Method for manufacturing copper clad laminate sample for CTE test and CTE test method

Abstract

The application discloses a manufacturing method of a copper-clad plate sample for testing CTE, and adopts a step-by-step pressing method to obtain a copper-clad plate sample for testing CTE with a larger thickness in X / Y directions, so that the copper-clad plate sample for testing CTE with a sufficient thickness can be obtained, and errors can be avoided when pressing multiple layers of prepreg during the manufacturing process of the sample, and the method is simple, convenient, efficient, and low in cost. The application further discloses a copper-clad plate X / Y direction CTE testing method.

Description

TECHNICAL FIELD

[0001] The present application relates to the production and manufacturing technology of copper-clad plate, in particular to a manufacturing method of copper-clad plate sample for testing CTE and a copper-clad plate X / Y direction CTE testing method. BACKGROUND

[0002] As an important raw material for preparing PCB (printed circuit board), many physical properties of copper-clad plate will be focused on to meet the job title or needs of PCB or downstream industry. Among them, the X / Y direction CTE (coefficient of thermal expansion) is one of the important thermal properties. This thermal property will play a decisive role in the heat resistance, stability, reliability and other properties of the material in PCB. In many special applications such as mini LED substrate, IC carrier plate, etc., the requirement of X / Y direction CTE will be very high. Therefore, in the copper-clad plate industry, we need a stable and fast measurement method to more efficiently obtain this thermal property.

[0003] In the current copper-clad plate industry, the instrument for testing CTE is usually TMA (thermal mechanical analyzer). In this instrument, by matching different clamps and programs, the CTE in Z direction or X / Y direction can be obtained. However, in the actual operation process, various problems will occur, which will greatly reduce the test efficiency.

[0004] (1) If the copper-clad plate samples prepared in advance are the same, which are small thin small cubes (4mm*4mm*1mm), two different clamps need to be used to obtain the CTE in Z direction and X / Y direction respectively. The compression clamp of TMA can directly obtain the CTE in Z direction. If the special tensile clamp for X / Y direction is used, the original compression clamp of TMA needs to be disassembled, the special tensile clamp for X / Y direction needs to be installed and calibrated before the test can be carried out, which will greatly prolong the test time. Moreover, the price of a new special tensile clamp for X / Y direction is not cheap, and the cost is too high.

[0005] (2) According to IPC-TM650, if the general clamp is used to test the CTE in X / Y direction, the sample needs to be placed horizontally, and the CTE in two directions needs to be measured respectively. In this case, the thickness of the sample needs to be increased to at least 4mm. For low CTE (low thermal expansion coefficient) cloth species mainly using thin glass cloth, at least 60 layers or more need to be laminated. If the traditional press and method are used, the phenomenon of slipping plate or pressure loss is easy to occur. SUMMARY

[0006] The present application aims to provide a manufacturing method of copper-clad plate sample for testing CTE, which can obtain copper-clad plate sample for testing CTE with sufficient thickness, avoid errors in pressing multi-layer prepreg during sample manufacturing, and has the advantages of simplicity, convenience, high efficiency and low cost.

[0007] To solve the above technical problems, the present application provides a manufacturing method of copper-clad plate sample for testing CTE, which comprises the following steps:

[0008] S1. cutting raw prepreg to obtain M*N+(M-1)*H pieces of sample prepreg with the same size, 2M<N, 2H<N, M is an integer greater than 1, N is an integer greater than 8, and H is a positive integer;

[0009] S2. dividing the M*N pieces of sample prepreg into M portions of stacked prepreg, each portion of stacked prepreg being stacked by N pieces of sample prepreg;

[0010] S3. covering the upper and lower sides of each portion of stacked prepreg with isolation film, and performing vacuum hot pressing to obtain M pieces of stacked prepreg blanks;

[0011] S4. removing the isolation film on the upper and lower sides of each stacked prepreg blank;

[0012] S5. stacking the M pieces of stacked prepreg blanks with removed isolation film and (M-1)*H pieces of sample prepreg together, and stacking H pieces of sample prepreg between adjacent two stacked prepreg blanks with removed isolation film to form M*N+(M-1)*H layers of stacked prepreg;

[0013] S6. covering the upper and lower sides of the M*N+(M-1)*H layers of stacked prepreg with copper foil, and performing vacuum hot pressing again to obtain a copper-clad plate sample;

[0014] S7. vertically cutting the copper-clad plate sample to obtain at least two copper-clad plate samples for testing CTE.

[0015] Preferably, in step S3, copper foil is used as the isolation film, and the copper foil is attached to the upper and lower sides of each portion of stacked prepreg, with the smooth surface of the copper foil attached to the prepreg and the rough surface of the copper foil facing outward.

