JPH10332735A - Housing structure of semiconductor acceleration sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the housing structure of a semiconductor acceleration sensor which can be made small without providing a pillar-state part. SOLUTION: In the housing structure of a semiconductor acceleration sensor provided with a body 1 having a bottom part 11 and a edge end 12, a semi-conductor sensor part provided with a sensor chip for detecting acceleration, a housing 3 formed in the shape of a box with a bottom having an opening end 31 and fitted into the body 1 for housing the semiconductor sensor part in the inside 32, and a stand-off 3 brought into contact with a substrate face 51 of a printed board 5 in plural projected and implemented from the bottom part 11 of the body 1 and forming a cavity between the substrate face 51 and the body 1, the stand-off 4 is so constituted that a contact piece 42 to be brought into contact with the opening end 31 of the housing 3 is projected toward outside from the edge end 12 of the body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a housing structure of a semiconductor acceleration sensor used for an automobile, an aircraft, an electric home appliance, or the like and having a sensor portion formed of a semiconductor.

[0002]

2. Description of the Related Art Conventionally, as a housing structure of a semiconductor acceleration sensor of this kind, there is a structure shown in FIGS. This is a rectangular body A having a bottom A1 and an edge A2, a semiconductor sensor B provided with a sensor chip B1 for detecting acceleration, and a bottomed body having an open end C1. A housing C that is formed in a box shape, is fitted to the body A, and houses the semiconductor sensor portion B in the inside C2.
And a plurality of protruding portions from the bottom A1 of the body A,
There is provided a standoff E which abuts on the substrate surface D1 of the printed circuit board D to be mounted on the substrate abutment surface to form a gap between the substrate surface D1 and the body A. In this case, however, the standoffs E are provided not at the four corners of the body A but at the center.

More specifically, the body A has columnar portions A3 provided on both sides facing each other, and a bottom surface C of the housing C.
By being in contact with the housing 3, the housing 3 is fitted by the housing C while being positioned with the housing C.

When mounted on the substrate surface D1 of the printed circuit board D, the standoff E comes into contact with the substrate surface D1 to form an air gap between the substrate surface D1 and the body A, thereby forming a so-called standoff structure. . This stand-off structure is such that when the terminal B2 led out of the body A is soldered and mounted, gas easily escapes and the strength of the solder is improved, or heat during soldering is not easily transmitted to the body A. It has been widely adopted because of its advantages.

[0005]

In the housing structure of the conventional semiconductor acceleration sensor described above, when the housing C is fitted to the body A, the columnar portion A3 comes into contact with the bottom surface C3 of the housing C, and positions each other. be able to.

However, since the columnar portions A3 are provided on both sides of the body A, there is a problem that the columnar portions A3 are enlarged on both sides by the width of the columnar portions A3.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a housing structure of a semiconductor acceleration sensor which can be reduced in size without providing a columnar portion.

[0008]

According to a first aspect of the present invention, there is provided a semiconductor device having a body having a bottom and an edge, and a semiconductor sensor provided with a sensor chip for detecting acceleration. A housing that is formed in a bottomed box shape having an open end, is fitted to the body and houses the semiconductor sensor unit therein, and a plurality of protruding portions from the bottom of the body and a board surface of a printed circuit board to be mounted A standoff that abuts on a substrate abutting surface to form an air gap between the substrate surface and the body, wherein the standoff abuts an open end of the housing. The contact piece is configured to protrude outward from the edge position of the body.

According to a second aspect of the present invention, in the first aspect, the semiconductor sensor portion is provided at a predetermined angle with respect to a substrate contact surface of the standoff. The off portions are arranged at the four corners of the rectangular body.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

Reference numeral 1 denotes a body, which is formed of an insulating resin and has a rectangular shape and a bottomed box shape, and has a bottom portion 11 and an edge end 12 and is provided with opposing side walls 13.

Reference numeral 2 denotes a semiconductor sensor unit.
, A first stopper 22 and a second stopper 23. The sensor chip 21 includes a weight portion 21a, a bent portion 21b, and a sensor portion 2 made of a thin silicon semiconductor.
1c and a support portion 21d. The bending portion 21 is bent so that the weight portion 21a bends when an acceleration is applied to the weight portion 21a.
b has one end connected to the weight portion 21a. Sensor part 2
1c is a bent portion 21 due to a piezoresistor made of a semiconductor.
b, and converts the acceleration into an electric signal based on the bending of the bending portion 21b and outputs the electric signal. Support part 21
A space d surrounds the outer peripheral edge of the weight portion 21a to support the other end of the flexible portion 21b.

