JPH0897529A - Surface mounting circuit board and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a surface mounting circuit board and a manufacturing method thereof, in which a connection state with a mother boat can be easily confirmed and a manufacturing process is very simple. [Structure] A predetermined circuit is formed on a ceramic substrate (laminate) 1 in which a sloping surface C is formed at a ridgeline portion formed by a back surface B and an end surface E, and a lead-out conductor film 6 of the predetermined circuit 1 is formed on the ceramic substrate 1. The back surface B is formed to the inclined surface C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a ceramic single plate substrate,
The present invention relates to a circuit board having connection terminals for enabling surface mounting of a circuit board such as a ceramic laminated board on a mother board and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, for example, in a laminated ceramic substrate, an internal wiring pattern is formed inside the laminated body, and a surface wiring pattern, a thick film resistor film, etc. are formed on the surface of the laminated body. An IC chip, a chip-shaped electronic component, etc. are joined to a part of the wiring pattern, and a predetermined circuit network including various electronic components is arranged in high density inside and on the surface of the laminate.

As a structure for connecting such a laminated ceramic substrate to a mother board, a lead-out conductor film for connecting with a part of a predetermined circuit is formed on the back surface of the laminate, and the lead-out conductor of this laminated ceramic circuit board is formed. Surface mounting is performed by abutting the film and a predetermined wiring pattern of the motherboard in a plane with solder interposed.

As another structure, a lead-out conductor film for connecting to a part of a predetermined circuit is formed on the end face of the laminated ceramic substrate, and the end-face lead-out conductor film of the laminated ceramic circuit substrate and a predetermined wiring of the mother board. The pattern and the solder are interposed, and the surface mounting is performed by the solder meniscus rising on the end face lead-out conductor film.

As a conductor film for leading out an end surface of a laminated ceramic substrate, a structure in which a conductor film for leading out an end face is formed on a divided end face after dividing a large-sized laminated substrate, and a through hole is formed in a portion to be divided in advance. There is a structure in which a conductive film is formed on the inner wall of the through hole, and the conductor film on the inner surface of the through hole is divided into two to form an end face lead-out conductor film in the final dividing step.

[0006]

However, in the structure in which the lead-out conductor film is formed on the back surface of the above-mentioned substrate, the solder connection between the wiring pattern of the mother board and the lead-out conductor film is substantially made by the laminated ceramic circuit board. Since it was hidden, the soldering condition could not be confirmed and the bonding reliability was poor.

Further, in the case where the lead-out conductor film is formed on the end face of the laminated body, the soldering state and even the solder meniscus can be confirmed, and the joining reliability is improved, but the end face lead-out conductor film There are problems that the manufacturing process for forming is very complicated, and that the lead-out conductor film cannot be formed stably.

That is, in the structure in which the conductor film for leading out the end face is formed after the large laminated substrate is divided, the large laminated substrate is divided, the individual laminated ceramic substrates are aligned, and the conductor film is formed on the end face. Therefore, the manufacturing process becomes very complicated.

When a through hole is previously formed in a large-sized laminated substrate and a conductor film is formed in this through hole, for example,
Printing must be performed while sucking the conductive paste from one side of the through hole, and a stable conductor film cannot be formed depending on the viscosity of the conductive paste and the suction conditions. Further, the conductor film on the inner surface of the through hole is divided in the direction in which the conductor film is torn and divided, so that there is a problem that the conductor film may be peeled off or brought to the side of the laminated body on one side.

The present invention has been devised in view of the above-mentioned problems, and an object thereof is to easily confirm the connection state with a mother boat and to have a very simple manufacturing process. And to provide a manufacturing method thereof.

Still another object is to provide a method for manufacturing a surface mounting circuit board which can stably achieve a lead-out conductor film in a dividing process in addition to the above-mentioned object.