[0016] In step S6, the rough surface of the copper foil is attached to the prepreg, and the smooth surface of the copper foil faces outward.

[0017] Preferably, the raw prepreg is made of electronic-grade glass fiber cloth.

[0018] The thickness of the electronic-grade glass fiber cloth is 36 μm to 100 μm.

[0019] Preferably, 3≤M≤6, 10≤N≤40, and 1≤H≤5.

[0020] Preferably, M is 4, N is 20, and H is 2.

[0021] Preferably, in step S7, the copper-clad plate sample is vertically cut to obtain a plurality of copper-clad plate samples for testing CTE, each having a transverse size of 4mm*4mm.

[0022] Preferably, the copper-clad plate sample has a thickness of 3.5mm-6mm.

[0023] The application also discloses a method for testing CTE of a copper-clad plate in X / Y directions, which uses a universal clamp at a testing end of a thermal mechanical analyzer to test the copper-clad plate sample for testing CTE obtained by the manufacturing method of any one of claims 1-8, so as to obtain CTE of the copper-clad plate in X / Y directions.

[0024] The manufacturing method of the copper-clad plate sample for testing CTE uses a step-by-step pressing method to obtain a copper-clad plate sample for testing CTE of X / Y directions and having a larger thickness, so as to obtain a copper-clad plate sample for testing CTE with a sufficient thickness and to avoid errors in pressing multiple layers of prepreg during the manufacturing process of the sample, and the method is simple, convenient, efficient and low in cost. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the present application, the drawings used in the present application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0026] Figure 1 is a flowchart of an embodiment of the manufacturing method of the copper-clad plate sample for testing CTE of the present application. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0028] The terms "first", "second", and similar terms used herein do not denote any order, quantity, or importance, but are used to distinguish different components. The terms "include", "contain", and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, without excluding other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", "front", "back", and the like are used only to indicate relative positional relationships, which can change when the absolute positions of the described objects change.

[0029] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0030] Embodiment one: as shown in a manufacturing method of a copper-clad plate sample for testing CTE, comprising the following steps: Figure 1

[0031] S1. Cutting a raw material prepreg to obtain M*N+(M-1)*H pieces of sample prepregs with the same size, 2M<N, 2H<N, M is an integer greater than 1, N is an integer greater than 8, and H is a positive integer;

[0032] S2. Divide the M*N pieces of sample prepregs into M portions of laminated prepregs, each portion of laminated prepregs being stacked by N pieces of sample prepregs;

[0033] S3. Cover the upper and lower sides of each portion of laminated prepregs with a release film, and perform vacuum hot pressing to obtain M pieces of laminated prepreg blanks;

[0034] S4. Remove the release film on the upper and lower sides of each laminated prepreg blank;

[0035] S5. Stack the M pieces of laminated prepreg blanks with the release film removed and (M-1)*H pieces of sample prepregs together, and stack H pieces of sample prepregs between adjacent two laminated prepreg blanks with the release film removed, to form a laminated prepreg with M*N+(M-1)*H layers;

[0036] S6. Cover the upper and lower sides of the laminated prepreg with M*N+(M-1)*H layers with a copper foil, and perform vacuum hot pressing again to obtain a copper-clad plate sample;

[0037] S7. Vertically cut the copper-clad plate sample to obtain at least two copper-clad plate samples for testing CTE.

[0038] ​The manufacturing method of the test CTE copper-clad plate sample of embodiment one uses a step-by-step pressing method to obtain a test CTE copper-clad plate sample with a larger thickness for testing the thermal expansion coefficient (CTE) in the X / Y direction. This method can obtain a test CTE copper-clad plate sample with sufficient thickness, avoid errors during the pressing of multiple layers of prepreg during the sample preparation process, and is simple, convenient, efficient, and low-cost.

[0039] Embodiment two: Based on the manufacturing method of the test CTE copper-clad plate sample of embodiment one, in step S3, copper foil is used as the isolation film, and copper foil is attached to the upper and lower sides of each layer of prepreg, with the smooth surface of the copper foil attached to the prepreg and the rough surface of the copper foil facing outward.

[0040] In step S6, the rough surface of the copper foil is attached to the prepreg, and the smooth surface of the copper foil faces outward.

[0041] The manufacturing method of the test CTE copper-clad plate sample of embodiment two, during the preparation of the prepreg stack, copper foil is attached to the upper and lower sides of each layer of prepreg in the opposite direction, which facilitates manual removal of the copper foil after vacuum heat pressing and saves the etching step. Moreover, as the isolation film, the copper foil is less likely to absorb impurities, which can prevent impurities from being introduced onto the surface of the prepreg during the preparation of the prepreg stack, thereby avoiding errors in the CTE test results of the test CTE copper-clad plate sample.

