JPH11145316A - Device molding structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable molding structure which demands thickness and high airtightness. SOLUTION: A device molding structure 100 is composed of a device 50, glass for bonding 30 and a cap 40. The device 50 has pad parts 12a to 12d, and a thickness formed on a die of a wafer level, demanded of high airtightness. The cap 40 is previously made etching, so that the pad parts 12a to 12d are exposed, and a space is formed between the cap and the device, such that the cap 40 is fixed with pressure to the device by inserting the glass for bonding 30 in a predetermined atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a device sealing structure, and more particularly to a device sealing structure which is thick and requires high airtightness.

[0002]

2. Description of the Related Art A micro-relay comprises a micro-relay body comprising a movable part and a fixed part, and a sealing structure for accommodating the micro-relay. The microrelay body has a thickness greater than that of a semiconductor element, and its sealing structure requires high airtightness.

[0003] The fixed portion of the microrelay main body is formed to have a substrate, fixed contacts, a metal pattern provided on the substrate, and a pad portion.

[0004] The movable portion of the microrelay main body is formed to have a movable surface and a movable portion contact corresponding to the movable surface.

[0005] Then, the movable portion and the fixed portion are engaged with each other, and the movable portion contact and the fixed portion contact are arranged so as to face each other at a predetermined interval to form a micro relay main body.

[0006] Such a microrelay main body often needs to be operated in a controlled atmosphere, and in order to seal and control the atmosphere of a microrelay main body manufactured by micromachining technology, a conventional method is used. As in the case of metal can mounting, the chips are mounted in a controlled atmosphere after dicing each chip.

Alternatively, as another means, a joining technique sandwiching a metal adhesive layer such as an anodic joining technique or Au-Au joining is used.

[0008]

[Problem to be Solved] In such a metal can mounting, since it is necessary to mount in a controlled atmosphere for each diced chip, it is not suitable for mass production, the manufacturing cost is high, and micromachining technology is used. One of the advantages, cost reduction, cannot be realized. Furthermore, since each chip is mounted on a metal can after dicing, adhesion of dust generated during dicing becomes a problem.

On the other hand, in bonding the substrate and the cap, a bonding technology sandwiching a metal adhesive layer such as an anodic bonding technology or an Au-Au bonding, which is known as a low-temperature bonding technology at a wafer stage before dicing, is a complete technology. To achieve airtightness, extremely complicated processing is required, and there is a problem in mass productivity. In the case where bonding is performed outside the pad portion, a complicated structure and processing are required, and even if high airtightness is achieved, electric characteristics, particularly high-frequency characteristics, are adversely affected, and there is a problem that manufacturing costs increase.

Accordingly, it is an object of the present invention to solve the above-mentioned problems and to provide a sealing structure for a device which is required to have a high thickness and high airtightness.

It is a further object of the present invention to provide a sealing structure in which mounting for sealing and atmosphere control is performed at a wafer stage.

It is a further object of the present invention to provide a microrelay that is inexpensive, small, and has good electrical characteristics, especially high frequency characteristics.

[0013]

SUMMARY OF THE INVENTION The above and other objects are to provide a device having a pad portion, which is formed on a wafer-level die and requires high airtightness, and a bonding glass, And a cap, which is pre-etched so that the pad portion is exposed so as to expose the pad portion, and is pressed against the device so that the pad portion is exposed in a predetermined atmosphere with the bonding glass interposed therebetween, thereby forming a space between the cap and the device. This is realized by a device sealing structure composed of:

[0014]

(Embodiment 1) FIG. 1 is a perspective view of a microrelay 100 composed of a microrelay body 50, an adhesive glass 30 and a cap 40 according to an embodiment of the present invention. The microrelay body 50 is the fixed part 1
0 and the movable section 20.

FIG. 2 is a plan view showing the fixing portion 10 of the micro relay main body 50 according to an embodiment of the present invention.
The substrate 11 is a die or chip in a wafer stage before dicing. The substrate 11 is made of a glass, silicon or gallium arsenide substrate. Hereinafter, a case where the substrate 11 is glass will be described as an example. The substrate 11 has a main surface A,
The metal pattern 12 is formed on the main surface A by using a method known to those skilled in the art such as a photolithography process. Pad portions 12a to 12d and pad portions 12
It includes a fixed part contact 12s located at the opposite end of b and 12c and a fixed part interconnection part 12i located at the corresponding end of the pad part 12d. Pad portions 12a to 12d,
Except for the fixed portion contacts 12s and the fixed portion interconnection portions 12i, the metal pattern 12 is covered with a fixed portion insulating film 13 (shaded portion in the figure) made of an oxide film or a nitride film.

