Copper clad laminate inter-board peel strength test method

Abstract

The present invention discloses a method for testing the inter-board peel strength of copper-clad laminates (CCLs). The method employs a unique adhesive method combining single-sided tape, thin tape, and strong double-sided tape to secure a CCL sample to the loading platform of a tensile testing machine. The single-sided tape facilitates keeping the loading platform surface of the tensile testing machine clean, while the thin tape facilitates removal of the double-sided tape, which stabilizes the CCL sample. The CCL inter-board peel strength testing method can effectively and stably secure the CCL sample, allowing for rapid cleaning and repeated testing. The CCL inter-board peel strength testing method can be implemented using a small tensile testing machine, significantly improving the efficiency of CCL inter-board peel strength testing and reducing testing costs.

Description

Technical Field

[0001] The present invention relates to a copper clad laminate testing technology, in particular to a method for testing the inter-board peeling strength of copper clad laminates. Background Art

[0002] Copper-clad laminate (CCL), also known as copper-clad laminate (CCL), is a prepreg (PP) made by impregnating a reinforcing material with resin and baking it at high temperature to form a solid. After slicing, one or more prepregs are laminated together, covered with copper foil on one or both sides, and then hot-pressed. It is primarily used in the manufacture of printed circuit boards (PCBs). Multiple PCBs are pressed together with prepreg to form a multilayer circuit board.

[0003] Current metal-clad laminates are mostly reinforced with electronic-grade fiberglass cloth. When manufacturing multi-layer laminates, the bond strength between the resin and the fiberglass cloth in the finished product is a crucial property. In laminates, which serve as the raw material for PCBs, a critical interface is the one between the resin and the fiberglass cloth. This interface is prone to failure (delamination, CAF) during subsequent PCB fabrication or in the finished PCB. To enhance the bond between the resin and the fiberglass cloth, current processes primarily use surface treatments (silane coupling agents) on the fiberglass cloth and treatments within the resin to achieve this.

[0004] After the finished multilayer board is manufactured, a method is needed to test the peel strength between the boards to determine the bond strength between the resin and the fiberglass cloth in the finished product. The data provided by the bond strength between the copper clad boards provides important guidance for the raw materials and processing of the laminate.

[0005] In terms of test methods and conditions, most current tests follow IPC TM 650 2.4.8 Copper Foil Peel Strength Test for Copper Clad Laminates, such as tensile speed. However, the specific methods differ greatly from the peel strength test, so more detailed methods need to be developed based on actual conditions.

[0006] Based on industry experience, most tensile tests are performed on tensile testing machines. The advantage of large tensile testing machines lies primarily in their accuracy. Connecting the machine to computer software allows real-time monitoring of the tensile force at each deformation stage, resulting in more accurate values. However, one disadvantage is the large number of steps involved. Since tensile testing machines are often used for multiple types of tests, each requiring different components, operators often need to replace components, increasing the number of steps required. Furthermore, large tensile testing machines are expensive and prone to mechanical issues that affect accuracy, making them difficult to repair and resulting in test delays.

[0007] In addition, the procedure for placing samples is also very different when conducting interlayer peel strength tests. Different from the peel test of copper foil, when conducting interlayer peel strength tests, the sample needs to be fixed on the flat plate in some way, and the fixing force cannot act on both sides of the sample. Therefore, using glue to fix the sample is a common method. Different types of glue have different degrees of influence on the fixing strength, fixing time and cleaning difficulty of the sample. Liquid glue such as 502 has the disadvantages of long curing time and difficulty in cleaning. Ordinary double-sided tape will have insufficient adhesion, and it will also take a lot of time to clean the double-sided tape. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a method for testing the peel strength between copper clad laminates, which can effectively and stably fix the copper clad laminate samples, and can be quickly cleaned and repeatedly tested, thereby greatly improving the efficiency of the peel strength test between copper clad laminates and reducing the test cost.