[0012]

The first invention of the present invention is as follows:
A surface mounting circuit board in which a desired circuit is formed on a ceramic substrate in which a sloping surface is formed on a ridgeline portion formed by a back surface and an end surface, and a conductor film for deriving the desired circuit is formed on the sloping surface from the back surface of the ceramic substrate. is there.

According to a second aspect of the present invention, a desired circuit is formed on a ceramic substrate having an inclined surface formed on a ridge line formed by a back surface and an end surface, and a conductor film for deriving the desired circuit is formed on the inclined surface from the back surface of the ceramic substrate. A method of manufacturing a formed surface mounting circuit board, the method comprising: forming a dividing groove on a front surface side of a large-sized board and forming a V groove on a rear surface side of the large board to divide the area into a plurality of areas to be a ceramic board; The step of forming the lead-out conductor film across the V-groove from the back side of each region so as to connect to a part of the desired circuit and the large-sized substrate on which the lead-out conductor film is formed are divided. A method of manufacturing a surface-mounting type circuit board, which includes a step of dividing each ceramic board along a groove and a V groove.

A third aspect of the present invention is further a surface mount type in which a second V groove having an opening angle smaller than the opening angle of the V groove is formed at the tip of the V groove formed on the back surface of the large-sized substrate. It is a method of manufacturing a circuit board.

[0015]

According to the first aspect of the present invention, the ridge portion formed by the back surface and the end surface of the surface-mounted circuit board is an inclined surface, and the lead-out conductor film is formed from the back surface to the inclined surface. Therefore, when solder is joined to the predetermined wiring pattern of the mother board, a solder meniscus can be easily formed on the lead-out conductor film on the inclined surface to firmly join, and the joining situation of this solder can be easily confirmed. Improves reliability.

According to the second aspect of the present invention, by forming the V-grooves for partitioning the regions to be the respective circuit boards, forming the conductor film on the back surface across the V-grooves, and further dividing by the V-grooves. Further, the lead-out conductor film can be easily formed, and the lead-out conductor film can be easily formed without complicating the manufacturing process as in the conventional case. Therefore, the overall cost of the circuit board can be significantly reduced.

Further, the conductor film is divided during the dividing process, but since the conductor film is cut so as to be bent in a plane, the conductor film may be peeled off or may be peeled off on one side of the circuit board. The lead-out conductor film is effectively suppressed and stably covers the substrate.

Further, according to the third invention, the V groove (first
Since the second V groove is formed at the tip of the V groove),
When the lead-out conductor film is formed on the entire surface of the V groove by printing on the conductive paste, the flow tension of the conductive paste is stopped by the surface tension of the paste at the ridges of the first V groove and the second V groove. However, it is possible to form the conductor film in a state of being separated from the lead-out conductor film in the region which is substantially the adjacent circuit board, and there is no peeling of the lead-out conductor film in the dividing process.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.
It should be noted that the embodiments will be described using a circuit board using a laminated ceramic circuit board.

FIG. 1 is a sectional view of a monolithic ceramic substrate for explaining the first invention, FIG. 2 is a rear perspective view thereof, and FIG. 3 is a side view showing a bonding state of a mother substrate.

The laminated ceramic substrate 10 includes the laminated body 1 and
Formed on the front surface side main surface B of the laminated body 1 and the surface wiring patterns 4 ... Formed on the front surface side main surface of the laminated body 1 and the electronic components 5 mounted on the front surface wiring pattern 4. And the derived conductor film 6 ...

The laminate 1 comprises, for example, 6 ceramic layers 1
a to 1f, each ceramic layer, 1a and 1b, 1
Internal wiring patterns 2b to 2f (collectively referred to as "2") forming a predetermined circuit are arranged between b and 1c ... 1e and 1f. Also, the ceramic layers 1a to 1
f is the via-hole conductors 3a to 3f that penetrate the thickness direction.
(Collectively referred to as “3”) is formed.

