JP2009100260A - Apparatus and method for inspecting camera module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the tact of inspection sharply in a camera module inspection apparatus using a camera module assembly, where a plurality of lens units are attached onto a sheet substrate onto which a plurality of image pickup devices are mounted, to capture the image of a prescribed chart for inspection. <P>SOLUTION: The camera module inspection apparatus comprises a holding member and a probe member. In the holding member, there are a plurality of conductor patterns electrically connected to the image pickup devices on the rear surface of the sheet substrate, the plurality of conductor patterns comprise a plurality of sets of conductor pattern groups corresponding to each of the plurality of image pickup devices, the camera module assembly is held, groups of conductor patterns can be exposed, and movement is made as required in a direction in parallel with the surface of a chart for inspection. In the probe member, two rows of probe groups, which comprise a plurality of probes that can be brought into pressure-contact with the plurality of conductor patterns and correspond to the conductor pattern groups, are arranged in two rows orthogonally crossing the moving direction of the holding member. The probe member moves to the holding member as required. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a camera module inspection apparatus and an inspection method thereof in which a plurality of camera modules including an imaging lens and an imaging element are arranged on a sheet substrate, and a predetermined inspection chart is imaged by the camera module.

  Conventionally, ultra-small camera modules have been installed in small and thin mobile terminals such as mobile phones and PDAs (Personal Digital Assistants), which enables not only voice communication but also image capture and communication. It has become.

  An example of such a camera module will be described with reference to FIG.

  The image sensor 12 is a CCD (Charge Coupled Device) type image sensor, a CMOS (Complementary Metal-Oxide Semiconductor) type image sensor, or the like. The image sensor 12 is mounted on the printed wiring board 13. The imaging lens 11 that forms a subject image on the imaging device 12 is held by a lens frame 15. Further, the lens frame 15 is bonded to the printed wiring board 13 with an adhesive S. An infrared cut filter 16 and a diaphragm plate 14 are disposed on the subject side of the imaging lens 11. In addition to the image sensor 12, a plurality of electronic components 19 such as resistors and capacitors are also mounted on the printed wiring board 13.

  About such a camera module, it test | inspects before mounting in a portable terminal.

Various inventions relating to the inspection of a camera module are disclosed in patent publications. As an example, there is an inspection apparatus in which a plurality of camera modules are arranged on a sheet substrate and an inspection chart is imaged by the camera module. Then, a probe for inputting / outputting a signal is arranged on the back side of the sheet substrate, and the probe is brought into pressure contact with a test pad of the sheet substrate for imaging. When the imaging of the predetermined camera module is completed, the probe is retracted. Subsequently, the sheet substrate moves sideways, and imaging is performed by the adjacent camera module (see Patent Document 1).
JP 2007-104302 A

  In Patent Document 1, since inspection is performed without dividing each camera module in a state where a plurality of camera modules are arranged on a sheet substrate, the tact time of inspection can be shortened while suppressing costs.

  However, the embodiment in Patent Document 1 describes an example in which 16 camera modules are arranged on a sheet substrate. In this case, operations such as probe pressing, imaging, probe retraction, and sheet substrate movement are described. Must be repeated 16 times. For this reason, when a large number of camera modules are inspected, the technique of Patent Document 1 is still insufficient to shorten the inspection tact.

  The present invention has been made in view of such problems, and a camera module inspection in which a plurality of camera modules including an imaging lens and an imaging element are arranged on a sheet substrate, and a predetermined inspection chart is imaged by the camera module. It is an object of the present invention to propose a camera module inspection apparatus and an inspection method thereof that can greatly reduce the inspection tact time compared to the related art.

