HK1195669B - Apparatus and method for obtaining uniform light source - Google Patents

Abstract

An apparatus and method for increasing uniformity in light from a light source at a plurality of targets of the light include a plurality of movable aperture elements, locatable between the light source and the targets, each aperture element defining an aperture through which the light passes from the light source to an associated one of the plurality of targets associated with the aperture element along a longitudinal axis of the aperture element. A holder movably holds the plurality of aperture elements, each of the plurality of aperture elements being movable within the holder along the longitudinal axis of the aperture element to change a feature of light incident on the target associated with the aperture element.

Description

Device and method for obtaining uniform light source

Technical Field

The present invention relates to the fabrication and testing of integrated image sensors formed on a wafer, and more particularly, to an apparatus and method for obtaining uniform illumination for testing integrated image sensors.

Background

In the manufacturing method of the image sensor, a large number of image sensing devices can be formed on the same wafer. The multiple image sensing devices on the wafer can be used for simultaneously carrying out wafer-level testing. After manufacturing and testing are completed, the image sensing devices are separated so that each image sensing device and its corresponding wafer portion become a die.

In wafer level testing, each image sensor is usually illuminated and the electrical signal generated by the illumination of the image sensor is detected to test the performance. To this end, the test apparatus typically includes a probe card (probecard) positioned between the source of illumination (i.e., light source) and the wafer. The probe card includes openings or holes to allow light from the light source to illuminate the wafer. The probe card also includes at least one conductive probe for detecting the electrical signal.

To reduce testing time and cost, multiple image sensing devices on a wafer are often tested simultaneously. To achieve this, the probe card includes a plurality of holes, each hole corresponding to one tested image sensor, and the probe card includes a plurality of probes, at least one of which corresponds to one tested image sensor. The light source used for illumination illuminates the tested image sensing component through the respective holes at the same time. This approach has the disadvantage that the light source is usually not perfectly uniform. As a result, all image sensing devices cannot obtain the same light intensity, which results in errors in testing.

The non-uniformity of the illumination depends on the distance between the light source and the wafer. That is, as the distance between the light source and the wafer increases, the non-uniformity of the illumination provided by the light source also increases. Accordingly, it is preferable to keep the distance between the light source and the wafer as small as possible. However, in a conventional testing environment, there are a variety of system components, such as an optical diffuser, at least one lens, and/or probes, disposed between the light source and the wafer such that a sufficient distance between the light source and the wafer is required to accommodate these components. Since the distance between the light source and the wafer is limited as described above, the uniformity of the illumination experienced by the image sensor assembly in the known system is also limited.

Disclosure of Invention

The present invention provides an apparatus for increasing the uniformity with which a plurality of targets receive light from a light source, and includes a plurality of movable aperture assemblies and a support member. The hole assemblies are arranged between the light source and the target, each hole assembly defines a hole, and light emitted by the light source passes through the hole along the long axis direction of the corresponding hole assembly to irradiate the corresponding target. The support supports the aperture elements, each aperture element being movable within the support along a long axis to change a property of light received by a target of the corresponding aperture element.

The present invention provides a method for increasing the uniformity of light received from a light source by a plurality of targets, comprising the steps of: arranging a plurality of movable hole assemblies between the light source and the target, wherein each hole assembly defines a hole, and light emitted by the light source passes through the hole along the long axis direction of the corresponding hole assembly to irradiate the corresponding target; and moving at least one of the aperture elements along its long axis to change the property of light received by the target corresponding to the aperture element.

Drawings

The foregoing and other features of the invention will be apparent from the following more particular description of the embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. Also, the drawings represent examples of the features of the invention and are not, and need not, be complete in nature. The dimensions of features in the figures may be exaggerated for clarity of illustration.

FIG. 1A is a diagram of a conventional system for testing a wafer having a plurality of image sensing devices thereon.

FIG. 1B is a detailed cross-sectional schematic view of a portion of the probe card of FIG. 1A. FIG. 1B shows a probe card unit.

FIG. 2 is a block diagram of a system for detecting light illumination as a function of distance.

FIG. 3 shows the central 120mm X120mm area of light generated by the light source tested in FIG. 2.

Fig. 4A-4F are graphs showing the results of six pitch-illumination tests, which were performed according to the configurations of fig. 2 and 3.

