JP2003227769A - Semiconductor pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the characteristics of a semiconductor substrate from changing because of deformation of a resin case, related to a semiconductor pressure sensor where both rear and main surfaces of the semiconductor substrate, which output deformation under pressure difference between both sides of a diaphragm as an electric signal, are jointed to one end surface of a pedestal by the outer peripheral part, with the pedestal bonded to the resin case using an adhesive. <P>SOLUTION: The pedestal is directly or indirectly bonded to the resin case so that a non-joint region to the resin case is formed on the other end surface of the pedestal opposed to one end surface of the pedestal bonded to the semiconductor substrate. Thus, even if the resin case is deformed under heat, or the like, the semiconductor substrate is not affected by it. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention joins an outer peripheral edge portion of a back main surface of a semiconductor substrate, which outputs a deformation due to a pressure difference on both sides of a diaphragm, as an electric signal to one end surface of a pedestal and bonds the pedestal. The present invention relates to an improvement of a semiconductor pressure sensor fixed to a resin case with an agent.

[0002]

2. Description of the Related Art A conventional semiconductor pressure sensor of this type is known in which a semiconductor substrate is anodically bonded to a glass pedestal and the other end surface of the pedestal is bonded to a resin case with an adhesive. There is.

[0003]

In such a conventional semiconductor pressure sensor, when the resin case is deformed by heat, the deformation is transmitted to the semiconductor substrate and the characteristics of the semiconductor substrate are changed. Therefore, it has been proposed to reduce the influence of deformation by increasing the length of the pedestal, but if the length of the pedestal is increased, there is a problem that leads to an increase in product size and cost, and If the pedestal is made of glass and exceeds a predetermined length, there is a problem that anodic bonding between the semiconductor substrate and the pedestal becomes impossible.

The present invention has been made in view of the above conventional circumstances, and a first object thereof is to provide a semiconductor pressure sensor in which the deformation of the resin case has little influence on the characteristics of the semiconductor substrate. It is intended.

A second object is to provide a small and inexpensive semiconductor pressure sensor.

[0006]

According to a first aspect of the semiconductor pressure sensor of the present invention, the outer peripheral edge portion of the back main surface of the semiconductor substrate that outputs deformation as an electric signal due to the pressure difference between both sides of the diaphragm is pedestal. In the semiconductor pressure sensor, which is joined to one end face of the pedestal, and the pedestal is fixed to a resin case with an adhesive, a non-joining region with the resin case is provided on the other end face facing the one end face of the pedestal. is there.

According to a second aspect of the invention, the outer peripheral edge portion of the back main surface of the semiconductor substrate that outputs the deformation due to the pressure difference between the two sides of the diaphragm as an electric signal is joined to one end surface of the pedestal and the pedestal is bonded. In a semiconductor pressure sensor fixed to a resin case with an agent, the outer circumference of the other end of the pedestal is fitted into a recess formed in the bottom of the resin case with a small gap, and the other end surface of the pedestal is The outer peripheral edge is brought into contact with the bottom surface of the recess.

According to a third aspect of the invention, the outer peripheral edge portion of the back main surface of the semiconductor substrate that outputs the deformation due to the pressure difference between both sides of the diaphragm as an electric signal is joined to one end surface of the pedestal and the pedestal is bonded. In a semiconductor pressure sensor fixed to a resin case with an agent, the outer circumference of the other end of the pedestal is fitted into a recess formed in the bottom of the resin case with a small gap, and the other end surface of the pedestal is An adhesive that abuts the outer peripheral edge on the bottom surface of the recess and provides a gap between a part of the outer periphery of the pedestal and the resin case, and fixes the pedestal to the resin case in the gap. It is filled.

According to a fourth aspect of the present invention, in the first aspect of the present invention, a tapered concave portion is formed on the inner bottom of the resin case, the taper recess being tapered outward in the resin case. Taper shaft portions each having a large diameter toward each side, and the taper shaft portions are fitted into the tapered recesses without any gap.

In a fifth aspect based on the fourth aspect, an adhesive is filled between the outer periphery of the one end surface side of the tapered shaft portion and the inner surface of the tapered recess to fix the pedestal to the resin case. It is a thing.