The object is achieved by the invention described below.
1. Using a camera module assembly in which a plurality of camera modules are arranged by mounting a plurality of lens units with imaging lenses on a sheet substrate on which a plurality of imaging elements are mounted, corresponding to the imaging elements. In the camera module inspection apparatus for imaging a predetermined inspection chart,
The back surface of the sheet substrate is provided with a plurality of conductor patterns electrically connected to the imaging element, and the plurality of conductor patterns are composed of a plurality of sets of conductor patterns corresponding respectively to the plurality of imaging elements,
A holding member that holds the camera module assembly, is configured such that the conductor pattern group can be exposed, and moves appropriately in a direction parallel to the surface of the inspection chart;
A plurality of probes that can be brought into pressure contact with the plurality of conductor patterns, and probe groups corresponding to the conductor pattern groups are arranged in two rows in a direction perpendicular to the moving direction of the holding member, A probe member that advances and retreats appropriately,
An apparatus for inspecting a camera module.
2. 2. The camera module inspection apparatus according to 1, wherein four sets of the probe groups are provided in one row.
3. The inspection chart includes a stripe pattern in which a plurality of black lines and white lines are alternately arranged, a reference pattern composed of a black thick line adjacent to one side of the stripe pattern, and the other of the stripe patterns. 3. The camera module inspection apparatus according to 1 or 2, wherein a plurality of sets of reference patterns composed of white thick lines adjacent to the side are arranged adjacent to each other in the width direction of each line.
4). The camera module inspection apparatus according to any one of claims 1 to 3, wherein a center portion of the probe member is disposed to face a center portion of the inspection chart.
5). The camera module inspection apparatus according to any one of claims 1 to 4, further comprising an illumination unit that illuminates the inspection chart.
6). When photographing with the camera module, the holding member is moved so that the conductor pattern groups of the camera module arranged in two rows in a direction orthogonal to the moving direction of the holding member are positioned to face the probe group. The control means for controlling to move the probe member so that each of the probes is pressed against each of the conductor patterns is provided. Camera module inspection device.
7). The camera module inspection apparatus according to any one of claims 1 to 6, further comprising a determination unit configured to determine whether the camera module is good or not based on an image obtained by imaging the inspection chart by the camera module.
A camera module inspection method for inspecting a camera module using the camera module inspection apparatus according to any one of 8.1 to 7,
Attaching the camera module assembly to the holding member;
Moving the holding member such that the conductor pattern groups of the camera modules arranged in two rows in a direction orthogonal to the moving direction of the holding member are positioned to face the probe groups of the probe member;
Moving the probe member so that the probe group is in pressure contact with the conductor pattern group of the camera module;
Imaging the inspection chart with the two rows of camera modules;
A camera module inspection method comprising:
9. 9. The camera module inspection method according to claim 8, further comprising: determining whether the camera module is good based on an image obtained by imaging the inspection chart.
10. A step of moving the probe member to retract the probe group from the conductor pattern group after completing the imaging of the two rows of camera modules;
Moving the holding member so that a conductor pattern group of a new camera module arranged in two rows in a direction orthogonal to the moving direction of the holding member is positioned to face the probe group of the probe member; ,
The camera module inspection method according to 8 or 9, wherein:

  According to the camera module inspection apparatus and the inspection method of the present invention, when inspecting a camera module assembly in which a plurality of camera modules including an imaging lens and an imaging element are arranged on a sheet substrate, the plurality of camera modules Since the inspection chart can be imaged at the same time, the inspection tact time is greatly reduced.

  Embodiments relating to a camera module inspection apparatus and a camera module inspection method according to the present invention will be described with reference to the drawings.

  This apparatus is similar to the camera module described in “Background Art”, and inspects a camera module including at least an imaging lens and an imaging element. The inspection is performed with respect to dust adhering to the resolution and the image sensor. However, the camera modules are not inspected one by one, but are inspected in the state of a camera module assembly described later.

  First, the camera module assembly will be described with reference to FIG. FIG. 2 is a perspective view of the camera module assembly.

  In FIG. 2, reference numeral 23 denotes a sheet substrate, and a plurality of sets of image pickup devices 12 and electronic components 19 similar to those shown in FIG. The number of sets is not limited, but in the sheet substrate 23 of FIG. 2, a total of 32 sets are mounted with 8 sets in the long side direction and 4 sets in the short side direction. In some cases, the electronic component 19 may not be mounted, but at least the image sensor 12 is mounted.

  Reference numeral 25 denotes a lens unit. The lens unit 25 has a configuration in which the printed wiring board 13, the imaging element 12, and the electronic component 19 are omitted from the camera module shown in FIG. 1, and at least the imaging lens 11 is provided inside.

