Combined screen plate for testing performance of front silver paste

Abstract

The utility model provides a combined screen plate for testing the performance of front-side silver paste, which comprises a first screen plate and a second screen plate, and the first screen plate and the second screen plate are configured to be matched for use so as to test the compatibility of front-side conductive silver paste and a resistor body and test the resistance temperature coefficient of the front-side conductive silver paste to the resistor body; the combined screen plate comprises a first screen plate and a second screen plate. Compared with the prior art, the combined screen plate for testing the performance of the front silver paste provided by the utility model can simulate the lap joint of C1-R in a device, can be matched with special TCR testing equipment, and can quickly test the influence of C1 on the TCR of a resistor body R under the condition that a final finished product does not need to be made, so that the research and development efficiency is greatly accelerated.

Description

Technical Field

[0001] The utility model relates to the technical field of screen printing, in particular to a combined screen for testing the performance of front silver paste. Background Art

[0002] Chip resistors are common electronic components, currently widely used in consumer electronics, new energy vehicles and other fields. The front conductive silver paste (hereinafter referred to as C1) is overlapped on both ends of the resistor body (hereinafter referred to as R), directly connecting the resistor body and acting as an electrode, connecting the resistor body to the circuit. It is a key material. In the general process, C1 at both ends is first printed and sintered on an alumina substrate, and then R is printed and sintered on the C1 sintered film, forming the core circuit of the chip resistor component.

[0003] There are two key performance requirements for front conductive silver paste:

[0004] 1. C1-R compatibility: Because both C1 and R pastes contain glass frit, metals, and oxides, component reactions, shrinkage mismatches, and localized overburning can occur during sintering, leading to sintering blistering at the C1-R overlap. In actual production, the overlap area between C1 and R is relatively small, making blistering difficult to detect.

[0005] 2. C1 itself has a certain impact on the TCR (temperature coefficient of resistance) of the resistor body R. If the impact is too significant, the chip resistor will exceed the original TCR design range, resulting in device failure. Generally, the TCR of chip electronic components is often tested at the final stage of the manufacturing process (the package testing stage). During the C1 development process, if the TCR is tested after each sample is completed, it will greatly affect development efficiency.

[0006] Therefore, it is crucial to develop a stencil for testing the performance of front-side conductive silver paste to ensure test accuracy while improving product development efficiency. Utility Model Content

[0007] 1. In view of the defects in the prior art, the purpose of the present invention is to provide a combined stencil for testing the performance of front silver paste. Through the combination of the first stencil and the second stencil, as well as the stencil pattern and its arrangement, it is possible to achieve simultaneous testing of two key performances: C1-R compatibility and the effect of C1 on the TCR of the resistor body R.

[0008] The utility model provides a combined stencil for testing the performance of front-side silver paste, comprising a first stencil and a second stencil. The first stencil and the second stencil are configured to be used in conjunction with each other to perform a compatibility test between the front-side conductive silver paste and the resistor, and a resistance temperature coefficient test of the front-side conductive silver paste on the resistor.

[0009] The combined mesh panel includes a first mesh panel and a second mesh panel;

[0010] The first screen plate includes:

[0011] First Silk Screen;

[0012] a first screen frame, on which the first screen is tensioned and fixed;

[0013] a first graphic region, wherein the first screen is coated with a photosensitive adhesive, which is exposed and developed to form the first graphic region; the first graphic region includes a rectangular graphic region A and a T-shaped graphic region disposed below the rectangular graphic region, the T-shaped graphic region including a horizontal portion and a vertical portion, the horizontal portion being parallel to a long side of the rectangular graphic region, and the vertical portion being located on a side of the horizontal portion facing away from the rectangular graphic region; the first graphic region also includes rectangular graphic regions B disposed on both sides of the vertical portion, with a gap between the horizontal portion and the rectangular graphic region B;

[0014] The second screen plate includes:

[0015] Second wire mesh;

[0016] a second screen frame, on which the second screen is tensioned and fixed;

[0017] The second graphic area, the second silk screen is coated with a photosensitive resin, and the photosensitive resin is exposed and developed to form the second graphic area; the second graphic area includes at least two rectangular graphic areas C matching the rectangular graphic area A, and a rectangular graphic area D for overlapping the horizontal part and the rectangular graphic area B, and the at least two rectangular graphic areas C are arranged to form a rectangular array.