FIG. 5A is a diagram of a system with a control loop for testing a wafer with a plurality of image sensors according to an embodiment of the present invention.

FIG. 5B is a schematic cross-sectional view of a detail of a portion of the system of FIG. 5A, including a control loop.

FIGS. 5C (a) - (c) are block diagrams of the test system showing three different positions of the ring.

Fig. 5D is a schematic plan view of a control loop according to an embodiment of the invention.

FIG. 5E is a schematic side view of a control loop according to an embodiment of the invention.

FIG. 5F is a diagram of a control loop according to an embodiment of the present invention.

Fig. 6a (a) - (c) respectively show a top view, a cross-sectional view along line a-a, and a perspective view of a ring according to an embodiment of the invention.

FIGS. 6B (a) - (d) respectively show a top view, a side view, a cross-sectional view along line A-A, and a perspective view of a ring support according to an embodiment of the invention for cooperating with the ring of FIG. 6A.

FIGS. 7A (a) - (c) show a top view, a cross-sectional view along line A-A, and a perspective view of the ring according to the embodiment of the present invention.

FIGS. 7B (a) - (d) respectively show a top view, a side view, a cross-sectional view along line A-A, and a perspective view of a ring support according to an embodiment of the invention for cooperating with the ring of FIG. 7A.

Fig. 8a (a) - (c) respectively show a top view, a cross-sectional view along a-a, and a perspective view of a ring according to an embodiment of the present invention.

FIGS. 8B (a) - (d) respectively show a top view, a side view, a cross-sectional view along line A-A, and a perspective view of a ring support according to an embodiment of the present invention for cooperating with the ring of FIG. 8A.

Fig. 9 is a flowchart illustrating a step of adjusting the loop of the control loop to make the illuminance received by the test points have uniformity according to an embodiment of the present invention.

Fig. 10 shows a table of illuminance test data, including data for testing a test point in a system with a control loop and a system without a control loop.

Detailed Description

FIG. 1A is a diagram of a conventional system for testing a wafer having a plurality of image sensing devices thereon. As shown in fig. 1A, the wafer 12 includes a plurality of image sensing devices 14 to be tested. After testing, the wafer 12 is separated into a plurality of dies, each of which may include an image sensing device 14. During testing of the system 10, each sensing element 14 receives the illumination light and detects a response of the sensing element 14 to the illumination light, such as detecting at least one electrical signal generated by the image sensing element 14 to the illumination light.

The test illumination is provided by a light source or illumination source 16. The probe card 18 is disposed between the light source 16 and the wafer 12 and can perform a plurality of tests at different points simultaneously. The probe card 18 includes a plurality of probe card units 21, which respectively correspond to a plurality of test points 26 on the wafer 12. Each probe card unit 21 includes a diffusion element 20 and a lens 22, the diffusion element 20 diffuses light from the light source, and the lens 22 focuses the diffused light from the diffusion element 20 to the test point 26 of each image sensor. Generally, each test point 26 corresponds to each image sensor 14. The probe card unit 21 includes a probe set 24, and the probe set 24 is electrically contacted with each image sensor 14 to detect an electrical reaction of the control light. Each probe set 24 may include at least one precision probe (pogo pin) and/or probe to contact the corresponding image sensing component 14.

FIG. 1B is a detailed cross-sectional schematic view of a portion of the probe card 18 of FIG. 1A. Fig. 1B shows a probe card unit 21. A light source 16 (not shown) is disposed above the probe card 18. As shown in FIG. 1B, the probe card 18 includes a Printed Circuit Board (PCB) layer 30 within which an opening 32 of the probe card unit 21 is defined. The diffuser assembly 20 is supported and secured within the opening 32 by a ceramic tube 34, the ceramic tube 34 supporting the diffuser assembly 20 against an O-ring 36 located below the diffuser assembly 20. The lower surface 31 of the printed circuit board layer 30 may include a conductive pattern 38. The conductive pattern 38 may be covered by a protective insulating layer 40. The spacer elements 48 may be disposed below the printed circuit board layer 30 and the diffusion member 20 may be optically sealed to the upper surface of the spacer elements 48 by the O-ring 36.

The spacer assembly 48 may be secured to a rigid structure that provides force to the probe card 18. In particular, the rigid structure may include an upper die 50 positioned above a lower die 52, both of which may be formed of a rigid material (e.g., stainless steel or other material). Spacer assembly 48 may be secured to an upper surface of upper die 50.

