JPH09283663A - Manufacture of electronic device and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the reliability and the yield of the product of an electronic device by a method wherein the manufacturing procedure of the device is improved in the electronic device of a structure wherein an electric wiring is formed through a through hole formed in a glass substrate laminated to a device main body. SOLUTION: A glass substrate 3 is laminated to a device main body 1 and thereafter, a through hole 4 is formed in a prescribed position on the substrate 3 to make the main body 1 expose through the depth of the hole 4 and an electrical wiring 5, which is electrically connected with the exposed part of the main body 1 by performing a deposition or the like, is formed through the hole 4. As a polishing of the side of the surface, which is bonded to the main body 1, of the substrate 3 is performed after the formation of the hole 4, it is eliminated that a break or the like is generated in an electronic device, the electric wiring is never cut and a hermetic sealing of the device never becomes incomplete.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electronic device having a structure in which a glass substrate is attached to a device body, and more particularly to a technique for forming electrical wiring reaching the device body through a through hole in the glass substrate.
This technology is applied to electronic devices such as microminiature acceleration sensors, pressure sensors, micro relays, and integrated circuits.

[0002]

2. Description of the Related Art A microminiature acceleration sensor having a structure as shown in FIG. 1 is known. This has a sandwich structure in which a semiconductor chip 1 which is a device body is sandwiched between a first glass substrate 2 and a second glass substrate 3. The semiconductor chip 1 has a structure of an acceleration sensor formed by a microfabrication technique for manufacturing an IC, and a cantilever 1b is arranged in a free space 1a. Then, the cantilever 1b is flexibly displaced in response to the acceleration, and an electric signal corresponding to the displacement is generated.

The semiconductor chip 1 is bonded onto the first glass substrate 2 by anodic bonding. Then, the second glass substrate 3 is bonded onto the semiconductor chip 1 by anodic bonding. As a result, the three plates are integrated, and the glass substrates 2 and 3 seal the free space 1a around the cantilever 1b.

A through hole 4 is formed at a predetermined position on the second glass substrate 3, and the through hole 4 reaches the surface of the semiconductor chip 1. An electric wiring 5 electrically connected to the surface of the semiconductor chip 1 is formed through the through hole 4. The electrical wiring 5 of this example is formed by patterning a conductor film on the upper surface of the glass substrate 3, the inner peripheral surface of the through hole 4 and the surface of the semiconductor chip 1 exposed at the back of the through hole 4 by vapor deposition or sputtering. is there.

Conventionally, this acceleration sensor has been manufactured by the following procedure. Semiconductor chip 1 and first glass substrate 2
And the second glass substrate 3 are respectively manufactured, the semiconductor chip 1 is bonded onto the first glass substrate 2, and the second glass substrate 3 is bonded onto the semiconductor chip 1. What is important here is that the through holes 4 are formed in the second glass substrate 3 in advance, and the second glass substrate 3 having the holes processed is bonded to the semiconductor chip 1. After this, the electric wiring 5 through the through hole 4 is formed.

[0006]

Conventionally, since the second glass substrate 3 having the through hole 4 formed therein is attached to the semiconductor chip 1 (device body), the manufacturing procedure is as follows. There was a problem.

The second glass substrate 3 with holes is processed by the following procedure. A glass substrate thicker than the target plate thickness is perforated to form a through hole, and then a polishing process is performed to thin the glass substrate to a target plate thickness. this is,
This was necessary to improve the yield, such as reducing the occurrence of defective products due to cracking during drilling.

Further, since the glass substrate is fixed to the mounting base (not shown) with an adhesive or the like when forming the through hole, the glass substrate is removed from the mounting base after the through hole is formed. Then, the adhesive adheres also to the glass substrate side. Therefore, the polishing is also performed in order to remove the adhesive.

Furthermore, since the thickness of the glass substrate when it is finally used as a sensor is very thin, if the through hole is formed in the state of being processed to that thickness, it will be broken.
In order to obtain the required strength, drilling is performed on a glass substrate that is thicker than the target thickness of the final product.

However, even in the second glass substrate 3 with a hole which is processed by the above procedure, as shown in FIG.
Is likely to be chipped (reference numeral k in the figure) or locally dripped to cause a phenomenon called surface sag (reference numeral m in the figure).

That is, during the above-mentioned polishing, abrasive particles or the like may hit and a chipping k may occur. Further, if the polishing is continued as it is, the chipped glass is mixed with the polishing particles and hits the periphery of the through hole, which causes a surface sag m.

When the acceleration sensor having the structure shown in FIG. 1 is assembled to form the electric wiring 5 by using the second glass substrate 3 having the above-mentioned chipping k and surface sag m, the defect as shown in FIG. Easy to produce goods. That is, one of the defects is that the conductor film of the electric wiring 5 does not connect to the surface of the semiconductor chip 1 at the edge portion of the through hole 4, resulting in wiring failure (disconnection). Another defect is that due to the surface sag m, a gap is created at the bonding interface between the second glass substrate 3 and the semiconductor chip 1, and the free space 1a of the semiconductor chip 1 is connected to the outside through the gap. The airtightness of the free space 1a is impaired.