The ceramic layers 1a to 1f are, for example, simple ceramics such as alumina, aluminum nitride and mullite, magnetic ceramics such as glass-ceramic, Mn-Zn and Ni-Zn (ceramics in a broad sense), Ba.
It is made of a dielectric ceramic material such as TiO _3, and the internal wiring pattern 2 and the via-hole conductor 3 are Ag-based (Ag.
A single or Ag alloy conductor, a Cu-based (Cu alone or Cu alloy) conductor, an Au-based conductor, and the like.

Specifically, the ceramic green sheets having the conductors serving as the via-hole conductors 3 filled in the through holes and having the conductor film serving as the internal wiring pattern 2 formed on the surface are stacked in consideration of the stacking order, and integrated. It is achieved by calcination.

The surface wiring pattern 4 ... Is a wiring pattern which is connected to the internal wiring 2 through the via-hole conductor 3a on the main surface of the laminated body 1 on the front surface side.
g conductor or Ag alloy) conductor, Cu (Cu alone or Cu alloy) conductor, Au conductor, and the like.

The electronic component 5 has a surface wiring pattern 4
Some of them are bonded as a bonding pad via solder, a conductive adhesive, or the like, and examples of the electronic component include an IC bare chip, a transistor, a chip resistor, a chip capacitor, and the like.

A feature of the present invention is that the laminated body 1 has an inclined surface C formed on the ridge line portion formed by the back surface side main surface B and the end surface E, the internal wiring pattern 2, the via hole conductor. 3, the lead-out conductor film 6 serving as an input / output terminal portion of a predetermined circuit including the surface wiring pattern 4, the electronic component 5, etc.
Is formed from the back surface side main surface B of the laminated body 1 to the inclined surface C.

For example, in FIG. 1, the lead-out conductor film 6 is connected to a predetermined circuit such as the internal wiring patterns 2b to 2f via the via-hole conductor 3f.

The lead-out conductor film 6 is made of Ag-based, Cu-based,
A conductive paste made of an Au-based conductor is selectively screen-printed from the back-side main surface B of the laminate 1 toward the end surface including the inclined surface C to form a conductor coating film and baking treatment. To be done.

In this way, the laminated ceramic circuit board 10 in which the lead-out conductor film 6 is formed on the inclined surface C of the ridge portion formed by the back surface side main surface B and the end surface E of the laminated body 1 is joined to the mother board. Is shown in FIG. In addition, in FIG.
Reference numeral 30 is a mother board, 31 is a predetermined wiring pattern, and 32 is solder.

As shown in the figure, a cream-like solder is applied onto the predetermined wiring pattern 31 of the mother board 30, and the predetermined wiring pattern 31 onto which the cream-like solder is applied,
Arranged so that the lead-out conductor film 6 of the laminated ceramic circuit board 10 is in contact, and put into a reflow furnace or the like to melt the cream-like solder and gradually cool it so that the predetermined wiring pattern 31 and the lead-out conductor film are formed. 6 will be firmly joined by the solder 32.

In particular, the lead-out conductor film 6 formed on the inclined surface C of the ridgeline formed by the back surface side main surface B and the end surface E of the laminate 1.
Are substantially inclined with respect to the predetermined wiring pattern 31 of the mother board 30, and a wedge-shaped gap is formed therebetween.

However, in reality, the meniscus of the solder is stably formed due to the surface tension of the molten solder 32, and the electrical connection between the mother board 30 and the monolithic ceramic circuit board 10 and the stronger mechanical strength. A physical bond will be achieved.

Moreover, since the state of formation of the solder meniscus can be easily visually checked from the outside of the laminated ceramic circuit board 10, the joining reliability is greatly improved.

A method of manufacturing such a laminated ceramic circuit board 10 will be described with reference to FIG. In this manufacturing method, a multi-cavity manufacturing method for extracting a plurality of laminated ceramic circuit boards from a large-sized ceramic board will be described with reference to the process diagram of FIG. 4 and the rear perspective view of the main process of FIG.