Light for testing the image sensor 14 passes through the diffuser element 20 and then through the opening 33 and the lens 22. The lens 22 is secured within the spacer assembly 48. The light passing through the lens 22 reaches the test points 26 corresponding to the probe card units 21 of the probe card 18. During testing, one of the image sensing devices 14 on the wafer 12 is positioned at the test site 26 and is illuminated by light passing through the lens 22.

As described above, the response of the image sensor 14 is monitored during the test by detecting at least one electrical signal generated by the image sensor 14 in response to the light. To this end, at least one probe set 24 (each probe set including at least one precision probe 42) is connected to the conductive pattern 38 of the printed circuit board layer 30. In the probe assembly 24, the precision probe 42 is electrically connected to at least one probe 44, 46, and the probe 44, 46 has a conductive end 45, 47 electrically connected to the image sensor 14. Thus, the electrical signals generated by the image sensor 14 in response to the illumination can be monitored by the probes 44, 46 and the precision probe 42 to the conductive pattern 38, so that the electrical signals generated by the image sensor 14 can be used to evaluate the performance thereof.

As described above, multiple image sensing devices 14 can be tested simultaneously. To this end, the probe card 18 includes a plurality of probe card units 21 corresponding to a plurality of test points 26. In one probe card configuration, 16 dies arranged in a 4x4 matrix can be tested simultaneously, with adjacent probe card units 21 being spaced apart from them by a distance of about a plurality of dies.

For testing, it is important that the light source 16 provide uniform illumination for proper evaluation of the image sensing devices, and therefore, each image sensing device 14 must receive the same intensity of light. Such uniformity is difficult to achieve because the distance between the light source 16 and the wafer 12 needs to be maintained the same. For the purpose of multi-point simultaneous testing, sufficient space is maintained between the light source 16 and the wafer 12 to accommodate system components such as diffusion elements, lenses, precision probes, and the like. In one embodiment, a preferred spacing is, for example, about 25 mm. However, the greater the distance between the light source 16 and the wafer 12, the poorer the uniformity of the illumination.

The illuminance (in lux) of a surface refers to the total flux of light incident on a unit area of the surface, which is a measure of the light source illuminating the surface. The greater the distance between the light source and the illuminated surface, the more uneven the illumination on the surface. The relationship between the spacing between the light source and the wafer and the illumination uniformity is described in fig. 2-4 and the following description.

FIG. 2 is a block diagram of a system for detecting light illumination as a function of distance. As shown in FIG. 2, system 70 includes a planar light source 74, such as an A32700799 (136 mm X136 mm) light source, manufactured and sold by the metallocene Electron Chroma Ate Inc. (66, Hwa-Ya1st Rd., Hwa-Ya Technology Park, Kuei-Shan Hsiang, Taoyean Hsien333, Taiwan). The light source 74 may be fixed on a movable and controllable X-Y stage 72 to precisely control the distance between the light source 74 and the sensing assembly 76. In accordance with the present invention, the light source 74 is defined as an area of 120mm X120 mm. The light source 74 is used to illuminate the sensing element 76. the sensing element 76 is coupled to an illuminometer 78. the illuminometer 78 can be, for example, a Minolta Model T-10 LuxMeter. Computer 80 is coupled to light meter 78, light source 74, and X-Y stage 72 to control the performance of the test.

Fig. 3 shows the central area of 120mm X120mm of light generated by the light source 74 tested. As shown in fig. 3, the central area is divided into 16 small areas, and the center point of each small area is represented by a solid point. In the present embodiment, the spacing between the light source 74 and the sensing element 76 is set to three levels, i.e., 2mm, 22mm, and 42 mm. The output illuminance of the light source 74 is set to two levels, i.e., 1000lux and 500 lux. In general, six combinations of pitch and light source output illumination were tested. Fig. 4A to 4F show graphs of the results of these six pitch-luminance tests. Fig. 4A is a graph of a pitch of 2mm and a light source illuminance of 1000lux, fig. 4B is a graph of a pitch of 2mm and a light source illuminance of 500lux, fig. 4C is a graph of a pitch of 22mm and a light source illuminance of 1000lux, fig. 4D is a graph of a pitch of 22mm and a light source illuminance of 500lux, fig. 4E is a graph of a pitch of 42mm and a light source illuminance of 1000lux, and fig. 4F is a graph of a pitch of 42mm and a light source illuminance of 500 lux. These results are represented by the graphs of fig. 4A-4F to provide a visual presentation of the contrast distribution. In fig. 4A to 4F, each graph includes 16 vectors, which correspond to the 16 center points shown in fig. 3, respectively.

