CN115683562A

CN115683562A - Light source uniformity testing device and testing method thereof

Info

Publication number: CN115683562A
Application number: CN202211173862.5A
Authority: CN
Inventors: 雷述宇
Original assignee: Ningbo Abax Sensing Electronic Technology Co Ltd
Current assignee: Ningbo Abax Sensing Electronic Technology Co Ltd
Priority date: 2022-09-26
Filing date: 2022-09-26
Publication date: 2023-02-03

Abstract

The application provides this application provides a light source degree of consistency testing arrangement, its characterized in that includes: a laser light source for emitting a uniform light field; a scientific camera sensor and a two-dimensional displacement platform; the scientific camera sensor is positioned on the two-dimensional displacement platform, and the range of the two-dimensional displacement platform can cover the uniform light field. The device and the method for testing the uniformity of the large-caliber uniform light field are provided by adopting a splicing mode, so that the uniformity of the light field can be accurately reflected under the condition that the whole light field distribution condition can be provided, and no extra requirement is made on the size of a sensor.

Description

Light source uniformity testing device and testing method thereof

Technical Field

The application relates to the field of chip testing, in particular to the field of a light source uniformity testing device of a chip testing system and a testing method thereof.

Background

IC chips all need to pass through the two most critical test points: wafer probe testing (CP) and Final Testing (FT). The CP test is a wafer-level chip test before packaging. And the FT test is the final test performed after the chip is packaged. In the CP test, an excitation signal is directly loaded on each chip on a wafer through a special probe, and the function of each chip is tested. The failure of different items will be indicated by different colors. After CP testing, the wafer is cut, the cut chips are classified according to the previous results, and only good chips are sent to a packaging factory for packaging. The CP test can not only screen out bad chips, save the packaging cost, but also bear multiple test items of the chips, reduce the test items of the FT test and improve the overall test efficiency.

In the test of the wafer-level chip, complete optical coverage (covering the photosensitive area of the chip) is provided for the chip through the shielding of the through hole of the probe board card, and when the chip is detected, the photosensitive area of the chip needs to be optically covered through the through hole of the probe board card. An ATE (Automatic Test Equipment) Test platform detects a wafer, generally, because the wafer has a large size and the number of chips to be detected is large, the ATE is required to provide uniform light with a large aperture, and the current Test method for the uniformity Test of a large-aperture uniform light field is small. How to test the uniformity of a large-caliber uniform light field is a technical problem which needs to be solved urgently.

Disclosure of Invention

The purpose of the present application is to provide a device and a method for testing the uniformity of a light source, which provides a device and a method for testing the uniformity of a large-diameter uniform light field by means of splicing, so as to accurately reflect the uniformity of the light field under the condition of providing the overall light field distribution condition, and do not make extra requirements on the size of the sensor.

In order to achieve the above purpose, the technical solutions adopted in the embodiments of the present application are as follows:

in a first aspect, the present application provides a device for testing uniformity of a light source, comprising:

a laser light source for emitting a uniform light field;

a scientific camera sensor and a two-dimensional displacement platform;

the scientific camera sensor is positioned on the two-dimensional displacement platform, and the range of the two-dimensional displacement platform can cover the uniform light field.

Optionally, the stepping and collecting speed of the two-dimensional displacement platform is set according to the effective area of the scientific camera sensor, and the whole uniform light field is traversed.

In a second aspect, the present application provides a method for testing uniformity of a light source, comprising the following steps:

the laser light source emits a uniform light field;

a scientific camera sensor tests the uniform light field;

and moving the two-dimensional displacement platform, wherein the stepping and acquisition speed of the two-dimensional displacement platform are set according to the effective area of the scientific camera sensor, and the range of the two-dimensional displacement platform can cover the uniform light field.

Optionally, the light distribution of each block matrix in the uniform light field is obtained according to the stepping and collecting speeds.

Optionally, the light distributions of the block matrixes are spliced, and the uniformity of the whole light field is obtained by calculating the spliced whole light field.

Alternatively, the uniformity of the light field is directly obtained by counting the gray levels of all pixels.

Optionally, respective uniformity of the light fields of the block matrices is calculated respectively, and then the uniformity of the whole two-dimensional light field is further obtained.

Optionally, the uniformity of the light field is: uniformity =1- σ ² Mu,/mu, where σ ² As the global variance, μ is the global mean.

