JP2008076628A - Imaging module and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging module having high heat resistance, keeping positional accuracy of an imaging device and a lens member in an optical axis direction high over a long term and made small in size and light in weight, and an imaging apparatus. <P>SOLUTION: The imaging module is equipped with: an imaging substrate 4 on which the imaging device 3 converting an image formed with light from a subject into an electrical signal is mounted; and a lens member 2 where a plurality of lenses to form a subject image on the imaging device 3 by constitution that the first lens counted from the subject side is a glass lens (first lens 8a) and the second and succeeding lenses are plastic lenses (second lens 8b, third lens 8c and fourth lens 8d) are arranged in a lens barrel 7 formed to project from the subject-side front face of an external case 6 to the inside of the external case 6, and where the plurality of lenses 8 are supported in the lens barrel 7 respectively so that the plastic lenses are positioned at the projecting part 7A of the lens barrel 7. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging module and an imaging apparatus including an imaging element such as a CCD.

  In recent years, imaging modules such as electronic cameras (electronic still cameras, video cameras) and in-vehicle cameras, as well as small onboard cameras incorporated in notebook computers and mobile phones, and imaging modules such as camera modules incorporated in these cameras have been developed. Yes.

As such an imaging module, a module in which a lens member in which a lens is accommodated in a lens barrel and an imaging substrate on which an imaging element such as a CCD is mounted has been developed (see, for example, Patent Documents 1 to 3). Here, FIG. 6 shows a schematic sectional view of a lens member 40 of a conventional imaging module. As shown in FIG. 6, the lens member 40 is fixed to an exterior case 41 and a plurality of lenses 43 are provided in a lens barrel 42. It consisted of a fitted configuration. The lens 40 on the most object side of the lens member 40 in FIG. 6 is fixed by a retainer 44.
JP 2002-90603 A JP 2004-146946 A JP 2004-309694 A

  However, in the conventional imaging module as shown in FIG. 6, the lens 43 and the lens barrel 42 become hot due to heat generated from the imaging device, and the optical axis is shifted or the resolution is reduced due to the thermal expansion difference between the lens 43 and the lens barrel 42. There is a problem that the lens deteriorates or the lens is distorted in some cases.

  An object of the present invention is to provide an imaging module and an imaging apparatus that can be used stably even in an environment where the heat resistance of the camera member is improved and a repeated heat history is applied.

  An imaging module according to the present invention includes an imaging board on which an imaging device for converting light from a subject into an electrical signal is mounted, and a lens barrel formed so as to protrude from the front side of the subject side of the outer case to the inside of the outer case. In addition, the first lens from the subject side is a glass lens, the second and subsequent lenses are plastic lenses, and a plurality of lenses for forming a subject image on the image sensor are arranged. And a lens member that supports the plurality of lenses on the lens barrel so as to be positioned at a protruding portion of the lens barrel.

  Here, in the above-described configuration, the lens is characterized in that the object-side front surface and the imaging element-side rear surface are supported in contact with a spacer or another lens provided between the lenses in the lens barrel.

  Further, in the above configuration, the inner wall surface of the lens barrel and the side surface of the plastic lens are arranged so as to have an interval of 50 to 100 μm at 25 ° C.

Moreover, the difference in the above structure, the linear thermal expansion coefficient of the linear thermal expansion coefficient of up to the glass transition point (alpha ₁₎ and from 25 ° C. of the outer casing to the glass transition point of from 25 ° C. of the glass lens and (alpha ₁₎ There 6 × 10 -5 ^/ ℃ or less linear thermal expansion coefficient of the linear thermal expansion coefficient of up to the glass transition point (alpha ₁₎ and from 25 ° C. of the outer casing to the glass transition point of from 25 ° C. of the plastic lens (alpha ₁ ) Is 2 × 10 ⁻⁵ / ° C. or less.

  Further, in the above configuration, a rubber packing is disposed between the glass lens and the lens barrel.

  Here, in the above-described configuration, the imaging substrate and the lens are overlapped while maintaining a predetermined gap with a support pin that is bonded to the imaging substrate and is embedded or penetrated in the exterior case. The imaging substrate is fixed to the exterior case so as to be fixed in a combined state.

  Further, in the above configuration, the imaging substrate is rectangular, the number of the through holes is two or three, and a first through hole provided at one corner of the imaging substrate, and the first through hole Are disposed at the corners including the corners provided with the second through holes provided at the opposite corners, and the support pins are respectively inserted and fixed to the respective through holes. It is characterized by that.

  Further, in the above configuration, the surface of the support pin and the surface portion of the imaging substrate that is bonded to the support pin are formed of gold or copper, and the surface of the support pin and the surface of the imaging substrate are made of solder. It is characterized by being bonded and fixed.

  Further, in the above configuration, the support pin has irregularities in at least one of an adhesion portion with the imaging substrate or an adhesion portion with the exterior case.