[0018] In one embodiment of the present invention, there are 56 rectangular graphic areas C, and the 56 rectangular graphic areas C are arranged to form a rectangular array.

[0019] In one embodiment of the present invention, a plurality of rectangular graphic areas B are provided, and the number of rectangular graphic areas D is the same as the number of rectangular graphic areas B.

[0020] In one embodiment of the present invention, there are N rectangular graphic areas B, where N is an even number greater than or equal to 2, and two sides of the vertical portion are provided with The rectangular graphic area B is parallel to the vertical portion.

[0021] In one embodiment of the present invention, six rectangular graphic areas B are provided.

[0022] In one embodiment of the present invention, the first wire mesh and the second wire mesh are both stainless steel wire meshes, and the first mesh frame and the second mesh frame are both stainless steel mesh frames.

[0023] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0024] 1. The combined stencil for testing the performance of the front silver paste provided by the present invention can achieve simultaneous testing of two key performances: C1-R compatibility and the effect of C1 on the TCR of the resistor R, through the combination of the first stencil and the second stencil, as well as the stencil pattern area patterns and their arrangement.

[0025] 2. The combined stencil for testing the performance of the front silver paste provided by the present invention can simulate the C1-R overlap in the device and can be adapted to special TCR testing equipment. Without the need to make the final product, the influence of C1 on the TCR of the resistor body R can be quickly tested, which greatly speeds up the R&D efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present invention will become more apparent from the detailed description of the non-limiting embodiments with reference to the following drawings:

[0027] Figure 1 This is a schematic diagram of the first screen structure in the present utility model;

[0028] Figure 2 This is a schematic diagram of the second screen structure in the present utility model;

[0029] Figure 3 This is a sample piece after sintering in the embodiment of the present utility model;

[0030] In the figure: first screen 1, first screen frame 2, rectangular graphic area A 3, T-shaped graphic area 4, rectangular graphic area B 5, second screen 6, second screen frame 7, rectangular graphic area C 8, rectangular graphic area D 9. DETAILED DESCRIPTION

[0031] The following examples will help those skilled in the art further understand the present invention, but are not intended to limit the present invention in any way. It should be noted that those skilled in the art may make various changes and improvements without departing from the scope of the present invention. Such changes and improvements are all within the scope of protection of the present invention.

[0032] The present invention will be described in detail below with reference to specific embodiments.

[0033] Example 1

[0034] This embodiment provides a combination stencil for testing the performance of front silver paste, which includes a first stencil and a second stencil. The first stencil and the second stencil are configured to be used together to perform compatibility testing of the front conductive silver paste and the resistor, and resistance temperature coefficient testing of the front conductive silver paste on the resistor.

[0035] The first screen in this embodiment includes:

[0036] First screen 1;

[0037] a first screen frame 2, on which the first screen 1 is tensioned and fixed;

[0038] A first graphic area, wherein the first screen 1 is coated with a photosensitive resin, which is exposed and developed to form the first graphic area; the first graphic area includes a rectangular graphic area A3, a T-shaped graphic area 4 provided within the rectangular graphic area, the T-shaped graphic area 4 including a horizontal portion and a vertical portion, the horizontal portion being parallel to the long side of the rectangular graphic area, and the vertical portion being located on a side of the horizontal portion facing away from the rectangular graphic area; the first graphic area also includes rectangular graphic areas B5 provided on both sides of the vertical portion, with a gap between the horizontal portion and the rectangular graphic area B5;

[0039] The second screen in this embodiment includes:

[0040] Second wire mesh 6;

[0041] A second screen frame 7, on which the second screen 6 is tensioned and fixed;

[0042] The second graphic area, the second screen 6 is coated with a photosensitive resin, and the photosensitive resin is exposed and developed to form the second graphic area; the second graphic area includes at least two rectangular graphic areas C8 matching the rectangular graphic area A3, and a rectangular graphic area D9 for overlapping the horizontal portion and the rectangular graphic area B5, and the at least two rectangular graphic areas C8 are arranged to form a rectangular array.