According to a sixth aspect of the invention, the outer peripheral edge portion of the back main surface of the semiconductor substrate, which outputs the deformation due to the pressure difference between both sides of the diaphragm as an electric signal, is joined to one end surface of the pedestal and the pedestal is bonded. In a semiconductor pressure sensor fixed to a resin case with an agent, the pedestal is supported by the resin case via a pedestal support, and a non-bonding region with another structure is provided on the other end surface of the pedestal. is there.

In a seventh aspect based on the sixth aspect, the pedestal support has a cylindrical shape, and a protrusion projecting toward the center is provided on the inner periphery of one end of the pedestal support, and a small gap is provided on the inner periphery of the pedestal support. Is formed between the outer circumference of the pedestal and the inner circumference of the pedestal support body by engaging the outer peripheral edge portion of the other end surface of the pedestal fitted via the projection with the protrusion. While filling the formed gap with an adhesive, the one end side outer periphery of the pedestal support is fitted into a recess formed in the bottom of the resin case with a small gap, and the pedestal support is fitted from the fitting portion. The outer circumference on the other end side,
An adhesive is filled between the resin case and the case.

According to an eighth aspect of the invention, in the sixth aspect of the invention, the outer periphery of the pedestal is fitted to the inner periphery of a cylindrical pedestal support, and the pedestal and the pedestal support are bonded with an adhesive. They are glued together.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Embodiment 1 of the present invention will be described with reference to FIG. In the figure, reference numeral 1 is a resin case, and a through hole 1 having a quadrangular opening shape at the bottom thereof.
a, a concave portion 1b which is concentric with the through hole 1a at the inner end of the through hole 1a and has a quadrangular inner circumference, and which is formed in a ring shape along the opening edge of the through hole 1a; Located concentrically on the outer side of the resin case 1 adjacent to the recess 1b,
The shape of the inner circumference is a quadrangle, and the inner circumference has a ring-shaped recess 1c in which the width between opposing sides is smaller than the recess 1b. 2 has a quadrangular shape in plan view, a diaphragm 2a is formed in the center thereof, and a semiconductor substrate 3 for converting the deformation of the diaphragm 2a due to the pressure applied to the diaphragm 2a into an electric signal, 3 is a through hole communicating with the through hole 1a at the center Hole 3a is a pedestal made of glass, and one end surface (upper end surface in the figure) of the pedestal
The outer peripheral edge surface on the back surface side of the semiconductor substrate 2 is joined by anodic bonding, the other end is fitted into the recess 1c through a small gap, and a part of the outer peripheral edge of the other end surface is formed on the bottom surface of the recess 1c. It was supported. An adhesive 4 fills a gap between the outer periphery of the pedestal 3 and the recess 1b, and fixes the pedestal 3 to the resin case 1. 5 is an external connection terminal inserted so as to penetrate the resin case 1, 6 is an external connection terminal 5
The wire wiring is wire-bonded across the exposed portion in the resin case 1 and the electrode (not shown) of the semiconductor substrate 2.

In such a structure, the diaphragm 2a is deformed by the pressure of the pressure detecting portion being applied through the pressure introducing hole constituted by the through hole 1a and the through hole 3a, and the deformation is caused. An electric signal according to the operation is generated in the semiconductor substrate 2 and output to the outside via the bonding wire 6 and the external lead-out terminal 5.

When the resin case 1 is deformed by an external factor such as ambient temperature, the other end portion of the pedestal 3 is provided with a non-bonding region with other portions, so that the pedestal 3 is not attached. Stress transmission to the semiconductor substrate 2 is reduced as compared with the conventional one in which the other end surface is bonded to the resin case with an adhesive.

The gap for inserting the adhesive 4 between the resin case 1 and the outer periphery of the pedestal 3 is not limited to the one having a plurality of recesses 1b and 1c as shown in FIG. It goes without saying that a single recess may be provided in the resin case 1 and a protrusion may be provided on the outer circumference of the pedestal 3 on the other end side to form a gap.