[0042] Embodiment three: Based on the manufacturing method of the test CTE copper-clad plate sample of embodiment one, the raw prepreg is made of electronic-grade glass fiber cloth.

[0043] The thickness of the electronic-grade glass fiber cloth is 36 μm to 100 μm.

[0044] For example, the raw prepreg can be made of Low CTE thin cloth T1067.

[0045] Embodiment four: Based on the manufacturing method of the test CTE copper-clad plate sample of embodiment one, 3 ≤ M ≤ 6, 10 ≤ N ≤ 40, and 1 ≤ H ≤ 5.

[0046] Preferably, M is 4, N is 20, and H is 2.

[0047] Embodiment five: Based on the manufacturing method of the test CTE copper-clad plate sample of embodiment one, in step S7, the copper-clad plate sample is vertically cut to obtain multiple test CTE copper-clad plate samples with a horizontal size of 4 mm * 4 mm.

[0048] Preferably, the thickness of the copper-clad plate sample is 3.5 mm to 6 mm.

[0049] The method for testing the X / Y direction CTE of the copper-clad plate by using the test CTE copper-clad plate sample obtained by the manufacturing method of embodiments 1 to 5, and the general fixture is used at the TMA (thermal mechanical analyzer) test end, the X / Y direction CTE of the test CTE copper-clad plate sample is tested, and the X / Y direction CTE of the copper-clad plate is obtained.

[0050] The X / Y direction CTE test method of the copper-clad plate of embodiment 6 uses the general fixture at the TMA (thermal mechanical analyzer) test end, does not need to replace the fixture, does not need to additionally purchase the customized fixture or instrument, reduces the test cost, and improves the test efficiency.

[0051] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of manufacturing a test CTE copper clad laminate sample, characterized by, It comprises the following steps: S1. Cutting the raw material prepreg to obtain M*N+(M-1)*H pieces of sample prepregs with the same size, 2M<N, 2H<N, M is an integer greater than 1, N is an integer greater than 8, and H is a positive integer; S2. Divide the M*N pieces of sample prepregs into M portions of laminated prepregs, each portion of laminated prepreg being stacked by N pieces of sample prepregs; S3. Cover the upper and lower sides of each portion of laminated prepreg with a release film respectively, and perform vacuum hot pressing to obtain M laminated prepreg blanks; S4. Remove the release film on the upper and lower sides of each laminated prepreg blank; S5. Stack the M laminated prepreg blanks with the release film removed and (M-1)*H pieces of sample prepregs together, and stack H pieces of sample prepregs between adjacent two laminated prepreg blanks with the release film removed to form a laminated prepreg with M*N+(M-1)*H layers; S6. Cover the upper and lower sides of the laminated prepreg with M*N+(M-1)*H layers with a copper foil respectively, and perform vacuum hot pressing again to obtain a copper-clad plate sample; S7. Vertically cut the copper-clad plate sample to obtain at least two test CTE copper-clad plate samples.

2. The manufacturing method of the test CTE copper-clad plate sample according to claim 1, characterized in that, in step S3, the copper foil is used as the release film, and the copper foil is attached to the upper and lower sides of each portion of laminated prepreg, the shiny surface of the copper foil is attached to the prepreg, and the matte surface of the copper foil faces outward; in step S6, the matte surface of the copper foil is attached to the prepreg, and the shiny surface of the copper foil faces outward.

3. The manufacturing method of the test CTE copper-clad plate sample according to claim 1, characterized in that, the raw material prepreg is made of an electronic-grade glass fiber cloth; the thickness of the electronic-grade glass fiber cloth is 36 μm to 100 μm.

4. The manufacturing method of the test CTE copper-clad plate sample according to claim 1, characterized in that, 3≤M≤6, 10≤N≤40, 1≤H≤5.

5. The manufacturing method of the test CTE copper-clad plate sample according to claim 4, characterized in that, M is 4, N is 20, and H is 2.

6. The manufacturing method of the test CTE copper-clad plate sample according to claim 1, characterized in that, in step S7, the copper-clad plate sample is vertically cut to obtain a plurality of test CTE copper-clad plate samples with a transverse size of 4 mm*4 mm.

7. The manufacturing method of the test CTE copper-clad plate sample according to claim 1, characterized in that, the thickness of the copper-clad plate sample is 3.5 mm to 6 mm.

8. A copper clad board X / Y direction CTE test method, characterized in that, The test CTE copper-clad plate sample obtained by the manufacturing method according to any one of claims 1 to 7 is tested by using a universal clamp at the test end of a thermal mechanical analyzer to obtain the CTE of the copper-clad plate in X / Y directions.

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