First, steps (a) to (f) of FIG. 4 are performed to divide a plurality of regions to be a laminated body of a laminated ceramic circuit board into division grooves on the front surface side and back surfaces and division end surfaces on the back surface side. V-grooves are formed so that their ridges are inclined surfaces, and a part of each predetermined circuit is led out on the back side of each region to form a large substrate.

First, in the step (a), green sheets to be the ceramic layers 1a to 1f are prepared.

Next, in the step (b), punching through holes to be the via-hole conductors 3a to 3f penetrating the thickness of the ceramic layers 1a to 1f are punched in the respective regions of the green sheets to be finally laminated. It is formed by processing.

Next, in the step (c), conductors to be the via-hole conductors 3a to 3f are formed in the through holes by filling a conductive paste, and internal wiring patterns 2b to 2f are formed on each green sheet. The conductor film is formed by printing a conductive paste.

Next, in the step (d), such green sheets are laminated in the order of lamination. As a result, the large-sized laminated substrate 50 in the unfired state shown in FIG. 5 is achieved.

In the figure, 50 is a large-sized laminated substrate in an unfired state, 30f ... Is an exposed portion of the conductor to be the via-hole conductor 3f, and dotted lines X ..., Y ... It is a virtual line that divides.

Next, in the step (e), a dividing groove for partitioning each region is formed on the front surface of the large-sized laminated substrate described above, and each region is formed on the back surface so as to become an inclined surface C when the final division processing is performed. A V-shaped groove and a dividing groove for partitioning are formed. This state is shown in FIG. In FIG. 6, a V groove 7 serving as an inclined surface C is formed in a dotted line Y direction that partitions each region of the back surface-side main surface B of the large-sized laminated substrate 50, and a dotted line X that partitions each region of the back surface-side main surface. The dividing groove 8 is formed in the direction. This is because the lead-out conductor film is not formed in the direction of the dotted line X that divides each region, so that there is no V groove. Therefore, the dividing process described later is performed to enhance the dividing property. Therefore, for example, when the lead-out conductor film is formed also in the dotted line X direction, the V groove is also formed in this X direction.

Further, dividing grooves 9 are formed vertically and horizontally so as to partition each region of the main surface on the front surface side of the large-sized laminated substrate 50.

The dividing grooves 8 and 9 have a V-shaped cross-sectional shape of the cutting edge.
V-shaped snap blade with press-molding
The groove 7 is formed by using a dicing saw whose cutting edge has a substantially V-shaped cross section. The dividing grooves 8 and 9 are also substantially V-shaped grooves, but in order to distinguish them from the groove 7 for forming the inclined surface C, the grooves 8 and 9 are referred to as “dividing groove” and groove 7. Is referred to as "V groove".

Next, in the step (f), the dividing grooves 8,
9, large-sized laminated substrate 50 in which the V groove 7 is formed in an unfired state
Is fired. As a result, the green sheets are firmly integrated by the sintering reaction, the conductor film becomes the internal wiring patterns 2b to 2f, and the conductor 30f becomes the via hole conductors 3a to 3f.

Next, the steps (g) to (h) of FIG. 4 are performed, and the lead-out conductor film which extends from at least the back-side main surface B of each region to the V groove 7 and is connected to a predetermined circuit part. A conductor film 60 to be 6 is formed. This state is shown in FIG.

Specifically, as the step (g), first,
The surface wiring pattern 4 is formed on the main surface on the front surface side of the baked large-sized laminated substrate 50 by printing and baking a conductive paste. At this time, other thick film circuit elements, for example, thick film resistor films may be formed at the same time, if necessary.

