CN102529232B - Double-sided copper-clad plate and manufacturing method thereof - Google Patents

Abstract

The invention relates to a double-sided copper-clad plate, which comprises a glass fiber cloth reinforced thermoplastic polyimide resin layer and copper foils pressed on two sides of the glass fiber cloth reinforced thermoplastic polyimide resin layer, wherein the glass fiber cloth reinforced thermoplastic polyimide resin layer comprises glass fiber cloth and thermoplastic polyimide resin distributed in the glass fiber cloth, and the thermoplastic polyimide resin is infiltrated into the glass fiber cloth after the thermoplastic polyimide resin layer covered on the copper foils is pressed and melted at high temperature. The double-sided copper-clad plate disclosed by the invention has better dimensional stability and greatly reduces the product cost due to the adoption of the glass fiber cloth as the framework of the thermoplastic polyimide resin layer, is suitable for manufacturing a rigid-flex circuit board, has better heat resistance and flexibility, and can better meet the requirements of parallel lifting three-dimensional assembly and static deflection operation of a flexible part in the rigid-flex circuit board. The invention also relates to a manufacturing method of the double-sided copper-clad plate.

Description

Double-sided copper clad laminate and manufacturing method thereof

technical field

The invention relates to a copper-clad laminate, in particular to a double-sided copper-clad laminate which can be used for making rigid-flexible circuit boards and a manufacturing method thereof.

Background technique

With the miniaturization and multi-functional development of electronic equipment, high-density and high-performance PCBs are required. The design of electronic products is also increasingly considering special forms such as rigid-flex combination, parallel-elevated three-dimensional assembly, and static deflection. Under this premise, the rigid-flexible circuit board is increasingly showing its unique advantages. Currently, the flex portion of many rigid-flex boards requires only multiple parallel elevated, static deflections. If the flexible part is made of a flexible copper clad laminate with excellent flexibility, its flexural performance will greatly exceed the requirements of parallel elevation and static deflection, which will not only result in waste of performance, but also increase the cost. For example, the epoxy resin modified by the flexible segment not only has poor folding resistance, but also has poor heat resistance.

Contents of the invention

The purpose of the present invention is to provide a double-sided copper-clad laminate, which uses glass fiber cloth as the skeleton of the thermoplastic polyimide resin layer, which not only has better dimensional stability, but also greatly reduces the cost of the product.

Another object of the present invention is to provide a method for manufacturing the above-mentioned double-sided copper-clad laminates, which can realize continuous production of double-sided copper-clad laminates.

In order to achieve the above object, the present invention provides a double-sided copper clad laminate, comprising a glass fiber cloth reinforced thermoplastic polyimide resin layer, and copper foils laminated on both sides of the glass fiber cloth reinforced thermoplastic polyimide resin layer, The glass fiber cloth reinforced thermoplastic polyimide resin layer includes glass fiber cloth and thermoplastic polyimide resin distributed in the glass fiber cloth, and the thermoplastic polyimide resin is covered on the copper foil The thermoplastic polyimide resin layer is impregnated into the glass fiber cloth after being pressed and melted at high temperature.

The glass fiber cloth is an electronic grade glass fiber cloth with a thickness less than 30 μm.

The glass transition temperature of the thermoplastic polyimide resin is 200-280°C.

The thermoplastic polyimide resin in the glass fiber cloth reinforced thermoplastic polyimide resin layer is made of a thermoplastic polyimide resin precursor solution through imidization, and the thermoplastic polyimide resin precursor solution The viscosity is 200-5000mPa·s.