  Further, in the above configuration, the support pin has any one of a groove shape, a groove shape, a convex shape, or a shape in which the support pin is hollow and a plurality of holes are formed on the surface thereof to form the unevenness. It is characterized by.

  Further, in the above configuration, the unevenness of the support pin is formed in a region extending from the through hole of the imaging substrate to the outside of the through hole.

  Furthermore, an imaging apparatus according to the present invention includes the imaging module.

  In the imaging module of the present invention, the lens member is formed in a lens barrel formed so as to protrude from the front surface on the subject side of the outer case to the inside of the outer case, and the first lens from the subject side is a glass lens, two lenses The lenses after the eye are arranged in a plastic lens, and a plurality of lenses for projecting a subject image on the image sensor are arranged, and each of the plurality of lenses is arranged so that the plastic lens is located at a protruding portion of the lens barrel. By adopting a structure that is supported by the lens barrel, the heat generated from the image sensor is delayed to be transmitted to the lens barrel and the lens accommodated in the protruding portion of the lens barrel, thereby increasing the amount of heat released to the air. And the temperature of the lens housed in the protruding portion of the lens barrel can be suppressed, and the protruding portion of the lens barrel is displaced only by the thermal expansion of the lens barrel, thereby changing the outer case. Since there is no influence of the fact that the displacement of the inner wall surface of the protruding portion of the lens barrel due to thermal expansion can be reduced, or shift the optical axis, the resolution is deteriorated, a problem that the lens is distorted can be eliminated. Moreover, according to the present invention, the first lens that is exposed to the outside and is easily damaged and is easily affected by thermal stress is a glass lens that is hard, does not deform, is not easily damaged, and is not easily affected by temperature changes. For the second and subsequent lenses, an aspherical surface can be easily processed, the lens design is easy, and an inexpensive plastic lens is used, so that the lens module is excellent in heat resistance and easy to handle.

  Here, each lens is supported by the object side front surface and the imaging device side rear surface being in contact with a locking portion provided in the lens barrel, a spacer provided between the lenses, or another lens, and the lens is a mirror. It is desirable that it is not supported by the inner wall surface of the tube in that it can prevent fatigue of the portion of the lens barrel that comes into contact with the glass lens due to lens distortion or repeated thermal history. At this time, when the inner wall surface of the lens barrel and the side surface of the plastic lens are arranged so as to have an interval of 50 to 100 μm at 25 ° C., it is possible to prevent the lens from deviating from the optical axis and to change the temperature. Lens distortion can be prevented.

Moreover, the difference is 6 × 10 and the linear thermal expansion coefficient of the linear thermal expansion coefficient of up to the glass transition point (alpha ₁₎ and to the glass transition point of from 25 ° C. of the outer casing (alpha ₁₎ from 25 ° C. of the glass lens ^{-5 /} ° C. or less, the difference between the linear thermal expansion coefficient of the linear thermal expansion coefficient of up to the glass transition point (alpha ₁₎ and to the glass transition point of from 25 ° C. of the outer casing (alpha ₁₎ from 25 ° C. of the plastic lens Is 2 × 10 ⁻⁵ / ° C. or lower, it is possible to suppress inconveniences such as optical axis misalignment and distortion of the lens due to thermal expansion, and resolution degradation even when the lens member changes in temperature.

  In addition, since the rubber packing is disposed between the glass lens and the lens barrel, the waterproofness of the lens member can be enhanced and the breakage of the fragile glass lens can be suppressed.

  Here, according to the present invention, a predetermined gap is maintained between the imaging substrate and the lens by a support pin that is bonded to the imaging substrate and is embedded in or penetrated through the exterior case. By fixing the imaging substrate to the exterior case so that the imaging substrate is fixed in a superposed state, adhesion is performed when the imaging substrate on which the imaging element is mounted is bonded to the support pin or when the lens member is bonded to the support pin. Since the position of the imaging substrate or the lens member can be finely adjusted before the agent is solidified, the positional accuracy in the optical axis direction between the imaging element and the lens member is high. In addition, since heat from the image pickup substrate is transmitted to the lens member only through the support pins, the heat transfer of the image pickup element that has become high can be reduced, and the temperature rise of the lens member can be suppressed. It is possible to reduce the influence of an optical axis shift or the like due to the temperature change.

  Further, the imaging substrate is rectangular, and two or three through holes are arranged, and a first through hole provided at one corner of the imaging substrate and the first through hole are provided. It is disposed at the corners including the corners and the second through holes provided at the opposite corners, and the support pins are inserted into the respective through holes and bonded and fixed. This is desirable in that the heat transfer of the image pickup device that has been reduced can be reduced to suppress the temperature rise of the lens member, and the influence of the temperature change of the lens member can be further reduced.