  A plurality of lens units 25 (32 in FIG. 2) are provided and mounted in correspondence with the imaging device 12 and the electronic component 19 mounted on the sheet substrate 23. Specifically, the lens unit 25 is placed on the sheet substrate 23 and bonded with the adhesive S. In this way, the camera module assembly 20 in which a plurality of camera modules are arranged on the sheet substrate 23 is obtained, and an inspection described later is performed.

  Further, since a long hole, a long groove or a perforation (not shown) is formed in the sheet substrate 23 between the lens units 25 in the camera module assembly 20, the sheet substrate 23 can be easily formed in the next process after the inspection is completed. It can be divided into a single camera module 1 as shown in FIG.

  Next, a camera module inspection apparatus that inspects the camera module assembly 20 will be described with reference to FIGS.

  3 is a perspective view of a holding base and a probe base for holding a camera module, FIG. 4 is a schematic view of a camera module inspection apparatus, and FIG. 5 is a view of a conductor pattern of a sheet substrate.

  First, as shown in FIG. 3, the camera module assembly 20 is placed and held on a holding table 30 (holding member). Then, the camera module assembly 20 is fixed with a fastener (not shown) so that the camera module assembly 20 does not float from the holding table 30. Further, since the camera module assembly 20 must be accurately placed at a predetermined position in the horizontal direction on the holding table 30, for example, two or more positioning pins are erected on the holding table 30 and the camera module assembly 20 is assembled. A positioning pin is inserted into a hole provided in the sheet substrate 23 of the body 20.

  As shown in FIG. 4, in the camera module assembly 20 fixed to the holding table 30, the internal imaging lens 11 faces the inspection chart 5.

  As shown in FIG. 5, a plurality of conductor patterns 23 a electrically connected to the image sensor 12 and the electronic component 19 are provided on the back surface of the sheet substrate 23 of the camera module assembly 20, and the plurality of image sensors 12. A plurality of sets (32 sets in the present embodiment) of conductor patterns 23A corresponding to the above are formed. The holding base 30 is configured such that the conductor pattern group 23A is exposed on the back surface, and for example, a hole through which the conductor pattern group 23A is exposed is provided.

  The holding table 30 is configured to be appropriately movable in parallel with the surface of the inspection chart 5 from a driving source (not shown).

  On the other hand, as shown in FIGS. 3 and 4, a probe base 40 (probe member) in which a plurality of probes 41 are erected is disposed below the holding base 30. Each probe 41 is disposed corresponding to the conductor pattern 23 a of the sheet substrate 23. The plurality of probes 41 form a plurality of probe groups 41A respectively corresponding to the conductor pattern group 23A.

  The base of each probe 41 is fixed to a resin base 42, and the tip is pressed against the conductor pattern 23a. For this reason, the probe 41 has a double structure, and is provided with a spring inside, and is configured to sink into the pedestal 42 when the tip is pressed. The pedestal 42 is fixed to a larger pedestal 43.

  Further, two rows of probe groups 41 </ b> A are connected in a direction orthogonal to the moving direction of the holding table 30. In FIG. 3, four groups of probe groups 41A are arranged in each row, and a total of eight groups of probe groups 41A are arranged. The central portion of the eight groups of probe groups 41 </ b> A faces the central portion of the inspection chart 5.

  Further, the probe base 40 is configured to be appropriately advanced and retracted in the direction of the holding base 30 from a drive source (not shown).

  Next, an inspection method using the camera module inspection apparatus will be described with reference to FIG.

  First, the camera module assembly 20 to be inspected is fixed to the holding table 30. Then, the holding base is set so that the conductor pattern groups 23A of the lens units 25 in the two rows at the extreme end in the direction orthogonal to the moving direction of the holding base 30 face the two rows of probe groups 41A of the holding base 30. Move 30. In FIG. 3, the conductive pattern groups 23 </ b> A of the eight lens units 25 in the two rows at the extreme end in the direction orthogonal to the moving direction of the holding table 30 are arranged in two rows on the holding table 30. It is made to oppose the probe group 41A of a group.

  In this state, the probe base 40 is moved in the direction of the holding base 30, and each probe 41 is brought into pressure contact with the conductor pattern 23a corresponding to the two rows of lens units 25.