Embodiment 2. FIG. 2 shows another embodiment. 1d is a quadrangular pyramid hole forming a part of the through hole 1a, which is formed so as to taper from the inner wall of the resin case 1 to the outside of the resin case 1. Is. Reference numeral 3b is a quadrangular pyramid shaft portion formed on the outer periphery of the pedestal 3 on the other end side, and the quadrangular pyramid has the same angle as the quadrangular pyramid hole 1d, and is configured to fit into the quadrangular pyramid portion of the quadrangular pyramid hole 1d. It will be. 7 is a gap formed between the other end surface of the pedestal 3 and the inner side surface of the resin case 1, and 8 is filled between the outer periphery of the pedestal 3 on the other end surface side of the quadrangular pyramid and the inner surface of the quadrangular pyramid hole. It is for fixing the pedestal 3 to the resin case 1 with an adhesive. The description of the other reference numerals is the same as that of the first embodiment and will not be repeated.

The operation of the semiconductor pressure sensor thus constructed is the same as that of the first embodiment.

Further, since the gap 7 is formed between the other end surface of the pedestal 3 and the inner side surface of the resin case 1, when the resin case 1 is deformed by an external factor such as ambient temperature, The stress transmission to the semiconductor substrate 2 is reduced as compared with the conventional one in which the other end surface of the pedestal 3 is bonded to the resin case with an adhesive.

Further, since the quadrangular pyramid shaft portion 3b of the pedestal 3 is fitted in the quadrangular pyramid hole 1d, the pedestal 3 for the resin case 1 is formed.
Not only is it possible to prevent the pedestal 3 from tilting during assembly, but also the fitting portion prevents the adhesive 8 from leaking into the gap 7 when the viscosity of the adhesive 8 is low.

Embodiment 3. FIG. 3 shows another embodiment, 9 is a pedestal support for supporting the pedestal 3, which has a through hole 9a at the center and is concentric with the through hole 9a at one end (upper end in the figure) side. And a ring-shaped recess 9b whose inner peripheral shape is a quadrangle, and which are arranged concentrically adjacent to the recess 9b on the outer side of the recess 9b on the outer side of the resin case 1, and the inner peripheral shape is a quadrangle. It has a ring-shaped recess 9c having a width between the opposite sides of its inner circumference smaller than that of the recess 9b, and the pedestal 3 is provided in the recess 9c.
The outer periphery of the other end (lower end in the figure) of is fitted with a small gap,
The outer peripheral edge of the other end surface of the pedestal 3 is supported by the bottom surface of the recess 9c, the outer periphery of the other end (lower side in the figure) is fitted into the recess 1c with a small gap, and the other end surface of the recess 1c is formed. It is supported on the bottom. 10 is a gap formed between the bottom surface of the recess 1c and the other end surface of the pedestal 3. Reference numeral 11 denotes an adhesive filled between the inner peripheral surface of the recess 1b and the outer peripheral surface of the pedestal support 9.
An adhesive 2 is filled between the inner peripheral surface of the recess 9b and the outer peripheral surface of the pedestal 3. The description of the other reference numerals is the same as that of the first embodiment and will not be repeated.

The operation of the semiconductor pressure sensor thus constructed is the same as that of the first embodiment.

The other end surface of the pedestal 3 and the resin case 1
Since a gap 10 is formed between the resin case 1 and the inner side surface of the base, when the resin case 1 is deformed by an external factor such as ambient temperature, the other end surface of the pedestal 3 is adhered to the resin case with an adhesive. The stress transmission to the semiconductor substrate 2 is reduced as compared with the above.

Since the pedestal support 9 is disposed between the resin case 1 and the pedestal 3, the material of the pedestal support 9 can be appropriately selected so that the distortion of the resin case 1 will not occur in the semiconductor substrate 2. Can be further reduced.

In the structure in which a gap for inserting the adhesive 12 is formed between the pedestal 3 and the outer periphery of the pedestal support 9, a single recess is provided on the inner periphery of the pedestal support to form a pedestal. A protrusion may be provided on the outer periphery of the other end side of the resin case 1.
And the outer periphery of the pedestal support 9, a structure for forming a gap into which the adhesive 11 is inserted is such that a single recess is provided in the resin case 1 and a protrusion is provided on the outer periphery of the other end of the pedestal support. It may be configured and is not limited to the embodiment of FIG.