  On the other hand, in the bonding portion between the support pin and the imaging element, the surface of the support pin and the surface portion of the imaging substrate are formed of gold or copper, and the surface of the support pin and the surface of the imaging substrate are used as solder. By being bonded and fixed, it can be firmly bonded in a short time and has excellent durability for long-term use.

  Further, the support pin has irregularities in at least one of the adhesion portion with the imaging substrate or the adhesion portion with the exterior case, so that the portion of the support pin that is adhered to the lens member becomes irregular and has an anchor effect. As a result of exhibiting and increasing the adhesive strength, the adhesive strength between the lens member and the support pin is also increased, and a stable position can be maintained for a long period of time. In addition, since the space for fixing provided in the imaging substrate and the lens member can be reduced as compared with the conventional method of fixing with the screw member, the imaging module can be reduced in size and weight.

  Further, the unevenness of the support pin is any one of a thread groove shape, a concave groove shape, a convex shape, or a shape in which the support pin is hollow and a large number of holes are formed on the surface thereof to form the unevenness. Therefore, when the unevenness of the support pin is a screw groove shape, the processing for forming the unevenness of the support pin is easy, and when the unevenness of the support pin is a groove shape, the unevenness of the support pin Processing for formation is easy, and the unevenness can be produced at a lower cost. Further, by making the support pin hollow, heat transfer from the imaging substrate to the lens member can be reduced.

  In addition, the unevenness of the support pin is formed in a region extending from the through hole of the imaging substrate to the outside of the through hole, so that stable and strong fixing is possible due to manufacturing variation when fixing the support pin. This is desirable.

  In addition, an imaging apparatus including the imaging module of the present invention described above is a small and high-performance imaging apparatus in which the imaging module has high heat resistance and positional accuracy in the optical axis direction is high over a long period of time.

  FIG. 1 shows a camera module 1 which is an example of a preferred embodiment of an imaging module of the present invention, where (a) is a schematic perspective view seen from the subject side, and (b) is a schematic perspective view seen from the opposite side of the subject. FIG. 2 is a schematic cross-sectional view of the camera module of FIG. 1, (a) is a cross-sectional view taken along line AA in FIG. 1 (a), and (b) is a cross-sectional view taken along line BB in FIG. 1 (a). 3 is a diagram for explaining a method of mounting the imaging substrate 4 on the lens member 2, and FIGS. 4A to 4D are enlarged cross-sectional views of the main part of the portion C in FIG. 2B. 5 (a) to 5 (e) are enlarged cross-sectional views of the main part of the D part in FIG. 2 (b).

  The camera module 1 is configured as an in-vehicle camera for imaging a white line on a road or a blind spot of a vehicle, for example, and an ECU (Engine Control Unit) (not shown) that controls driving of the automobile. It functions as a part of the imaging device whose operation is controlled by the above. The electric signal output from the camera module 1 is converted into an image signal by the ECU and displayed on a display (not shown), for example.

  The camera module 1 includes a lens member 2 that mainly collects subject light, an image pickup device 3 that forms an image of light from the lens member 2 and converts it into an electrical signal, and an image pickup substrate 4 on which the image pickup device 3 is mounted. The lens member 2 and the imaging substrate 4 are overlapped and fixed while maintaining a predetermined gap.

  As shown in FIG. 2, which is a cross-sectional view taken along the line AA of FIG. 1, the lens member 2 has a subject 7 in a lens barrel 7 formed so as to protrude from the subject-side front surface of the exterior case 6 to the inside of the exterior case 6. The first lens 8a from the side is a glass lens, and the second and subsequent lenses (in FIG. 2, the second lens 8b, the third lens 8c, and the fourth lens 8d) are arranged in a plastic lens configuration. A plurality of lenses (three in FIG. 2) are respectively arranged so that the plastic lenses (the second lens 8b, the third lens 8c, and the fourth lens 8d) are positioned on the protruding portion 7A of the lens barrel 7. Consists of a configuration housed inside.

  With the above configuration, the heat generated from the imaging device 3 can be dissipated into the air by delaying the propagation of the heat to the lens 7 and the lens 8 housed in the protruding portion 7A of the lens barrel 7, resulting in an increase in temperature at the lens 8. Since the position of the projection 7A of the lens barrel 7 is changed only by the thermal expansion of the lens barrel 7 and is not affected by the thermal expansion of the other exterior case 6, the inner wall surface due to the temperature change can be reduced. The displacement can be reduced. Therefore, the optical axis is shifted, the resolution is deteriorated, the portion of the lens barrel 7 adjacent to the glass lens (first lens 8a) is deteriorated due to fatigue, or the plastic lens (second lens 8b, third lens 8c, The problem that the fourth lens 8d) is distorted can be solved. In addition, according to the present invention, the first lens (first lens 8a) that is exposed to the outside and is easily damaged and is easily affected by thermal stress is hard, does not deform, is not easily damaged, and is affected by temperature changes. A difficult glass lens is used, and the second and subsequent lenses (the second lens 8b, the third lens 8c, and the fourth lens 8d) are made of plastic lenses that can be easily aspherically processed, are easy to design, and are inexpensive. By using it, the camera module 1 is excellent in heat resistance and easy to handle. 2, the outer case 6 and the lens barrel 7 are integrally formed. However, in the present invention, the outer case 6 and the lens barrel 7 are formed as separate bodies and the two are fitted together. It may be.

