JPH102913A - Semiconductor acceleration sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acceleration sensor, which can be assembled readily and can be constituted at a low cost by using a relatively small substrate. SOLUTION: This sensor has the structure, wherein an IC circuit substrate 12' as a signal processing substrate and an acceleration sensor chip 11' are laminated and tightly bonded on a main mounting substrate 13'. The surface area of the main mounting substrate 13' is reduced to the about half of a conventional substrate. Furthermore, an electrode taking-out part is provided at the surface part of each portion. These parts are conducted to the conductor pattern parts provided at the main mounting substrate 13' under the state, wherein these parts are mutually laminated in this structure. Since the dimensions of the respective substrates at the acceleration sensor chip 11' are unified and connecting parts to external conductive connection members are omitted, the assembling can be performed by the bonding of one time by soldering in comparison with a conventional sensor, and the connecting process-step using bonding wire and the like can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor acceleration sensor used for purposes such as collision detection of an automobile and attitude control in an attitude control device.

[0002]

2. Description of the Related Art Conventionally, an acceleration sensor chip which is a main part of this type of capacitance type semiconductor acceleration sensor is, for example, shown in FIG.
FIG. 3A is a cross-sectional side view in one direction, and FIG.
FIG.

In the acceleration sensor chip 11, a silicon substrate 1 on which a convex movable electrode portion 1a also serving as a weight and a concave beam portion 1b located around the movable electrode portion 1a are formed. A pair of insulating substrates 2 and 3 are provided on one side and the other side (upper and lower sides in FIG. 3A).
Are tightly joined by sandwiching the silicon substrate 1 by electrostatic bonding or the like. A fixed electrode portion 4 is provided on a step portion 2a provided on one insulating substrate 2 so as to include a through hole 2b, and a through hole 3b is provided on a step portion 3a provided on the other insulating substrate 3.
The fixed electrode unit 5 is provided so as to include Here, the pair of insulating substrates 2 and 3 are formed by a combination of steps 2a and 3a provided in a storage space separated from the movable electrode section 1a, respectively, and fixed electrode sections provided in the steps 2a and 3a, respectively. Reference numerals 4 and 5 form a capacitance with the movable electrode portion 1a. An electrode take-out portion 6 is provided on a part of the outside of the insulating substrate 2, and a through hole 3c is provided on a part of the outside of the insulating substrate 3.
Are provided, and the other portions are provided with electrode take-out portions 8 and 9. Further, the electrode take-out portion 6 is connected to the conductive paste portion 10 at one end of the acceleration sensor chip 11.
Is connected to the electrode take-out unit 9 by the Incidentally, low-resistance silicon is used for the silicon substrate 1.

In the acceleration detection by the acceleration sensor chip 11, when the acceleration is generated, the movable electrode 1a is displaced by the inertial force, and the capacitance value in the capacitor portion corresponding to the space volume inside the sensor changes accordingly. Therefore, the change is performed by electrically detecting the change in the capacitance value using an electric circuit.

As shown in FIG. 4, such an acceleration sensor chip 11 has a dedicated IC circuit in the form of a bare chip in a cutout portion of a main mounting substrate 13 provided with an external lead plate 14 at a predetermined position. The components of the acceleration sensor chip 11 are mounted on the main mounting substrate 13 in a planar manner together with the substrate 12, and are connected to the conductor pattern portion connected to the external lead plate 14 by a bonding wire or the like. And is configured as a semiconductor acceleration sensor.

[0006]

In the case of the above-described semiconductor acceleration sensor, the acceleration sensor chip and the IC circuit board are bonded and fixed in a plane on the main mounting board, and these electrode take-out portions and the main mounting board are mounted on the main mounting board. Although it is necessary to connect a predetermined portion of the provided conductor pattern portion with a bonding wire or the like, such a bonding process and a connection process require time and labor, and thus, there is a problem that assembly is complicated. is there.

In addition, since the acceleration sensor chip and the IC circuit board 3 are mounted two-dimensionally on the main mounting board, the main mounting board requires a large-sized one having a large surface area. There is also a problem that it becomes expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and its technical problem is that a semiconductor acceleration which can be easily assembled and which can be formed at a low cost by using a relatively small substrate. It is to provide a sensor.

[0009]

According to the present invention, one side surface and the other side surface of a silicon substrate are joined by being sandwiched between a pair of insulating substrates, and a first electrode for external conductive contact is provided on a predetermined surface portion. An acceleration sensor chip provided with a take-out portion, and a second electrode take-out portion for external conductive contact provided between a first electrode take-out portion at a predetermined surface location, and an acceleration sensor at the time of applying acceleration. A signal processing substrate for processing a detection signal obtained from the chip, and a predetermined conductive pattern portion to be brought into contact with the second electrode extraction portion; and for mounting the signal processing substrate and the acceleration sensor chip. And a signal processing substrate and an acceleration sensor chip are laminated and adhered in this order on the main mounting substrate, and a first electrode extraction portion is formed by a second electrode extraction portion. The semiconductor acceleration sensor capable conduction with a predetermined conductive pattern section via is obtained.