  At this time, it is desirable to erect a guide shaft on the probe base 40 and to provide a guide hole corresponding to the guide shaft on the holding base 30 so that each probe 41 is surely pressed against each conductor pattern 23a.

  Further, the rear end portion of each probe 41 is connected to the image forming apparatus 7, and the image forming apparatus 7 is connected to the image discriminating apparatus 8.

  In this state, the inspection chart 5 is illuminated as uniformly as possible by a plurality of illumination devices 6 (illuminating means), and images are taken simultaneously by a plurality (eight in the present embodiment) of lens units 25.

  The chart 5 for inspection may be any chart as long as it can inspect a plurality of camera modules simultaneously. For example, it may be a resolution inspection chart composed of a fringe pattern and a reference pattern, which will be described later with reference to FIGS. 6 to 8, or a dust inspection chart composed of a white background with a uniform density. The focus adjustment chart (tracking chart) in Patent Document 1 is not suitable as the inspection chart 5 because only one camera module can be inspected.

  The captured optical image of the inspection chart 5 is photoelectrically converted by the image sensor 12 and output to the image forming apparatus 7 as an image signal. In the image forming apparatus 7, predetermined image processing is performed on the image signal to generate an image signal.

  For example, the image signal of the inspection chart 5 is automatically determined by an image determination device 8 (determination means) for determining whether or not eight camera modules are acceptable.

  When the inspection of the eight camera modules is completed, the probe base 40 is moved in a direction away from the holding base 30, and each probe 41 is retracted from each conductor pattern 23a.

  Subsequently, the holding table 30 is moved so that the conductor pattern group 23A of two new rows of camera modules adjacent to the eight camera modules inspected faces the probe group 41A.

  Thereafter, in the same manner as described above, the probe base 40 is moved to bring the probes 41 into pressure contact with the conductor patterns 23a, and the inspection chart 5 is imaged with a new camera module.

  Note that the control means 9 comprising a CPU or the like controls the movement of the holding table 30 and the probe table 40 in accordance with the above timing.

  The holding table 30 moves every time when the inspection of the two rows of camera modules is completed, but when the inspection of all the camera modules is completed, the holding table 30 moves in the opposite direction at a stroke and returns to the initial position.

  Next, a chart for inspecting the resolution as the inspection chart 5 will be described with reference to FIGS.

  FIG. 6 is an overall view of the inspection chart 5.

  In the inspection chart 5, inspection patterns 50 for inspecting the resolution are arranged at the center and at the four corners. The inspection pattern 50 includes a black line and a white line as will be described later. Then, an inspection pattern 50 in which black and white lines are arranged in the vertical direction in order to inspect the horizontal resolution of the imaging screen, and a black and white line is arranged in the horizontal direction in order to inspect the vertical resolution of the imaging screen. The inspection patterns 50 thus arranged are respectively arranged.

  FIG. 7 is an enlarged view of the inspection pattern.

  The test pattern 50 is provided with a stripe pattern 51 in which a plurality of black lines and white lines are alternately arranged, a reference pattern 52 composed of a black thick line is provided next to the stripe pattern 51, and a stripe is provided next to the reference pattern 52. A pattern 51 is provided, a reference pattern 53 composed of a white thick line is provided next to the pattern 51, and a stripe pattern 51 is provided next to the reference pattern 53. In other words, the reference pattern 52 is adjacent to one side of the stripe pattern 51, and the reference pattern 53 is adjacent to the other side of the stripe pattern 51.

  In addition, as for the stripe pattern 51, it is desirable that 4 to 10 black lines and white lines are alternately arranged. That is, if the number of black and white lines is 3 or less, the accuracy of the inspection of the camera module, which will be described later, is lowered. In particular, when the focus adjustment of the imaging lens with respect to the imaging device is not appropriate, it is easily affected. On the other hand, if the number of black and white lines is 11 or more, the stripe pattern 51 is too large, and the influence of illumination unevenness is increased.

  In addition, it is desirable that the black thick line width of the reference pattern 52 and the white thick line width of the reference pattern 53 be 2 to 6 times the black or white line width of the stripe pattern 51. That is, if the line widths of the reference patterns 52 and 53 are too thin, the white line and the black line are close to gray when the focus adjustment of the image pickup lens with respect to the image pickup device is not appropriate, and it is difficult to be a reference for discrimination. On the other hand, if the line widths of the reference patterns 52 and 53 are too large, the inspection pattern 50 becomes large, and as a result, the resolution inspection chart 5 also becomes large, which is not preferable.