The first stopper 22 is made of Pyrex glass formed in a substantially square shape, and has a weight 21a at the center.
Has a first contact surface 22a with which it can contact, a gap is formed between the first contact surface 22a and the weight portion 21a, and is fixed to one surface side of the support portion 21d. Similarly, the second stopper 23 is made of Pyrex glass formed in a substantially square shape, and has a second contact surface 23a with which the weight portion 21a can contact at the center, and the second stopper surface 23a and the weight Part 21
A gap is provided between the supporting portion 21a and the supporting portion 21d and the supporting portion 21d is fixed to the other surface side.

Reference numeral 3 denotes a housing, which is made of metal and formed in a rectangular box-like shape having an open end 31 and fitted to the body 1.

Reference numeral 4 denotes a standoff, which is formed integrally with the body 1 by an insulating resin, and has a bottom 11
And a contact piece 4 protruding from the end of the piece 41 outward from the edge 12 of the body 1.
2, a total of four are disposed at each of the four corners of the body 1 formed in a substantially L-shape and formed in a rectangular shape. Then, one surface of the piece 41 and one surface of the contact piece 42 form a substrate contact surface 43.

The printed board 5 is made of an insulating resin.
The substrate surface 51 is formed in a flat plate shape, and the wiring pattern is formed on the substrate surface 51.
Are applied in the orthogonal direction.

Another printed board 6 is provided with a plurality of terminals 61, the semiconductor sensor unit 2 is mounted, and the sensor chip 21 and the terminals 61 are connected by wire bonding. Then, the terminal 61 is fixed to the side walls 13 of the body 1 and the terminal 61 is led out of the body 1. The sealing portion 7 seals a gap between the body 1, the terminal 61, and the housing 3 with a sealing material.

Here, as shown in FIG. 5, the semiconductor sensor section 2 has a straight line 21e connecting the center of gravity of the weight section 21a of the sensor chip 21 and the sensor section 21c with respect to the substrate contact surface 43 of the standoff 4. Are provided at a predetermined angle with respect to the substrate contact surface 43 so as to be positioned in parallel.

The housing 3 is fitted to the body 1 and accommodates the semiconductor sensor section 2 in the interior 32. At this time, since the contact piece 42 of the standoff 4 projects outward from the position of the edge 12 of the body 1, the contact piece 42 comes into contact with the opening end 31 of the housing 3 and Are positioned relative to each other.

When the body 1 is mounted on the board surface 51 of the printed board 5, the board contact surface 4 of the stand-off 4 is mounted.
3 is in contact with the substrate surface 51, and the substrate surface 51 and the body 1
And a gap is formed between them. Since the standoffs 4 are arranged at the four corners of the body 1, the distance between the standoffs 4 and 4 in both directions orthogonal to each other on the substrate surface 51 becomes longer, and the standoffs 4 abut on the substrate surface 51 in a stable state. Therefore, the straight line 21e of the sensor chip 21 is accurately positioned parallel to the substrate surface 51, that is, the sensor chip 21
Are accurately inclined at a predetermined angle with respect to the substrate surface 51.

The operation of the above will be described. When the acceleration is applied, the weight portion 21a is displaced in a direction opposite to the direction in which the acceleration is applied, and the bending portion 21b is bent, and the piezo-resistance as the sensor portion 21c formed on one surface of the bending portion 21b is bent. The resistance value of the piezo resistor changes. Bending portion 21b
On one surface, a resistance part (not shown) for temperature compensation having the same structure as the piezo resistance is formed, and the piezo resistance and the resistance part are connected to each other to form a bridge circuit (not shown). . The acceleration is detected by measuring the resistance value of the piezoresistor by a bridge circuit.

Here, the sensor chip 21 is
Since the straight line 21e connecting the center of gravity of a with the sensor section 21c is accurately and parallel to the substrate surface 51, the acceleration is detected with high accuracy orthogonally to the acceleration direction.