  Here, as shown in FIG. 2, the lens 8 is supported by contacting the object-side front surface and the imaging device-side rear surface with a spacer 10 provided between the lenses in the lens barrel 7 or another lens, The fact that the lens 8 is not supported by the inner wall surface of the lens barrel 7 applies stress to the lens barrel 7 due to thermal expansion of the glass lens (first lens 8a), and the fixing accuracy of the glass lens 8a deteriorates due to repeated use. In addition to this, it is possible to prevent distortion of the lens due to thermal expansion of the plastic lens (second lens 8b, third lens 8c, and fourth lens 8d). The subject-side front surface of the first lens 8a is fixed in contact with the retainer 15.

At this time, with the inner wall surface and the plastic lens barrel 7 (second lens 8b, a third lens 8c, fourth lens 8d) the distance _{d 2,} d 3, _{d 4} of 50~100μm in side and is 25 ° C. of In such a case, it is possible to prevent distortion of the lenses (second lens 8b, third lens 8c, and fourth lens 8d) even by a temperature change while suppressing deviation of the optical axis of the lens. Note that a mask or a diaphragm may be provided at an appropriate position between the lenses 8 of the lens member 2. As for the side surface of the inner wall surface and the glass lens barrel 7 (first lens 8a), to have a distance d ₁ of 20~50μm at 25 ° C., mechanical degradation and waterproof wall within the barrel 7 Desirable to prevent degradation of

Furthermore, from 25 ° C. of glass lens (first lens 8a) linear thermal expansion coefficient of the linear thermal expansion coefficient of up to the glass transition point (alpha ₁₎ and from 25 ° C. of the outer case 6 to the glass transition point (alpha ₁₎ and the The difference is 6 × 10 ⁻⁵ / ° C. or less, the linear thermal expansion coefficient (α ₁ ) from 25 ° C. to the glass transition point of the plastic lens (second lens 8b, third lens 8c, and fourth lens 8d) and the outer case 6 The difference between the coefficient of linear thermal expansion (α ₁ ) from 25 ° C. to the glass transition point of 2 × 10 ⁻⁵ / ° C. or less is a lens caused by thermal expansion even when the temperature of the lens member 2 changes. 8 such as optical axis misalignment and distortion, and resolution degradation can be suppressed.

The material of the outer case 6 is polyphthalamide (PPA: α ₁ = 1 to 4 × 10 ⁻⁵ / ° C.), polybutylene terephthalate (PBT: α ₁ = 10 × 10 ⁻⁵ / ° C.), polyphenylene sulfide. (PPS: α ₁ = 6 to 7 × 10 ⁻⁵ / ° C.) can be preferably used.

  In addition, since the rubber packing 16 is disposed between the glass lens 8a and the lens barrel 7, the waterproofness of the lens member 2 can be improved and the glass lens (first lens 8a) having a risk of being damaged. ) Can be prevented from being damaged by impact.

  Here, according to the present invention, a predetermined gap is maintained between the imaging substrate 4 and the lens 8 by the support pins 11 that are adhered to the imaging substrate 4 and are embedded or penetrated in the outer case 6. Thus, the imaging substrate 4 is fixed to the outer case 6 so as to be fixed in a superposed state. Accordingly, when the imaging substrate 4 on which the imaging element 3 is mounted is bonded to the support pins 11 or the lens member 2 is bonded to the support pins 11, the position of the imaging substrate 4 or the lens member 2 is set before the adhesive is solidified. Therefore, the positional accuracy in the optical axis direction between the image sensor 3 and the lens 8 is high. In addition, since heat from the imaging substrate 4 is transmitted to the lens member 2 only through the support pins 11, the heat transfer of the imaging element 3 that has become high can be reduced, and the temperature change of the lens member 2. It is possible to reduce the influence of misalignment of the optical axis. The support pin 11 may be in the form of a solid bar, but may be in the form of a hollow bar such as a tube or a shape in which a cross section is formed in a C shape by slitting the support pin 11.

  In addition, the imaging substrate 4 is rectangular and has two or three through holes 13, and a first through hole 13 a and a first through hole 13 a provided at one corner of the imaging substrate 4 are provided. Two or three support pins 11 (shown in FIG. 1 and the lens member 2) are arranged at the corners including the corners provided and the second through holes 13b provided at the corners located diagonally. Each of the through holes (in FIG. 1 and FIG. 4, the third through holes) are provided, which are provided for explaining the method of incorporating the substrate 4, and are provided with three through holes in FIG. 4. 13c), the heat propagation of the image pickup device 3 having a high temperature can be further delayed, and the influence of the temperature change of the lens member 2 can be further reduced. .