Fourth Embodiment FIG. 4 shows another embodiment, in which 13 is a cylindrical pedestal support body fitted to the outer periphery of the pedestal 3, which has a through hole 13a at the center and the other end (lower side in the figure). The outer periphery of the part is fitted in the recess 1c with a small gap, and the other end surface is supported by the bottom surface of the recess 1c. Reference numeral 14 is an adhesive that bonds the outer peripheral surface of the pedestal 3 to one end of the pedestal support 13. The description of the other reference numerals is the same as that of the third embodiment and will not be repeated.

The operation of the semiconductor pressure sensor thus constructed is the same as that of the first embodiment.

Further, since the gap 10 is formed between the entire other end surface of the columnar pedestal 3 and the inner side surface of the resin case 1, the resin case 1 is deformed by an external factor such as ambient temperature. In this case, the stress transmission to the semiconductor substrate 2 is significantly reduced as compared with the conventional one in which the other end surface of the pedestal 3 is bonded to the resin case with an adhesive.

Further, by appropriately selecting the material of the pedestal support 13, the influence of the distortion of the resin case 1 on the semiconductor substrate 2 can be further reduced.

The position of the adhesive 14 for adhering the base 3 and the base support 13 may be between the outer peripheral surface of the column base 3 and the inner peripheral surface of the base support 13. Needless to say, it is not limited to.

Further, in the first to fourth embodiments, the configuration in which the sensed pressure is applied to the back surface of the diaphragm, that is, the back surface of the semiconductor substrate 2 has been exemplified.
It goes without saying that the invention of the present application can be applied to a structure in which the pressure to be sensed is applied to the surface of the diaphragm, that is, the surface of the semiconductor substrate 2.

[0033]

Since the present invention is constituted as described above, it has the following effects.

According to the first aspect of the present invention, when the resin case is deformed by an external factor such as ambient temperature, the other end surface of the pedestal is provided with a non-bonding region with other parts. In comparison with the conventional one in which the other end surface of the pedestal is adhered to the resin case with an adhesive, stress transmission to the semiconductor substrate is reduced, and as a result, there is an effect that it is possible to provide a semiconductor sensor in which the characteristic change of the semiconductor substrate is small.

Further, according to the second aspect of the invention, since the pedestal is directly supported by the resin case, there is an effect that it is possible to provide a semiconductor pressure sensor which is extremely simple in structure and inexpensive.

According to the third aspect of the invention, since the adhesive is filled between the outer periphery of the pedestal and the inner surface of the recess of the resin case, the pedestal and the resin case are covered with a small amount of adhesive. There is an effect that can be effectively adhered with.

According to the fourth aspect of the invention, since the quadrangular pyramid shaft portion of the pedestal is fitted into the quadrangular pyramid portion of the quadrangular pyramid hole, the inclination of the pedestal during assembly of the pedestal with respect to the resin case is prevented. There is an effect that can be done.

Further, according to the fifth invention, there is an effect that the pedestal and the resin case can be effectively bonded together with a small amount of adhesive.

According to the sixth aspect of the invention, the effect of strain of the resin case on the semiconductor substrate can be effectively reduced by appropriately selecting the material of the pedestal support.

According to the seventh invention, not only the relative positioning of the pedestal and the pedestal support and the relative positioning of the pedestal support and the resin case can be easily performed, but also the pedestal and There is an effect that the pedestal support and the pedestal support can be effectively adhered to the resin case with a small amount of adhesive.

According to the eighth aspect of the invention, since a gap is formed between the entire other end surface of the pedestal and the inner side surface of the resin case, the resin case causes external factors such as ambient temperature. When the deformation occurs, the entire other end surface of the pedestal is a non-bonded area with other parts, so that the other end surface of the pedestal is bonded to the resin case with an adhesive as compared with the conventional one. The stress transmission to the semiconductor substrate is remarkably reduced, and as a result, there is an effect that it is possible to provide a semiconductor sensor in which the characteristic change of the semiconductor substrate is extremely small.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional view showing a second embodiment of the present invention.