[0009] In order to solve the above technical problems, the present invention provides a method for testing the peel strength between copper clad laminates, which comprises the following steps:

[0010] S1. Prepare a tensile testing machine comprising a loading platform, a fixture, a drive device, and a force sensor; the loading platform has a loading surface on its upper surface; the drive device is used to drive the fixture to move up and down and left and right relative to the loading surface; the force sensor is used to detect the tension applied to the fixture;

[0011] Prepare a copper clad laminate sample. The copper clad laminate sample is long and has an even number of layers. The middle adjacent layer of the right section of the copper clad laminate sample in the length direction is separated to form a right section upper layer and a right section lower layer. The middle section and the left section are kept together. The length of the right section is 1 / 5 to 1 / 3 of the length of the copper clad laminate sample.

[0012] S2. Apply a rectangular layer of single-sided tape to the loading surface of the loading platform. The length of the single-sided tape should be greater than the length of the copper-clad laminate sample, and the width should be greater than the length of the copper-clad laminate sample.

[0013] S3. Attach two thin tapes to the single-sided tape; attach a layer of double-sided tape to the single-sided tape and the two thin tapes, with the lengths of the single-sided tape, the thin tape, and the double-sided tape all being in the left-right direction; the single-sided tape and the double-sided tape have the same shape and overlap, the thin tape being longer than the single-sided tape and having a width of 1 / 10 to 1 / 3 the width of the single-sided tape;

[0014] S4. The right end of the upper right section of the copper clad laminate sample is fixed to the clamp of the tensile machine, and the lower side of the copper clad laminate is attached to the double-sided tape as a whole, so that the copper clad laminate sample is fixed to the loading platform along the left and right directions;

[0015] S5. The driving device drives the clamp to move, so that the right end of the upper right section of the copper clad laminate sample is pulled upward, and the right section of the upper right section of the copper clad laminate sample is perpendicular to the lower right section of the copper clad laminate sample;

[0016] S6. The driving device drives the clamp to move vertically upward at a set speed, and the force sensor detects the vertical tension applied to the clamp and outputs the inter-board peel strength value of the copper clad laminate sample currently being tested;

[0017] S7. Remove the copper clad laminate sample currently being tested, remove the double-sided tape and thin tape, and proceed to step S3 if continuing the test.

[0018] Preferably, in step S7, after taking down the copper clad laminate sample currently being tested and removing the double-sided tape and the thin tape, if the test is finished, the single-sided tape on the loading surface of the loading platform is removed.

[0019] Preferably, in step S6, the force sensor detects the stable vertical tensile force applied to the fixture as the inter-board peeling strength value of the copper clad laminate sample currently being tested.

[0020] Preferably, the loading plane of the loading platform is rectangular, and the length of the rectangular loading plane is greater than the length of the single-sided tape, and the width is greater than the width of the single-sided tape.

[0021] Preferably, the length of the thin tape is 1.02 to 1.2 times the length of the rectangular single-sided tape.

[0022] Preferably, the single-sided tape is a transparent tape.

[0023] Preferably, the copper clad laminate sample is in the shape of a 50mm*12.7mm strip.

[0024] Preferably, the set speed is 50.8 mm / min.

[0025] Preferably, a blade or a shovel is used to separate the adjacent layers in the middle of the right section in the length direction of the copper clad laminate sample.

[0026] The present invention's inter-board peel strength testing method for copper-clad laminates utilizes a unique adhesive method combining single-sided tape, thin tape, and strong double-sided tape to secure copper-clad laminate samples to the loading platform of a tensile testing machine. The single-sided tape helps keep the loading platform surface of the tensile testing machine clean, while the thin tape facilitates removal of the double-sided tape, which stabilizes the copper-clad laminate sample. This inter-board peel strength testing method can effectively and stably secure the copper-clad laminate sample, allowing for rapid cleaning and repeated testing. This inter-board peel strength testing method can be implemented using a small tensile testing machine, significantly improving the efficiency of inter-board peel strength testing for copper-clad laminates and reducing testing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 The present invention is a flow chart of an embodiment of a method for testing the peel strength between copper clad laminates. DETAILED DESCRIPTION