  Further, it is desirable that two or more stripe patterns 51 are provided so that inspection can be performed at a predetermined position on the imaging screen even if the imaging lens is displaced with respect to the imaging element.

  When the inspection chart 5 having such an inspection pattern 50 is imaged by the camera module and the image signal is generated by the image forming apparatus 7, the waveform shown in FIG. 8 is obtained.

  FIG. 8A shows a waveform obtained by imaging a camera module in which the resolution of the imaging lens is good and the focus of the imaging lens is properly adjusted with respect to the imaging element, and FIG. 8B shows the waveform of the imaging lens. It is the waveform which imaged the camera module in which the resolution is not favorable or the focus adjustment of the imaging lens with respect to the imaging device is not properly performed.

  In FIG. 8A, the signal of the reference pattern 52, which is a black thick line, has the lowest gradation level, and the signal of the reference pattern 53, which is a white thick line, has the highest gradation level. The contrast ratio is set to C11 with the tone level as a reference. In this case, the black line of the stripe pattern 51 also has a sufficiently low gradation level, the white line also has a sufficiently high gradation level, and this contrast ratio is L12. Then, the ratio of L12 to L11 becomes a sufficiently large value.

  On the other hand, in FIG. 8B, if the contrast ratio between the reference pattern 52 and the reference pattern 53 is C21, C21 is not much different from C11. However, the black line of the stripe pattern 51 has a higher gradation level, the white line has a lower gradation level, and this contrast ratio is L22. Then, the ratio of L22 to L21 becomes a small value.

  In this way, the image discrimination device 8 calculates the contrast ratio of the fringe pattern 51 on the basis of the tone level of the black reference pattern 52 and the tone level of the white reference pattern 53, and judges pass / fail.

  In the inspection pattern 50, since the reference patterns 52 and 53 are adjacent to the fringe pattern 51, even if a plurality of camera modules are inspected at a time, the determination of acceptability is affected by the position of the camera module. I do not receive it. Further, whether the camera module is good or not can be accurately determined even if the imaging lens is individually displaced with respect to the imaging element or there is uneven illumination on the inspection chart 5.

  As the inspection chart 5, a dust inspection chart made of a white background having a uniform density may be used. If dust is attached to the image sensor, an image of the dust is also captured in the captured image. Therefore, if the image is larger than a preset size, the image determination device 8 can determine that the image is defective.

  Note that the probe 41 may not be surely pressed against the conductor pattern 23a due to deformation of the probe 41 or adhesion of dust. In such a case, it is preferable that the probe groups 41 </ b> A are arranged in two rows because the press contact state can be viewed from the lateral direction. Of course, it can be visually recognized even in one row, but it is not preferable because the inspection efficiency is lower than in the case of two rows. Moreover, since it cannot visually recognize the press-contact state of the probe 41 in a center row | line, it is not preferable that it is 3 rows or more.

  Further, when the probe group 41A has two rows, it is easy to arrange the lens units 25 and the conductor pattern group 23A in the module assembly 20 in even rows (eight rows in FIGS. 2 and 3). As a result, every time one module assembly 20 is inspected, all the probe groups 41A are in pressure contact with the conductor pattern group 23A at the same number of times. Accordingly, since the probe 41 is worn and deteriorated evenly over the long term, maintenance work is facilitated. However, when the probe group 41A has, for example, three rows, in order to configure similarly, the lens unit 25 and the conductor pattern group 23A in the module assembly 20 must be set to a multiple of three. The degree of freedom in manufacturing 20 is reduced. When the conductor pattern 23a or the like cannot be set to a multiple of 3, the number of contact of the probe group 41A varies depending on the row of the probe group 41A each time one module assembly 20 is inspected. That is, in the row of the probe group 41A, the number of contact is one less than the other rows, the state of wear / deterioration is different in the long term, and the maintenance work becomes complicated.

