JP2021064708A - Sensor module - Google Patents

Abstract

To provide a sensor module in which heat can be efficiently dissipated from a sensor element.SOLUTION: A sensor module 1 comprises: a substrate 30 having a first surface 30a and a second surface 30b that direct to directions opposite to each other; a support member 12 that supports the substrate from the first surface side; a sensor element 20 mounted on the first surface; and a heat sink 40 that cools the substrate. The heat sink includes: a main plate portion 41 that is arranged to face the second surface and covers at least a part of the second surface; and a side plate 42 that bends from the end portion of the main plate portion to the substrate side and covers at least a part of the end surface of the substrate and the surface of the support member.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sensor module.

In recent years, devices having sensor elements, such as image pickup devices, have been miniaturized. In such a device, the reliability of the sensor element may be impaired due to the high temperature of the sensor element mounted on the substrate. Patent Document 1 describes a configuration in which the heat of the heat generating element is transferred to the heat radiating plate by arranging the heat radiating plate on the upper side of the heat generating element.

Japanese Unexamined Patent Publication No. 2010-11200

However, when the element that generates heat is a sensor element such as a CMOS sensor, a heat dissipation member cannot be arranged because the detection target of the sensor (for example, a lens) is arranged on the upper side of the sensor element, and the heat dissipation structure Was an issue.

In view of the above problems, one object of the present invention is to provide a sensor module capable of efficiently dissipating heat from a sensor element.

The sensor module of one aspect of the present invention is mounted on the first surface, a substrate having a first surface and a second surface facing each other, a support member for supporting the substrate from the first surface side, and the first surface. A sensor element and a heat radiating plate for cooling the substrate are provided. The heat radiating plate is arranged so as to face the second surface, and has a main plate portion that covers at least a part of the second surface and bends from an end portion of the main plate portion toward the substrate side to support the end surface of the substrate and the support. It has a side plate portion that covers at least a part of the surface of the member.

According to the present invention, it is possible to provide a sensor module capable of efficiently dissipating heat from a sensor element.

FIG. 1 is a perspective view of the sensor module of one embodiment. FIG. 2 is a cross-sectional view of the sensor module of one embodiment. FIG. 3 is a partial cross-sectional view of the sensor module of one embodiment.

Hereinafter, embodiments will be described with reference to the drawings. The XYZ coordinate system is shown in each figure. In the following description, each direction will be described based on each coordinate system as necessary.
The XYZ coordinate system does not indicate the positional relationship or direction when incorporated into an actual device or the like.

FIG. 1 is a perspective view of the sensor module 1. FIG. 2 is a cross-sectional view of the sensor module 1 along the optical axis L. FIG. 3 is a partial cross-sectional view of the sensor module 1 along the central axis of the support bolt 50.

The sensor module 1 includes a substrate 30, a sensor element 20 mounted on the substrate 30, a heat dissipation plate 40, a lens portion 10 having an optical axis L, and a support member that supports the substrate 30, the heat dissipation plate 40, and the lens portion 10. 12 and.

In the following description, it is assumed that the optical axis L of the lens unit 10 is parallel to the Y axis in each figure. Hereinafter, each part of the sensor module 1 will be described with the + Y direction as the rear, the −Y direction as the front, the + Z direction as the upper side, and the −Z direction as the lower side.

The lens portion 10 has a columnar shape. Although not shown, the lens unit 10 has a plurality of lenses having the same optical axis L and a lens barrel for holding the lenses.

The support member 12 has a main body portion 13 which is a substantially rectangular block, a fitting hole 12a and a screw hole 12f provided in the main body portion 13, and a support bolt 50 to be inserted into the screw hole 12f. The main body 13 has a front surface 13a facing forward and a rear surface 13b facing rearward. The main body 13 faces the substrate 30 in the front-rear direction on the rear surface 13b.

As shown in FIG. 3, the screw hole 12f opens in the rear surface 13b of the main body 13 and extends in the front-rear direction. As will be described later, the support bolt 50 inserted into the screw hole 12f supports the substrate 30 via the adhesive B.

As shown in FIG. 2, the fitting hole 12a extends along the optical axis L. The lens portion 10 is fitted into the fitting hole 12a from the front. The lens portion 10 is fixed to the support member 12 by means such as screwing. Further, the fitting hole 12a accommodates a part of the sensor element 20 in a region behind the rear end of the lens portion 10.