Next, a conductor film 60 to be the lead-out conductor film 6 is formed on the main surface B on the back surface side of the fired large-sized laminated substrate 50 by printing and baking a conductive paste. Structurally, the conductive film 60 is formed so as to be electrically connected to the via-hole conductor 3f exposed on the back-side main surface B of each region and a part of the conductor film 60 reaches the V-groove 7. To do. still,
In FIG. 7, in order to commonly form the conductor film 60 across the adjacent regions via the V groove 7, the vicinity of the central portion of the conductor film 60 is formed in the V groove 7, and both ends thereof are formed. It is formed so as to cover the via-hole conductors 3e in different regions.

Next, the surface treatment step (h) is carried out, if necessary. That is, various electronic components 5 are mounted at predetermined positions on the surface wiring pattern 4, and a predetermined circuit is formed for each area.

Finally, in the step (i) of FIG. 4, the large-sized laminated substrate 5 on which the conductor film 60 serving as the lead-out conductor film is formed.
0 is divided into individual monolithic ceramic circuit boards 10 along the dividing grooves 8 and 9 and the V groove 7. This state is shown in FIG.
As a result, the V-groove 7 partitioning the two adjacent regions is divided into the inclined surface C, and two conductor films 60 are formed across the V-groove 7 partitioning the two adjacent regions. To be the lead-out conductor film 6 respectively.

In the laminated ceramic circuit board 10 formed by the above steps, the inclined surface C of the ridgeline portion formed by the back-side main surface B and the end surface E has the V groove 7 formed in the large-sized laminated board 50, and This is achieved by dividing the V-groove 7 into two parts for the dividing process, so that the V-groove 7 can be formed very easily. Further, the lead-out conductor film 6 formed on the back surface B to the inclined surface C is printed or printed with a conductive paste so as to cover the V groove 7 on the back surface side main surface B of the large-sized laminated substrate 50. Moreover, this is also very simple to form, as it is achieved by dividing the splitting process in two as described above.

As in the prior art, after the division processing, printing / baking is performed on the division end surface, or
The manufacturing process is greatly simplified as compared with forming a through hole to be an end face electrode and forming a conductor film on the inner wall of the through hole.

When the large laminated substrate 50 is divided along the dividing groove 8 and the V groove 7, the large laminated substrate 50 is formed in the V groove 7 without being cut so as to be split from, for example, the front surface side of the conductor film as in the conventional case. Since the conductor film 60 is cut so as to be bent in a plane, the conductor film 60 is not peeled off and is stably separated without being taken by the laminated ceramic circuit board on one side. .

Moreover, this process is a multi-piece manufacturing method, and the surface treatment, that is, the mounting of various electronic components 5 and the like can be performed on the large laminated substrate, so that the mounting efficiency of the electronic components 5 can be improved. Therefore, the mass productivity is excellent, and the cost of the laminated ceramic circuit board can be reduced.

Considering the shape of the V groove 7, the angle θ formed between the back surface B and the inclined surface C of the V groove 7 is a shape for stably forming the conductor film 60 in the V groove 7. ₁
Is preferably 120 ° to 150 ° (opening angle 60 to 120 ° at the tip of the V groove 7).

When the angle θ ₁ is less than 120 °, the angle of the inclined surface C becomes steep, and when a conductive film is formed by printing a conductive paste on the back surface, the projected shadow area per unit becomes small. , A conductor film having a stable film thickness is not formed.

Further, when the angle θ ₁ exceeds 150 °, when placed on the predetermined wiring pattern 31 of the mother board 30, the wedge-shaped gap between the wiring pattern 31 and the lead-out conductor film 6 becomes small, The formation of the solder meniscus is reduced, the bonding strength cannot be sufficiently obtained, and it becomes difficult to confirm the bonding state of the solder 32.

When the depths of the V-groove 7 and the dividing groove are examined, generally, the thickness of the laminated ceramic circuit board is 0.
8 to 1.0 mm, and the depth of the V groove 7 is 0.2 to 0.5.
A range of mm is desirable. For example, when the depth is less than 0.2 mm, the above-mentioned <shaped gap becomes small, and
If it exceeds 0.5 mm, the opening width of the V-groove 7 increases accordingly, which is not practical in manufacturing.

