JPH08110351A - Semiconductor dynamic sensor device - Google Patents

Abstract

PURPOSE: To miniaturize a device by eliminating a glass stage between an IC for control and an acceleration sensor. CONSTITUTION: An IC 2 for control and an IC for drive 3 are die-mounted on a ceramic substrate 1 with an adhesive 5a and an acceleration sensor 4 is die-mounted to a center region on the IC 2 for control with an adhesive 5b. Then, the acceleration sensor 4 and the IC 2 for control are electrically connected with a wire 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor dynamic sensor device for detecting acceleration or pressure.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional configuration. (A) is a top view and (b) is an AA sectional view. The semiconductor acceleration sensor 4 has a cantilever structure that is displaced according to acceleration. This cantilever structure is formed by etching a silicon substrate, and is mounted on the stage 11 used as a pedestal of the acceleration sensor 4. Conventionally, glass is used as the stage 11 in terms of flatness and etching processability.

Further, since the acceleration sensor 4 does not function by itself, it requires a monolithic IC for control and a power IC for driving, that is, a circuit chip. Therefore, FIG.
As shown in FIG. 3, three chips of the acceleration sensor 4, the control IC 2, and the driving power IC 3 are mounted on the same plane of the ceramic substrate 1.

[0004]

The acceleration sensor 4 is formed by etching a silicon substrate, and the stress applied to the weight portion 4a is converted into electric resistance change for sensing. Therefore, it is necessary to reduce as much as possible the stress other than the stress generated by the original acceleration, for example, the stress generated by the mismatch of thermal expansion. Therefore, there is a constraint that the glass stage 11 must be selected to have a coefficient of thermal expansion as close as possible to that of silicon in order to absorb the difference in thermal expansion between the ceramic substrate 1 and the acceleration sensor 4. Furthermore, this glass stage 11
Since the acceleration sensor 4 has a cantilever structure, it is necessary to provide a through hole 11a as shown in FIG. 7B in the portion directly below the weight portion 4a or to provide a recess by etching.

Therefore, the provision of the glass stage 11 itself has the above-mentioned restrictions and structural problems. It is an object of the present invention to solve the above problems by adopting a configuration in which the glass stage is abolished.

[0006]

In order to achieve the above object, the invention according to claim 1 has a displacement portion (4a) which is displaced by the action of force, and the displacement of this displacement portion (4a) is A semiconductor dynamic sensor (4) for detecting, and a circuit chip (2) electrically connected to the semiconductor dynamic sensor (4) and electrically processing a detection signal from the semiconductor dynamic sensor (4) are provided. The semiconductor dynamic sensor is characterized in that the semiconductor dynamic sensor (4) is mounted on the circuit chip (2) via an adhesive (5b).

According to the second aspect of the present invention, the semiconductor dynamic sensor (4) has a displacement portion (4a) which is displaced by the action of force, and detects the displacement of the displacement portion (4a).
A substrate (1) on which electrical wiring (9) is formed, and a substrate (1) installed on the substrate (1) and having a pad on the upper portion, the pad and the electrical wiring (9) on the substrate (1) are The first wire (7) is electrically connected to the semiconductor dynamic sensor (4) to electrically process a detection signal from the semiconductor dynamic sensor (4). 1
Electric wire (9) on the substrate (1) from the wire (7)
In a semiconductor dynamic sensor device provided with a circuit chip (2) for outputting a processing signal to the outside (3) via a semiconductor dynamic sensor (4), the pad on the upper part of the circuit chip (2) is formed. The semiconductor dynamic sensor (4) and the circuit chip (2) are mounted on the non-exposed area via the adhesive (5b) and the second wire (6)
It is characterized by being electrically connected by.

According to a third aspect of the present invention, in the first or second aspect of the invention, the displacement portion is a weight portion that is displaced by receiving acceleration, and the adhesive is the semiconductor dynamic sensor and the semiconductor dynamic sensor. It is characterized in that it is an adhesive containing beads that makes the gap between the circuit chips constant. According to a fourth aspect of the invention, in the invention according to any one of the first to third aspects, the semiconductor dynamic sensor is made of silicon, and the circuit chip is made of silicon. It is characterized by being a chip.

The reference numerals in parentheses of the above-mentioned means indicate the correspondence with the concrete means described in the embodiments described later.