  Further, according to FIG. 5, nickel plating 18 and gold plating 19 are sequentially applied to the surface of the support pin 11 to form the surface of the support pin 11 with gold, and the inner wall surface of the through hole 13 of the imaging substrate 4 The copper metallization 20 is deposited and the surface portion of the imaging substrate 4 that is bonded to the support pins 11 is formed of copper. In addition, the support pins 11 and the imaging substrate 4 are bonded to each other by the solder 17. In this case, the gold (gold plating 19) on the surface of the support pin 11 and the copper (copper metallized 20) on the surface of the imaging substrate 4 are soldered with the solder 17, and the support pins are compatible with each other. 11 and the imaging substrate 4 have high adhesive strength, can be firmly bonded in a short time, and can be stably bonded and fixed.

  According to the present embodiment, the other end of the support pin 11 is bonded to the imaging substrate 4 with the solder 17. However, in the present invention, the bonding method is not limited to the method using the solder 17. A method of bonding using an adhesive may also be used. When the solder 17 is used, it can be firmly bonded in a short time.

  Here, according to FIGS. 1 and 3, the imaging substrate 4 has a rectangular shape having notches 35 at the four corners, and the first through hole 13 a provided at one corner of the imaging substrate 4 and the first penetration. It includes a corner portion provided with a hole 13a and a second through hole 13b provided at a corner portion located diagonally. In FIG. 1, a third through hole 13c is further provided. Two or three support pins 11 (three in FIG. 1) are provided, and are inserted into and fixed to at least the first through hole 13a and the second through hole 13b (further, the third through hole 13c in FIG. 1), respectively. Has been. According to this configuration, the space is saved, and the gap between the imaging substrate 4 and the lens member 2 can be easily finely adjusted, and there is no possibility of positional deviation. In addition, the heat generated in the imaging substrate 4 can be delayed from being transmitted to the lens member 2.

  Further, as shown in FIGS. 4 and 5, the support pin 11 has irregularities 24 in at least one of the adhesion portion with the imaging substrate 4 or the adhesion portion with the exterior case 6, thereby forming the support pin 11 shown in FIG. 2. As a result that the portion bonded to the lens member 2 or the imaging substrate 4 becomes uneven and exhibits an anchoring effect to increase the bonding strength, the bonding strength between the lens member 2 and the support pin 11 is also increased for a long period of time. A stable position can be maintained.

  Further, the unevenness 24 of the support pin 11 is a screw groove-like unevenness 24a (see FIGS. 4A and 5A), a recessed groove-like unevenness 24b (see FIGS. 4B and 5B), a convex 24c (see FIG. 4 (c), FIG. 5 (c)), a plurality of convex / concave protrusions 24b (see FIG. 4 (d), FIG. 5 (d)) or the support pin 11 is tubular and on its surface A shape in which a large number of holes 25 are formed to form irregularities (see FIGS. 4E and 5E) can be employed. With these shapes, when the unevenness 24 of the support pin 11 has a thread groove shape, the processing for forming the unevenness of the support pin 11 is easy, and the unevenness of the support pin 11 has a recessed groove shape. In addition, the processing for forming the unevenness of the support pin is easy, and the unevenness can be produced at a lower cost. Moreover, although the case where the support pin 11 was a solid rod shape was illustrated in FIGS. 4 and 5 (a) to (d), the support pin 11 may be a hollow rod shape in these forms.

  In addition, the unevenness | corrugation 24 in this invention points out that the difference of the depth (height) direction of the surface in the side surface of the support pin 11 is 20 micrometers or more.

  According to FIG. 4, a concave hole 37 is formed at a predetermined position of the exterior case 6 of the lens member 2, and the support pin 11 is inserted into the concave hole 37, and the support pin 11 is fixed to the fixing adhesive 38. Is adhered to the outer case 6. According to this configuration, the support pins 11 can be attached to the exterior case 6 later than when the exterior case 6 is formed.

  Further, the support pin 11 is embedded in the outer case 6, and the unevenness 24 of the support pin 11 is disposed at a position spaced 0.2 to 5 mm away from the tip portion where the support pin 11 is embedded. This is desirable in that the end side of the unevenness 24 exhibits an anchor effect and helps to prevent it from coming off.

The support pins 11 do not necessarily have to be inserted into the through holes of the imaging substrate 4, and may be bonded and fixed to the side end surface of the imaging substrate 4, for example.