Further, the depth of the dividing groove 9 on the front surface side varies depending on the depth of the V groove 7 and the thickness of the laminated body 1, and the total depth of the dividing groove 9 and the V groove 7 is the lamination. It is about 30 to 60% of the total thickness of the body 1. For example,
If the depth of the V-groove 7 is 0.3 mm and the depth of the dividing groove 9 is 0.08 mm, which is about 10% of the entire substrate, for the laminate 1 having a thickness of 0.8 mm, the thickness of the laminate 1 About 48% of the whole
It will be about.

If the total depth of the dividing grooves 9 and the V-grooves 7 is less than about 30% of the total thickness of the laminated body 1, the dividing property will be deteriorated and, for example, unevenness will occur on the dividing end faces. I will end up.

Further, when it exceeds 60%, for example, when the surface wiring pattern 4 is formed or when the conductor film 60 to be the lead-out conductor film 6 is formed, it is divided between the dividing groove 9 and the V groove 7. As a result, the manufacturing method for producing a large number of pieces causes complication of manufacturing.

The dividing groove 8 formed on the back side main surface B preferably has a depth substantially similar to that of the V groove 7 from the viewpoint of dividing property.

Further, it is ideal that the lead-out conductor films 6 in the area of the adjacent circuit board formed in the V groove 7 are not joined. This is to prevent the lead-out conductor film 6 from peeling off during the dividing process, and the surface of the lead-out conductor film 6 can be plated if necessary before the dividing process. This is because.

As a result of various studies by the present inventors, as shown in the sectional view of FIG. 9, the second V-shaped groove 71 having an opening angle smaller than the opening angle of the V-shaped groove 7 is formed at the tip portion of the V-shaped groove 7. It has been found that, by forming the lead-out conductor film 6, the lead-out conductor film 6 can be formed without being joined to each region of the adjacent circuit board.

As described in the above manufacturing method, the V groove 7 is formed.
The conductor film 60 to be the lead-out conductor film 6 is printed with a conductive paste by screen printing. At this time, it is practically impossible for the plate-making screen or the squeegee to come into contact with the surface in the V-groove 7, and the actual conductor film 60 is printed from the back side main surface B of the substrate to the V-groove 7 by screen printing. The conductive paste that has passed through the plate-making screen and that has flowed from the back-side main surface B flows along the inclined surface C of the V groove 7 and is applied.

Here, by forming the second V-groove 71 at the tip of the V-groove 7, the conductive paste flowing on the inclined surface C of the V-groove 7 is V-groove 7 and the second V-groove 71. At the ridgeline formed by and, the inflow is stopped by the surface tension action of the paste.

Therefore, the conductor film 60 to be the lead-out conductive film 6 formed in the V groove 7 is formed in a separated state with the second V 71 as a boundary.

Therefore, after the firing process, the dividing groove 9 and the second V
Even if the Y direction is divided along the groove 71, the conductor film 60 is not applied to the second V groove 71 which is the divided portion, and therefore the lead-out conductor film 6 is not peeled at all.

Further, since the lead-out conductor film 6 is formed separately, a very thin solder wettability film can be formed before the dividing process. This solder wettability coating is for improving solder wettability, and for example, solder coating can be exemplified. The solder coating can be manufactured by various conventionally known methods. Even if the solder wettability coating is formed in this way, the lead-out conductor film 6 independent in the area of the circuit board divided into the same V groove 7 is formed.
Since it is formed on the upper side, the solder wettability film can be stably divided during the dividing process. still,
As a method for coating the solder, a solder deposition method in which an organic solution in which a metal component of solder is dissolved is deposited on the surface of the lead-out conductor film 6 and dried is preferable.