As shown in fig. 4A to 4F, it is clear that the uniformity is not much affected by the change of the illuminance of the light source output. In particular, if comparing fig. 4A with fig. 4B, fig. 4C with fig. 4D, and fig. 4E with fig. 4F, it can be found that the variation of the illumination of the light source from 1000lux to 500lux has a very small influence on the uniformity. However, it is also found from fig. 4A to 4F that the variation of the spacing of the light source and the sensing assembly has a great influence on the uniformity. Thus, it can be concluded that as the separation of the light source from the sensing assembly increases, the uniformity decreases. In addition, when the pitch is relatively small, the rate of reduction in uniformity is also relatively high. In fact, in the case of the conventional multi-point probe card having a working distance of about 25mm, the illuminance is considerably uneven.

In accordance with the present invention, the problem of non-uniformity caused by the need for sufficient spacing to accommodate system components is solved by placing a control ring between the light source and the probe card. In one embodiment, the control ring includes 16 movable orifice assemblies, such as a plurality of ring units, for example, arranged in a 4X4 matrix. These 16 ring units correspond to 16 probe card units 21 (see fig. 1A and 1B) for simultaneously performing optical testing on 16 dies on the wafer 12.

Fig. 5A is a schematic diagram of a system 100 with a control loop according to an embodiment of the invention, the system 100 being used for testing a wafer with a plurality of image sensing devices. Fig. 5B is a cross-sectional schematic view of a detail of a portion of the system 100 of fig. 5A, including the control loop 110. Parts of the components of fig. 5A and 5B are the same as those of fig. 1A and 1B and are denoted by the same reference numerals, and thus, are not described herein again.

As shown in fig. 5A and 5B, the control ring 110 is positioned above the probe card 18 and includes a ring support 112 and at least one ring 114, the ring 114 being supported within the ring support 112. A plurality of supports 123 are located at the bottom of the ring support 112 and support the control ring 110 on the probe card 18. The inner aperture 116 of each ring 114 aligns the diffuser element 20 and lens 22 of the corresponding probe card unit 21 and thereby forms an optical path from the light source 16 to the corresponding image sensing element 14 (located at the test point 26). Light from the light source 16 above the control ring 110 passes through the ring 114, through the corresponding diffuser element 20 and lens 21, and finally to the corresponding test point 26 on the wafer 12.

Each ring 114 is supported in the ring support 112 so as to be movable up and down along a light path defined by the holes of the ring. Such movement may be achieved, for example, by mating threads on the outer diameter of the ring 114 and the inner diameter of the ring support 112. In this aspect, each ring 114 may be adjusted up or down by being turned, such as by turning the ring 114 by a key or screwdriver or other similar component over a groove in the annular upper surface of the ring 114. Alternatively, the inner edge of ring 114 may be polygonal rather than circular in shape, such that, for example, a hex key (e.g., Allen wrench) may be used to rotate ring 114 to move it up and down. By moving the ring 114 up and down, i.e., closer to or further away from the light source 16, the light flux on the wafer 12 corresponding to the respective test points 26 can be adjusted. Thus, although the illumination provided by the light source 16 is not uniform, the light applied to the 16 test points 26 of the wafer 12 can be made uniform by adjusting the 16 rings 114 individually.

FIGS. 5C (a) - (c) are block diagrams of the test system 100 showing three different positions of the ring 114. In FIG. 5C (a), ring 114 is in a neutral or standard position; in fig. 5c (b), the ring 114 is in a higher position than in the intermediate or standard position; in fig. 5c (c), the ring 114 is in a lower position than in the intermediate or standard position. Fig. 5D is a schematic plan view of the control ring 110 according to the embodiment of the invention. FIG. 5E is a schematic side view of the control loop 110 according to the embodiment of the invention. FIG. 5F is a diagram of the control loop 110 according to an embodiment of the invention.

