First, what is the current board, printed circuit boards and electronic products have become indispensable for the vast majority of the major components. Single, double-sided PCB manufacturing is in the substrate material - copper clad laminate (Copper- (2lad I.aminates, CCI) on selectively drilling, copper plating, copper plating, etching, etc. processing, to obtain the desired circuit pattern. Another multilayer printed circuit board manufacturing, but also within the core of thin copper-clad laminates as substrate, the conductive pattern layers and prepreg (Pregpr'eg) alternately laminated by a one-time bonding together to form a conductive pattern layer interconnect between three or more layers. Thus it can be seen as a substrate material in PCB manufacturing, either CCL or prepreg in the printed board plays a very important role. It has a conductivity, insulation and support three aspects of the function. PCB performance, quality, manufacturing workability, manufacturing cost, the manufacturing level, etc., depends largely on the substrate material.
Second, the development history of the substrate substrate material and production technology, has gone through half a century of development, the world's annual output has reached 290 million square meters, the development time by electronic machine products, semiconductor manufacturing technology, electrical installation technology, printed circuit board technology innovative development driven from CCL 1943 phenolic resin substrate made into practical since the beginning of the development of the substrate material very quickly. In 1959, Texas Instruments Inc. to produce the first integrated circuit, for printing board of a higher high-density assembly requirements, thus contributing to the plywood production. In 1961, the United States Hazeltine Corpot ation company successfully developed a metal vias technology law multilayer technology. 1977 resin, BT resin to achieve a industrial production, to the world and provides a multilayer development of new low Tg substrate material. 1990 IBM Japan announced a photosensitive resin as the insulating layer laminated multilayer technology law, in 1997, including laminated plywood, including high density multilayer interconnect technology to develop maturity. At the same time, in order to BGA, CSP is a typical representative of the plastic package substrate has been rapid development. Late, some of the free bromine, antimony and other new green flame retardant board is rising rapidly in the 1990s, to the market. Of the substrate material already 40 years of development, it has formed the production scale of about 90 billion yuan in output value. In 2000, China's mainland CCL production has reached 64 million square meters, the output value of 5.5 billion yuan. In which the paper-based CCL production has ranked third in the world. But in technology, product varieties, particularly the development of new substrate, with foreign advanced countries there are still a considerable gap.
Third, the classification of the general PCB board substrate materials can be divided into two categories: rigid substrate material and the flexible substrate material. Important species is generally rigid substrate materials CCL. It is the reinforcing material (Reinforeing Material), impregnated with resin adhesive, by drying, cutting, folding synthesis blank, then covered with foil, with steel as a mold, in a high temperature and pressure in a hot press forming in the system into. Multilayer prepreg general use, it is CCL semi-finished products in the production process (mostly glass cloth impregnated with resin, dried processed). There are several classifications of copper clad board. Usually by reinforcing material plate is different, it can be divided into: paper-based, glass fiber cloth, composite matrix (CEM series), laminated plywood base and specialty materials group (ceramics, metal core group, etc.) five categories. If you press the resin adhesive plate used to classify different common paper-based CCI. They are: various types of phenolic resin (XPc, XxxPC, FR a 1, FR-2, etc.), epoxy resin (FE-3), a polyester resin. Common glass fiber cloth CCL epoxy (FR-4, FR-5), which is a glass fiber cloth type most widely used. There are also other particularity resin (glass fiber cloth, poly amide fibers, non-woven material is increased): modified bismaleimide triazine resin (BT), polyimide resin (PI) , diphenylene ether resin (PPO), maleic anhydride imide - styrene resin (MS), polycyanate ester resin, a polyolefin resin or the like. CCL by flame retardant classification can be divided into flame retardant (UL94 a VO, UL94 a V1 level) and non-flame retardant (UL94 HB level a) two boards. Nearly two years, with more emphasis on environmental issues, the flame-retardant CCL CCL in turn branch breed a new bromine-free material, it can be called "green flame retardant cCL". With the rapid development of electronic products and technology, to cCL higher performance requirements. Therefore, the performance of CCL classification, divided into general performance CCL, low dielectric constant CCL, high heat resistance, CCL (general board of L at above 150 ℃), low thermal expansion coefficient of the CCL (generally used on the package substrate ) and other types.