[0010]

According to the invention described in claims 1 to 4, since the semiconductor dynamic sensor is mounted on the circuit chip via the adhesive, the circuit chip also serves as the conventional glass stage. Therefore, the conventional glass stage can be eliminated.

Further, by mounting the acceleration sensor on the circuit chip, the circuit chip and the acceleration sensor are three-dimensionally configured, so that the space on the plane can be reduced. Further, according to the third aspect of the invention, since the gap between the semiconductor dynamic sensor and the circuit chip is made constant by the adhesive containing beads, the movement of the weight portion that is displaced by receiving acceleration is prevented. , And can be regulated with the constant gap, and can properly function as an acceleration sensor.

Further, according to the invention of claim 4,
Since the semiconductor dynamic sensor and the circuit chip are made of silicon, the stress due to the difference in thermal expansion between them can be reduced.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a plan view of an acceleration sensor module (acceleration detection device), and FIG. 1B is a sectional view taken along line AA. In FIG. 1, a control IC is mounted on a ceramic substrate 1.
2 and the driving IC 3 are die-mounted with an adhesive 5a, and the acceleration sensor 4 is provided with an adhesive 5b near the center of the chip (a space where the acceleration sensor 4 can be mounted) excluding the Al pad portion of the control IC 2. Die mounted by.

Here, as the adhesive 5b, glass beads for forming an air gap (for example, 20 μm) in a resin having a low Young's modulus in order to absorb thermal and mechanical stress acting on the acceleration sensor 4. Adhesive mixed with is used. By mixing the glass beads of uniform particle size into the resin, it is possible to form a predetermined gap between the control IC 2 and the acceleration sensor 4, and the weight portion 4a.
It is possible to regulate the movement when the is displaced according to the acceleration. That is, it is possible to adopt a configuration that can be applied to an acceleration sensor having a cantilever structure.

Further, a pad on the acceleration sensor 4 and a pad on the control IC 2 are connected by a wire 6 of Al or Au. Also, the wires 7 and 8 of Al or Au connect the pads of the control IC 2 and the drive IC 3 to the wiring 9 on the ceramic substrate 1. Input / output as a module having the above configuration is performed by the external extraction pin 10 through the wiring 9 on the ceramic substrate 1.

The control IC 2 electrically processes the detection signal from the acceleration sensor 4 to obtain an acceleration signal (processed signal).
Is output to the driving IC 3 via the wire 7 and the wiring 9, and the driving IC drives an actuator (for example, an actuator for an airbag or a brake in a vehicle). The acceleration sensor module is manufactured as follows.

First, the wiring 9 and the external extraction pin 10
The control IC 2 and the driving IC 3 are die-mounted with the adhesive 5a on the ceramic substrate 1 on which the acceleration sensor 4 is attached to the vicinity of the center of the chip excluding the Al pad portion of the control IC 2 with the adhesive 5b. To die mount. In this case, when the control IC 2 is in a wafer state (= before dicing), the adhesive 5b is applied by printing, the acceleration sensor 4 is mounted on the adhesive 5b, and after curing, the control IC 2 is diced. You may

After the whole is cured at once, the pad on the acceleration sensor 4 and the pad on the control IC 2 are connected by the wire 6. Then, the wires 7 and 8 connect the pads of the control IC 2 and the drive IC 3 to the wiring 9 on the ceramic substrate 1. In the above-mentioned configuration, the connection from the acceleration sensor 4 to the control IC 2 is made by the wire 12 and the wiring 9 on the ceramic substrate 1 as in the conventional one shown in FIG.
And wire 6 rather than via wire 7.
The signal line is shortened,
It is very effective in preventing signal delay and noise.

The control IC 2 and the acceleration sensor 4 are connected to each other.
By configuring in a stacked manner, the control IC 2 can also serve as the conventional glass stage 11, and it is possible to eliminate the glass stage 11 which is a separate component which has been a problem in the related art. Furthermore, since the control IC 2 is a silicon chip and is used as a stage, the thermal expansion difference between the control IC 2 and the acceleration sensor 4 is 0, and the problem of thermal stress can be solved.