Referring to fig. 5A to 5F, the control ring 110 is located above the probe card 18 and below the planar light source 16. The Inner Diameter (ID) of the ring 114, i.e., the diameter of the hole 116 of the ring 114, is set to Φ, the distance between the top of the ring 114 and the light source 16 is set to H, and the viewing angle is θ (as shown in fig. 5C). In addition, if the intensity of illumination of the light source 16 is p and is close to a certain value for convenience of description, the illumination I (H, Φ) can be expressed as a function of H and Φ as follows:

the value of the inner diameter phi provides a first variable to adjust the illumination intensity I. Larger Φ results in larger I. After selecting Φ, spacing H may be adjusted by I as a second variable. In one embodiment, the H value is usually 4-8 mm, the phi value is usually 6-10 mm, and the viewing angle can be set to 45 degrees, for example.

For illustrative purposes, assuming that the first variable Φ is 8mm, the second variable H can be adjusted to allow further fine tuning of the illumination I. In one embodiment, the H value may be set to 6mm as a reference value. If the illumination is to be reduced, the ring 114 may be rotated to move up closer to the light source, so that the H value is adjusted to, for example, 4.5 mm. This may reduce the illumination by about 44%. Conversely, if the illumination is to be increased, the ring 114 may be moved downward away from the light source 16 so that the H value is adjusted to, for example, 8.5 mm. This may increase the illuminance by about 101%.

In one embodiment, the inner diameter Φ of the aperture 116 can be set to one of three possible values, for example. These values are, for example, 6mm, 8mm and 10 mm. In one embodiment, the thickness of the ring 114, i.e., the outer diameter minus the inner diameter Φ of the ring 114, may be about 2 mm. Thus, the outer diameter of the ring 114 is about 8mm, 10mm or 12 mm. In one embodiment, the height of the ring 114 may be about 3 mm. In one embodiment, the threads 119 on the ring 114 may be 0.5 mm/turn.

Fig. 6a (a) - (c) respectively show a schematic top view, a schematic cross-sectional view along a-a line, and a schematic perspective view of the ring 114.1 according to the embodiment of the invention. Fig. 6b (a) - (d) respectively show a top view, a side view, a cross-sectional view along line a-a, and a perspective view of the ring support 112.1 of the ring 114.1 of fig. 6A according to an embodiment of the present invention. Fig. 7a (a) - (c) respectively show a schematic top view, a schematic cross-sectional view along a-a line, and a schematic perspective view of the ring 114.2 according to the embodiment of the present invention. Fig. 7b (a) - (d) respectively show a top view, a side view, a cross-sectional view along line a-a, and a perspective view of a ring support 112.2 of the ring 114.2 of fig. 7A according to an embodiment of the present invention. Fig. 8a (a) - (c) respectively show a schematic top view, a schematic cross-sectional view along a-a line, and a schematic perspective view of the ring 114.3 according to the embodiment of the present invention. Fig. 8b (a) - (d) respectively show a top view, a side view, a cross-sectional view along line a-a, and a perspective view of a ring support 112.3 of the ring 114.3 of fig. 8A according to an embodiment of the present invention.

In the embodiment of fig. 6A and 6B, the ring 114.1 has an inner diameter of about 6mm and an outer diameter of about 8 mm. In the embodiment of fig. 7A and 7B, the ring 114.2 has an inner diameter of about 8mm and an outer diameter of about 10 mm. In the embodiment of fig. 8A and 8B, the ring 114.3 has an inner diameter of about 10mm and an outer diameter of about 12 mm.

Referring to fig. 6A and 6B, the outer surface of the ring 114.1 is formed with a plurality of threads 119.1 that mate with the threads of the ring support 112.1. The ring 114.1 includes a slot or groove 117.1 that can be matched with a tool, such as a screw driver, to allow the ring 114.1 to be rotated within the ring support 112.1 to adjust the height of the ring 114.1 within the ring support 112.1, i.e., to adjust the spacing between the ring 114.1 and the light source 16, so that the intensity of illumination at each test point 26 is adjustable. The ring support 112.1 also includes a plurality of supports 123.1 to support the ring support 112.1 on the probe card 18 (see fig. 5A).