[0043] In this embodiment, the steps for testing the performance of the front silver paste using the combined stencil are as follows:

[0044] (1) Using the first screen, different types of 2.1C1 slurries (for comparison) were printed on an alumina substrate and then sintered in air;

[0045] (2) Use a second screen to print the same R paste on the alumina substrate that has completed C1 printing and sintering, wherein the rectangular graphic area D 9 is required to overlap the lower part of the horizontal part and the upper part of the rectangular graphic area B 5; the rectangular graphic area C8 is completely printed above the rectangular graphic area A 3, so that at least two rectangular graphic areas C 8 are in overall contact with R, increasing the C1-R contact area and making it easier to observe whether bubbles appear after sintering, and then complete the sintering in an air atmosphere.

[0046] (3) C1-R compatibility test: Observe the number of bubbles in at least two rectangular graphic areas C8 and calculate the bubble ratio to evaluate the compatibility of different C1 to R.

[0047] (4) TCR test: insert the sample after sintering into the fixture of TCR special test equipment, and clamp the T-shaped graphic area 4 and the rectangular graphic area B 5 (such as Figure 3 As shown in the figure, a conductive path similar to the chip resistor C1-R overlap can be achieved. The TCR test of the R sample with completed overlap is performed to evaluate the impact of C1 on the R TCR.

[0048] In this embodiment, there are 56 rectangular graphic areas C 8, and the 56 rectangular graphic areas C 8 are arranged to form a rectangular array.

[0049] In this embodiment, a plurality of rectangular graphic areas B5 are provided, and the number of rectangular graphic areas D9 is the same as the number of rectangular graphic areas B5.

[0050] In the embodiment, there are N rectangular graphic areas B5, where N is an even number greater than or equal to 2, and two sides of the vertical portion are provided with The rectangular graphic areas B 5 are parallel to the vertical portion. Specifically, in this embodiment, there are 6 rectangular graphic areas B 5.

[0051] In one embodiment, the first wire mesh 1 and the second wire mesh 6 are both stainless steel wire meshes, and the first mesh frame 2 and the second mesh frame 7 are both stainless steel mesh frames.

[0052] The following describes the method of using the combined stencil in this application using a specific slurry:

[0053] (1) Using the first screen, different types of C1 paste (for comparison) were printed on an alumina substrate and then sintered in an air atmosphere.

[0054] (2) Use the second screen to print the same R paste on the alumina substrate that has completed C1 printing and sintering. The 56 rectangular graphic areas C 8 graphics are in contact with R as a whole, increasing the C1-R contact area and making it easier to observe whether bubbles appear after sintering. Figure 3 As shown, sintering is then completed in an air atmosphere.

[0055] (3) C1-R compatibility test

[0056] Observe and count the number of bubbles in the 56 rectangles in the upper part of rectangular graphic area D 9 and rectangular graphic area C 8, and calculate the bubble ratio to evaluate the compatibility of different C1 with R

[0057] (4) TCR test

[0058] After sintering, the sample piece is inserted into the fixture of the TCR special test equipment, and the probe clamps the T-shaped pattern area 4 and the rectangular pattern area B 5 (as shown in FIG. Figure 3 As shown in the figure, a conductive path similar to the chip resistor C1-R overlap can be achieved. TCR testing is performed on the six R samples with completed overlap to evaluate the impact of C1 on R TCR.

[0059] C1-R compatibility test results

[0060] This experiment uses two different types and specifications of C1 slurry, numbered 1#, 2#, and 3#, and the same R slurry (control variable). The first and second stencils are used to prepare samples, and the C1-R compatibility and TCR data of C1 are statistically analyzed, as shown in Table 1.

