Preparation method of high-gauge-safety low-warping single-sided flexible copper-clad plate

Abstract

The invention discloses a preparation method of a high-gauge-safety low-warping single-sided flexible copper-clad plate. The method comprises the following steps: S1, sequentially laminating a copper foil, a dielectric layer, a release film, a dielectric layer and a copper foil, and performing high-temperature pressing to prepare a double-sided flexible copper-clad plate; and S2, performing release treatment on the double-sided flexible copper-clad plate prepared in the step S1 to obtain the single-sided flexible copper-clad plate. In the step S1, the temperature of high-temperature pressing is 330-380 DEG C; the pressure of the high-temperature pressing is 2 to 5 MPa. The single-sided flexible copper-clad plate prepared by the method disclosed by the invention is good in dimensional stability and not easy to warp, and the method is easy to implement and can be used for mass production.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic materials, and in particular relates to a method for preparing a high-security and low-warpage single-sided flexible copper-clad laminate. Background Art

[0002] For circuit board materials with simple design and small footprint, single-sided flexible copper-clad laminates are used for easy layout, short production cycle and low cost. Single-sided flexible copper-clad laminates are composed of copper foil and dielectric layer, and are prepared by high-temperature pressing of the dielectric layer and copper foil. When this method is used to prepare single-sided flexible copper-clad laminates, since the dielectric layer is in a molten state during pressing, it is easy to cause problems such as contamination of production equipment, warping of product appearance, and unqualified physical properties of the copper-clad laminates. Therefore, it cannot meet the processing and application requirements of downstream printed circuit boards (PCBs) for such products.

[0003] Therefore, it is very important to provide a method for preparing a single-sided flexible copper clad laminate with low warpage and high dimensional stability. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a single-sided flexible copper-clad laminate with high dimensional stability and low warpage in view of the shortcomings of the prior art. The single-sided flexible copper-clad laminate prepared by the method has good dimensional stability and is not prone to warpage. The method is easy to implement and can be mass-produced.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for preparing a high-strength, low-warpage single-sided flexible copper-clad laminate, comprising the following steps:

[0007] S1: stacking copper foil, dielectric layer, release film, dielectric layer, and copper foil in sequence, and pressing at high temperature to prepare a double-sided flexible copper clad laminate;

[0008] S2: subjecting the double-sided flexible copper-clad laminate obtained in step S1 to a release treatment to obtain a single-sided flexible copper-clad laminate.

[0009] In step S1 of the present invention, the temperature of the high temperature pressing is 330-380° C.; the pressure of the high temperature pressing is 2-5 MPa.

[0010] The pressing speed is 0.5-3 m / mim.

[0011] In step S2 of the present invention, the double-sided flexible copper-clad laminate prepared in step S1 is passed through a rewinding machine to separate the dielectric layer with copper foil from both sides of the release film.

[0012] In the present invention, the thickness of the copper foil does not exceed 36 μm.

[0013] In the present invention, the thickness of the dielectric layer is 10-100 μm.

[0014] The dielectric layer is one of a fluororesin film, a polyimide film, and a liquid crystal polymer film.

[0015] In the present invention, the thickness of the release film is 20 to 80 μm.

[0016] The release film is formed by sequentially stacking a polytetrafluoroethylene resin layer, a perfluoroalkoxy resin layer, a polyimide film, a perfluoroalkoxy resin layer and a polytetrafluoroethylene resin layer.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention improves the production efficiency of the product by first preparing a double-sided flexible copper clad laminate and then subjecting the laminate to a release treatment to obtain a single-sided flexible copper clad laminate. A release film is used as an intermediate layer to avoid the contamination of production equipment caused by the melting of a dielectric layer during high-temperature pressing during the preparation of a traditional single-sided flexible copper clad laminate. A symmetrical pressing method is used in the preparation of the double-sided flexible copper clad laminate to eliminate side effects such as thermal stress that occur during the preparation of the single-sided flexible copper clad laminate, reduce the warpage of the single-sided flexible copper clad laminate, and improve the dimensional stability of the single-sided flexible copper clad laminate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of a double-sided flexible copper-clad laminate prepared in an embodiment;

[0020] Figure 2 Schematic diagram of the structure of the single-sided flexible copper-clad laminate prepared in the embodiment and the comparative example;

[0021] Figure 3 Schematic diagram of the structure of the release film in the embodiment. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to specific embodiments, but is not limited thereto.

[0023] like Figure 1 As shown, in a specific embodiment of the present invention, a double-sided flexible copper-clad laminate is prepared by high-temperature pressing, which is formed by sequentially stacking and pressing a copper foil 1, a dielectric layer 2, a release film 3, a dielectric layer 2, and a copper foil 1;

[0024] like Figure 2 As shown, the single-sided flexible copper-clad laminate prepared in the specific embodiment of the present invention includes a copper foil 1 and a dielectric layer 2;

[0025] like Figure 3 As shown, in the specific embodiment of the present invention, the release film is formed by stacking a polytetrafluoroethylene resin layer 31, a perfluoroalkoxy resin layer 32, a polyimide film 33, a perfluoroalkoxy resin layer 32, and a polytetrafluoroethylene resin layer 31 in sequence.

