JP2006227324A - Solid-state imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems in which a plurality of receiving faces, which serves as focus adjustment mechanisms, cannot be formed in a group on a holder and a positional relation between optical components and a solid-state imaging apparatus needs to be adjusted more highly accurately. <P>SOLUTION: In the solid-state imaging apparatus, a housing comprises a combination of an approximately cylindrical lens barrel having the optical components fixed therein and the holder having an IC fixed thereto and engaged with the lens barrel. The holder has a plurality of bearing faces of identical height in its axial direction, which are formed at regular intervals in its circumferential direction. The lens barrel has the plurality of receiving faces, serving as the focus adjustment mechanisms, formed along the cylindrical wall face such that the bearing faces are disposed in contact with the receiving faces. The contact of the bearing faces with the plurality of receiving faces, serving as the focus adjustment mechanisms, makes it possible to adjust the positions of the lens barrel and holder in the direction of the height. In addition, each of the plurality of receiving faces, serving as the focus adjustment mechanisms, has a step-like shape that has a minute level difference or an inclined shape. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a focus adjustment mechanism of an individual imaging apparatus.

  An imaging device incorporated in a digital camera, a notebook computer with a camera, a mobile phone, or the like includes a solid-state imaging device and components such as a circuit board, a lens, a lens holder, and a filter. In the process of assembling the imaging device, the positional relationship between optical components such as lenses and filters and the solid-state imaging device must be finished with high accuracy. In particular, a compact imaging module is used for a camera-equipped mobile phone or the like. For example, when the solid-state imaging device has a level of 100,000 pixels, it appears in focus even if the focal position is shifted by about 50 μm, but 300,000 pixels If it is above, the image appears blurred when it is shifted by about 20 μm. Therefore, as a device for ensuring the positional relationship with high accuracy, a device in which the deposition position of an integrated circuit (IC), which is a solid-state imaging device, is variable has been devised (see, for example, Patent Document 1).

However, in the proposal of Patent Document 1, for example, the positional relationship is matched by the bump height or the like at the time of mounting an integrated circuit which is a solid-state imaging device. The integrated circuit must be mounted before the assembly of the optical component system, and this proposal is an attempt to ensure accuracy by combining high-precision components, and high-precision components inevitably increase the cost. .
In addition, there is a description that the elastic deformation stroke can be widened by mounting the integrated circuit through the low elastic layer, but if the positional relationship adjustment is dependent on the elastic deformation, it becomes difficult to fix the integrated circuit, Furthermore, a change with time also becomes a problem.
Furthermore, although there is a description that there is a method of aligning the positional relationship with positioning protrusions, no specific method is described.
As described above, the proposal of Patent Document 1 is intended to maintain the positional relationship between the optical component and the integrated circuit that is the imaging element with high accuracy by using high-precision and expensive components, and uses relatively inexpensive components. It is not a proposal to maintain performance.

In order to solve such a problem, there is a method of making it possible to adjust the positional relationship between the optical component and the solid-state imaging device after assembling.
In this method, an optical component including a lens and a filter and an IC that is a solid-state imaging element are generally fixed to a casing in a solid-state imaging device. However, the casing has a substantially cylindrical shape to which the optical component is fixed. The lens barrel is divided into a holder that fixes the IC and fits into the lens barrel, and the positional relationship between the optical component and the solid-state imaging device is adjusted when the lens barrel and the holder are fitted. .

FIG. 4 is a diagram for explaining a method for adjusting the positional relationship between the optical component and the solid-state imaging device after assembling.
4 is a perspective view showing a fitting surface of the holder 10, and 12 is a perspective view showing a fitting surface of the lens barrel 12.
In FIG. 4, a plurality of receiving surfaces 20, 18, 16, 14 formed in a step shape having a minute step (for example, 10 μm) are continuously provided at four places along the cylindrical wall surface on the fitting surface of the holder 10. The four seating surfaces 22 are provided on the fitting surface of the lens barrel 12, and the heights of the four seating surfaces 22 are equal.
When the lens barrel 12 and the holder 10 are fitted, any one of the receiving surfaces 20, 18, 16, and 14 provided at the four positions comes into contact with the seat surface 22. The heights of the four receiving surfaces, which are the receiving surfaces with which the four seating surfaces 22 are in contact, are equal. At this time, the stepwise receiving surfaces 20, 18, 16, and 14 are formed in advance so that the height direction position when the receiving surface near the center and the seating surface are in contact with the design target value. I will keep it. When the receiving surface near the center is not focused, another adjacent receiving surface is selected and the lens barrel 12 and the holder 10 are rotated to bring the receiving surface and the seating surface having different heights into contact with each other. As a result, the positional relationship between the optical component and the solid-state imaging device, that is, the focal position can be adjusted.