  Further, as shown in FIGS. 5A, 5D, and 5E, the unevenness 24 of the support pin 11 is formed over a region extending from the through hole 13 of the imaging substrate 4 to the outside of the through hole 13 (FIG. 5 ( When a part of the screw groove-like unevenness 24a of a), a part of the plurality of convex unevenness 24b of FIG. 5D, and a part of the hole 25 of FIG. It is desirable in that stable and strong fixation is possible due to manufacturing variations of the above. Further, as shown in FIGS. 5A to 5E, the solder forming the bonding portion between the image pickup substrate 4 and the support pin 11 is also bonded from the through hole of the image pickup substrate 4 to the outside of the through hole 13, which is strong. Adhesion is possible.

  Furthermore, since the support pin 11 is formed of columnar or cylindrical copper having a diameter of 0.8 to 1.5 mm, the support pin 11 is made of copper having a diameter of 0.8 mm or more. Since it is configured, it has rigidity, does not bend during use and does not shift in position, and the diameter of the support pin 11 is 1.5 mm or less, so that heat generated in the imaging substrate 4 is less transmitted to the lens member 2. In addition, it is desirable in that the space can be reduced and the space can be saved. The support pin 11 only needs to extend in the optical axis direction and be fixed to the imaging substrate 4 and the lens member 2 on the outer peripheral side surface thereof. For example, the support pin 11 may not have conductivity like resin or ceramics. Other metal members such as stainless steel may be used. Further, when the support pins 11 are made of resin, the support pins 11 can be formed integrally with the outer case 6. Furthermore, the cross-sectional shape is not a circular rod shape, and the cross-sectional shape may be a triangle, a quadrilateral polygon, or a C-shape such as a C-shape. If the shape is cylindrical, the heat capacity of the support pin 11 can be reduced. In addition to being able to attach easily, it is possible to prevent heat generated in the imaging substrate 4 from being transmitted to the lens member 2 side. Furthermore, the support pin 11 may be fixed to the side surface portion instead of the front surface portion of the exterior case 6 of the lens member 2.

  When the support pin 11 is made of a conductive member, the ground layer of the imaging substrate 4 and the support pin 11 are bonded with the solder 17 when a ground layer is provided as a conductor pattern provided in the imaging substrate 4. By this, it will be electrically connected with the exterior case 6 via the support pin 11, and the earth | ground of a ground layer can also be taken.

  The imaging device 3 is constituted by, for example, a CCD (charge coupled device) or a CMOS transistor (complementary MOS sensor). For example, as shown in FIG. 2, the imaging device 3 is housed in a cavity 27 of a sub-board 26 that is a ceramic wiring board mainly composed of alumina, and the cavity 27 is sealed with a glass lid 28. A plurality of terminals 30 extend from the sub-board 26 and are fixed to the imaging board 4 with solder or the like. The imaging element 3 and the imaging substrate 4 are electrically connected by a terminal 30, and the sub-substrate 26 is supported by the imaging substrate 4.

  The imaging substrate 4 is configured by, for example, a printed wiring board formed by impregnating a glass cloth with an epoxy resin or adding a glass filler to the epoxy resin. The addition amount of the glass cloth or the glass filler is preferably set so that the thermal expansion coefficient of the sub-substrate 26 and the thermal expansion coefficient of the imaging substrate 4 are approximated. Further, as shown in FIG. 1, on the surface of the imaging substrate 4 opposite to the imaging device 3, an electronic component 32 such as an IC, a capacitor, a coil, or a resistor that processes an electrical signal from the imaging device 3, an imaging substrate A connector 33 or the like for connecting a cable (not shown) for connecting 4 to an ECU (not shown) is provided.

  Although not shown, the cable connected to the connector 33 is connected to an external connector that is inserted into and fixed to a rear case member (not shown), and is further led to an external cable.

  On the other hand, in addition to the through-hole 13, the imaging board 4 is provided with a notch 35 in which the edge of the imaging board 4 is cut out to facilitate positioning when the rear case member is mounted.

  An example of a method for assembling the camera module 1 will be described.

  First, at a predetermined position with respect to the outer case 6 in which a concave hole 37 or a through hole for inserting the support pin 11 having a diameter slightly larger than the diameter of the support pin 11 at a predetermined position and a lateral groove as required is formed. When the lenses 8a to 8d are attached and the outer case 6 and the lens barrel 7 are separated from each other, the lens barrel 7 is fitted into the outer case 6 and then fixed by the retainer 15 to assemble the lens member 2 (lens fixing step). ). As a result, the lenses 8 a to 8 d of the lens member 2 cannot move with respect to the outer case 6 in any of the optical axis direction, the optical axis periphery, and the direction orthogonal to the optical axis.