[0029] The following is a clear and complete description of the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0030] Example 1

[0031] like Figure 1 As shown, the inter-board peel strength test method of copper clad laminates includes the following steps:

[0032] S1. Prepare a tensile testing machine comprising a loading platform, a fixture, a drive device, and a force sensor; the loading platform has a loading surface on its upper surface; the drive device is used to drive the fixture to move up and down and left and right relative to the loading surface; the force sensor is used to detect the tension applied to the fixture;

[0033] Prepare a copper clad laminate sample. The copper clad laminate sample is long and has an even number of layers. The middle adjacent layer of the right section of the copper clad laminate sample in the length direction is separated to form a right section upper layer and a right section lower layer. The middle section and the left section are kept together. The length of the right section is 1 / 5 to 1 / 3 of the length of the copper clad laminate sample.

[0034] S2. Apply a rectangular layer of single-sided tape to the loading surface of the loading platform. The length of the single-sided tape should be greater than the length of the copper-clad laminate sample, and the width should be greater than the length of the copper-clad laminate sample.

[0035] S3. Attach two thin tapes to the single-sided tape; attach a layer of double-sided tape to the single-sided tape and the two thin tapes, with the lengths of the single-sided tape, the thin tape, and the double-sided tape all being in the left-right direction; the single-sided tape and the double-sided tape have the same shape and overlap, the thin tape being longer than the single-sided tape and having a width of 1 / 10 to 1 / 3 the width of the single-sided tape;

[0036] S4. The right end of the upper right section of the copper clad laminate sample is fixed to the clamp of the tensile machine, and the lower side of the copper clad laminate is attached to the double-sided tape as a whole, so that the copper clad laminate sample is fixed to the loading platform along the left and right directions;

[0037] S5. The driving device drives the clamp to move, so that the right end of the upper right section of the copper clad laminate sample is pulled upward, and the right section of the upper right section of the copper clad laminate sample is perpendicular to the lower right section of the copper clad laminate sample;

[0038] S6. The driving device drives the clamp to move vertically upward at a set speed, and the force sensor detects the vertical tension applied to the clamp and outputs the inter-board peel strength value of the copper clad laminate sample currently being tested;

[0039] S7. Remove the copper clad laminate sample currently being tested, remove the double-sided tape and thin tape, and proceed to step S3 if continuing the test.

[0040] The copper-clad laminate inter-board peel strength test method of Example 1 uses a unique adhesive method combining single-sided tape, thin tape, and strong double-sided tape to secure the copper-clad laminate sample to the loading platform of the tensile testing machine. The single-sided tape helps keep the surface of the tensile testing machine's loading platform clean, while the thin tape makes the double-sided tape easy to remove. The double-sided tape can stabilize the copper-clad laminate sample. This copper-clad laminate inter-board peel strength test method can effectively and stably secure the copper-clad laminate sample and can be quickly cleaned and repeatedly tested. This copper-clad laminate inter-board peel strength test method can be performed using a small tensile testing machine, significantly improving the efficiency of copper-clad laminate inter-board peel strength testing and reducing testing costs.

[0041] Example 2

[0042] Based on the inter-board peel strength test method of the copper clad laminate of Example 1, in step S7, the copper clad laminate sample currently being tested is removed, and after the double-sided tape and the thin tape are removed, if the test is completed, the single-sided tape on the loading surface of the loading platform is removed.

[0043] Preferably, in step S6, the force sensor detects the stable vertical tensile force applied to the fixture as the inter-board peeling strength value of the copper clad laminate sample currently being tested.

[0044] Preferably, the loading plane of the loading platform is rectangular, and the length of the rectangular loading plane is greater than the length of the single-sided tape, and the width is greater than the width of the single-sided tape.

[0045] Preferably, the length of the thin tape is 1.02 to 1.2 times the length of the rectangular single-sided tape.

[0046] Preferably, the single-sided tape is a transparent tape.

