JPH07113706A - Package structure for semiconductor pressure sensor - Google Patents

Abstract

PURPOSE:To provide a package structure, in which operability in a product assembly process and adhesion between a resin case and a cap in an adhesion process can be improved by adding a simple means between the resin case and the cap, for a semiconductor pressure sensor. CONSTITUTION:In a semiconductor pressure sensor package structure, which is assembled in such ways as integrating a diaphragm type pressure sensor chip 1 and an external lead out terminal 3 in a resin case, connecting a wire 4 between the sensor chip 1 and the external lead out terminal 3, sealing the surface of the sensor chip 1 by silicon gel 5, and then, covering the resin case by a cap 7 provided with a connecting hole so that both of them are fixed together by an adhesive 8, an engaging projection 9 serving as a temporally locking engaging part, which holds the cap 7 in the installed position, is arranged on the circumferential wall face of a fitting groove 7a of the cap 7 while facing the circumferential wall part, 6a of the resin case, so that the cap 7 is engagingly held in the installed position by means of gearing between the projection and the circumferential wall on the case side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface pressure type semiconductor pressure sensor package structure.

[0002]

2. Description of the Related Art First, an assembly structure of a conventional surface pressure type semiconductor pressure sensor is shown in FIG. In the figure, 1 is a diaphragm type pressure sensor chip in which strain gauge resistors, operational amplifiers, etc. are integrated on a Si substrate having a diaphragm, 2 is a glass pedestal on which the sensor chip 1 is mounted, 3 is an external lead terminal, and 4 is a sensor. A connecting wire wired between the chip 1 and the external lead-out terminal 3, 5 is a silicone gel that seals the surface of the sensor chip 1, the connecting wire 4, and 6 is a sensor chip 1, a glass pedestal 2, and an external lead-out terminal 3 A resin case having an open top surface, and 7 is a peripheral wall portion 6 of the resin case 6.
a cap made of a resin which is fitted on a in a fitting manner and fixed with an adhesive 8; a fitting groove 7a which fits into the peripheral wall portion 6a;
Reference numeral 7b is a pressure guiding hole formed on the upper surface of the cap 8.

Such a semiconductor pressure sensor is assembled in the following steps. First, the sensor chip 1 is placed on the glass pedestal 2 with the diaphragm portion 1a facing downward, and the two are airtightly joined by anodic bonding or soldering in a vacuum atmosphere. Next, the assembly 2 is housed in a resin case 6 integrally molded with the external lead-out terminal 3, and the pedestal 2 is fixed to the resin case 6.
After bonding the connection wire 4 between the sensor chip 1 and the external lead-out terminal 3, the silicone gel 5 is injected into the resin case 1 to clean the surface of the sensor chip 1 and the connection wire 4. Seal. The silicone gel 5 is provided to protect the pressure sensor from the atmosphere of the outside air entering the case through the pressure guiding hole 7b when the pressure sensor is actually used. Next, the fitting groove 7a of the cap 7 is fitted over the peripheral wall portion 6a of the resin case 6, and the resin case 6 and the cap 7 are fixed by the adhesive 8 to complete the product.

The operation of such a surface pressure type semiconductor pressure sensor is well known, and its explanation is omitted here.

[0005]

By the way, with the conventional package structure as described above, the handling property in the assembly process,
Also, there is the following problem in terms of adhesiveness between the resin case and the cap. (1) In the assembly process, the steps such as mounting the sensor chip in the resin case, wire bonding, and silicone gel injection are performed with the cap removed. In some cases, an object may accidentally hit from the outside, resulting in chip damage or wire cutting.

(2) When the cap is adhered to the resin case, if the cap is simply adhered to the resin case with the cap still covered, the cap is lifted by the elasticity of the adhesive and the joint with the resin case is not brought into close contact with the resin case. Sometimes. In order to prevent this, it is necessary to take measures such as pressing the cap against the resin case until the adhesive is hardened using a pressing jig, which complicates the assembly process.

The present invention has been made in view of the above points, and a package structure of a semiconductor pressure sensor which can solve the above problems by adding a simple means between a resin case and a cap. The purpose is to provide.

[0008]

In order to achieve the above object, in the package structure of the present invention, the cap is placed between the peripheral wall of the resin case and the peripheral wall of the cap fitted to the resin case at the attached position. A temporary fixing engaging portion for locking and holding is provided. Further, the temporary fixing engagement portion in the above configuration can be formed by an engagement protrusion protruding from either one of the peripheral wall surface of the resin case or the peripheral wall surface of the cap toward the peripheral wall surface of the mating member. In order to make the engagement even more reliable, there is a configuration in which an engaging groove is formed on the peripheral wall surface of the mating member so as to face the engaging projection and engage with the projection.