Further, in the conventional device shown in FIG. 7, the three chips of the acceleration sensor 4, the control IC 2 and the driving IC 3 are mounted on the same plane of the ceramic substrate 1, but in the above embodiment. , The acceleration sensor 4 to the control I
Since the chip is mounted in an empty area in the center of the chip other than the pad portion around C2, the area conventionally required for mounting the acceleration sensor is unnecessary, and the board size can be reduced, that is, the product can be downsized. .

The acceleration sensor module shown in FIG. 1 is finally packaged in a medium airtight structure by cap sealing or a can package. FIG. 2 shows a structure in which a cap 20 is bonded onto the ceramic substrate 1 with solder or resin to form a medium airtight structure. FIG. 3 shows the acceleration sensor module housed in a can package 21 as in the conventional case and sealed by resistance welding. 4 shows a structure in which a concave multi-layer ceramic substrate 22 is used and a ceramic substrate 23 is bonded with solder or resin to cover the same.

As the acceleration sensor module in the above embodiment, the structure in which the acceleration sensor 4 is stacked in two stages on the control IC 2 is shown. However, when the driving IC 3 has low power or a plurality of control ICs 2 are provided. In some cases, as shown in FIG. 5, a structure having three or more layers can be used. By doing so, the size of the substrate can be further reduced, and the product can be downsized.
In FIG. 5, reference numeral 30 is a drive IC 3 or another control IC.

Instead of the face-up only structure shown in FIG. 5, bumps can be connected to each other by using face-down flip chips as shown in FIG. Although the present invention is applied to the semiconductor acceleration sensor device in the above embodiment, it may be applied to a semiconductor pressure sensor device that detects the pressure of the medium to be measured.

[Brief description of drawings]

1A and 1B show an acceleration sensor module according to an embodiment of the present invention, in which FIG. 1A is a plan view and FIG. 1B is a sectional view taken along line AA.

FIG. 2 is a sectional view showing an example in which an acceleration sensor module is cap-sealed.

FIG. 3 is a cross-sectional view showing an example in which an acceleration sensor module is housed in a can package.

FIG. 4 is a cross-sectional view showing an example in which an acceleration sensor module is housed in a multilayer ceramic substrate and a ceramic substrate as a lid.

FIG. 5 is a cross-sectional view showing a structure in which an acceleration sensor 4, a control IC 2 and the like are stacked in three stages.

FIG. 6 is a cross-sectional view showing a structure in which a face-down flip chip is used in contrast to the structure shown in FIG.

FIG. 7 shows a conventional acceleration sensor module,
(A) is a top view and (b) is an AA sectional view.

[Explanation of symbols]

1 ... Ceramic substrate, 2 ... Control IC, 3 ... Driving IC, 4 ... Acceleration sensor, 5a, 5b ... Adhesive,
6-8 ... Wire, 9 ... Wiring.

Claims (4)

[Claims] 1. A displacement portion that is displaced by the action of force,
A semiconductor dynamic sensor including a semiconductor dynamic sensor that detects a displacement of the displacement portion and a circuit chip that is electrically connected to the semiconductor dynamic sensor and that electrically processes a detection signal from the semiconductor dynamic sensor, The semiconductor dynamic sensor device is characterized in that the semiconductor dynamic sensor is mounted on the circuit chip via an adhesive. 2. Having a displacement portion that is displaced by the action of force,
A semiconductor dynamic sensor for detecting the displacement of the displacement portion, a substrate on which electric wiring is formed, a pad installed on the substrate, and having a pad on the upper portion, the pad and the electric wiring on the substrate are the first It is electrically connected by a wire and is electrically connected to the semiconductor dynamic sensor to electrically process a detection signal from the semiconductor dynamic sensor, and an electric wiring on the substrate is connected from the first wire. In a semiconductor dynamics sensor device including a circuit chip that outputs a processing signal to the outside through, the semiconductor dynamics sensor, in the region in which the pad in the upper portion of the circuit chip is not formed, is mounted via an adhesive, A semiconductor dynamic sensor device, wherein the semiconductor dynamic sensor and the circuit chip are electrically connected by a second wire. 3. The displacing portion is a weight portion that is displaced by receiving acceleration, and the adhesive is a beaded adhesive that keeps a gap between the semiconductor dynamic sensor and the circuit chip constant. The semiconductor dynamic sensor device according to claim 1 or 2, which is characterized. 4. The semiconductor dynamic sensor is made of silicon, and the circuit chip is an IC chip made of silicon. Semiconductor dynamic sensor device.