When the substrate 11 is a silicon or gallium arsenide substrate, an insulating film (not shown) is patterned under the metal pattern 12 in advance.

FIG. 3 is a bottom view of the movable portion 20 of the micro relay main body 50 according to an embodiment of the present invention.
The movable portion 20 is made of a conductor such as silicon or metal, and has a bottom surface.
With B When silicon is used as an electrode of a microrelay, it can be treated as a conductor. Bottom
A movable part interconnection part 22i and a movable part contact 22s are formed on B by using a method known to those skilled in the art such as a photolithography process. A movable portion insulating film 23 is formed between the movable portion contact 22s and the bottom surface B of the movable portion 20.

FIG. 4 is a perspective view of the bottom surface B of the movable portion 20 of the micro relay main body 50 according to an embodiment of the present invention.

FIG. 5 is a plan view of a micro relay main body 50 in which the fixed part 10 and the movable part 20 according to one embodiment of the present invention are combined. The bottom surface B of the movable part 20 is the main surface A of the substrate 11
The microrelay main body 50 is formed by anodic bonding opposite to. The contacts of the micro relay main body 50 are formed by disposing the movable portion contacts 22s of the movable portion 20 so as to face the fixed portion contacts 12s on the substrate 11 at a predetermined interval. The movable section 20 includes a fixed section interconnection section 12i (see FIG. 2) and a movable section interconnection section 22i (FIG. 3).
) Is electrically coupled to the pad portion 12d.

When the substrate 11 is made of silicon, the microrelay body 50 is formed by bonding the bottom surface B of the movable portion 20 to the main surface A of the substrate 11 with an adhesive layer interposed therebetween. Gold is most often used as the adhesive layer.

When a silicon wafer is used for the movable part 20, the thickness is about 500 micrometers,
Thinning to about 5 to 20 micrometers
ng). The thinning method may be a chemical or mechanical method, and is performed by a method well known to those skilled in the art. Silicon on insulator (SOI: Silico
n On Insulator), thinning can be easily performed by alkali etching.

Further, a swastika spring structure is formed on the movable portion 20 by etching.

However, it is not intended to specify the order of joining the movable portion 20 to the fixed portion 10, thinning, and forming the spring structure, nor is it intended to specify the shape of the spring structure of the movable portion 20.

The operation of the micro relay main body 50 will be described below. When a DC voltage is applied to the metal patterns 12a and 12d on the main surface A of the substrate 11, the metal pattern 1
2d is electrically connected to the movable part 20 via the fixed part interconnection part 12i and the movable part interconnection part 22i, so that an electrostatic attraction is generated between the fixed part 10 and the movable part 20. As a result, the movable section 20 operates in the direction of the fixed section 10, and the movable section contact 22 s operates accordingly and contacts the fixed section contact 12 s. Also,
When the DC voltage is released to the metal patterns 12a and 12d on the main surface A of the substrate 11, the electrostatic attraction between the fixed part 10 and the movable part 20 is eliminated, and the movable part 20 is spring-shaped. 20 operates in the opposite direction to the fixed portion 10, and the movable portion contact 22s is separated from the fixed portion contact 12s.

FIG. 6 shows a cap 4 according to an embodiment of the present invention.
0 shows a bottom view. The cap 40 has a bottom surface C. The material of the cap 40 is not limited as long as it can be adhered to the micro relay main body 50. Although it is possible to use glass, it is preferably formed of silicon, and the pad region 31 is etched off by alkali etching in advance so that the pad portions 12a to 12d are opened when joined to the substrate 11. I have. The bonding glass 30 is patterned on the bottom surface C of the cap 40 so as to surround the movable portion 20 of the micro relay main body 50 at a predetermined interval. The bonding glass 30 may be patterned around the movable portion 20 on the substrate 11 side. Adhesive glass 3
The height of zero is usually several tens of micrometers and the width is about several hundred micrometers, but preferably the height is 10 to 30 micrometers and the width is 100 to 600 micrometers. Patterning of the bonding glass 30 on the cap is performed by an organic paste mixed with a glass frit by a screen printing method, and an organic substance is removed by a subsequent heat treatment. The method of patterning the bonding glass 30 is a method well known to those skilled in the art, and is not limited to such a method. The bonding glass 30 has an insulating property, and furthermore, the metal pattern 12 formed on the substrate 11 and the movable part interconnection part 2 formed on the movable part 20.
It is sufficient that the bonding can be performed at a temperature low enough not to affect the characteristics of the 2i and the movable contact 22s.
0 degrees or less, preferably about 390 degrees Celsius.
Further, it is desirable that the bonding glass 30 has a coefficient of thermal expansion that does not cause distortion due to joining of the substrate 11 and the cap 40.