  Further, the support pin 11 is fixed to the outer case 6. As a method of fixing, for example, in a state where the support pin 11 is inserted into the concave hole 37 or the through hole for inserting the support pin 11, liquid is introduced into the hole from the gap or lateral groove of the concave hole 37 or the through hole. A fixing adhesive 38 such as an epoxy resin is injected and filled, and solidified by heating or ultraviolet irradiation. At this time, the fixing adhesive 38 can be solidified while the support pin 11 is held in parallel with the optical axes of the lenses 8a to 8d. In order to ensure the parallelism between the optical axes of the lenses 8a to 8d and the support pins 11, it is desirable to cure the resin such as the fixing adhesive 38 with the support pins 11 fixed to a jig.

  Thereafter, the imaging substrate 4 to which the imaging element 3 and the sub-substrate 26 are attached is fixed to the lens member 2 (substrate fixing step). Specifically, first, as shown in FIG. 3, the imaging board 4 is positioned by inserting the support pins 11 into the through holes 13 of the imaging board 4. At the time of positioning, a cable (not shown) is connected to the connector 33 and further connected to an inspection device (not shown), and an image captured by the image sensor 3 is referred to by the inspection device, for example, from the lens member 2. It is evaluated whether or not the focus position, the optical axis, the image quality, and the like of the camera module 1 match the test subject separated by a predetermined distance. Then, the imaging substrate 4 is positioned based on the evaluation. In positioning, the position of the imaging substrate 4 in the optical axis direction with respect to the lens member 2, the tilt with respect to the optical axis, and the position in the direction orthogonal to the optical axis are adjusted. The imaging substrate 4 and the support pin 11 are soldered at the adjusted position, whereby the imaging substrate 4 and the support pin 11 are bonded and fixed, and the imaging substrate 4 and the lens member 2 are bonded and fixed.

  In the above assembly, a part or the whole may be automated, or the operator may perform it manually. For example, the process of adjusting the position of the imaging board 4 and soldering the support pins 11 is an operation. The person may visually check the image and perform soldering while evaluating the image quality, or the adjustment and soldering process may be automated.

  The imaging apparatus including the camera module 1 or the like as the imaging module of the present invention as described above has high heat resistance of the imaging module, and the imaging module has high positional accuracy in the optical axis direction and is small and lightweight. The imaging device is small and has high performance. Examples of the imaging device including the camera module include an in-vehicle imaging device in which the above-described camera module is attached to the rear or side of a vehicle and this signal is transmitted to the driver's seat.

  In addition, this invention is not limited to the example of the above embodiment, You may implement in a various aspect. For example, the camera module is not limited to a vehicle-mounted one, and may be for a mobile phone or a surveillance camera, for example.

  Cutouts 35 are provided at four corners of the imaging substrate 4 made of a build-up multilayer resin substrate having a square main surface and having a thickness of 0.8 mm, and two of the four corners are more than the cutouts. A through hole 13 was formed at a position as shown in FIG. 3 shifted by 5 mm, and copper metallization was formed on the inner wall surface of the through hole 13. Further, the sub-board 26 and the plurality of electronic components 16 in which the CCD (the image pickup device 3) is housed and sealed at a predetermined position of the image pickup board are mounted.

  On the other hand, Tables 1 and 2 in which a concave hole 37 having a diameter of 1.2 mm × depth of 10 mm is formed at a position shown in FIGS. 2, 4 and 6 and a lateral groove having a diameter of 3 mm is formed from a direction perpendicular to the concave hole 37 are shown in Tables 1 and 2. As shown in FIG. 2, three lenses 8 a to 8 d shown in Table 1 were attached to the exterior case 6 having the members and shapes shown in FIG. 2 and fixed by the retainer 15 to produce the lens member 2.

  On the other hand, three support pins 11 made of a copper structure having a diameter of 1.1 mm and a length of 20 mm and having a nickel plating 18 and a gold plating 19 on the surface are fixed to a predetermined position of the outer case with a fixing adhesive 38. Fixed. In addition, the support pin 11 was used in which irregularities 24a were formed near both ends.

Then, the image pickup board 4 is fitted into the lens member 2 while inserting the support pins 11 into the through holes 13 of the image pickup board 4, and the position of the image pickup board 4 is positioned while checking the image picked up by the image pickup device 3 with the inspection device image. did. Then, by soldering the imaging substrate 4 and the support pins 11 at the adjusted position, the imaging substrate 4 and the support pins 11 are bonded and fixed, and the imaging substrate 4 and the lens member 2 are bonded and fixed, and the camera module is mounted. Assembled.

  With respect to the obtained camera modules (50 sets each), the image resolution in a state where the image sensor 3 and the electronic component 16 were operated for 10 minutes was confirmed. The results are shown in Table 2.

  As apparent from Table 2, the sample No. In 1 to 6, it was confirmed that all the resolutions of the images in the state where the imaging device 3 and the electronic component 16 were operated were good.