In order to achieve the above object, the present invention also provides a method for manufacturing a double-sided copper-clad laminate, comprising the following steps:

Step 1: Provide copper foil and synthetic thermoplastic polyimide resin precursor solution;

Step 2: Coating a layer of thermoplastic polyimide resin precursor solution synthesized in step 1 on the copper foil, sending it into an oven for baking, and then performing continuous imidization in a connecting imidization machine to make the thermoplastic polyimide resin The imidization of the imide resin precursor solution is completed, and a single panel with a thermoplastic polyimide resin layer on one side is obtained by winding;

Step 3: Provide glass fiber cloth, lay the single panel prepared in step 2 respectively on the upper and lower sides of the glass fiber cloth, make the thermoplastic polyimide resin layer of the single panel face the glass fiber cloth, and then place the three on the High-temperature pressing is performed in a high-temperature roller press, and the thermoplastic polyimide resin on the single panel is melted and soaked in glass fiber cloth under pressure to form a glass fiber cloth-reinforced thermoplastic polyimide resin layer, and a glass fiber cloth-reinforced thermoplastic polyimide resin layer is obtained. Double-sided copper clad laminate with polyimide resin layer.

The viscosity of the thermoplastic polyimide resin precursor solution is 200-5000 mPa·s.

The glass fiber cloth is an electronic grade glass fiber cloth with a thickness less than 30 μm.

In the step 2, the temperature of the oven is 120°C-250°C when baking after coating, and the temperature of the continuous imidization machine is 300°C-420°C during continuous imidization, and the thermoplastic obtained after continuous imidization The glass transition temperature of the polyimide resin layer is 200-280°C; in the step 3, the pressing temperature of the high-temperature roller press is 300-400°C during high-temperature pressing.

In the step 2, the temperature of the oven is 150°C-180°C when baking after coating, and the temperature of the continuous imidization machine is 350°C-400°C during continuous imidization, and the thermoplasticity obtained after continuous imidization The glass transition temperature of the polyimide resin layer is 220-240° C.; in the step 3, the pressing temperature of the high-temperature roller press is 350-390° C. during high-temperature pressing.

Beneficial effects of the present invention: In the double-sided copper-clad laminate of the present invention, the glass fiber cloth reinforced thermoplastic polyimide resin layer (insulation layer) is composed of glass fiber cloth and thermoplastic polyimide resin, and the thermoplastic polyimide resin itself It has good flexibility, and the glass fiber cloth also has a certain folding resistance, so the double-sided copper clad laminate made of the two has sufficient folding resistance, and can be used in the production of rigid-flexible circuit boards; The insulation layer of the two-layer double-sided flexible copper clad laminate traditionally used for rigid-flexible circuit boards is usually made of thermoplastic polyimide resin/thermosetting polyimide resin/thermoplastic polyimide resin (/TPI/PI/ TPI) three-layer structure or thermosetting polyimide resin/thermoplastic polyimide resin/thermosetting polyimide resin (PI/TPI/PI) three-layer structure, the resin layer structure of the double-sided copper clad laminate of the present invention is completely different , due to the glass fiber cloth as a skeleton reinforcement, the double-sided copper clad laminate of the present invention has better dimensional stability than ordinary flexible copper clad laminates; and because the glass fiber cloth is much cheaper than polyimide resin, the present invention The copper clad laminate of the present invention and its manufacture method have lower cost; In addition, because polyimide resin has higher heat resistance and flexibility than epoxy resin, thereby the copper clad laminate of the present invention is made than flexible epoxy resin Compared with copper clad laminates, it not only has better flexibility to better meet the parallel lifting three-dimensional assembly and static bending operation of the flexible parts in rigid-flex circuit boards, but also has higher heat resistance.

In order to further elaborate the technical means and effects adopted by the present invention to achieve the predetermined purpose, please refer to the following detailed description and accompanying drawings of the present invention. It is believed that the purpose, characteristics and characteristics of the present invention should be able to gain a deep and specific understanding from this , however, the accompanying drawings are provided for reference and illustration only, and are not intended to limit the present invention.

Description of drawings

The technical solutions and other beneficial effects of the present invention will be apparent through the detailed description of specific embodiments of the present invention below in conjunction with the accompanying drawings.

In the attached picture,

Fig. 1 is the structural representation of double-sided copper-clad laminate of the present invention;

FIG. 2 and FIG. 3 are schematic production flow diagrams of the manufacturing method of the double-sided copper-clad laminate of the present invention.