The sensor element 20 is, for example, a CMOS image sensor. The sensor element 20 captures a subject image formed through the lens unit 10. The sensor element 20 may be another type of solid-state image sensor such as a CCD image sensor. Further, the detection target of the sensor element 20 is not limited to light. For example, the sensor element 20 may detect a magnetic field.

The substrate 30 is located behind the lens portion 10. The substrate 30 extends along a plane orthogonal to the optical axis L. The substrate 30 has a first surface 30a facing forward, a second surface 30b facing rearward, and an end surface 30c connecting the first surface 30a and the second surface. The first surface 30a and the second surface 30b face opposite to each other. The sensor element 20 is mounted on the first surface 30a. The substrate 30 is supported by the support member 12 from the first surface 30a side. The substrate 30 faces the heat radiating plate 40 on the second surface 30b.

The substrate 30 is provided with a plurality of (two in this embodiment) through holes 31 penetrating in the plate thickness direction. A support bolt 50 is inserted through the through hole 31.

As shown in FIG. 3, the shaft portion 52 of the support bolt 50 is arranged in the through hole 31 in a non-contact manner. The inner diameter of the through hole 31 is larger than the outer diameter of the head 51 of the support bolt 50. The head 51 is located behind the second surface 30b of the substrate 30. As a result, it is possible to prevent the substrate 30 from being separated from the sensor module.

A heat conductive thin film 2 is provided on the inner peripheral surface 31a of the through hole 31. The thin film 2 is, for example, a copper foil formed in the same process as the wiring pattern 3 provided on the surface of the substrate 30. The thin film 2 provided on the inner peripheral surface 31a may be connected to a part of the wiring pattern 3 provided on one surface of the substrate 30. Further, when the substrate 30 is a laminated substrate, the thin film 2 may be connected to a part of the wiring pattern of each layer. The wiring pattern connected to the thin film 2 on the inner peripheral surface 31a is preferably a portion corresponding to the ground in the circuit.

A heat transfer material G is interposed between the inner peripheral surface 31a of the through hole 31 and the support bolt 50. As the heat transfer material G arranged between the inner peripheral surface 31a and the support bolt 50, for example, thermal paste can be adopted. Further, the heat transfer material G may be a semi-solid body (or gel-like) having flexibility that easily changes its shape with respect to pressure. Further, the heat transfer material G may be a curable substance that has fluidity in an uncured state and is cured after coating.

The head portion 51 of the support bolt 50 has a seating surface 51a facing forward. The seat surface 51a faces the second surface 30b of the substrate 30 in the front-rear direction. A predetermined gap is secured between the seat surface 51a and the second surface 30b. As a result, the seat surface 51a is in a non-contact state with the second surface 30b. The gap is filled with the adhesive B. That is, the adhesive B is provided between the seating surface 51a of the head 51 and the substrate 30. As a result, the substrate 30 is supported by the support bolts 50 via the adhesive B. As the adhesive B, an ultraviolet curable adhesive can be used.

In the step of assembling the substrate 30 to the support member 12, first, the substrate 30 is held in a non-contact state behind the support member 12 to which the lens portion 10 is assembled by using a predetermined device. Next, the shaft portion 52 of the support bolt 50 is passed through the through hole 31 of the substrate 30 and further screwed into the screw hole 12f of the support member 12. Next, the heat transfer material G is filled between the inner peripheral surface 31a of the through hole 31 of the substrate 30 and the shaft portion 52. Next, the adhesive B is placed between the seating surface 51a of the head 51 of the support bolt 50 and the second surface 30b of the substrate 30. Next, the position and orientation of the sensor element 20 with respect to the optical axis L of the lens unit 10 are adjusted using a predetermined optical axis adjusting device (not shown). Next, the adhesive B is cured by irradiating it with ultraviolet rays or the like. By the above procedure, the step of assembling the substrate 30 to the support member 12 is completed.

The heat radiating plate 40 is a metal plate material. As the material of the heat radiating plate 40, an aluminum alloy having a high thermal conductivity or the like is preferably adopted. The heat radiating plate 40 is formed by, for example, press working. The heat sink 40 cools the substrate 30 from behind the substrate 30. The heat radiating plate 40 has a main plate portion 41 and a pair of side plate portions 42.

The main plate portion 41 faces the second surface 30b of the substrate 30 in the front-rear direction. Further, the main plate portion 41 extends along the second surface 30b. The main plate portion 41 is arranged so as to overlap the sensor element 20 when viewed from the plate thickness direction of the substrate 30. The area of the main plate portion 41 is larger than the area of the sensor element 20 when viewed from the plate thickness direction. When viewed from the plate thickness direction, the entire area of the sensor element 20 is included inside the main plate portion 41.