[0009]

According to the above construction, when the cap is put on the resin case and held in a temporarily fixed state during transfer and handling during the assembly process, the pressure sensor chip and the connecting wire are unexpectedly exposed from the outside. These parts can be safely protected without directly hitting. Also, in the step of fixing the resin case and the cap with the adhesive, the engagement of the temporary fixing engagement portion prevents the cap from being unduly lifted from the fixed position due to the elasticity of the adhesive. It can be adhered by keeping the space in close contact. This prevents defective adhesion.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In each embodiment, the same members corresponding to those in FIG. 4 are designated by the same reference numerals. Example 1 In FIG. 1, the assembly structure of the semiconductor pressure sensor is basically the same as that of FIG. 4, but the inner peripheral wall surface of the fitting groove 7a of the cap 7 fitted to the peripheral wall portion 6a of the resin case 6 is As the temporary engagement portion, one spherical engagement protrusion 9 is formed on each of the four surrounding sides so as to protrude toward the groove.
Then, when the cap 7 is put on the resin case 6 and pushed in from above, the engagement projection 9 presses the peripheral wall portion 6a of the resin case 6 facing the engagement projection 9 and the two are locked and held in a meshed state.

In this case, the protrusion height, area, etc. of the engaging projections 9 may be hit by an object during transfer or handling during the assembly process while the resin case 6 is covered with the cap 7 and temporarily fixed. Even if 7 is facing down, cap 7 is easy
Does not come off, and the required temporary holding force can be maintained even if the cap 7 is repeatedly attached and detached several times. Further, when the cap 7 is fixed to the resin case 6 by the adhesive 8, the elasticity of the adhesive The cap 7 is designed so as to obtain a holding force that does not lift the cap 7 from the attached position.

Then, the pressure sensor chip 1 is incorporated,
In each process such as bonding the connecting wire 4 and injecting the silicone gel 5, the work is performed with the cap 7 removed from the resin case 6, and the transfer and handling operations are performed with the cap 7 covered and temporarily held between the processes. In the last bonding step, the resin case 6 is covered with the cap 7, and the end faces are abutted against each other and fixed with the adhesive 8.

Embodiment 2 FIG. 2 shows an application embodiment of FIG. 1. In this embodiment, the engaging projection 9 described in FIG. 1 is formed on the peripheral wall portion 6a of the resin case 6, In the state where the cap 7 is covered, the engagement protrusion 9 is pressed against the peripheral wall surface on the cap side. Thereby, the same effect as that described in the first embodiment can be obtained.

Embodiment 3 FIG. 3 shows an applied embodiment in which the embodiment shown in FIG. 1 is further improved. It faces the engaging projection 9 formed on the peripheral wall surface of the cap 7 and faces the peripheral wall of the resin case 6. A concave groove 10 that fits with the protrusion 9 is formed on the peripheral surface of the portion 6a. With this configuration, the engaging projection 9 and the recessed groove 10 are fitted and mesh with each other in a state where the cap 7 is attached to the resin case 6, so that the temporary holding force is further increased. In contrast to the illustrated example, the engagement protrusion 9 may be provided on the resin case 6 side, and the engagement groove 10 may be provided on the cap 7 side.

[0015]

As described above, the package structure of the present invention has the following effects. (1) Incorporation of pressure sensor chip, wire bonding, transfer between assembly processes such as silicone gel injection, etc. By covering the resin case during handling and holding it in a temporarily fixed state, the resin case during transfer between processes It is possible to prevent problems such as pressure sensor chips, connecting wires, and other parts that are built into the internal parts from being directly hit from the outside, resulting in damage or disconnection.

(2) In the final assembly step of covering the resin case with the cap and fixing with the adhesive, the cap is prevented from floating from the fixed position due to the elasticity of the adhesive without using a holding jig, and high bonding is achieved. As a result, strength can be secured, which greatly contributes to the improvement of product quality and yield.

[Brief description of drawings]

FIG. 1 is an assembly structure diagram of a semiconductor pressure sensor according to a first embodiment of the present invention, in which (a) is a vertical sectional view of a package,
(B) Bottom view of the cap

FIG. 2 is an assembly structure diagram of a semiconductor pressure sensor according to a second embodiment of the present invention.

FIG. 3 is an assembly structure diagram of a semiconductor pressure sensor according to a third embodiment of the present invention.

FIG. 4 is an assembly structure diagram of a conventional surface pressure type semiconductor pressure sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure sensor chip 3 External lead-out terminal 4 Connection wire 5 Silicone gel 6 Resin case 6a Peripheral wall portion 7 Cap 7a Fitting groove 7b Pressure guide hole 8 Adhesive 9 Engagement protrusion 10 Engagement groove

Claims (3)

[Claims] 1. A diaphragm-type pressure sensor chip, an external lead-out terminal is incorporated in a resin case, a wire is connected between the sensor chip and the external lead-out terminal, and the surface of the sensor chip is sealed with a gel resin. , In a package structure of a semiconductor pressure sensor assembled by covering a resin case with a cap having pressure guiding holes in a fitting manner and fixing them with an adhesive between them, between the peripheral wall of the resin case and the peripheral wall of the cap fitted to the resin. A package structure for a semiconductor pressure sensor, comprising: a temporary engagement portion for holding the cap at the attached position. 2. The package structure according to claim 1, wherein
The package structure of the semiconductor pressure sensor, wherein the temporary fixing engagement portion is an engagement projection protruding from one of the peripheral wall surface of the resin case and the peripheral wall surface of the cap toward the peripheral wall surface of the mating member. . 3. The package structure according to claim 2, wherein
A package structure for a semiconductor pressure sensor, characterized in that an engaging groove is formed on a peripheral wall surface of a mating member facing the engaging protrusion so as to engage with the protrusion.