  Further, if the number of probes 41 in one row of the probe group 41A is the same as the number of lens units 25 and conductor pattern groups 23A in one row in the module assembly 20, it is not necessary to limit to four. However, this is determined by the number of inspection charts 5 that can be imaged simultaneously, as described above, and considering the inspection efficiency, three or four are preferable, and about five at most.

It is sectional drawing of a camera module. It is a perspective view of a camera module assembly. It is a perspective view of a holding stand holding a camera module and a probe stand. It is a schematic diagram of a camera module inspection apparatus. It is a figure of the conductor pattern of a sheet | seat board | substrate. It is a general view of the inspection chart. It is an enlarged view of the pattern for a test | inspection. It is a figure of an image signal of an inspection chart.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera module 11 Imaging lens 12 Image pick-up element 13 Printed wiring board 19 Electronic component 20 Camera module assembly 23 Sheet substrate 23a Conductor pattern 23A Conductive pattern group 25 Lens unit 30 Holding stand 40 Probe stand 41 Probe 41A Probe group 5 Inspection chart 6 Illumination device 7 Image forming device 8 Image discrimination device

Claims (10)

Using a camera module assembly in which a plurality of camera modules are arranged by mounting a plurality of lens units with imaging lenses on a sheet substrate on which a plurality of imaging elements are mounted, corresponding to the imaging elements. In the camera module inspection apparatus for imaging a predetermined inspection chart,
The back surface of the sheet substrate is provided with a plurality of conductor patterns electrically connected to the imaging element, and the plurality of conductor patterns are composed of a plurality of sets of conductor patterns corresponding respectively to the plurality of imaging elements,
A holding member that holds the camera module assembly, is configured such that the conductor pattern group can be exposed, and moves appropriately in a direction parallel to the surface of the inspection chart;
A plurality of probes that can be brought into pressure contact with the plurality of conductor patterns, and probe groups corresponding to the conductor pattern groups are arranged in two rows in a direction perpendicular to the moving direction of the holding member, A probe member that advances and retreats appropriately,
An apparatus for inspecting a camera module. The camera module inspection apparatus according to claim 1, wherein four sets of the probe groups are provided in one row. The inspection chart includes a stripe pattern in which a plurality of black lines and white lines are alternately arranged, a reference pattern composed of a black thick line adjacent to one side of the stripe pattern, and the other of the stripe patterns. 3. The camera module inspection apparatus according to claim 1, wherein a plurality of sets of reference patterns composed of white thick lines adjacent to the side are arranged adjacent to each other in the width direction of each line. The camera module inspection apparatus according to any one of claims 1 to 3, wherein a central portion of the probe member is disposed to face a central portion of the inspection chart. The camera module inspection apparatus according to claim 1, further comprising an illumination unit that illuminates the inspection chart. When photographing with the camera module, the holding member is moved so that the conductor pattern groups of the camera module arranged in two rows in a direction orthogonal to the moving direction of the holding member are positioned to face the probe group. The control means for controlling to move the probe member so that each of the probes is in pressure contact with each of the conductor patterns is provided, according to any one of claims 1 to 5. The camera module inspection apparatus as described. The camera module inspection according to claim 1, further comprising: a determination unit that determines whether the camera module is good or bad based on an image obtained by imaging the inspection chart. apparatus. A camera module inspection method for inspecting a camera module using the camera module inspection apparatus according to any one of claims 1 to 7,
Attaching the camera module assembly to the holding member;
Moving the holding member such that the conductor pattern groups of the camera modules arranged in two rows in a direction orthogonal to the moving direction of the holding member are positioned to face the probe groups of the probe member;
Moving the probe member so that the probe group is in pressure contact with the conductor pattern group of the camera module;
Imaging the inspection chart with the two rows of camera modules;
A camera module inspection method comprising: The camera module inspection method according to claim 8, further comprising: determining whether the camera module is good based on an image obtained by imaging the inspection chart. A step of moving the probe member to retract the probe group from the conductor pattern group after completing the imaging of the two rows of camera modules;
Moving the holding member so that a conductor pattern group of a new camera module arranged in two rows in a direction orthogonal to the moving direction of the holding member is positioned to face the probe group of the probe member; ,
The camera module inspection method according to claim 8, wherein the camera module inspection method is provided.

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