Method for testing peel strength of flexible copper-clad foil material of printed circuit

Abstract

The invention discloses a method for testing the peel strength of a flexible copper-clad foil material of a printed circuit, which comprises the following specific steps of: 1, preparing the flexible copper-clad foil material of the printed circuit, and preparing a flexible electrolytic copper foil, a flexible prepreg and a thick electrolytic copper foil for later use; 2, the rough surface of the flexible electrolytic copper foil is combined with the flexible prepreg, and the smooth surface of the thick electrolytic copper foil is combined with the flexible prepreg; and step 3, etching the pressed to-be-tested flexible copper-clad foil material of the printed circuit into a test strip with the width of 3cm, fixing the test strip on a clamp of a measuring system, enabling the end of the test strip to be positioned at a vertical position, and testing the anti-stripping strength through vertical stretching. According to the method, through a physical method, the copper foil with sufficient strength and the flexible copper foil to be tested are pressed together during pressing, a traditional clamping plate and a traditional double-sided adhesive tape are replaced, the test accuracy is not affected, and test data are better in stability and can better represent the anti-stripping level of the flexible copper-clad foil material of the printed circuit.

Description

Technical Field

[0001] The invention relates to the technical field of copper foil, in particular to a method for testing the peeling strength of a flexible copper foil material for a printed circuit. Background Art

[0002] Copper foil is an indispensable part of flexible copper clad laminate as a cost-effective conductive material. Copper foil manufacturers need to accurately test the peel strength of flexible copper foil to ensure that the quality of the copper foil they produce meets customer requirements. At present, most companies use clamps or double-sided tape to fix the flexible copper clad laminate on a rigid material, and then test its vertical peel strength. When the clamp and the flexible copper clad foil material of the printed circuit to be tested slide against each other, or the double-sided tape has insufficient adhesion, the flexible copper clad foil material of the printed circuit to be tested is separated from the rigid material that fixes it, the accuracy of the peel strength test will be affected. This method uses a physical method to use a copper foil with sufficient strength to press together with the flexible copper foil to be tested, replacing the clamp and double-sided tape, and will not affect the accuracy of the test. Summary of the invention

[0003] The object of the present invention is to provide a method for testing the peel strength of a flexible copper-clad foil material for a printed circuit. The specific steps of the method for testing the peel strength of a flexible copper-clad foil material for a printed circuit are as follows:

[0004] Step 1: Preparation of flexible copper-clad foil material for printed circuits: prepare flexible electrolytic copper foil, flexible prepreg, and thick electrolytic copper foil for standby use;

[0005] Step 2, the matte surface of the flexible electrolytic copper foil is combined with the flexible prepreg, and the smooth surface of the thick electrolytic copper foil is combined with the flexible prepreg, and they are pressed into a printed circuit flexible copper clad foil material by vacuum pressing;

[0006] Step 3: Etch the laminated flexible copper-clad foil material of the printed circuit to be tested into a test strip with a width of 3 cm, fix the test strip on the fixture of the measurement system, with the end of the test strip in a vertical position, and perform vertical tensile testing on the peel strength.

[0007] Preferably, the thickness of the flexible prepreg is 3-20 μm, and the number of laminated layers of the flexible prepreg is 2-5; the thickness of the thick electrolytic copper foil is ≥175 μm, and the number of laminated layers is 1.

[0008] Preferably, the thickness of the flexible electrolytic copper foil is 8-25 μm, and the flexible prepreg is a polyester, polyimide or polyfluorine film.

[0009] Preferably, the flexible prepreg, the flexible electrolytic copper foil and the thick electrolytic copper foil are 20*20 cm in size.