Referring to fig. 7A and 7B, the outer surface of the ring 114.2 is formed with a plurality of threads 119.2 that mate with the threads of the ring support 112.2. The ring 114.2 includes a slot or groove 117.2 that can be matched with a tool, such as a screw driver, to allow the ring 114.2 to be rotated within the ring support 112.2 to adjust the height of the ring 114.2 within the ring support 112.2, i.e., to adjust the spacing between the ring 114.2 and the light source 16, so that the intensity of illumination at each test point 26 is adjustable. The ring support 112.2 also includes a plurality of supports 123.2 to support the ring support 112.2 on the probe card 18 (see fig. 5A).

Referring to fig. 8A and 8B, the outer surface of the ring 114.3 is formed with a plurality of threads 119.3 that mate with the threads of the ring support 112.3. The ring 114.3 includes a slot or groove 117.3 that can be matched with a tool, such as a screw driver, to allow the ring 114.3 to be rotated within the ring support 112.3 to adjust the height of the ring 114.3 within the ring support 112.3, i.e., to adjust the spacing between the ring 114.3 and the light source 16, so that the intensity of illumination at each test point 26 is adjustable. The ring support 112.3 also includes a plurality of supports 123.3 to support the ring support 112.3 on the probe card 18 (see FIG. 5A).

Fig. 9 is a flowchart illustrating a step of adjusting the loop of the control loop to make the illuminance received by the test points have uniformity according to an embodiment of the present invention. According to the calibration procedure, a reference image sensor is used to measure the respective illumination of each test point (i.e. 16 test points). For this calibration, the light source 16 is activated and the control loop 110 is placed over the probe card 18. The image sensing component for reference is arranged at each test point, one test point at a time. At each test point, it is necessary to determine whether the illuminance needs to be adjusted. If desired, the ring 114 at the test point can be adjusted appropriately, moving up or down, to achieve the desired intensity of illumination. This procedure is continued until all test points are measured and the loop adjustment is properly performed so that the illumination of all 16 test points is consistent and then accurate multi-point testing can be performed simultaneously.

Referring to FIG. 9, the process 300 begins at step 302, where the control ring 110 is positioned over the probe card 18 and all of the rings 114 are set at the same height at step 302. For example, all of the rings 114 may be set in a neutral position, as shown in FIG. 5C (a). Next, in step 304, the light source 16 is activated and set at a predetermined intensity and defines an image sensing element (chip or die) for reference. In step 306, the image sensing device for reference is located at one of the test points for the next test. And adjusting the light intensity detected by the reference image sensing component by adjusting the ring at the test point until the light intensity is set at a preset value. In step 308, step 306 is repeated for all rings and their corresponding test points so that all control rings are corrected. In step 310, the calibration procedure is completed by fixing the rings in their adjusted positions, for example by means of an adhesive material (e.g. glue or epoxy).

Fig. 10 shows a table of illuminance test data, including data for testing a test point for a system with a control loop to provide uniform illumination and for a system without a control loop.

First, as a control experiment, a light source with non-uniformity is known to illuminate a wafer for optical testing without a control ring. The results are shown on the left side of the table in fig. 10. Where MeanR refers to the mean of the red signal. Meang1 and Meang2 refer to the mean of two green light signals. MeanB refers to the mean of the blue signal. The image sensor die reads the red, green, and blue light components according to a filtering technique using a Bayer pattern. The range of values is 8-bit values and can be measured by the image sensor die. Any of the red, green, or blue lights can be used in the operation shown in fig. 9 to correct the ring of 16 test points. In this aspect, correction of the ring uses a reading of green light. Therefore, the data shown in fig. 10 shows that the uniformity of the illuminance is optimal in the case of the green light component.

Next, the control loop is placed between the light source and the probe card, and the operations shown in FIG. 9 can be performed to adjust the loops and calibrate the control loop. Thus, the illumination of 16 test points becomes uniform. The wafer may then be optically tested. The results are shown on the right side of the table in FIG. 10.

Referring to FIG. 10, 16 test points are tested and the results are listed in the table. The maximum and minimum values and the difference between the maximum and minimum values (Max-Min) for each point, and the offset ratio are calculated and listed in the table. It should be noted that smaller maximum to minimum differences and offset ratios represent more uniform results. Fig. 10 shows that the illuminance can be made uniform at 16 test points by performing the calibration procedure shown in fig. 9 using the control loop.

Combinations of features

Various features of the invention have been described in detail above. The invention covers any and all combinations of the above features unless a combination of features is excluded from the description. The following examples illustrate some combinations of features in accordance with the present invention.