When an excessive acceleration is applied, the weight portion 21a is connected to the first contact surface 22 of the first stopper 22.
When excessive acceleration in the opposite direction is applied to a,
It contacts the second contact surface 23a. That is, the first stopper 2
The second and second stoppers 23 prevent the bending of the bending portion 21b from exceeding a certain value and prevent the bending of the bending portion 21b.

In the housing structure of the semiconductor acceleration sensor according to one embodiment, as described above, the body 1
When the housing 3 is fitted to the body 1, the opening thereof opens when the contact piece 42 projects outward from the edge 12 of the body 1 to the standoffs 4 projecting from the bottom 11. Since the end portion 31 is positioned in contact with the contact piece 42 of the standoff 4, unlike the related art in which the columnar portion A3 that is provided on both sides of the body 1 and contacts the bottom surface C3 of the housing 3 is required, Miniaturization can be achieved only in the width direction of the columnar portion.

Further, since the body 1 is formed in a rectangular shape and the standoffs 4 are provided at the four corners of the body 1, the body 1 is mounted on the board surface 51 of the printed circuit board 5.
In this case, the distance between the stand-offs 4 and 4 in both directions orthogonal to each other on the substrate surface 51, that is, the distance between the two substrate contact surfaces 43 and 43 becomes longer.
3, 43 and the substrate surface 51 are positioned parallel to each other, that is, the sensor chip 21 is tilted with respect to the substrate surface 51 with high accuracy at a predetermined angle, and the applied acceleration can be detected with high accuracy.

In this embodiment, the standoffs 4 are provided at each of the four corners of the body 1 formed in a rectangular shape. However, the standoffs need not be the four corners. It should just be provided in a part, and it is not limited.

[0027]

According to the first aspect of the present invention, the housing is fitted to the body because the abutting pieces are protruded outward from the edge of the body to the stand-offs projecting from the bottom of the body. When it is attached, its open end abuts against the abutting piece of the stand-off, so that it is positioned. Miniaturization can be achieved only in the width direction of the columnar portion.

According to a second aspect of the present invention, in addition to the effects of the first aspect, if the semiconductor sensor portion is provided to be inclined at a predetermined angle with respect to the stand-off substrate contact surface, the body is provided. Are formed in a rectangular shape, and the standoffs are provided at the four corners of the body, respectively.Therefore, when the body is mounted on the board surface of the printed circuit board, between both standoffs in both directions orthogonal to each other on the board surface, that is, Since the distance between the two contact surfaces becomes long, the two contact surfaces and the substrate surface are positioned in parallel, that is, the sensor chip is accurately tilted at a predetermined angle with respect to the substrate surface, and the applied acceleration is increased. Can be detected with high accuracy.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along a line XX of an embodiment showing an embodiment of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a sectional view taken along the YY side of the above.

FIG. 4 is a bottom view of the above.

FIG. 5 is a cross-sectional view of the semiconductor sensor unit according to the first embodiment;

FIG. 6 is a sectional view taken along a ZZ side showing a conventional example.

FIG. 7 is a bottom view of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body 11 Bottom part 12 Edge 2 Semiconductor sensor part 21 Sensor chip 3 Housing 31 Open end part 4 Standoff 42 Contact piece 43 Board contact surface 5 Printed board 51 Board surface

Claims (2)

[Claims] 1. A body having a bottom portion and an edge, a semiconductor sensor portion provided with a sensor chip for detecting acceleration, and a bottomed box shape having an open end fitted to the body and fitted inside. A housing for accommodating the semiconductor sensor unit in
A semiconductor acceleration sensor comprising: a plurality of standoffs projecting from a bottom of the body; and a standoff configured to abut on a board surface of a printed circuit board to be mounted on the board contact surface to form a gap between the board surface and the body. The housing structure of a semiconductor acceleration sensor according to claim 1, wherein the standoff has a contact piece that contacts an open end of the housing protruding outward from an edge position of the body. . 2. The semiconductor sensor part is provided to be inclined at a predetermined angle with respect to a substrate contact surface of the standoff, and the standoff is provided at four corners of the rectangular body. 2. The housing structure of a semiconductor acceleration sensor according to claim 1, wherein said housing structure is provided.