Referring again to FIG. 1, the fixed portion 10 and the movable portion 20
The sealing between the microrelay main body 50 and the cap 40 made of the following will be described. After aligning the cap 40 and the substrate 11 of the fixing part 10 using an optical microscope, the bonding glass is crushed over the entire surface of the wafer at a temperature at which the bonding glass can flow in an atmosphere required for the micro relay. Is applied to join the cap 40 and the substrate 11. The method of aligning the cap 40 and the substrate 11 is a method well known to those skilled in the art, and is not limited to the above method. By this crimping, the microrelay 100 is sealed and airtight with the outside is maintained, and a space 60 that satisfies the atmosphere required for the microrelay is formed between the microrelay main body 50 and the cap 40.

FIG. 7 is a perspective plan view of a micro relay sealing structure in which a micro relay main body 50 and a cap 40 according to an embodiment of the present invention are pressure-bonded using an adhesive glass 30.

FIGS. 8 to 10 show the relationship between XX and YY in FIG.
FIG. 2 shows a cross-sectional view of each of FIG. The glass 30 for adhesion is flowed and crushed by pressure bonding, and the surroundings of the metal patterns 12a to 12d are embedded (FIG. 8), the micro relay is completely sealed, and the micro relay main body 5 is formed.
A space 60 that satisfies the atmosphere required for the micro relay is formed between the zero and the cap 40, and atmosphere control is also achieved (FIGS. 8 to 10).

FIG. 11 is a perspective view of a micro relay 100 sealed at a wafer stage according to an embodiment of the present invention. The microrelay 100 sealed in this way can be subsequently diced on a wafer, and can be mounted at low cost using a plastic package or the like used for an integrated circuit or the like.

(Embodiment 2) Next, another embodiment of the present invention will be described. In the description of the second embodiment, the same components are denoted by the same reference numerals as those in the first embodiment, and if different, primes (') are used.

FIG. 12 is a sectional view of a cap 40 'according to Embodiment 2 of the present invention. The cap 40 'is provided with a concave portion by previously etching a region facing the movable portion 20 of the micro relay on a surface C' facing the main surface A of the substrate 11 by a method known to those skilled in the art such as alkali etching. The cap 40 'provided with the concave portion is bonded to the substrate 11 via the bonding glass 30 as in the first embodiment.

FIG. 13 is a sectional view taken along the line ZZ in FIG. 4 according to the second embodiment. In the second embodiment, the cap 40 ′ can be used for capping when the movable portion 20 of the micro relay main body 50 is thicker than the bonding glass 30. In addition, since the width of the adhesive layer 30 can be reduced by reducing the thickness of the adhesive layer 30 even for the micro relay main body 50 in which the movable portion 20 is thinner than the bonding glass 30, the die size can be reduced and the cost can be reduced. Can be measured.

[0033]

The present invention has the following effects.

According to the present invention, the hermetic sealing can be performed for each wafer, and the use of a plastic package after dicing can greatly reduce the overall manufacturing cost as compared with the related art.

Since the sealing is performed before the dicing, the inflow of dust generated by the process after the dicing into the die can be prevented, and the reliability is improved.

When glass is used for the substrate 11, since an inorganic insulating thick film is used as an adhesive layer formed on the signal wiring, a small parasitic capacitance and good high-frequency characteristics can be obtained. It is also useful as a high frequency relay.

Further, by using the cap etched in a concave shape, the thickness of the bonding glass layer can be reduced as much as possible, and the width of the glass layer can be reduced, so that the die size can be reduced and the cost can be reduced. Can be measured.

Although the circuit of the present invention has been described herein with reference to a specific embodiment, those skilled in the art will be able to modify and modify the circuit of the present invention. However, the circuits of the present invention are not limited to the specific embodiments disclosed herein. For example, although the micro relay is described as an example in the embodiment, the present invention can also be applied to a device such as a gyro having a thickness and requiring high airtightness or a device requiring sealing by an airtight and controlled atmosphere. However, the device of the present application is not limited to a micro relay. Further, the number of devices to be sealed is not limited to one, and the present invention can also be used for sealing a plurality of devices. Further, the shape of the terminal and the number of terminals are not intended to be specified. Such modifications and changes are also within the scope of the technical idea of the present invention, and are included in the scope of the claims.