This method does not require excessively high accuracy in both the lens barrel to which the optical component is fixed and the holder to which the IC is fixed, and is a finished component including variations in lenses and the like, and slight positional deviation of the solid-state image sensor. These characteristics can be adjusted when the lens barrel and the holder are fitted, so that the yield can be significantly increased and the assembling time can be shortened.

However, there are problems when considering further cost reduction.
In order to reduce the cost, it is effective to mold at least one of the lens barrel and the holder in a collective state of several tens of units. Of these, the lens barrel requires a relatively high accuracy for fixing optical parts and the like, and therefore it has to be processed by a single unit. Therefore, the holders are formed in a collective state of several tens of units. However, since a plurality of receiving surface portions that are the focus adjustment mechanisms require relatively high accuracy, all holders are formed in the collective state. However, it was difficult to meet the specifications. For this reason, it is necessary to reduce the required accuracy and reduce the number of products to be obtained, which has been a problem of reduced product characteristics and production efficiency.

Another problem has arisen. Recently, there has been a strong demand for higher image quality and more pixels for solid-state imaging devices, and more precise adjustments have become necessary to meet this demand. When the receiving surface, which is the focus adjustment mechanism, is formed in a stepped shape, a step of about 10 μm is the processing limit from the viewpoint of economical manufacturing accuracy, but the adjustment width is too rough to cope with the increase in the number of pixels with high image quality. This means that more precise adjustments have become necessary.

JP 2001-333332 A

The problem to be solved is that when a plurality of receiving surfaces, which are focus adjustment mechanisms, are formed on the holder, it is difficult to form in a collective state. In addition, it is necessary to adjust the positional relationship between the optical component and the solid-state imaging device with higher accuracy.

  The solid-state imaging device of the present invention is a solid-state imaging device in which an optical component including a lens and a filter and an IC that is a solid-state imaging element are fixed to a casing. The casing is a substantially cylindrical lens barrel in which the optical component is fixed. And a holder that fixes the IC and fits into the lens barrel, and the holder has a plurality of seating surfaces having the same axial height formed at equal intervals in the circumferential direction. The lens barrel is formed with a plurality of receiving surfaces that are focus adjustment mechanisms with which each of the seating surfaces abuts along a cylindrical wall surface, and the seating surfaces are a plurality of receiving surfaces that are the focus adjusting mechanisms; By abutting, the height direction position of the lens barrel and the holder can be adjusted.

  In the solid-state imaging device of the present invention, the plurality of receiving surfaces that are the focus adjustment mechanism formed in the lens barrel are formed in a stepped shape having a minute step, and the seating surface is a stepped portion of the receiving surface. The position of the lens barrel and the holder in the height direction can be adjusted by selecting and abutting any one of the surfaces in the shape.

  In the solid-state imaging device of the present invention, the plurality of receiving surfaces that are the focus adjustment mechanism formed in the lens barrel are formed in an inclined shape, and the seating surface is formed from the inclined surfaces of the receiving surface. The position of the lens barrel and the holder in the height direction can be adjusted by selecting any position and contacting.

  In the solid-state imaging device of the present invention, the plurality of seating surfaces are at the same height, and the receiving surfaces corresponding to each of the plurality of seating surfaces have the same height.

In addition, the solid-state imaging device according to the present invention includes an IC that is the solid-state imaging element and the optical component by a plurality of receiving surfaces that are the focus adjustment mechanism formed on the lens barrel and a seating surface that is formed on the holder. The position in the height direction is adjusted.

According to the present invention, since the position can be adjusted when the lens barrel and the holder are fitted, it is possible to use parts with relatively low accuracy, and the holder can be molded in a gathered state with a high yield, so that the part yield can be improved and produced. The cost can be reduced by improving the efficiency.
In addition, the position can be adjusted with higher accuracy than before.