One of the pair of side plate portions 42 is connected to the upper end portion of the main plate portion 41, and the other is connected to the lower end portion of the main plate portion 41. The side plate portion 42 is formed by bending from the end portion (upper end portion or lower end portion) of the main plate portion 41 toward the substrate 30 side. The side plate portion 42 covers a part of the end surface 30c of the substrate 30. Further, the side plate portion 42 covers at least a part of the surface of the support member 12.

A predetermined gap is secured between the main plate portion 41 and the second surface 30b of the substrate 30. As a result, the main plate portion 41 is in a non-contact state with the second surface 30b. This gap is filled with the heat transfer material G. That is, the heat transfer material G is interposed between the heat radiating plate 40 and the substrate 30. Further, there is a gap between the side plate portion 42, the end surface 30c of the substrate 30, and a part of the surface of the support member 12, and the heat transfer material G is also filled in this gap. As the heat transfer material G arranged between the heat radiating plate 40 and the substrate 30, it is preferable to use an insulating material, and for example, an insulating heat radiating sheet is exemplified.

In this embodiment, the case where the heat transfer material G is interposed between the heat radiating plate 40 and the substrate 30 will be described. However, the heat transfer material G does not necessarily have to be interposed between the heat radiating plate 40 and the substrate 30. Further, the heat radiating plate 40 may come into direct contact with the substrate 30 as long as the surface is provided with an insulating film.

The tip portions 42a of the pair of side plate portions 42 are curved toward the inside of the support member 12. The tip portion 42a is, for example, adhesively fixed to the surface of the support member 12. As a result, the heat radiating plate 40 is supported by the support member 12. Further, a heat transfer material G is interposed between the heat radiating plate 40 and the support member 12.

The sensor element 20 needs to be cooled in order to avoid becoming hot due to heat generation. However, since the lens portion 10 is arranged in front of the sensor element 20, the surface of the sensor element 20 cannot be directly cooled. According to the present embodiment, the heat radiating plate 40 covers at least a part of the second surface 30b of the substrate 30 in the main plate portion 41. As a result, the heat of the sensor element 20 can be transferred to the heat sink 40 via the substrate 30. That is, the sensor element 20 can be cooled from the rear side, and the reliability of the operation of the sensor element 20 can be improved.

According to the present embodiment, the main plate portion 41 is arranged so as to overlap the sensor element 20 when viewed from the plate thickness direction of the substrate 30. Therefore, the heat of the sensor element 20 can be smoothly transferred from the sensor element 20 to the main plate portion 41, and the cooling efficiency of the sensor element 20 can be improved. Further, since the area of the main plate portion 41 is larger than the area of the sensor element 20 when viewed from the plate thickness direction, the heat of the sensor element 20 can be sufficiently absorbed by the main plate portion 41. In addition, according to the present embodiment, the heat transfer material G is interposed between the heat radiating plate 40 and the substrate 30, so that the heat transfer can be made smoother.

According to this embodiment, the side plate portion 42 of the heat radiating plate 40 covers a part of the end surface 30c of the substrate 30. As a result, the heat radiating plate 40 can also receive the heat of the substrate 30 from the end surface 30c of the substrate 30, and the cooling efficiency of the sensor element 20 via the substrate 30 can be improved.

According to the present embodiment, the side plate portion 42 of the heat radiating plate 40 covers at least a part of the surface of the support member 12. Therefore, the heat of the heat sink 40 can be transferred to the support member 12. That is, according to the present embodiment, the heat of the sensor element 20 can be dissipated to the support member 12 via the substrate 30 and the heat radiating plate 40. Further, according to the present embodiment, the heat transfer material G is interposed between the heat radiating plate 40 and the support member 12, so that the heat transfer can be smoothed.

In this embodiment, the support member 12 is made of a metal material. In this case, the heat capacity of the support member 12 can be increased to enhance the endothermic effect from the heat radiating plate 40, and as a result, the cooling efficiency of the sensor element 20 can be enhanced.
Further, the support member 12 may be made of a resin material. The resin material can be manufactured at low cost even when the surface shape is complicated. Therefore, in this case, it is possible to secure a large surface area of the support member 12 and enhance the heat dissipation effect from the support member 12.