The ridge line between the V groove 7 and the second V groove 71 blocks the inflow of the conductive paste.
The angle θ _{2 of the} ridge and the viscosity of the conductive paste are important. As a result of various experiments, when the viscosity of the conductive paste is in the range of 100 to 300 poise, the conductive paste steadily flows from the rear surface main surface B of the substrate 1 to the V groove 7, and the rear surface main surface of the substrate 1 The film thickness of the conductor film 60 does not become extremely thin at the ridge portion between the surface B and the V groove 7, and a substantially uniform conductor film 60 can be formed in the V groove 7.

In the case of such a conductive paste having a viscosity of 100 to 300 poise, the inclined surface of the V groove 7 and the second V groove 7 are formed.
The angle θ ₂ formed by the inclined surface of 1 is 125 to 167.5 °,
That is, the opening angle of the tip of the second V groove 71 is 10 to 35 °.
It turns out that it is desirable to set. For example, when the opening angle exceeds 35 °, the angle θ ₂ formed by the inclined surface of the V groove 7 and the inclined surface of the second V groove 71 becomes close to 180 °,
When the restraining effect of the conductive paste is reduced, and when the opening angle is less than 10 °, the opening width of the second V groove 71 becomes narrow, and even if the restraining effect of the conductive paste is exerted, the reverse surface tension causes If the width of the second V-groove 71, which is the boundary of the circuit board region, for example, about 20 μm is exceeded, both conductor films are integrated.

As described above, in the manufacturing method, the conductor film 60 serving as the lead-out conductor film 6 ... Is already formed in the V-groove 7 on the back-side main surface of the large-sized laminated substrate before the division treatment. As long as it is sufficient, the steps may be interchanged or omitted.

Next, an example of a circuit board using a single ceramic substrate will be described.

FIG. 10 is a sectional view thereof. In the figure, on the surface of a ceramic substrate 91, formed are conductive films 92 and 94, an insulating film 93, a resistor film, etc., if necessary, using a thick film technique, and further, an electronic component as necessary. And so on.

An inclined surface C is formed on a ridge portion formed by the back surface-side main surface B and the end surface E of the ceramic substrate 91, and the lead-out conductor film 6 is formed by utilizing the back surface main surface B and the inclined surface C. ing.

Here, the thick conductor film 9 on the front surface side of the substrate 91
The predetermined circuit composed of 2 or the like and the lead-out conductor film 6 on the back main surface of the substrate 91 are connected to each other through a conductive through hole 95 (a through hole having a conductor film formed on the inner wall surface) or a via-hole conductor. (Through hole filled with a conductor) is formed.

In the manufacturing method of the substantial embodiment, V
The groove 7 was formed on the large-sized laminated substrate 50 in an unfired state.
A groove may be formed.

Further, the lead-out conductor film 6 is connected to the via-hole conductor 3f, the conductive through hole 95, etc.,
It is electrically connected to a predetermined circuit and mechanically connected to a mother board or the like, but is not mechanically connected to the via hole conductor 3f, the conductive through hole 95, or the like. You may form the conductor film 6 only for the purpose of connecting.

[0079]

As described above, according to the surface-mounting type circuit board of the present invention, the ridge portion formed by the back surface and the end surface of the surface-mounting type circuit board is an inclined surface, and is led from the back surface to the inclined surface. A conductor film for use is formed. Therefore, when solder is joined to the predetermined wiring pattern of the mother board, a solder meniscus can be easily formed on the lead-out terminal film on the inclined surface,
Since it is possible to firmly bond and the bonding status of the solder can be easily confirmed, the bonding reliability is improved.

Further, according to the method of manufacturing the surface mount type circuit board of the present invention, the V groove for partitioning the area to be each circuit board is formed, and the conductor film is formed on the back surface across the V groove. Furthermore, the lead-out conductor film can be easily formed by the dividing process in the V groove, and the lead-out conductor film can be easily formed without complicating the manufacturing process as in the conventional case. For this reason,
It is suitable for a method for manufacturing a multi-piece circuit board, and can significantly reduce the overall cost.

