300 is
The protrusions 1800 and 1801 of the ink tank corresponding to 900 and 2000 are longer than the above-mentioned protrusions 1012, and the parts that penetrate through the support 300 are heat-sealed to fix the support 300 to the side surface thereof. belongs to. A straight line 1 that is perpendicular to the above-mentioned line and passes through this protrusion 1800.
, when the straight line passing through the protrusion 1801 is L2, the straight line L3
Since almost the center of the supply port 1200 is located above,
This is a preferable configuration because it works to stabilize the bonded state between the mouth 1200 of the supply section and the supply pipe 2200, and reduces the load on these bonded states even when dropped or impacted. Also, straight line L2. L corresponds to the chair, and there are protrusions 18oo and 180 around the protrusion 1012 on the ejection port side of the head IJH.
1 exists, it further produces the effect of reinforcing the positioning of the head IJH with respect to the tank. Note that the curve indicated by L4 is the outer wall position when the ink supply member 600 is attached. Since the protrusions 1800° and 1801 are along the curve L4, they provide sufficient strength and positional accuracy even for the weight of the distal end side configuration of the head IJH. In addition, 2700
is the tip flange of the ink tank IT, and is attached to the front plate 4 of the carriage.
This is provided in case of an abnormal situation where the ink tank is inserted into the 000 hole and the displacement of the ink tank becomes extremely poor. 21
01 is an engagement part with a further positioning part with the carriage HC.

The ink tank IT has a shape that surrounds the unit IJU except for the lower opening by covering it with the lid 800 after the unit IJU is installed, but the inkjet cartridge IJC has a lower opening for placing it on the carriage HC. Since it is close to the carriage HC, it forms a substantial four-sided surrounding space.

Therefore, although the heat generated from the head IJH in this enclosed space is effective as a heat-retaining space, the temperature rises only slightly during long-term continuous use. Therefore, in this example, in order to help the natural heat dissipation of the support, the cartridge IJ
A slit 17 with a width smaller than this space on the upper surface of C.
00, it was possible to prevent temperature rise and to make the temperature distribution of the entire unit IJU uniform without being affected by the environment.

When assembled as an inkjet cartridge IJC, ink is supplied from inside the cartridge into the supply tank 600 through the supply port 1200, the hole 320 provided in the support 300, and the introduction port provided on the solid surface side of the supply tank 600. After passing through the interior thereof, the ink flows from the outlet into the common liquid chamber via an appropriate supply pipe and the ink inlet 1500 of the top plate 400. A packing made of, for example, silicone rubber or butyl rubber is disposed at the above-mentioned connection portion for ink communication, and this seals the ink supply path to ensure an ink supply path.

In this embodiment, the top plate 1300 is made of a resin such as polysulfone, polyethersulfone, polyphenylene oxide, or polypropylene, which has excellent ink resistance, and is molded together with the orifice plate part 400 in a mold. be.

As mentioned above, the integrally molded parts include the ink supply member 600,
Top plate and orifice plate integrated, ink tank body 10
00, it not only achieves a high level of assembly accuracy, but is also extremely effective in improving quality in mass production. Furthermore, since the number of parts has been reduced compared to the prior art, excellent desired characteristics can be reliably exhibited.

(iii) Description of attaching the inkjet cartridge IJC to the carriage HC In FIG. 7, 5000 is a platen roller that guides the recording medium P from the bottom to the top of the page. The carriage HC moves along the platen roller 3000, and has a front plate 4000 (2 m thick) located on the front side of the inkjet cartridge IJC on the front platen side of the carriage.
m), a flexible sheet 4005 having pads 2011 corresponding to the pads 201 of the wiring board 200 of the cartridge IJC, and each pad 2
An electrical connection support plate 4003 that holds a rubber pad 4006 for generating an elastic force to press against the inkjet cartridge IJC, and a positioning hook 4001 for fixing the inkjet cartridge IJC to the recording position are provided. The front plate 4000 has a positioning protrusion 410 connected to the above-mentioned positioning protrusion 2500 of the cartridge support 300.
2600, and after the cartridge is installed, a vertical force is applied to the protruding surface 4010.

For this reason, reinforcing ribs are placed on the platen roller side of the front plate.
It has a plurality of ribs (not shown) facing in the direction of the perpendicular force. This rib is located at the front surface when the cartridge IJC is installed, and also forms a head protection protrusion that protrudes slightly (about 0.1 mm) toward the platen roller. The electrical connection support plate 4003 has a plurality of reinforcing ribs 4004 not in the direction of the ribs but in the vertical direction, and the proportion of lateral protrusion is reduced from the platen side toward the hook 4001 side. This also serves the function of tilting the position when the cartridge is installed as shown in the figure. In addition, in order to stabilize the electrical contact state, the support plate 4003 has a positioning surface 4008 on the platen side and a positioning surface 4007 on the hook side, and a pad contact area is formed between these and a notch corresponding to the pad 2011 is provided. Uniquely defines the amount of deformation of 4006. These positioning surfaces come into contact with the surface of the wiring board 300 when the cartridge IJC is fixed at a recordable position. The distribution of the pads 201 in this example is such that the amount of deformation of each notch of the rubber sheet 4006 is made uniform and the contact pressure of the pads 2011 and 201 is made more stable.
There are two rows below and two rows vertically.