[0010] Preferably, the peel strength is tested by vertical tensile testing at a speed of 50 mm / min.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention uses a physical method to use a copper foil with sufficient strength to be pressed together with the flexible copper foil to be tested during pressing, replacing the traditional plywood and double-sided tape, and will not affect the accuracy of the test. The test data has better stability and can better represent the anti-peeling level of the flexible copper foil material of the printed circuit board. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0013] Example 1

[0014] A flexible copper foil with a thickness of 12μm, two layers of 12μm polyimide film and a thick electrolytic copper foil with a thickness of 205μm are placed. The smooth surface of the thick electrolytic copper foil is in contact with the polyimide film. The flexible copper clad laminate is pressed into a flexible copper clad laminate by vacuum pressing. Then the flexible copper clad laminate is covered with etching tape on the surface of the thick electrolytic copper foil and the sample to be tested. The laminate is placed in an etching machine, and the pattern to be tested and the thick electrolytic copper foil layer are retained. The sample to be tested is etched into 10 strips of 3mm*20cm in size. The test strips are fixed on the fixture of the measurement system, with the ends of the test strips in a vertical position. The peel strength is tested by vertical tensile testing at a speed of 50mm / min. The test data is as follows:

[0015]

[0016]

[0017] Example 2

[0018] This embodiment is different from the embodiment 1 in that the thickness of the flexible copper foil is 18 μm, and the thickness of the polyimide film is 30 μm. The test data are as follows:

[0019]

[0020] Comparative Example 1

[0021] This comparative example is different from Example 1 in that the pressing plate does not use 205 μm thick electrolytic copper foil. After the winding copper clad laminate is pressed by vacuum pressing, the flexible copper clad laminate is covered with etching tape on the surface of the thick electrolytic copper foil and the sample strip to be tested, and placed in an etching machine to retain the pattern to be tested. The sample strip to be tested is etched into 10 strips of 3 mm*20 cm in size, and the test strip is fixed on the fixture of the measurement system. The end of the test strip is in a vertical position, and the peel strength is tested at a speed of 50 mm / min. The test data are as follows:.

[0022] The test data is as follows:

[0023]

[0024]

[0025] By comparing the test data of the embodiment and the comparative example, it can be known that compared with the comparative example, the embodiment uses a physical method to press the copper foil with sufficient strength together with the flexible copper foil to be tested during pressing, replacing the traditional plywood and double-sided tape, and will not affect the accuracy of the test. The test data stability is better and can better represent the anti-peeling level of the flexible copper clad foil material of the printed circuit.

[0026] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for testing the peel strength of flexible copper-clad foil materials for printed circuits, characterized in that: The specific steps of the test method for the peel strength of the printed circuit flexible copper foil material are as follows: Step 1: Preparation of flexible copper-clad foil material for printed circuits: prepare flexible electrolytic copper foil, flexible prepreg, and thick electrolytic copper foil for standby use; Step 2, the matte surface of the flexible electrolytic copper foil is combined with the flexible prepreg, and the smooth surface of the thick electrolytic copper foil is combined with the flexible prepreg, and they are pressed into a printed circuit flexible copper clad foil material by vacuum pressing; Step 3: Etch the laminated flexible copper-clad foil material of the printed circuit to be tested into a test strip with a width of 3 cm, fix the test strip on the fixture of the measurement system, with the end of the test strip in a vertical position, and perform vertical tensile testing on the peel strength.

2. The method for testing the peel strength of a printed circuit flexible copper-clad foil material according to claim 1, characterized in that: The thickness of the flexible prepreg is 3-20 μm, and the number of laminated layers of the flexible prepreg is 2-5.

3. The method for testing the peel strength of a printed circuit flexible copper-clad foil material according to claim 1, characterized in that: The thickness of thick electrolytic copper foil is ≥175μm, and the number of laminated layers is 1.

4. The method for testing the peel strength of a printed circuit flexible copper-clad foil material according to claim 1, characterized in that: The thickness of the flexible electrolytic copper foil is 8-25 μm, and the flexible semi-cured sheet is a polyester, polyimide and polyfluorine film.

5. The method for testing the peel strength of a printed circuit flexible copper clad foil material according to claim 1, characterized in that: The sizes of the flexible prepreg, the flexible electrolytic copper foil and the thick electrolytic copper foil are 20*20 cm.

6. The method for testing the peel strength of a printed circuit flexible copper clad foil material according to claim 1, characterized in that: During the test, the peel strength was tested at a vertical tensile speed of 50 mm / min.

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