In a solid-state imaging device in which an optical component including a lens and a filter and an IC which is a solid-state imaging device are fixed to a casing, the casing fixes a substantially cylindrical lens barrel to which the optical component is fixed, and the IC A combination of a holder that fits into the lens barrel, and a plurality of seating surfaces having the same axial height are formed in the holder at equal intervals in the circumferential direction. A plurality of receiving surfaces that are focus adjustment mechanisms with which each of the surfaces abuts are formed along a cylindrical wall surface, and the plurality of seating surfaces abut on each of the plurality of receiving surfaces that are the focus adjustment mechanisms, The height position of the lens barrel and the holder can be adjusted.
The plurality of receiving surfaces as the focus adjusting mechanism are formed in a stepped shape having a minute step or in an inclined shape.

The solid-state imaging device according to the present invention will be described below with reference to the drawings.
FIG. 1 is a central longitudinal sectional view showing a solid-state imaging device of the present invention.
In FIG. 1, the housing of the solid-state imaging device 30 includes a substantially cylindrical lens barrel 36 to which optical components such as a lens to be described later are fixed, and a substantially cylindrical holder 46 to which an IC that is a solid-state imaging device to be described later is fixed. Have been separated. Reference numeral 48 denotes an FPC (flexible wiring board), which is bonded to the lower end surface of the holder 46. A connecting portion for connecting to the outside from the FPC 48 protrudes from the left side surface of the holder 46. Reference numeral 52 denotes an IC which is a solid-state image sensor, and is face-down mounted on the FPC 48. Reference numeral 50 denotes a sealing resin covering the periphery of the IC 52 excluding the light receiving surface.
A counterbore part is formed at the upper center of the lens barrel 36, and a light receiving opening 54 is formed at the center thereof.
Reference numeral 38 denotes a first lens accommodated in contact with the lens barrel 36; 40, a second lens superimposed on the first lens 38; 56, a light shielding spacer sandwiched between the first lens 38 and the second lens 40; Is a ring-shaped lens pressing member, and is fixed to the lens barrel 36 by pressing the lower surface of the second lens 40. Reference numeral 34 denotes an infrared cut filter fixed to the counterbore part, and reference numeral 32 denotes a transparent cosmetic seal fixed on the filter 34 of the counterbore part. Reference numeral 42 denotes a light shielding O-ring disposed between the holder 46 and the lens barrel 36. Reference numeral 62 denotes an FPC that is an interface for connecting the solid-state imaging device 30 to an external device, and is connected to a connection portion of the FPC 48 by a connector such as an ACF. Reference numerals 64 and 66 denote seating surfaces, which will be described later, and are provided at fitting portions with the lens barrel 36 on the holder 46. A plurality of receiving surfaces, which are focus adjustment mechanisms, are provided on the surface of the lens barrel 36 fitted to the seat surfaces 64 and 66, which will be described with reference to FIGS. In FIG. 1, the seating surfaces (64, 66) are drawn at four locations at equal intervals in the circumferential direction of the holder 46.
In the following drawings, the same members are denoted by the same numbers.

FIG. 2 is a perspective view of the fitting surface of the solid-state imaging device according to the first embodiment of the present invention.
2 is a perspective view showing a fitting surface of the holder 46, and 36 is a perspective view showing a fitting surface of the lens barrel 36. For the sake of simplicity, the drawing of the lens barrel 36 is drawn upside down with respect to FIG. This relationship is the same in FIG.
In FIG. 2, a plurality of receiving surfaces 72, 74, 76, 78 formed in a staircase shape having a minute step (for example, 10 μm) are continuously provided on the fitting surface of the lens barrel 36 along the cylindrical wall surface. The focus adjustment mechanism is arranged at four locations every °, and the seating surfaces 64, 68, 66, and 70 are provided at equal intervals in the circumferential direction on the fitting surface of the holder 46. The four seating surfaces 64, 68, 66, and 70 have the same height.
When the lens barrel 36 and the holder 46 are fitted, any one of the receiving surfaces 72, 74, 76, 78 provided at the four locations and the seating surfaces 64, 68, 66, 70 are not in contact with each other. Touch. The heights of the four receiving surfaces, which are the receiving surfaces with which the four seating surfaces 64, 68, 66, 70 are in contact, are equal. At this time, among the stepped receiving surfaces 72, 74, 76 and 78, the height direction position when the receiving surface near the center and the seat surface are in contact with each other is set to a design target value. I will keep it. When the focus is not achieved at the receiving surface near the center, another adjacent receiving surface is selected and the lens barrel 36 and the holder 46 are rotated to bring the receiving surface and the seating surface having different heights into contact with each other. As a result, the positional relationship between the optical component and the solid-state imaging device, that is, the focal position can be adjusted.
In addition, the required specifications include how many parts of the receiving surface and seating surface, which are the focus adjustment mechanism, are provided, how many steps the stepped receiving surface is, and how many steps are set on the stepped receiving surface. This is a design matter that is determined in consideration of manufacturing capacity and the like.