The beneficial effect of this application is:

the application provides a light source degree of consistency testing arrangement, its characterized in that includes:

a laser light source for emitting a uniform light field;

a scientific camera sensor and a two-dimensional displacement platform;

the scientific camera sensor is positioned on the two-dimensional displacement platform, and the range of the two-dimensional displacement platform can cover the uniform light field. The device and the method for testing the uniformity of the large-caliber uniform light field are provided by adopting a splicing mode, so that the uniformity of the light field can be accurately reflected under the condition that the whole light field distribution condition can be provided, and no extra requirement is made on the size of a sensor.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic diagram of probing by a probe card provided in the prior art;

fig. 2 is a schematic view of a large-caliber uniform optical field testing apparatus provided in an embodiment of the present application;

fig. 3 is a schematic diagram of a spliced optical field distribution according to an embodiment of the present application;

FIG. 4 is a schematic view of a distribution of uniformity of light fields of each of the block matrices provided in the embodiment of the present application;

fig. 5 is a schematic diagram of a uniformity distribution of a segmented light field according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, as presented in the figures, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

FIG. 1 is a schematic diagram of probing by a probe card provided in the prior art; as shown in fig. 1, the wafer testing system includes a wafer 101 to be tested; a probe head 102; pad (pad) 103; and a PCB board 104 in the probe card that undertakes the primary architectural functions. In wafer level testing, a probe card having a plurality of conductive probes is used to transmit a test signal output from a test apparatus to a semiconductor wafer. Typically, in wafer level testing, a probe card 102 is used to inspect dies on a semiconductor wafer such that probes individually contact the pads 103 of each die. After the probe with conductivity is contacted, the test signal is inputted to facilitate the execution of inspection and to detect the defective product.

Fig. 2 is a schematic view of a large-aperture uniform light field testing apparatus provided in an embodiment of the present application, and includes a scientific camera sensor, a two-dimensional displacement platform, and a uniform light field emitted by a laser source as shown in fig. 2. Arranging the scientific camera sensor on the two-dimensional displacement platform, ensuring that the moving range of the platform can cover the uniform light field, setting the stepping and collecting speed of the platform according to the effective area of the scientific camera sensor, traversing the whole uniform light field, and obtaining the light distribution of each block matrix in the uniform light field. The ATE direct-current light source emits uniform light through the collimator, the aperture of a light beam is phi 110mm, the scientific camera is arranged on a two-dimensional displacement platform, the level of the scientific camera is guaranteed, the moving range of the platform is 120mm multiplied by 120mm, the platform can cover the light field and is slightly larger than the light field, the size of a sensor of the scientific camera is 4.8mm multiplied by 3.6mm, the corresponding number of pixels is 1600 multiplied by 1200, the central effective area pixel is selected to be 840 multiplied by 800, the transverse stepping of the platform is set to be 2.52mm, the longitudinal stepping is set to be 2.4mm, the acquisition speed is 3 s/time, each row of displacement is stepped for 46 times, each row of displacement is stepped for 48 times, a stepping program of the displacement platform is set, and the whole light field is traversed to carry out stepping acquisition.

Fig. 3 is a schematic diagram of a spliced light field distribution provided in the embodiment of the present application. Splicing the block matrixes in the embodiment of FIG. 2, wherein the distribution of the spliced light field is shown in FIG. 3; and calculating the uniformity of the spliced whole light field.

Fig. 4 is a schematic view of the distribution of the light field uniformity of each of the block matrices according to the embodiment of the present application. There are two methods for obtaining the uniformity of the light field, one is to count the gray levels of all pixels and directly calculate the uniformity of the light field; the other is that when the overall optical field distribution matrix is too large, the respective uniformity of each block matrix can be respectively calculated, and then the overall two-dimensional uniformity is further calculated, wherein the uniformity calculation formula is as follows: uniformity =1- σ ² Mu,/mu, where σ ² For the global variance, μ is the global mean.

Fig. 5 is a schematic view of a uniformity distribution of a blocked light field according to an embodiment of the present application. The collected light field distributions of the block matrixes are spliced to obtain the overall light field distribution, the overall uniformity distribution of the block matrixes divides a large light field into 46-48 light splitting fields as shown in fig. 5, and finally the overall uniformity of the obtained light field is 95.28%, so that the light field meets the light source standard.

It is to be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined or explained in subsequent figures. The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made to the present application by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A device for testing uniformity of a light source, comprising:

a laser light source for emitting a uniform light field;

a scientific camera sensor and a two-dimensional displacement platform;

2. The apparatus of claim 1, wherein the stepping and collection speed of the two-dimensional displacement stage is set according to the effective area of the scientific camera sensor to traverse the entire uniform light field.

3. A method for testing the uniformity of a light source is characterized by comprising the following steps:

the laser light source emits a uniform light field;

a scientific camera sensor tests the uniform light field;

4. The method as claimed in claim 3, wherein the distribution of light in each of the block matrices in the uniform light field is obtained according to the step and capture speed.

5. The apparatus for testing uniformity of a light source according to claim 4, wherein the light distributions of the block matrices are connected, and the uniformity of the whole light field is calculated from the connected whole light field.

6. The apparatus for testing uniformity of a light source of claim 5, wherein the uniformity of said light field is directly obtained by counting the gray levels of all pixels.

7. The apparatus for testing uniformity of a light source according to claim 5, wherein the uniformity of each of said light field of said block matrix is calculated respectively, and further the uniformity of the light field in two dimensions is obtained as a whole.

8. The apparatus for testing the uniformity of a light source of claim 7, wherein the uniformity of the light field is: uniformity =1- σ ² Mu,/mu, where σ ² For the global variance, μ is the global mean.