According to the present invention, in the semiconductor acceleration sensor, an acceleration sensor chip, a signal processing board,
In addition, the main mounting board is mechanically fixed and electrically connected by a single bonding process to obtain a semiconductor acceleration sensor integrally formed.

Further, according to the present invention, in any one of the semiconductor acceleration sensors described above, with respect to the acceleration sensor chip, the silicon substrate is formed of a convex movable electrode portion also serving as a weight and a concave movable electrode portion located around the movable electrode portion. Having a beam portion,
The pair of insulating substrates are formed by combining the movable electrode portion and the storage space separated from each other by the step portions provided respectively,
The step portion is provided with a fixed electrode portion forming a capacitance between the movable electrode portion and the movable electrode portion, and the first electrode take-out portion is a semiconductor acceleration including one connected to the movable electrode portion and the fixed electrode portion in a conductive manner. A sensor is obtained.

[0012]

According to the semiconductor acceleration sensor of the present invention, the signal processing substrate (IC circuit substrate) and the acceleration sensor chip are laminated and bonded on the main mounting substrate, so that the surface area of the main mounting substrate is smaller than that of the conventional one. It has been reduced to about half the size. In addition, an electrode extraction portion is provided at a surface portion of each portion, and these are configured to be electrically connected to a conductor pattern portion provided on the main mounting board in a laminated state, and that the dimensions of each substrate in the acceleration sensor chip are reduced. Since the connection portion to the external conductive connection member (external lead wire, etc.) is unified, the connection process using a conventional bonding wire or the like is not required, and the reflow process requires soldering. And the like, it is possible to perform mechanical fixing and electrical connection by performing only one joining process.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing an external configuration of a semiconductor acceleration sensor according to an embodiment of the present invention.

This semiconductor acceleration sensor has an IC circuit board 12 as a signal processing board on a main mounting board 13 '.
And the acceleration sensor chip 11 'are laminated and adhered in this order.

Of these, the main mounting substrate 13 'has a surface area reduced to about half that of the substrate shown in FIG. 4 (main mounting substrate 13), and no cutout portion is formed. However, the external lead plate 14 and the conductive pattern portion are provided at predetermined positions in common (however, the pattern of the conductive pattern portion is notched. The shape and dimensions are different from those of the prior art due to the fact that the flat plate is not provided with a flat plate.

The acceleration sensor chip 11 'is shown in FIG.
(A) and (b) (the acceleration sensor chip 1
Since the basic configuration is the same as 1), the detailed configuration is not described, but here the dimensions of each substrate (silicon substrate 1 and a pair of insulating substrates 2 and 3) are unified and external lead wires are used. And the like, in that a connection portion to an external conductive connection member such as the above is excluded.

The size of the IC circuit board 12 'is substantially the same as that of the IC circuit board 12 shown in FIG. 4 (IC circuit board 12), but the arrangement pattern of the electrode take-out portions provided on the surface is different. ing.

That is, in this semiconductor acceleration sensor, a first electrode extraction portion for external conductive contact is provided on a predetermined surface of the acceleration sensor chip 11 ', and the first electrode extraction portion has a movable electrode portion 1a. (Silicon substrate 1) and those (electrode extraction portions 6 to 9) which are connected to the fixed electrode portions 4 and 5 so as to be conductive, respectively, are included. The IC circuit board 12 'processes a detection signal obtained from the acceleration sensor chip 11' at the time of applying an acceleration, and a predetermined surface portion thereof has a top view of FIG. 2A, a side view of FIG. 2
As shown in the bottom view of (c), second electrode extraction portions 12a to 12i for external conductive contact are provided. These second electrode extraction portions 12a to 12i
Are the first electrode take-out parts (electrode take-out parts 12a to 12c) that come into contact with a specific corresponding part (electrode take-out parts 7, 8, 9) and the IC circuit board 12
And a predetermined conductive pattern portion provided on a main mounting substrate 13 'for mounting the acceleration sensor chip 11' (electrode extraction portions 12d to 12i)
And divided into

Therefore, in this semiconductor acceleration sensor, the first electrode take-out portion (the electrode take-out portions 6 to 9) is provided in a state where the IC circuit board 12 'and the acceleration sensor chip 11' are stacked and adhered on the main mounting board 13 '. ) Can be electrically connected to a predetermined conductive pattern portion via the second electrode extraction portions (electrode extraction portions 12a to 12i).