Detailed ways

As shown in Figure 1, the double-sided copper-clad laminate of the present invention includes a glass fiber cloth reinforced thermoplastic polyimide resin layer 10 and copper foil laminated on both sides of the glass fiber cloth reinforced thermoplastic polyimide resin layer 10 20. The glass fiber cloth reinforced thermoplastic polyimide resin layer 10 includes a glass fiber cloth 11 and a thermoplastic polyimide resin 12 distributed in the glass fiber cloth 11, and the thermoplastic polyimide resin 12 is made of The thermoplastic polyimide resin layer covered on the copper foil 20 is impregnated into the glass fiber cloth 11 after being pressed and melted at high temperature.

The glass fiber cloth 11 is an electronic grade glass fiber cloth with a thickness less than 30 μm.

The glass transition temperature of the thermoplastic polyimide resin 12 is 200-280°C.

The thermoplastic polyimide resin 12 in the glass fiber cloth reinforced thermoplastic polyimide resin layer 10 is made of a thermoplastic polyimide resin precursor solution through imidization, and the thermoplastic polyimide resin precursor The viscosity of the solution is preferably 200 to 5000 mPa·s.

In the double-sided copper-clad laminate of the present invention, the glass fiber cloth reinforced thermoplastic polyimide resin layer (insulation layer) is made of glass fiber cloth and thermoplastic polyimide resin, and the thermoplastic polyimide resin itself has good flexibility, and the glass fiber cloth Fiber cloth also has a certain folding resistance, so the double-sided copper clad laminate made of the two has sufficient folding resistance, and can be used in the production of rigid-flexible circuit boards; compared with traditional rigid-flexible circuit boards The insulation layer of the double-sided flexible copper-clad laminate made of two-layer method usually adopts a three-layer structure of thermoplastic polyimide resin/thermosetting polyimide resin/thermoplastic polyimide resin (/TPI/PI/TPI) or thermosetting Polyimide resin/thermoplastic polyimide resin/thermosetting polyimide resin (PI/TPI/PI) three-layer structure, the resin layer structure of the double-sided copper clad laminate of the present invention is completely different, because there is glass fiber cloth as The skeleton is reinforced, so that the double-sided copper clad laminate of the present invention has better dimensional stability than ordinary flexible copper clad laminates; and because glass fiber cloth is much cheaper than polyimide resin, the copper clad laminate of the present invention has a lower cost Cost; In addition, because polyimide resin has higher heat resistance and flexibility obviously than epoxy resin, thereby the copper clad laminate of the present invention is compared with the copper clad laminate that flexible epoxy resin is made, not only has better flexibility In order to better meet the requirements of parallel and elevated three-dimensional assembly of flexible parts in rigid-flexible circuit boards, static bending operations, and also have higher heat resistance.

The manufacture method of double-sided copper-clad laminate of the present invention comprises the following steps:

Step 1: Provide copper foil and synthetic thermoplastic polyimide resin precursor solution;

Step 2: Coating a layer of thermoplastic polyimide resin precursor solution synthesized in step 1 on the copper foil, sending it into an oven for baking, and then performing continuous imidization in a connecting imidization machine to make the thermoplastic polyimide resin The imidization of the imide resin precursor solution is completed, and a single panel with a thermoplastic polyimide resin layer on one side is obtained by winding;

Step 3: Provide glass fiber cloth, lay the single panel prepared in step 2 respectively on the upper and lower sides of the glass fiber cloth, make the thermoplastic polyimide resin layer of the single panel face the glass fiber cloth, and then place the three on the High-temperature pressing is performed in a high-temperature roller press, and the thermoplastic polyimide resin on the single panel is melted and soaked in glass fiber cloth under pressure to form a glass fiber cloth-reinforced thermoplastic polyimide resin layer, and a glass fiber cloth-reinforced thermoplastic polyimide resin layer is obtained. Double-sided copper clad laminate with polyimide resin layer.

The molecular structure of the thermoplastic polyimide resin can be selected in many ways, and the monomers to be synthesized can also be selected in many ways, and various published and known formulas can also be selected.

In order to ensure a certain degree of penetrability, the viscosity of the thermoplastic polyimide resin after melting must not be too high, otherwise it will be difficult to infiltrate after melting at high temperature lamination and the production efficiency will be low.