  On the other hand, sample No. using a lens barrel having the shape of FIG. 7, the resolution of the image deteriorated while the imaging device 3 and the electronic component 16 were operated. This was because the plastic lens was distorted. Sample No. 1 in which all the lenses are formed of glass lenses. In No. 8, it was difficult to make a lens shape, and the resolution was lowered and the cost was increased. Furthermore, sample No. 1 in which all the lenses are formed of glass lenses. 9, the resolution of the image deteriorated while the imaging device 3 and the electronic component 16 were operated. This is because the plastic lens constituting the first lens on the subject side is distorted.

FIG. 2 shows an example of an embodiment of an imaging module of the present invention, (a) a schematic perspective view seen from the subject side, and (b) a schematic perspective view seen from the opposite side of the subject. 2 is a schematic cross-sectional view of (a) AA cross section and (b) BB cross section in the imaging module of FIG. 1. FIG. It is a schematic diagram for demonstrating the mounting process of the camera module of FIG. It is a principal part expanded sectional view about the C section of FIG.2 (b). It is a principal part expanded sectional view about the D section of FIG.2 (b). It is a schematic sectional drawing which shows the shape of the exterior case in the conventional imaging module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera module 2 Lens member 3 Image pick-up element 4 Imaging board 6 Exterior case 7 Lens barrel 7A Protrusion part 8 Lens 8a 1st lens 8b 2nd lens 8c 3rd lens 8d 4th lens 10 Spacer 11 Support pin 11
13 Through hole 13
13a 1st through-hole 13b 2nd through-hole 13c 3rd through-hole 15 Retainer 16 Rubber packing 17 Solder 18 Nickel plating 19 Gold plating 20 Copper metallization 22 Notch 22
24 Concavity and convexity 24a Screw groove-like concavity and convexity 24b Concavity and concavity 24c Convex and concavity 24d Concavity and convexity 25 in which a large number of holes are formed on the surface of the support pin Hole 38 The distance between the inner wall surface of the fixing adhesives d ₁ and d ₂ and the side surface of the plastic lens at 25 ° C.

Claims (12)

An imaging board on which an imaging device that converts light from a subject into an electrical signal is mounted;
In the lens barrel formed so as to protrude from the front surface of the exterior case to the exterior side of the exterior case, the first lens from the subject side is composed of a glass lens, and the second and subsequent lenses are composed of plastic lenses. A plurality of lenses for forming an image of a subject on an image sensor, and a lens member that supports the plurality of lenses on the lens barrel so that the plastic lens is positioned at a protruding portion of the lens barrel;
An imaging module comprising: 2. The imaging module according to claim 1, wherein the lens is supported by a subject-side front surface and an imaging element-side rear surface being in contact with a spacer provided between the lenses in the lens barrel or another lens. 3. The imaging module according to claim 1, wherein an inner wall surface of the lens barrel and a side surface of the plastic lens are arranged so as to have an interval of 50 to 100 μm at 25 ° C. 4. Difference 6 × 10 ^-5 and linear thermal expansion coefficient of linear thermal expansion coefficient of up to the glass transition point (alpha ₁₎ and to the glass transition point of from 25 ° C. of the outer casing (alpha ₁₎ from 25 ° C. of the glass lens / ℃ below, the difference between the linear thermal expansion coefficient of up to a glass transition point from 25 ℃ (α ₁₎ and the linear thermal expansion coefficient of up to a glass transition point from 25 ° C. of the outer casing (alpha ₁₎ of the plastic lens 2 The imaging module according to claim 1, wherein the imaging module is × 10 ⁻⁵ / ° C. or lower. The imaging module according to claim 1, wherein a rubber packing is disposed between the glass lens and the lens barrel. The imaging board and the lens are fixed in a state of being superposed while maintaining a predetermined gap with a support pin that is bonded to the imaging board and is embedded or penetrated in the exterior case. The imaging module according to claim 1, wherein the imaging substrate is fixed to the exterior case. The imaging substrate is rectangular,
The number of the through holes is two or three, and a first through hole provided at one corner of the imaging substrate, and a corner located diagonally to the corner provided with the first through hole. Arranged in the corner including the second through hole provided,
The imaging module according to claim 6, wherein the support pins are respectively inserted into and fixed to the through holes. The surface of the support pin and the surface portion of the imaging substrate to be bonded to the support pin are formed of gold or copper, and the surface of the support pin and the surface of the imaging substrate are bonded and fixed with solder. The imaging module according to claim 6. The imaging module according to claim 6, wherein the support pin has irregularities in at least one of an adhesion portion with the imaging substrate or an adhesion portion with the exterior case. The unevenness of the support pin is one of a screw groove shape, a concave groove shape, a convex shape, or a shape in which the support pin is hollow and a large number of holes are formed on the surface thereof to form unevenness. The imaging module according to claim 9. The imaging module according to claim 9 or 10, wherein the unevenness of the support pin is formed in a region extending from the through hole of the imaging substrate to the outside of the through hole. An imaging apparatus comprising the imaging module according to claim 1.

Images