Here, focusing of the solid-state imaging device will be described. First, optical components such as the first lens 38, the second lens 40, the light shielding spacer 56, and the infrared cut filter 34 are assembled and fixed in the lens barrel 36, and an IC 52, which is a solid-state imaging device, is mounted on the holder 46. Each assembly is formed. Next, the lens barrel 36 assembly and the holder 46 assembly are combined. At this time, the receiving surfaces 72, 74, 76, 78 of the lens barrel 36 are any of the seating surfaces 64, 68, 66, 70 of the holder 46. The rotation position is adjusted and held so as to contact one. In this state, for example, the light emitted from the chart surface of the test chart previously disposed in front of the lens barrel 36 assembly forms an image on the light receiving surface of the IC 52 through the filter 34, the first lens 38, and the second lens 40. The sharpness of the image is confirmed on the monitor screen connected to the FPC 62 of the interface drawn out from the FPC 48.
When the in-focus state is not achieved, another adjacent receiving surface can be selected and the lens barrel 36 and holder 46 can be rotated to bring the seating surface into contact with a different receiving surface to adjust the focal position. When the focal position is determined, an adhesive is applied to the gap between the lens barrel 36 and the assembly of the holder 46 in that state, and both are fixed. At this time, since a large stress is not applied to the fitting surface between the lens barrel 36 and the holder 46, it can be stably bonded. In addition, since the lens barrel and the holder are fixed by bonding, it is possible to reduce the fear of characteristic deterioration due to impact.

What should be noted in the first embodiment is that a receiving surface which is a focus adjusting mechanism is provided on the lens barrel 36 side.

The lens barrel is processed with a single piece because it requires relatively high precision for fixing optical components.
Since the receiving surface, which is a focus adjustment mechanism, also requires relatively high accuracy, it is suitable for single processing. In addition, since it is manufactured as a single unit, it has become possible to improve product accuracy.
On the other hand, the fixing and seating surface of the IC in charge of the holder do not require a great degree of accuracy and can be easily modified, so it is possible to mold in a collective state of several tens of units, and the cost can be reduced by improving the yield. Realized.

FIG. 3 is a second embodiment according to the present invention, and FIG. 3A is a perspective view of a fitting surface of the solid-state imaging device.
In FIG. 3, the receiving surface, which is the focus adjustment mechanism of the lens barrel 36, is not stepped, but is divided into three locations 80, 82, 84 every 120 ° and is inclined along the cylindrical wall surface.
Although not shown, the bearing surfaces of the opposing holders are provided at three locations at equal intervals of 120 ° in the circumferential direction, and the surfaces are inclined surfaces similar to the inclined portions 80, 82, 84.
With this configuration, when the lens barrel 36 and the holder 46 are fitted, the inclined surfaces of the receiving surfaces 80, 82, and 84 provided at three locations come into contact with the seating surface of the holder. The heights of the receiving surfaces 80, 82 and 84 with which the three seating surfaces are in contact are equal. At this time, the position in the height direction when the receiving surface near the center of the inclined receiving surfaces 80, 82, 84 and the seat surface are in contact with each other is set to a design target value. To. When the focus is not achieved at the receiving surface near the center, the lens barrel 36 and the holder 46 are rotated, and the receiving surface and the seating surface having different heights are brought into contact with each other, so that the optical component and the solid-state imaging device The positional relationship, that is, the focal position can be adjusted. At this time, in the second embodiment shown in FIG. 3, the position can be continuously adjusted, so that the adjustment can be performed with higher accuracy than in the first embodiment.