The glass fiber cloth is an electronic grade glass fiber cloth with a thickness less than 30 μm.

In the above step 2, the baking after coating is mainly to remove part of the solvent, so that the thermoplastic polyimide resin is semi-cured. The temperature of the oven during baking is 120°C-250°C, preferably 150°C-180°C. During curing, the maximum temperature of the continuous imidization machine must be above 300°C to ensure that the entire thermoplastic polyimide resin is completely cured. The glass transition temperature of the thermoplastic polyimide resin layer obtained after imidization is 200-280°C, preferably 220-240°C, so that thermal compression can be performed at a high temperature above 300°C, and the copper clad laminate can be guaranteed. With sufficient thermal stability and sufficient mechanical properties, the continuous imidization oven can have multiple high-temperature ovens to form a combination of ovens that gradually change from low temperature to high temperature; The lamination temperature is 300°C-400°C, preferably 350-390°C, which can obtain good lamination effect and high lamination speed. Polyimide resins with different formulations have different melting temperatures, but the temperature for high-temperature lamination must be higher than the melting point of the thermoplastic polyimide used, so as to ensure that the thermoplastic polyimide has sufficient adhesion after high-temperature lamination. The fluidity thus impregnates the glass fiber cloth smoothly. The high-temperature rolling machine can be protected by PI film to ensure that the copper foil is free from oxidation during high-temperature rolling, and the method of passing nitrogen in the rolling area can also be used to ensure that the copper foil is free from oxidation during high-temperature rolling.

As shown in Figure 2 and Figure 3, it is the production process of the production method of the double-sided copper-clad laminate of the present invention. During production, after coating the thermoplastic polyimide resin precursor solution on the copper foil 20 by the coating head 1 of the gluing machine , into the oven 2 for baking at a temperature not higher than 300°C, and then carry out continuous imidization in the connecting imidization machine 3 with a maximum temperature of 400°C to complete the imidization of the thermoplastic polyimide resin precursor solution Amination, winding to obtain a single panel 4 covered with a thermoplastic polyimide resin layer; the single panel 4 is respectively laid on the upper and lower sides of the glass fiber cloth 11, so that the thermoplastic polyimide resin layer of the single panel 4 Facing the glass fiber cloth 11, then the three are pressed together at a temperature higher than 300°C in a high-temperature roller press 5, and the thermoplastic polyimide resin on the single panel 4 is melted and soaked in the glass fiber under pressure The cloth 11 forms a glass fiber cloth reinforced thermoplastic polyimide resin layer to obtain a double-sided copper clad board with a glass fiber cloth reinforced thermoplastic polyimide resin layer.

For the above-mentioned double-sided copper-clad laminate and its manufacturing method, further detailed illustration and description are given in the following embodiments.

Synthesis example (synthesis of polyimide resin precursor solution)

Add 750g of N-methylpyrrolidone (NMP) to a 1L three-necked flask, add 82.1g of 2,2'-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), and then the solution Place in a water bath to cool, and protect with nitrogen, add 59.43g of biphenyltetracarboxylic dianhydride (BPDA) after 30min, continue high-speed stirring for 3 hours, and carry out polymerization reaction to obtain a polyimide resin with a viscosity of 600mPa.s. A body solution, the polyimide resin precursor solution is a thermoplastic polyimide resin precursor solution.

Example

Coat the thermoplastic polyimide resin precursor solution obtained in the synthesis example on the 12 μm copper foil, control the coating thickness so that the thickness after complete imidization is 16-20 μm, and the baking temperature of the gluing machine is 180°C. The vehicle speed is 3m/min to make it semi-cured, and then continue to enter the imidization machine for imidization. The maximum temperature of imidization is 350°C, and the vehicle speed is 3m/min. Nitrogen protection is required for over-imidization. After the panel comes out of the oven, it is rolled up. Lay the obtained single panel on both sides of the glass fiber cloth with a thickness of 30 μm, and the three enter into the high-temperature roller press together for high-temperature pressing. The temperature of the upper and lower hot rollers of the high-temperature roller press is set at 380°C, the pressure of the lamination line is set at 10MPa, and the speed of the machine is controlled at 1m/min. After lamination, a double-sided copper-clad laminate can be obtained.