The hook 4001 has a long length that engages with the fixed shaft 4009, and uses this long movement space to rotate counterclockwise from the position shown in the figure, and then moves to the left side along the platen roller 5000. This positions the inkjet cartridge IJC with respect to the carriage HC. The hook 4001 may be moved in any way, but a configuration in which it can be moved using a lever or the like is preferable.

In any case, when the hook 4001 rotates, the cartridge IJC moves toward the platen roller and moves to a position where the positioning projections 2500 and 2600 can come into contact with the positioning surface 401O of the front plate, and the hook 4001 moves to the left. The 90° hook surface 4002 is connected to the cartridge IJC.
The cartridge IJ is in close contact with the 90° surface of the claw 2100.
C is rotated in a horizontal plane around the contact area of the positioning surface 2500.4010 and finally the pad 201.2011
Like-minded contacts begin. Then, when the hook 4001 is held in a predetermined or fixed position, the pad 201.201
1 complete contact state and positioning surface 2500.401
0 comrades' complete surface contact, two-surface contact between the 90-degree surface 4002 and the 90-degree surface of the claw, and the wiring board 300 and positioning surface 4007.
．． At the same time, surface contact with 4008 is formed, and retention of the cartridge IJC with respect to the carriage is completed.

(iv) General description of the main body of the apparatus FIG. 8 shows an inkjet recording apparatus I to which the present invention can be applied.
In the general view of JRA, the carriage HC that engages with the spiral groove 5004 of the lead screw 5005, which rotates via the drive force transmission gears 5011 and 5009 in conjunction with the forward and reverse rotation of the drive motor 5013, is (as shown),
It is moved back and forth in the directions of arrows a and b. Reference numeral 5002 denotes a paper holding plate that holds the paper on the platen 5 in the direction of carriage movement.
Press against 000. Reference numerals 5007 and 5008 are home position detection means for confirming the presence of the lever 5006 of the carriage in this area using a photocoupler and switching the rotational direction of the motor 5013. Reference numeral 5016 is a member that supports a cap member 5022 that caps the front surface of the recording head, and 5015 is a suction means for suctioning the inside of this cap to perform suction recovery of the recording head through an opening 5023 in the cap. 5017 is a cleaning blade,
Reference numeral 5019 denotes a member that allows this blade to move in the front and back direction, and these are supported by a main body support plate 5018. The blade is not in this form (it goes without saying that a well-known cleaning blade can be applied to this example. Also, 5012 is a lever for starting suction for suction recovery, and the movement of the cam 5020 that engages with the carriage The drive force from the drive motor is controlled by known transmission means such as clutch switching.

These capping, cleaning, and suction recovery are configured so that the desired processes can be performed at the corresponding positions by the action of the lead screw 5005 when the carriage comes to the home position side area. Any of these can be applied to this example as long as they are activated.

Each of the configurations described above is an excellent invention whether viewed singly or in combination, and represents a preferable configuration example for the present invention.

(Others) The present invention brings about excellent effects particularly in a bubble jet type recording head and recording apparatus among inkjet recording types.

According to such a method, recording density and definition have been increased, and
This is because the problems mentioned above will occur.

As for typical configurations and principles thereof, it is preferable to use the basic principles disclosed in, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740,796. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, it is necessary to arrange the liquid (ink) in accordance with the sheet and liquid path that hold it. The electrothermal converter that is
Generating thermal energy in the electrothermal transducer and producing film boiling on the thermally active surface of the recording head by applying at least one drive signal that corresponds to recorded information and provides a rapid temperature rise above nucleate boiling. As a result, bubbles in the liquid (ink) can be formed in a one-to-one correspondence with this drive signal, which is effective. The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one droplet. If this drive signal is in the form of a pulse, bubble growth and contraction will occur immediately and appropriately.
Particularly responsive liquid (ink) ejection can be achieved,
More preferred. This pulse-shaped drive signal is described in U.S. Pat. Nos. 4,463,359 and 4,345,262.
Those described in the specification are suitable. Furthermore, if the conditions described in US Pat. No. 4,313,124 concerning the invention regarding the temperature increase rate of the heat acting surface are adopted, even more excellent recording can be performed.