Further, the conductor film is divided during the dividing process, but since the conductor film is cut so as to be bent in a plane, the conductor film may be peeled off or may be peeled off to one side circuit board side. The lead-out conductor film is effectively suppressed and stably covers the substrate.

Further, since the second V groove having an opening angle narrower than the opening angle of the V groove is formed at the tip portion of the V groove, the V groove and the second V groove portion are formed when the lead-out conductor film is formed. It is possible to prevent the conductive paste from flowing into the ridge portion. As a result, the lead-out conductor film in the V groove can be formed separately in the regions of the respective circuit boards, so that the dividing reliability during the dividing process is further improved.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a monolithic ceramic substrate which is a surface mount type circuit substrate of the present invention.

FIG. 2 is a partial perspective view of the back surface side of the laminated ceramic substrate of the present invention.

FIG. 3 is a partial side view showing a state where the laminated ceramic substrate of the present invention is bonded to a mother board.

FIG. 4 is a process drawing for explaining the manufacturing method of the second invention.

FIG. 5 is a partial perspective view of the back surface side in the main manufacturing process.

FIG. 6 is a partial perspective view of the back surface side in the main manufacturing process.

FIG. 7 is a partial perspective view of the back surface side in the main manufacturing process.

FIG. 8 is a partial perspective view of the back surface side in the main manufacturing process.

FIG. 9 is a cross-sectional view in the main process for explaining the manufacturing method of the third invention.

FIG. 10 is a partial cross-sectional view of a thick film circuit board showing another embodiment of the present invention.

[Explanation of symbols]

 10 ... Laminated ceramic circuit board 1 ... Laminated bodies 1a to 1f ... Ceramic layer 2 ... Internal wiring pattern 3 ... Via hole conductor 4 ... Surface wiring pattern 5 ...・ ・ Electronic parts 6 ・ ・ ・ ・ Leading conductor film B ・ ・ ・ ・ Back side main surface E ・ ・ ・ ・ End surface C ・ ・ ・ ・ Inclined surface

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Nakamura 1-1 Yamashita-cho, Kokubun-shi, Kagoshima Prefecture Kyocera Stock Company Kagoshima Kokubun Plant (72) Inventor Hiroki Uemura 1-1, Yamashita-cho, Kokubun-shi, Kagoshima Kyocera Stock company Kagoshima Kokubu factory (72) Inventor Shigeo Nakamura 1-1 Yamashita-cho, Kokubun-shi, Kagoshima Kyocera Stock company Kagoshima Kokubu factory

Claims (3)

[Claims] 1. A desired circuit is formed on a ceramic substrate having an inclined surface formed on a ridge line formed by a back surface and an end surface, and a conductor film for deriving the desired circuit is formed on the inclined surface from the back surface of the ceramic substrate. Surface mount circuit board characterized by. 2. A surface mounting in which a desired circuit is formed on a ceramic substrate having an inclined surface formed on a ridge line formed by a back surface and an end surface, and a conductor film for deriving the desired circuit is formed on the inclined surface from the back surface of the ceramic substrate. A method of manufacturing a circuit board for use, comprising: forming a dividing groove on a front surface side of a large-sized substrate and forming a V groove on a back surface side of the large-sized substrate to divide the area into a plurality of regions to be a ceramic substrate; Forming a lead-out conductor film from the back surface side of each region across the V-groove so as to connect to a part thereof; and a large-sized substrate on which the lead-out conductor film is formed,
A method of manufacturing a surface mount type circuit board, which comprises a step of dividing each ceramic board along a groove. 3. The second V groove having an opening angle smaller than the opening angle of the V groove is formed at the tip of the V groove formed on the back surface of the large-sized substrate. A method for manufacturing the surface mount type circuit board as described above.