[0061] Table 1

[0062] Sample number Number of foaming samples Normal sample number Foaming ratio 1# 0 56 0％ 2# 3 53 5.4％ 3# 35 21 62.5％

[0063] As shown in Table 1, sample 1# exhibited no blistering, sample 2# exhibited a small amount of blistering, and sample 3# exhibited significant blistering. Comparison revealed that sample 1# exhibited the best sintering compatibility with R, while sample 2# and 3# exhibited poor compatibility. Sample 2#, through extensive printing and increased C1-R contact area, exhibited minimal blistering, successfully achieving identification.

[0064] TCR test results

[0065] In this experimental example, three C1 slurries were used in combination with the same R slurry. Samples were prepared according to the established test method and TCR was tested. The data are shown in Table 2.

[0066] Table 2

[0067] HTCR / ppm 1 2 3 4 5 6 A 358.2329373 355.7462553 362.1605996 360.9441637 353.432645 358.1675979 B 271.0158803 273.4705277 271.8245907 267.8091678 269.3103452 274.8563842 C 688.3300457 676.1131564 668.8779385 666.4433136 660.8049225 666.9909913 CTCR / ppm 1 2 3 4 5 6 A 379.4794366 378.8036845 385.215328 383.8323951 377.11824 381.6288752 B 303.1654423 305.7059662 304.6290592 300.2438579 302.3519506 307.1715067 C 700.8108956 688.6819873 681.795237 679.2503271 673.6441266 679.9439297

[0068] According to the test results, sample B has the smallest HTCR / CTCR, which proves that sample B has the smallest impact on the TCR of R.

[0069] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A composite stencil for testing the performance of front silver paste, characterized in that: The combined stencil comprises a first stencil and a second stencil, wherein the first stencil and the second stencil are configured to be used in conjunction with each other to perform a compatibility test between the front conductive silver paste and the resistor, and a resistance temperature coefficient test between the front conductive silver paste and the resistor; The combined mesh panel includes a first mesh panel and a second mesh panel; The first screen plate includes: First Silk Screen; a first screen frame, on which the first screen is tensioned and fixed; a first graphic region, wherein the first screen is coated with a photosensitive adhesive, which is exposed and developed to form the first graphic region; the first graphic region includes a rectangular graphic region A and a T-shaped graphic region disposed below the rectangular graphic region, the T-shaped graphic region including a horizontal portion and a vertical portion, the horizontal portion being parallel to a long side of the rectangular graphic region, and the vertical portion being located on a side of the horizontal portion facing away from the rectangular graphic region; the first graphic region also includes rectangular graphic regions B disposed on both sides of the vertical portion, with a gap between the horizontal portion and the rectangular graphic region B; The second screen plate includes: Second wire mesh; a second screen frame, on which the second screen is tensioned and fixed; The second graphic area, the second silk screen is coated with a photosensitive resin, and the photosensitive resin is exposed and developed to form the second graphic area; the second graphic area includes at least two rectangular graphic areas C matching the rectangular graphic area A, and a rectangular graphic area D for overlapping the horizontal part and the rectangular graphic area B, and the at least two rectangular graphic areas C are arranged to form a rectangular array.

2. The combined stencil for testing front silver paste performance according to claim 1, characterized in that: There are 56 rectangular graphic areas C, and the 56 rectangular graphic areas C are arranged to form a rectangular array.

3. The combined stencil for testing front silver paste performance according to claim 1, characterized in that: There are multiple rectangular graphic areas B, and the number of rectangular graphic areas D is the same as the number of rectangular graphic areas B.

4. The combined stencil for testing front silver paste performance according to claim 1, characterized in that: The rectangular graphic area B is provided with N, N is an even number greater than or equal to 2, and the vertical portion is provided with The rectangular graphic area B is parallel to the vertical portion.

5. The combined stencil for testing front silver paste performance according to claim 4, characterized in that: There are 6 rectangular graphic areas B.

6. The combined stencil for testing front silver paste performance according to claim 1, characterized in that: The first wire mesh and the second wire mesh are both stainless steel wire meshes, and the first mesh frame and the second mesh frame are both stainless steel mesh frames.

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