In one embodiment, the characteristic of the light that is changed by moving one of the aperture elements may be the illumination of the object being illuminated.

In one embodiment, at least one of the aperture assemblies may be moved such that uniformity of illumination of the illuminated objects is improved.

In one embodiment, each aperture may have a selectable inner diameter such that the illumination of the illuminated target may be adjusted.

In one embodiment, if the inner diameter of the hole is increased, the illumination of the illuminated target is also increased, and if the inner diameter of the hole is decreased, the illumination of the illuminated target is also decreased.

In one embodiment, each aperture assembly may be moved such that the spacing between the aperture assembly and the light source is adjustable such that the illumination of the illuminated target may be adjusted.

In one embodiment, if the spacing between the aperture element and the light source is increased, the illumination of the illuminated target is also increased; if the spacing between the aperture assembly and the light source is reduced, the illumination of the illuminated target is also reduced.

In one embodiment, the spacing between each aperture element and the light source is determined by selectively moving the aperture element to adjust the illumination of the target element for reference, thereby allowing the support and aperture elements to be calibrated to provide more uniform illumination.

In one embodiment, the plurality of targets may include a plurality of image sensing elements formed on the wafer.

In one embodiment, the support and the hole assembly are disposed between the light source and the probe card for testing the image sensor assembly on the wafer.

In one embodiment, a plurality of image sensing devices can be simultaneously illuminated by the light source to be tested simultaneously.

In one embodiment, the plurality of hole elements may be supported within the support member by mating threads and the plurality of hole elements may be moved along the long axis by rotation according to the long axis thereof.

The foregoing is by way of example only, and not limiting. It is intended that all equivalent modifications or variations not departing from the spirit and scope of the present invention be included in the claims.

Claims (12)

1. An apparatus for adjusting the intensity of light from a light source at a plurality of targets, comprising:

a plurality of movable aperture assemblies disposed between the light source and the target, each aperture assembly defining an aperture, light emitted by the light source passing through the aperture along a long axis of the corresponding aperture assembly to illuminate the corresponding target; and

a support member movably supporting the movable orifice assembly,

wherein each of the movable aperture elements is movable within the support along the longitudinal axis to adjust the luminous flux of light received by the target corresponding to the aperture element, respectively

Wherein the movable bore component is supported within the support member by mating threads and the movable bore component moves along the long axis direction by rotating according to the long axis direction thereof.

2. The apparatus of claim 1, wherein each of the movable orifice assemblies has a respective selectable inner diameter.

3. The apparatus of claim 1, wherein each movable aperture element is selectively movable such that a spacing between the movable aperture element and the light source is adjustable.

4. The apparatus of claim 1, wherein the target comprises a plurality of image sensing elements formed on a wafer.

5. The apparatus of claim 4, wherein the support and the aperture assembly are disposed between the light source and a probe card for testing the image sensing assembly on a wafer.

6. A method for adjusting the intensity of light received by a plurality of targets from a light source, comprising the steps of:

arranging a plurality of movable hole assemblies between the light source and the target, wherein each movable hole assembly defines a hole, and light emitted by the light source passes through the hole along the long axis direction of the corresponding hole assembly to irradiate the corresponding target; and

moving at least one of the movable aperture assemblies along a long axis thereof to adjust the luminous flux received by the target corresponding to the aperture assembly, respectively.

7. The method of claim 6, wherein each of the movable aperture elements is separately and individually movable within the support along the longitudinal axis to separately adjust the illumination of light received by the target.

8. The method of claim 7, wherein each of the holes may have a separately selectable inner diameter.

9. The method of claim 7, wherein each aperture assembly is selectively movable such that a spacing between the aperture assembly and the light source is adjustable such that an illumination of the illuminated target is adjustable.

10. The method of claim 6, further comprising:

and supporting the hole assembly in a support piece, wherein the support piece is arranged between the light source and the probe card and is used for testing the image sensing assembly on the wafer.

11. The method of claim 10, wherein the image sensing devices are simultaneously illuminated by a light source to be tested simultaneously.

12. The method of claim 10, wherein said bore hole assembly is supported in said support member by mating threads, and wherein moving at least one of said movable bore hole assemblies along its longitudinal axis comprises:

rotating at least one of the plurality of movable orifice elements according to the direction of the long axis thereof.