FIG. 3B is a side view of the lens barrel 36 for explaining the receiving surfaces 80, 82, and 84. When viewed from the side, the receiving surface 88 is formed on the wall surface 86 of the lens barrel 36 in an inclined manner. In this embodiment, the height of the receiving surface is set to 0.2 mm.
Design where the receiving surface and seating surface, which are the focus adjustment mechanism, are divided into several locations, and how the angle of the inclined receiving surface is set, etc., taking into account the required specifications, manufacturing capacity, etc. It is the above matter.

As described above, according to the present invention, it is possible to match the characteristics of a finished part including variations of lenses and the like, and slight positional deviation of a solid-state image sensor when fitting the lens barrel and the holder. Increases yield and shortens assembly time.
In addition, since the portion requiring relatively high accuracy is concentrated on the lens barrel, it is possible to improve the product accuracy by using the lens barrel as a single-piece molded product.
In addition, since the portion requiring high accuracy is removed from the holder portion, it is possible to perform collective molding with a high yield, and there is a great cost for cost reduction.
Furthermore, since the receiving surface, which is the focus adjustment mechanism, is inclined, the position can be adjusted with higher accuracy, which is very effective.

  In the present specification, of the surfaces of the lens barrel 36 and the holder 46 to be fitted, the surface on the lens barrel side is expressed as “receiving surface”, and the surface on the holder side is expressed as “seat surface”. There is no problem even if the surface on the lens barrel side is expressed as “seat surface” and the surface on the holder side is expressed as “receiving surface” in the same manner as described in the book. That is, the technical contents are substantially the same even if all the descriptions of “receiving surface” in this specification are replaced with “seat surface” and the description of “seat surface” is replaced with “receiving surface”.

It is a center longitudinal cross-sectional view which shows the solid-state imaging device of this invention. 1 is a perspective view of a fitting surface of a solid-state imaging device according to a first embodiment of the present invention. FIG. 6 is a perspective view of a fitting surface of a solid-state imaging device according to a second embodiment of the present invention. It is a figure explaining one method which enables adjustment of the positional relationship of both after assembling an optical component and a solid-state image sensor.

Explanation of symbols

38, 40 Lens 34 Filter 52 IC
36 Lens tube 46 Holder 64, 66, 68, 70 Seat surface 72, 74, 76, 78, 80, 82, 84 Reception surface

Claims (5)

  In a solid-state imaging device in which an optical component including a lens and a filter and an IC which is a solid-state imaging device are fixed to a casing, the casing fixes a substantially cylindrical lens barrel to which the optical component is fixed, and the IC The holder is configured to be combined with a holder that fits into the lens barrel, and a plurality of seating surfaces having the same axial height are formed in the holder at equal intervals in the circumferential direction. A plurality of receiving surfaces that are focus adjustment mechanisms with which each of the surfaces abuts are formed along a cylindrical wall surface, and the plurality of seating surfaces abut on each of the plurality of receiving surfaces that are the focus adjustment mechanisms, A solid-state imaging device characterized in that the position of the lens barrel and the holder in the height direction can be adjusted.   The plurality of receiving surfaces that are the focus adjustment mechanism formed on the lens barrel are formed in a stepped shape having a minute step, and the seating surface is any one of the stepped surfaces of the receiving surface. The solid-state imaging device according to claim 1, wherein the position in the height direction of the lens barrel and the holder can be adjusted by selecting and contacting.   The plurality of receiving surfaces, which are the focus adjusting mechanism formed on the lens barrel, are formed in an inclined shape, and the seating surface is in contact with any position selected from the inclined surfaces of the receiving surface. The solid-state imaging device according to claim 1, wherein the height position of the lens barrel and the holder can be adjusted.   4. The solid-state imaging device according to claim 1, wherein the plurality of seating surfaces are at the same height, and the receiving surfaces corresponding to each of the plurality of seating surfaces have the same height. The position in the height direction between the IC that is the solid-state image sensor and the optical component is adjusted by a plurality of receiving surfaces that are the focus adjusting mechanism formed on the lens barrel and a seating surface that is formed on the holder. The solid-state imaging device according to claim 1, wherein

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