[Brief description of the drawings]

FIG. 1 is a perspective view of a micro relay according to the present invention.

FIG. 2 is a plan view of a fixing portion of the micro relay body according to the present invention.

FIG. 3 is a bottom view of a movable portion of the micro relay main body according to the present invention.

FIG. 4 is a perspective view of a bottom surface of a movable portion of the micro relay body according to the present invention.

FIG. 5 is a microrelay body according to the present invention. FIG.

FIG. 6 is an enlarged rear view of the cap according to the present invention.

FIG. 7 is a perspective plan view of a microrelay sealing structure according to the present invention.

FIG. 8 is a sectional view taken along line XX of FIG. 7 according to the present invention.

9 is a cross-sectional view taken along the line YY of FIG. 7 according to the present invention.

FIG. 10 is a sectional view taken along the line ZZ of FIG. 7 according to the present invention.

FIG. 11 is a perspective view of a micro relay sealed in a wafer stage according to the present invention.

FIG. 12 is a sectional view of a cap according to a second embodiment.

FIG. 13 is a sectional view taken along the line ZZ in FIG. 4 according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fixed part 11 Substrate 12 Metal pattern 12a-12d Pad part 12i Fixed part interconnection part 12s Fixed part contact 13 Fixed part insulation film 20 Movable part 22i Movable part interconnection part 22s Movable part contact 23 Movable part insulation film 30 Adhesive glass 40 cap 50 micro relay main body 60 space 100 micro relay

Claims (7)

[Claims] 1. A device sealing structure (100) comprising: a device (5) having pad portions (12a to 12d).
0), a device (50) formed on a wafer and requiring high airtightness;
0); and a cap (40) pressed to the device (50) with the bonding glass (30) interposed therebetween, wherein the pad portions (12a to 1a) are held in a predetermined atmosphere.
2d) a device sealing structure comprising a cap (40) which is press-bonded to the device while exposing the device to form a space (60) between the cap (40) and the device. body. 2. A micro-relay sealing structure (100): a micro-relay body (50): a substrate (11) made of a wafer; pad portions (12a to 12d); fixed portion contacts (12s). And a metal pattern (12) on a substrate having a fixed part interconnection part (12i);
And a movable part contact (22s) and a movable part interconnect (22i).
Faces the fixed portion contact (12s) at a predetermined interval, and the movable portion interconnection portion (22i) is connected to the fixed portion interconnection portion (12i) by a movable portion (20); Micro relay body (50) constituted;
0) an adhesive glass (30) arranged so as to surround the periphery of the movable portion (20); and a cap (40), wherein the microrelay body ( 50. A microrelay sealing structure comprising: a cap (40) that is press-fitted to (50) to form a space (60) between itself and the microrelay body (50). 3. The device sealing structure according to claim 1, wherein the thickness of the device is 10 micrometers or more. 4. The device sealing structure according to claim 1, wherein the airtightness of the space is equal to or higher than the atmospheric pressure. 5. The device sealing structure according to claim 1, wherein the cap (40) has a concave portion facing an upper portion of the movable portion (20) of the micro relay main body (50). . 6. A method for manufacturing a micro relay, comprising: forming a micro relay body (50): preparing a substrate (11) comprising a wafer; and applying a metal pattern (12) to the substrate (11). Patterning on the metal pattern (12);
12d), patterning the fixed part insulating film (13) so as to expose the fixed part contact (12s) and the fixed part interconnection part (12i);
s) and preparing a movable part (20) having a movable part interconnection part (22i); and the movable part contact (22s) and the fixed part contact (12s) are opposed to each other at a predetermined interval, and Disposing the movable part (20) on the substrate (11) so as to couple the fixed part interconnection part (12i) and the movable part interconnection part (22i). Forming a main body (50); preparing a cap (40);
0) preliminarily patterning the bonding glass (30) on the cap (40) in a shape surrounding the periphery of the movable portion (20); and applying the cap (40) to the micro relay body (50) in a predetermined atmosphere. Forming a space (60) by crimping and sealing in the inside. 7. The method according to claim 6, wherein the cap (40) has a concave portion facing the upper part of the movable portion (20) of the micro relay body (50).