The present invention has been made in view of the above background, and an object thereof is to solve the above problems and form an electric wiring through a through hole of a glass substrate bonded to a device body. To provide an electronic device manufacturing method and an electronic device capable of improving the reliability and yield of products by improving the manufacturing procedure.

[0014]

In order to achieve the above object, in the method of manufacturing an electronic device according to the present invention, a glass substrate is attached to a device body, and then a through hole is formed at a predetermined position of the glass substrate. The device body is formed so as to be exposed in the depth of the through hole, and an electric wiring electrically connected to the exposed portion is formed through the through hole (claim 1).

In this manufacturing method, preferably, an appropriate contact is formed at a position to be the exposed portion of the device body before bonding the glass substrate (claim 2) or the through-hole. After forming a hole and before forming the electric wiring, an appropriate contact is formed in the exposed portion at the back of the through hole (claim 3).

Here, as the electronic device, there is a semiconductor substrate (silicon substrate) when it is used for a sensor as shown in the embodiments. As a contact method, when the electronic device is a semiconductor as described above, there is a method of forming an impurity layer to form a low resistance layer.

In the present invention, after the glass substrate is attached to the device body, a hole is formed to form a through hole to expose the surface of the device body. As a result, the bonded surface side of the glass substrate is not polished after the through hole is formed, and no chipping or surface sagging occurs.

As an actual electric wiring process, for example, a conductor film is formed on a predetermined portion of the surface of the glass substrate including the through hole, and the exposed portion of the device main body and the glass via the conductor film. It is to electrically connect with the surface of the substrate (claim 4).

Then, the conductor film formed on the surface of the glass substrate is connected and wired to an external circuit by various kinds of bonding, whereby the exposed portion of the main body of the electronic device and the external circuit are connected through the conductor film. Can be conducted.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Several embodiments in which the present invention is applied to the manufacturing process of the microminiature acceleration sensor having the structure of FIG. 1 described in detail in the section "Prior Art" will be described. 4 and subsequent figures showing the embodiment of the present invention, parts common to those in FIG. 1 are denoted by the same reference numerals, and the matters already described in detail will not be explained again.

A first embodiment of the present invention is shown in FIGS. At the stage of FIG. 4A, the first glass substrate 2
The semiconductor chip 1 is bonded onto the semiconductor chip 1, and the second glass substrate 3 is bonded onto the semiconductor chip 1. What should be noted here is that the through hole is not yet formed in the second glass substrate 3.

In the next step of FIG. 4B, the through hole 4 is formed at a predetermined position of the second glass substrate 3. This drilling is performed by ultrasonic processing or blast processing. The through-hole 4 may bite into the semiconductor chip 1 side during the drilling process. In other words, surely the semiconductor chip 1
In order to expose the surface of the above, it is preferable that the through hole 4 is slightly bited into the semiconductor chip 1 side.

After that, as shown in FIG. 5, the electrical wiring 5 electrically connected to the surface portion of the semiconductor chip 1 exposed at the back of the through hole 4 is formed through the through hole 4. The electrical wiring 5 of this example is formed by patterning a conductor film on the upper surface of the glass substrate 3, the inner peripheral surface of the through hole 4 and the surface of the semiconductor chip 1 exposed at the back of the through hole 4 by vapor deposition or sputtering. is there.

Since the second glass substrate 3 is bonded and integrated with the semiconductor chip 1 and the first glass substrate 2, sufficient strength is maintained and the bonding surface side is polished as in the conventional case. Since it is unnecessary, the thickness of the second glass substrate 3 may be the same as the target thickness of the final product. In such a case, the conventional polishing process becomes unnecessary and the number of processes can be reduced.

The thickness of the second glass substrate 3 may of course be thicker than the target thickness. In that case, the upper surface is polished after the through hole 4 is formed. In this case, the abrasive particles may hit the glass substrate around the upper edge of the through hole 4, and there is a risk that the glass particles may still be chipped and the surface may be sagged. However, even if a chip or the like occurs, the problem of airtightness, which is a conventional problem, does not occur. If a chip is further formed on the upper surface, the angle β formed by the chip becomes an obtuse angle and becomes a gentle tapered surface, so that there is no fear of disconnection of the electrical wiring 5 formed thereafter.

A second embodiment of the present invention is shown in FIGS. The difference from the above-described first embodiment is that
As shown in FIG. 6, before the second glass substrate 3 is bonded onto the semiconductor chip 1, a proper contact 6 is formed at a position which will be the exposed portion of the semiconductor chip 1. In this embodiment, the contact 6 is an impurity layer formed by ion implantation or impurity diffusion. With this contact, the signal can be taken out with the loss amount suppressed as much as possible.

