Method for preparing low-shrinkage-factor copper clad laminate by applying nano-stuffing

Abstract

The invention discloses a method for preparing a low-shrinkage-factor copper clad laminate by applying a nano-stuffing, which comprises the following process flows: adding a nano-powder stuffing on a system of FR-4 / CEM-3, impregnating fiberglass cloth / fiberglass paper with a facing material and core material glue, and preparing the stuffing into a semi-solid state at a temperature of between 130 and 180 DEG C to prepare a facing material and a core material; superposing 1 to 20 sheets of the facing material according to the thickness requirement, and covering a copper foil on one side or both sides of the facing material to prepare an FR-4 sheet material; superposing 1 to 20 sheets of the core material, pasting the facing material on the upper surface and the lower surface of the core material, and covering a copper foil on one side or both sides of the core material to prepare a CEM-3 sheet material; and performing hot press molding on the combination of the FR-4 / CEM-3 at a temperature of between 90 and 180 DEG C, at a pressure of between 10 and 60 Kg / cm, and at a vacuum degree of -60 mmHg. The FR-4 / CEM-3 copper clad laminate prepared by the method obviously reduces the heat expansion coefficient, remarkably improves the dimensional stability, overcomes the defects that the FR-4 / CEM-3 sheet material prepared by the prior art has large CTE and poor dimensional stability, is more adaptable to the production of PCB and the assembly technique of electronic products, and remarkably improves the reliability.

Description

technical field [0001] The invention discloses a method for reducing the coefficient of linear thermal expansion (CTE) and dimensional stability of a copper-clad laminate, specifically a method for preparing a low-shrinkage copper-clad laminate with nanofillers, which belongs to the technology of electronic products field. Background technique [0002] With the development of electronic products towards thinner and smaller, high performance and multi-functionality and the advancement of electronic assembly technology, printed circuit board products for electronic interconnection have gone through the through-hole technology (THT) stage, comprehensive Embarked on the surface mount technology (SMT) stage, and gradually moved to the chip scale package (CSP) stage. The process of soldering surface mount components (SMD) on a printed circuit board is to heat from room temperature at about 23°C to a soldering temperature of about 230-260°C for soldering, and then cool and solidif...

AI Technical Summary

Problems solved by technology

Therefore, how to reduce the CTE of the board and increase its reliability is an important issue. In addition, if the size shrinkage of the copper clad laminate is too large during the production and processing of the circuit board, it will cause inaccurate installation of components, or failure to assemble, etc. problem, and therefore needs to be improved

Usually, the method to improve the CTE and dimensional stability of the plate is to increase the glass transition temperature (Tg) of the plate. Generally, the resin is below the Tg temperature, and its CTE is 40-100ppm / °C, but when the temperature exceeds Tg, its CTE is 200ppm / °C. ℃, so the CTE corresponding to increasing the Tg of the resin system will also be significantly reduced. The disadvantage is that the flexibility of the plate will deteriorate, the machinability will deteriorate, and the cost will increase.

The second is to use reinforcing materials with low expansion coefficients. The thermal expansion coefficients of different reinforcing materials are quite different. For example, the CCL of a copper clad laminate made of organic fibers formed by aromatic polyamides can reach 8-12ppm / ℃; the disadvantage is that its The price of reinforcement materials is too high for ordinary customers to accept

Since the particle size of ordinary fillers is above 1 μm, if too much is added, the plasticity, electrical properties, and machinability of the sheet will be deteriorated.

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