[0047] Preferably, the copper clad laminate sample is in the shape of a 50mm*12.7mm strip with a small area, which is convenient for repeated sampling and repeated testing, and reduces waste.

[0048] Preferably, the set speed is 50.8 mm / min.

[0049] Preferably, a blade or a shovel is used to separate the adjacent layers in the middle of the right section in the length direction of the copper clad laminate sample.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for testing the peel strength between copper clad laminates, characterized in that: It includes the following steps: S1. Prepare a tensile testing machine comprising a loading platform, a fixture, a drive device, and a force sensor; the loading platform has a loading surface on its upper surface; the drive device is used to drive the fixture to move up and down and left and right relative to the loading surface; the force sensor is used to detect the tension applied to the fixture; Prepare a copper clad laminate sample. The copper clad laminate sample is long and has an even number of layers. The middle adjacent layer of the right section of the copper clad laminate sample in the length direction is separated to form a right section upper layer and a right section lower layer. The middle section and the left section are kept together. The length of the right section is 1 / 5 to 1 / 3 of the length of the copper clad laminate sample. S2. Apply a rectangular layer of single-sided tape to the loading surface of the loading platform. The length of the single-sided tape should be greater than the length of the copper-clad laminate sample, and the width should be greater than the length of the copper-clad laminate sample. S3. Attach two thin tapes to the single-sided tape; attach a layer of double-sided tape to the single-sided tape and the two thin tapes, with the lengths of the single-sided tape, the thin tape, and the double-sided tape all being in the left-right direction; the single-sided tape and the double-sided tape have the same shape and overlap, the thin tape being longer than the single-sided tape and having a width of 1 / 10 to 1 / 3 the width of the single-sided tape; S4. The right end of the upper right section of the copper clad laminate sample is fixed to the clamp of the tensile machine, and the lower side of the copper clad laminate is attached to the double-sided tape as a whole, so that the copper clad laminate sample is fixed to the loading platform along the left and right directions; S5. The driving device drives the clamp to move, so that the right end of the upper right section of the copper clad laminate sample is pulled upward, and the right section of the upper right section of the copper clad laminate sample is perpendicular to the lower right section of the copper clad laminate sample; S6. The driving device drives the clamp to move vertically upward at a set speed, and the force sensor detects the vertical tension applied to the clamp and outputs the inter-board peel strength value of the copper clad laminate sample currently being tested; S7. Remove the copper clad laminate sample currently being tested, remove the double-sided tape and thin tape, and proceed to step S3 if continuing the test.

2. The method for testing the peel strength between copper clad laminates according to claim 1, wherein: In step S7, the copper clad laminate sample currently being tested is taken down, and after the double-sided tape and the thin tape are removed, if the test is finished, the single-sided tape on the loading surface of the loading platform is removed.

3. The method for testing the peel strength between copper clad laminates according to claim 1, wherein: In step S6, the stable vertical tensile force applied to the clamp by the force sensor is detected as the inter-board peeling strength value of the copper clad laminate sample currently being tested.

4. The method for testing the peel strength between copper clad laminates according to claim 1, wherein: The loading plane of the loading platform is rectangular, and the length of the rectangular loading plane is greater than the length of the single-sided tape, and the width is greater than the width of the single-sided tape.

5. The method for testing the peel strength between copper clad laminates according to claim 1, wherein: The length of the thin tape is 1.02 to 1.2 times the length of the rectangular single-sided tape.

6. The method for testing the peel strength between copper clad laminates according to claim 1, wherein: The single-sided tape is a transparent tape.

7. The method for testing the peel strength between copper clad laminates according to claim 1, wherein: The copper clad laminate sample is in the shape of a 50mm*12.7mm strip.

8. The method for testing the peel strength between copper clad laminates according to claim 1, wherein: The set speed is 50.8 mm / min.

9. The method for testing the peel strength between copper clad laminates according to claim 1, wherein: Use a blade or shovel to separate the adjacent layers in the middle of the right section of the copper clad laminate sample in the length direction.

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