After that, as in the first embodiment, the second
Through holes 4 are formed at predetermined positions of the glass substrate 3 (see FIG. 7). At this time, as shown in an enlarged view in FIG. 7B, the excavation depth of the through hole 4 may cut into the semiconductor chip 1 side, but the bottom surface 4 a of the through hole 4 is the bottom surface 6 a of the contact 6. Naturally, it should be positioned above.

Then, similarly to the processing of FIG. 5 in the first embodiment, the through hole 4 is formed and the exposed portion including the contact 6 is provided with the electric wiring 5 by vapor deposition, sputtering or the like (see FIG. 8). ).

Further, in the present embodiment, the contact 6 is formed so as to be located on the entire surface of the exposed portion, but it goes without saying that the contact 6 may be present on at least a part thereof.

The third embodiment of the present invention is shown in FIGS.
Is shown in In the present embodiment, as shown in FIG.
The same steps as those in the first embodiment are performed until the through holes are formed.

In this embodiment, unlike the first embodiment, the electrical wiring 5 is formed after the through hole 4 is formed in the second glass substrate 3 bonded to the semiconductor chip 1. 10A before this step is to form an appropriate contact 7 on the exposed portion of the semiconductor chip 1 at the back of the through hole 4 by ion implantation or impurity diffusion. Then, after forming the contact 7, the electric wiring 5 is formed by vapor deposition, sputtering or the like.

The fourth embodiment of the present invention is shown in FIG. Here, the structure of the electric wiring through the through hole 4 is different from that in each of the above-described embodiments. In the electrical wiring structure of FIG. 11, the through hole 4 is filled with a conductive material 5a such as solder, a conductive paste, or a conductive resin, and the lead wire 5b for external extraction is fixed with the conductive material 5a. Although the configuration has been shown as an example applied to the first embodiment in the illustrated example, the present invention is not limited to this, and may be applied to the second and third embodiments. Of course.

[0033]

According to the present invention, a glass substrate is attached to a device body, a through hole is formed at a predetermined position of the glass substrate, the device body is exposed in the depth of the through hole, and the exposed portion is exposed. Since the electrical wiring to be electrically connected is formed through the through hole, the polishing process on the joint surface side, which is a cause of chipping or surface sagging, is unnecessary. As a result, the occurrence of chipping or the like can be suppressed as much as possible. As a result, the signal cannot be taken out due to the breakage of the electric wiring, the deterioration of the characteristics due to the airtightness is eliminated, and the reliability and the yield of the product are improved.

[Brief description of drawings]

FIG. 1 is a structural diagram of a microminiature acceleration sensor which is an example of an electronic device to which the present invention is applied.

FIG. 2 is a diagram showing a conventional manufacturing procedure for the acceleration sensor shown in FIG.

FIG. 3 is a diagram showing a conventional manufacturing procedure for the acceleration sensor shown in FIG.

FIG. 4 is a diagram showing a manufacturing procedure of the acceleration sensor shown in FIG. 1 according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a manufacturing procedure of the acceleration sensor shown in FIG. 1 according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a manufacturing procedure of the acceleration sensor shown in FIG. 1 according to a second embodiment of the present invention.

FIG. 7 is a diagram showing a manufacturing procedure of the acceleration sensor shown in FIG. 1 according to a second embodiment of the present invention.

FIG. 8 is a diagram showing a manufacturing procedure of the acceleration sensor shown in FIG. 1 according to a second embodiment of the present invention.

FIG. 9 is a diagram showing a manufacturing procedure of the acceleration sensor shown in FIG. 1 according to a third embodiment of the present invention.

FIG. 10 is a diagram showing a manufacturing procedure of the acceleration sensor shown in FIG. 1 according to the third embodiment of the present invention.

FIG. 11 is a diagram showing an electric wiring structure according to another embodiment of the present invention.

[Explanation of symbols]

 1 Semiconductor Chip (Device Main Body) 2 First Glass Substrate 3 Second Glass Substrate 4 Through Hole 5 Electrical Wiring 5a Conductive Material 5b Lead Wire 6 Contact 7 Contact

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Claims (5)

[Claims] 1. A glass substrate is attached to a device body, a through hole is formed at a predetermined position of the glass substrate, the device body is exposed in the depth of the through hole, and the exposed portion is electrically exposed. A method for manufacturing an electronic device, characterized in that electric wiring to be connected is formed through the through hole. 2. The method of manufacturing an electronic device according to claim 1, wherein an appropriate contact is formed at a position to be the exposed portion of the device body before the glass substrates are bonded together. 3. The method according to claim 1, wherein after forming the through hole and before forming the electric wiring, an appropriate contact is formed in the exposed portion at the back of the through hole. Electronic device manufacturing method. 4. The electric wiring forms a conductor film on a predetermined site on the surface of the glass substrate including the through hole, and exposes the device body through the conductor film and the surface of the glass substrate. 4. The method for manufacturing an electronic device according to claim 1, wherein the electronic device is electrically connected. 5. An electronic device manufactured by the method according to any one of claims 1 to 4.