The configuration of the recording head includes, in addition to the combination configuration of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, a heat acting section. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which the wafer is placed in a bending region. In addition, Japanese Patent Application Laid-Open No. 1989-5 discloses a configuration in which a common slit is used as a discharge part of a plurality of electrothermal converters.
No. 9-123670 and Japanese Patent Application Laid-Open No. 59/1989 which discloses a configuration in which a discharge portion is made to correspond to an opening that absorbs pressure waves of thermal energy.
The effects of the present invention are also effective even if the structure is based on the publication No.-138461. In other words, regardless of the form of the printhead, printing can be performed reliably and efficiently.

Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by a recording apparatus.

Such a recording head may have either a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration as a single recording head formed integrally. In addition, even the serial type shown above has a replaceable chip-type recording head that can be attached to the main body of the device to enable electrical connection to the main body of the device and supply of ink from the main body of the device. Alternatively, the present invention is also effective when using a cartridge type recording head that is integrally provided with the recording head itself as shown in FIGS. 4 to 8.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention, because the effects of the present invention can be further stabilized. Specifically, these include capping means for the recording head, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof; It is also effective to perform a preliminary ejection mode in which ejection is performed separately from printing in order to perform stable printing.

In addition, regarding the type and number of recording heads installed, for example, in addition to one type that corresponds to single-color ink, there is also a plurality of recording heads that correspond to multiple inks with different recording colors and densities. It may be something that can be done.

In addition, inkjet recording devices to which the present invention is applied include those used as image output terminals for information processing equipment such as computers, copying devices combined with readers, etc., and facsimile devices having transmitting and receiving functions. It may take a form.

Furthermore, it goes without saying that the substrate according to the present invention can be applied not only to inkjet recording heads but also to thermal heads.

[Effects of the Invention] As described above, according to the present invention, a plurality of semiconductor elements having high breakdown voltage and excellent electrical isolation between elements can be formed on a single substrate.

Therefore, for example, in a matrix-connected circuit, there is no need to externally attach individual elements, and the number of processes can be reduced, reducing the number of failure points and ensuring high reliability of the resulting recording head. be able to.

Furthermore, according to the present invention, by defining the junction area and junction length of the semiconductor element when flowing the N-type emitter, there is little variation in characteristics no matter what shape the semiconductor element is designed. A semiconductor element with sufficient reliability can be obtained.

[Brief explanation of drawings]

1(a) and (b) are a sectional view and an equivalent circuit diagram schematically showing the wiring portion of a recording head substrate according to an embodiment of the present invention, and FIG. 2(a) and (b) are respectively (
b) is a perspective view and a sectional view taken along the line EE' of a recording head according to an embodiment of the present invention, and FIGS. 3(a) to (k) illustrate a method of manufacturing a recording head according to this embodiment, respectively. FIG. 3 (l and (m) are schematic cross-sectional views for explaining the emitter junction area. FIG. 4 is an exploded view of a cartridge that can be configured by applying the recording head according to the present invention. 5 is an assembled perspective view of FIG. 4, FIG. 6 is a perspective view of the inkjet unit shown in FIG. 4, and FIG. 7 is a perspective view of the cartridge shown in FIG. 8 is an external view of a device to which the cartridge shown in FIG. 4 is applied, and FIG. 9 is a schematic cross-sectional view of a conventional recording head. 1... P-type silicon substrate, 2... N-type Collector buried region, 3... P-type isolation eye buried region, 4... N-type epitaxial region, 5... P-type base region, 6... P-type isolation region, 7... N-type collector region, 8... High concentration P-type base region, 9... High concentration P-type isolation region, 10...
N-type emitter region, 11... High concentration N-type collector region, 12... Collector/base common electrode, 13... Emitter electrode, 14... Isolation electrode, 100... Recording head substrate ( heater board), 10
3... Heat generating resistance layer, 104... Electrodes 105, 106... Protective layer, 500... Discharge port. Figure 5 Procedural Amendment Statement April 25, 1991

Claims (1)

[Claims] 1) A liquid ejection section having an ejection port for ejecting ink, and an electrothermal conversion for generating thermal energy used to eject the ink supplied to the liquid ejection section. A recording head comprising: a substrate provided with an element and a functional element electrically connected to the electrothermal transducer; the junction area between the anode electrode and the cathode electrode of the functional element is such that the driving current is 200 mA; 5x10^-^5cm^2 or more, 300mA or more when less than 300mA
A recording head characterized in that when the current is less than 400 mA, the current is 1×10^-^4 cm^2 or more. 2) In a recording head substrate in which a functional element electrically connected to the electrothermal conversion element is provided on the same substrate, the junction area between the anode electrode and the cathode electrode of the functional element is such that the driving current is 200 mA. 5x10^-^5cm^2 or more, 300mA or more when less than 300mA
A recording head characterized in that when the current is less than 400 mA, the current is 1×10^-^4 cm^2 or more. 3) An inkjet recording apparatus comprising: the recording head according to claim 1; means for supplying ink to the head; and means for conveying a recording medium to a recording position by the recording head. .