FIG. 3 is a vertical sectional view showing a third embodiment of the present invention.

FIG. 4 is a vertical sectional view showing a fourth embodiment of the present invention.

[Explanation of symbols]

1 resin case, 1a through hole, 2 semiconductor substrate, 2
a diaphragm, 3 pedestal, 3a through hole, 4 adhesive, 8 adhesive, 9 pedestal support, 9a through hole, 11
Adhesive, 12 adhesive, 13 pedestal support, 14 adhesive

Claims (8)

[Claims] 1. An outer peripheral edge portion of a back main surface of a semiconductor substrate that outputs a deformation due to a pressure difference on both sides of a diaphragm as an electric signal is joined to one end surface of a pedestal, and the pedestal is made into a resin case with an adhesive. In the fixed semiconductor pressure sensor, a non-bonding region with the resin case is provided on the other end surface of the pedestal opposite to the one end surface thereof. 2. The outer peripheral edge portion of the back main surface of the semiconductor substrate that outputs the deformation due to the pressure difference between both sides of the diaphragm as an electric signal is joined to one end surface of the pedestal, and the pedestal is made into a resin case with an adhesive. In the fixed semiconductor pressure sensor, the outer periphery of the other end side of the pedestal is fitted into a recess formed in the bottom of the resin case with a small gap, and the outer peripheral edge of the other end surface of the pedestal is the recess. The semiconductor pressure sensor according to claim 1, wherein the semiconductor pressure sensor is brought into contact with the bottom surface of the. 3. The outer peripheral edge portion of the back main surface of the semiconductor substrate that outputs the deformation due to the pressure difference on both sides of the diaphragm as an electric signal is joined to one end surface of the pedestal, and the pedestal is made into a resin case with an adhesive. In the fixed semiconductor pressure sensor, the outer periphery of the other end side of the pedestal is fitted into a recess formed in the bottom of the resin case with a small gap, and the outer peripheral edge of the other end surface of the pedestal is the recess. And a gap is provided between a part of the outer periphery of the pedestal and the resin case, and the gap is filled with an adhesive for fixing the pedestal to the resin case. The semiconductor pressure sensor according to claim 2. 4. An inner bottom portion of the resin case is provided with a tapered recessed portion which is tapered outward in the resin case, and a taper shaft portion having a large diameter from the other end surface side to the one end surface side of the pedestal is provided. 2. The semiconductor pressure sensor according to claim 1, wherein the tapered shaft portion is fitted in the tapered recess without any gap. 5. The semiconductor pressure sensor according to claim 4, wherein an adhesive is filled between the outer periphery of the one end surface side of the tapered shaft portion and the inner surface of the tapered recess to fix the pedestal to the resin case. . 6. The outer peripheral edge portion of the back main surface of the semiconductor substrate, which outputs the deformation due to the pressure difference between both sides of the diaphragm as an electric signal, is joined to one end surface of the pedestal, and the pedestal is attached to a resin case with an adhesive. In a fixed semiconductor pressure sensor, the pedestal is supported by the resin case via a pedestal support, and a non-bonding region with another structure is provided on the other end surface of the pedestal. . 7. An outer peripheral edge portion of the other end surface of the pedestal in which the pedestal support has a cylindrical shape and a protrusion projecting toward the center is provided on the inner circumference of one end side of the pedestal support, and the inner circumference of the pedestal support is fitted with a small gap. To engage with the protrusion, and to fill the gap formed between the outer periphery of the pedestal on one end side of the pedestal from the fitting portion and the inner periphery of the pedestal support with an adhesive, The outer circumference of the one end side of the support is fitted into a recess formed in the bottom of the resin case with a small gap, and the outer circumference of the other end side of the pedestal support from the fitting part and the resin case. 7. The semiconductor pressure sensor according to claim 6, wherein the semiconductor pressure sensor is filled with an adhesive. 8. The pedestal and the pedestal support are bonded to each other with an adhesive while the outer circumference of the pedestal is fitted to the inner circumference of a cylindrical pedestal support. Semiconductor pressure sensor.