The properties of the double-sided copper-clad laminates obtained in the examples are shown in Table 1.

The embodiment of table 1 makes the performance of double-sided copper-clad laminate

The test methods for the above characteristics are as follows:

(1) Dimensional stability: Tested according to IPC-TM-650 method 2.2.4.

(2) Folding resistance: The test of folding resistance adopts the MIT method, the bending radius is 2.0mm, and the clamping force is 4.9N. The more times of folding resistance tested, the better the flexibility of the insulating layer.

As mentioned above, for those of ordinary skill in the art, other various corresponding changes and modifications can be made according to the technical scheme and technical concept of the present invention, and all these changes and modifications should belong to the appended claims of the present invention scope of protection.

Claims (6)

1. a double face copper, it is characterized in that, comprise that glass fabric strengthens thermoplastic polyimide resin layer and is pressed together on the Copper Foil that described glass fabric strengthens thermoplastic polyimide resin layer two sides, described glass fabric strengthens thermoplastic polyimide resin layer and comprises glass fabric and be distributed in the thermoplastic polyimide resin in described glass fabric, and described thermoplastic polyimide resin is infiltrated in described glass fabric in high-temperature roller press by the thermoplastic polyimide resin layer covering on described Copper Foil after high-temperature laminating melting;

The glass transition temperature of described thermoplastic polyimide resin is 200-280 ℃;

The thermoplastic polyimide resin that described glass fabric strengthens in thermoplastic polyimide resin layer is made through imidization by thermoplastic polyimide resin precursor solution, and the viscosity of described thermoplastic polyimide resin precursor solution is 200～5000mPas.

2. double face copper as claimed in claim 1, is characterized in that, described glass fabric is electronic-grade glass fiber cloth, and its thickness is less than 30 μ m.

3. a preparation method for double face copper, is characterized in that, comprises the steps:

Step 1: Copper Foil and synthetic thermoplastic polyimide resin precursor solution are provided;

Step 2: the thermoplastic polyimide resin precursor solution that is coated with one deck step 1 synthesized on described Copper Foil, send into baking oven baking, then in connecting imidization machine, carry out continuous imidization and make thermoplastic polyimide resin precursor solution complete imidization, rolling obtains the single sided board that one side is covered with thermoplastic polyimide resin layer;

Step 3: glass fabric is provided, the prepared single sided board of the upper and lower surface laid step 2 of difference at glass fabric, make the thermoplastic polyimide resin layer of described single sided board towards glass fabric, then three is carried out in high-temperature roller press to high-temperature laminating, after thermoplastic polyimide resin melting on single sided board, sized glass fibres cloth forms glass fabric and strengthens thermoplastic polyimide resin layer under pressure, obtains the double face copper that tool glass fabric strengthens thermoplastic polyimide resin layer;

The viscosity of described thermoplastic polyimide resin precursor solution is 200～5000mPas;

In described step 2, after imidization, the glass transition temperature of resulting thermoplastic polyimide resin layer is 200-280 ℃ continuously; In described step 3, during high-temperature laminating, the pressing-in temp of high-temperature roller press is 300 ℃-400 ℃.

4. the preparation method of double face copper as claimed in claim 3, is characterized in that, described glass fabric is electronic-grade glass fiber cloth, and its thickness is less than 30 μ m.

5. the preparation method of double face copper as claimed in claim 3, is characterized in that, in described step 2, while toasting after coating, the temperature of baking oven is 120 ℃-250 ℃, and during continuous imidization, the temperature of continuous imidization machine is 300 ℃-420 ℃.

6. the preparation method of double face copper as claimed in claim 3, it is characterized in that, in described step 2, while toasting after coating, the temperature of baking oven is 150 ℃-180 ℃, during continuous imidization, the temperature of continuous imidization machine is 350 ℃-400 ℃, and after imidization, the glass transition temperature of resulting thermoplastic polyimide resin layer is 220-240 ℃ continuously; In described step 3, during high-temperature laminating, the pressing-in temp of high-temperature roller press is 350-390 ℃.