[0026] Example 1

[0027] The present embodiment provides a method for preparing a high-strength, low-warpage single-sided flexible copper-clad laminate, comprising the following steps:

[0028] S1 12μm copper foil (Rikuang, JEJXEFL-BHM, 1 / 3oz), 25μm fluororesin film (Zhongshan New High, ASG-TK0008), 50μm release film (Zhongshan New High, ASG-TL1013, release film structure as shown Figure 3 As shown) Figure 1 The structure shown in the figure is pressed and molded in a double-belt press (HLED, E166-42) to obtain a double-sided flexible copper-clad laminate, wherein the pressing temperature is 380°C, the pressing speed is 1.6 m / min, and the pressing pressure is 4 MPa.

[0029] S2: The double-sided flexible copper-clad laminate prepared in step S1 is placed on a rewinder (Acme, ACMM-FJ-750), and the fluororesin film with copper foil is separated from both sides of the release film to obtain a laminate as shown in FIG. Figure 2 The structure is shown as a single-sided flexible copper clad laminate.

[0030] Example 2

[0031] The present embodiment provides a method for preparing a high-strength, low-warpage single-sided flexible copper-clad laminate, comprising the following steps:

[0032] S1 18μm copper foil (Rikuang, JEJXEFL-BHM, 1 / 2oz), 50μm fluororesin film (Zhongshan New High, ASG-TK0008), 75μm release film (Zhongshan New High, ASG-TL1025, release film structure as shown Figure 3 As shown) Figure 1 The structure shown in the figure is pressed and molded in a double-belt press (HLED, E166-42) to obtain a double-sided flexible copper-clad laminate, wherein the pressing temperature is 330° C., the pressing speed is 1.6 m / min, and the pressing pressure is 5 MPa.

[0033] S2: The double-sided flexible copper-clad laminate prepared in step S1 is placed on a rewinder (Acme, ACMM-FJ-750), and the fluororesin film with copper foil is separated from both sides of the release film to obtain a laminate as shown in FIG. Figure 2 The structure is shown as a single-sided flexible copper clad laminate.

[0034] Comparative Example 1

[0035] This comparative example provides a method for preparing a single-sided flexible copper-clad laminate, comprising the following steps:

[0036] S1: 12μm copper foil (Rikuang, JEJXEFL-BHM, 1 / 3oz) and 25μm fluororesin film (Zhongshan Xingao, ASG-TK0008) were prepared as follows: Figure 2 The structure shown in the figure is pressed and molded in a double steel belt press (HLED, E166-42) to obtain a single-sided flexible copper clad laminate, wherein the pressing temperature is 380°C, the pressing speed is 1.6 m / min, and the pressing pressure is 4 MPa.

[0037] Performance Testing

[0038] The single-sided flexible copper clad laminates prepared in Example 1 and Comparative Example 1 were subjected to performance tests.

[0039] Test method:

[0040] The performance tests such as peel strength, dielectric constant (Dk), tensile strength, warpage, water absorption and dimensional stability are carried out according to the test methods specified in IPC-TM-650, JIS C6471 and SPDR.

[0041] The test results are shown in Table 1.

[0042] Table 1 Single-sided flexible copper clad laminate performance results

[0043]

[0044] It can be seen from Table 1 that the single-sided flexible copper-clad laminate prepared by the preparation method of Examples 1-2 of the present invention has significantly better dimensional stability and warpage performance than the single-sided copper-clad laminate prepared in Comparative Example 1. In addition, the single-sided panels prepared in Examples 1 and 2 have good performance in physical properties such as water absorption, peel strength, and mechanical strength, meeting the processing and application requirements of the downstream printed circuit board (PCB) end.

Claims

1. A method for preparing a high-strength, low-warpage single-sided flexible copper-clad laminate, characterized in that The following steps are involved: S1: stacking copper foil, dielectric layer, release film, dielectric layer, and copper foil in sequence, and pressing at high temperature to prepare a double-sided flexible copper clad laminate; S2: subjecting the double-sided flexible copper-clad laminate obtained in step S1 to a release treatment to obtain a single-sided flexible copper-clad laminate.

2. The method for preparing a high-strength, low-warpage single-sided flexible copper-clad laminate according to claim 1, characterized in that In step S1, the temperature of the high temperature pressing is 330-380°C; the pressure of the high temperature pressing is 2-5 MPa; and the pressing speed is 0.5-3 m / mim.

3. The method for preparing a high-strength, low-warpage single-sided flexible copper-clad laminate according to claim 1, characterized in that In step S2, the double-sided flexible copper-clad laminate prepared in step S1 is passed through a rewinding machine to separate the dielectric layer with copper foil from both sides of the release film.

4. The method for preparing a high-strength, low-warpage single-sided flexible copper-clad laminate according to claim 1, characterized in that The copper foil has a thickness not exceeding 36 μm.

5. The method for preparing a high-strength, low-warpage single-sided flexible copper-clad laminate according to claim 1, characterized in that The thickness of the dielectric layer is 10-100 μm.

6. The method for preparing a high-strength, low-warpage single-sided flexible copper-clad laminate according to claim 5, characterized in that The dielectric layer is one of a fluororesin film, a polyimide film, and a liquid crystal polymer film.

7. The method for preparing a high-strength, low-warpage single-sided flexible copper-clad laminate according to claim 1, characterized in that The release film has a thickness of 20 to 80 μm.

8. The method for preparing a high-strength, low-warpage single-sided flexible copper-clad laminate according to claim 7, characterized in that The release film is formed by sequentially stacking a polytetrafluoroethylene resin layer, a perfluoroalkoxy resin layer, a polyimide film, a perfluoroalkoxy resin layer and a polytetrafluoroethylene resin layer.

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