According to this embodiment, the substrate 30 is fixed to the support member 12 by the adhesive B. Therefore, after adjusting the position of the sensor element 20 with respect to the optical axis L of the lens portion 10 supported by the support member 12, the adhesive B can be cured and the sensor element 20 can be fixed to the lens portion 10. As a result, it is not necessary to fasten the screws after adjusting the position of the optical axis, and it is possible to prevent the position of the optical axis from shifting due to the work involved in fixing.

According to the present embodiment, the support member 12 and the substrate 30 are fixed via the adhesive B and are in a non-contact state with each other. As a result, the substrate 30 can be arbitrarily moved with respect to the support member 12 when the position of the sensor element 20 with respect to the optical axis L of the lens unit 10 is adjusted. As a result, the sensor element 20 can be easily aligned by moving it in the direction of the optical axis L, in the direction perpendicular to the optical axis L, or by tilting it with respect to the optical axis L, and the optimum position and orientation The sensor element 20 can be arranged in. In the present specification, the non-contact state means that the support member 12 and the substrate 30 are not in direct contact with each other. However, the state in which the adhesive is interposed between the two members is also included in the non-contact state.

According to the present embodiment, the heat transfer material G is interposed between the support bolt 50 of the support member 12 and the inner peripheral surface 31a of the through hole 31 of the substrate 30. As a result, heat can be transferred from the substrate 30 to the support bolt 50 and the main body 13 of the support member 12 via the heat transfer material G, and as a result, the cooling efficiency of the sensor element 20 can be improved. In particular, in the present embodiment, since the substrate 30 and the support bolt 50 do not come into direct contact with each other, direct heat transfer from the substrate 30 to the support bolt 50 is unlikely to occur. According to this embodiment, heat can be transferred from the substrate 30 to the support bolt 50 even in such a configuration.

According to this embodiment, the heat conductive thin film 2 is provided on the inner peripheral surface 31a of the through hole 31. As a result, the efficiency of heat transfer from the substrate 30 to the heat transfer material G filled in the through hole 31 is increased, and heat can be smoothly transferred from the substrate 30 to the support member 12.

Although various embodiments of the present invention have been described above, the configurations and combinations thereof in each embodiment are examples, and the configurations are added, omitted, replaced, etc. within the scope of the gist of the present invention. And other changes are possible. Further, the present invention is not limited to the embodiments.

1 ... sensor module, 2 ... thin film, 12 ... support member, 12f ... screw hole, 20 ... sensor element, 30 ... substrate, 30a ... first surface, 30b ... second surface, 30c ... end face, 31 ... through hole, 31a ... Inner peripheral surface, 40 ... Heat sink, 41 ... Main plate, 42 ... Side plate, 50 ... Support bolt, 51 ... Head, 51a ... Seat surface, B ... Adhesive, G ... Heat transfer material

Claims (10)

A substrate having a first surface and a second surface facing opposite sides,
A support member that supports the substrate from the first surface side, and
The sensor element mounted on the first surface and
A heat sink for cooling the substrate is provided.
The heat radiating plate
A main plate portion that is arranged to face the second surface and covers at least a part of the second surface.
It has a side plate portion that is bent from an end portion of the main plate portion toward the substrate side and covers at least a part of the end surface of the substrate and the surface of the support member.
Sensor module. The main plate portion is arranged so as to overlap the sensor element when viewed from the plate thickness direction of the substrate.
The sensor module according to claim 1. The area of the main plate portion is larger than the area of the sensor element when viewed from the plate thickness direction of the substrate.
The sensor module according to claim 2. A heat transfer material is interposed between the heat sink and the substrate.
The sensor module according to any one of claims 1 to 3. A heat transfer material is interposed between the heat sink and the support member.
The sensor module according to any one of claims 1 to 4. The substrate is provided with a plurality of through holes.
The support member has a support bolt inserted into the through hole and a screw hole into which the support bolt is inserted.
A heat transfer material is interposed between the inner peripheral surface of the through hole and the support bolt.
The sensor module according to any one of claims 1 to 5. An adhesive is provided between the seating surface of the head of the support bolt and the substrate.
The substrate is supported by the support bolts via the adhesive.
The sensor module according to claim 6. A thermally conductive thin film is provided on the inner peripheral surface of the through hole.
The sensor module according to claim 6 or 7. The support member is made of a metal material.
The sensor module according to any one of claims 1 to 8. The support member is made of a resin material.
The sensor module according to any one of claims 1 to 8.

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