Incidentally, such a semiconductor acceleration sensor has a structure in which a main mounting board 13 ', an IC circuit board 12', and an acceleration sensor chip 11 'are laminated, so that a conventional bonding wire or the like is used. It eliminates the need for a connecting process, and provides a mechanical fixation and electrical connection by performing only one joining process in a batch process such as a reflow process that requires a soldering process. Can be assembled.

The procedure for manufacturing and assembling the main parts of the semiconductor acceleration sensor will be briefly described below.

First, in order to form the electrode extraction portions 12d to 12i on the main mounting substrate 13 'side with respect to the IC circuit board 12', the IC circuit board 1 is formed by paste solder printing.
While the paste solder is printed on the bottom surface of 2 ′, the electrode take-out portions 12a to 1a on the acceleration sensor chip 11 ′ side are similarly printed.
IC by paste solder printing to form 2c
The paste solder is printed on the upper surface of the circuit board 12 '.

Next, after temporarily fixing the IC circuit board 12 'on the main mounting board 13', the acceleration sensor chip 11 'is further temporarily fixed thereon and laminated thereon. To melt the paste solder to make the components mechanically fixed and electrically connected. As a result, a semiconductor acceleration sensor in which the components shown in FIG. 1 are integrally laminated and adhered to each other is assembled and manufactured.

[0025]

As described above, according to the semiconductor acceleration sensor of the present invention, the signal processing board and the acceleration sensor chip are laminated and adhered on the main mounting board, and the surface of each part is The electrode extraction portions provided are in a structure in which they are electrically connected to the conductor pattern portion provided on the main mounting board in a stacked state, and the dimensions of each substrate in the acceleration sensor chip are unified so that the connection portion to the external conductive connection member is formed. Since it has been eliminated, the conventional connection process using a bonding wire or the like is not required, and only one joining process is performed in a batch process such as a reflow process that requires soldering, so that it is mechanically fixed. And electrical connection becomes possible. As a result, simplification and speeding up of the assembly and manufacturing can be achieved, and the size of each substrate can be reduced (especially, the main mounting substrate can be reduced to half the surface area of the conventional one). Costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a semiconductor acceleration sensor according to one embodiment of the present invention.

FIG. 2 shows an I used in the semiconductor acceleration sensor shown in FIG.
FIG. 3A shows an arrangement pattern relating to a C circuit board and an electrode extraction portion thereof, FIG.
(B) relates to a side view in one direction, and (c) relates to a bottom view.

3A and 3B show a basic configuration of an acceleration sensor chip which is a main part of a conventional semiconductor acceleration sensor, wherein FIG. 3A relates to a sectional side view in one direction, and FIG. 3B relates to a top view. .

FIG. 4 is a perspective view showing the appearance of a semiconductor acceleration sensor including the acceleration sensor chip shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Silicon substrate 1a Movable electrode part 1b Beam part 2,3 Insulating substrate 2a, 3a Step part 2b, 3b, 3c Through-hole part 4,5 Fixed electrode part 6-9,12a-12i Electrode extraction part 10 Conductive paste part 11, 11 'acceleration sensor chip 12, 12' IC circuit board 13, 13 'main mounting board 14 external lead plate

Claims (3)

[Claims] 1. An acceleration sensor chip comprising one side surface and the other side surface of a silicon substrate sandwiched and joined by a pair of insulating substrates, and a first electrode extraction portion for external conductive contact provided at a predetermined surface portion. A second electrode extraction portion for external conductive contact with the first electrode extraction portion provided at a predetermined surface location, and processes a detection signal obtained from the acceleration sensor chip when acceleration is applied. Main board for mounting the signal processing board and the acceleration sensor chip, the board having a predetermined conductive pattern portion to be contacted between the signal processing board to be formed and the second electrode take-out section Further, the signal processing substrate and the acceleration sensor chip are laminated and adhered in this order on the main mounting substrate, and the first electrode extraction portion is formed of the second electrode. A semiconductor acceleration sensor capable of conducting with the predetermined conductive pattern portion via a take-out portion. 2. The semiconductor acceleration sensor according to claim 1, wherein the acceleration sensor chip, the signal processing board,
The semiconductor acceleration sensor is characterized in that the main mounting board is mechanically fixed and electrically connected in one joining process to be integrally formed. 3. The semiconductor acceleration sensor according to claim 1, wherein, with respect to the acceleration sensor chip, the silicon substrate has a convex movable electrode portion also serving as a weight and a concave movable electrode portion located around the movable electrode portion. A beam portion, and the pair of insulating substrates are formed by combining the movable electrode portion with a storage space separated from the movable electrode portion. A semiconductor acceleration sensor, comprising: a fixed electrode portion that forms a capacitance according to (1), wherein the first electrode lead-out portion includes one connected to the movable electrode portion and the fixed electrode portion so as to be conductive.