PCB conductive silver paste and preparing method thereof

Abstract

PCB conductive silver paste is prepared by raw materials of, by weight, 5 to 10 parts of silver powder 10 nm to 20 nm in grain size, 30 to 40 parts of silver powder 1 micron to 10 micron in grain size, 15 to 20 parts of flaky silver coated copper powder containing 10% to 15% of silver, 0.2 to 0.3 part of a silane coupling agent KH-560, 8 to 12 parts of glass powder, 0.5 to 1 part of polyvinylpyrrolidone, 7 to 9 parts of polyvinyl butyral, 3 to 5 parts of ethyl cellulose, 6 to 8 parts of ethylene glycol, 2 to 4 parts of phthalic acid ester, 4 to 6 parts of isoamyl acetate, 5 to 7 parts of cyclohexanone, 2 to 4 parts of ethylene glycol monoethyl ether acetate and 1 to 2 parts of vitamin C. According to the PCB conductive silver paste, the use amount of the silver powder is reduced, the excellent conductive effect is achieved, after the glass powder is added, the properties such as moisture, surface smoothness and intermiscibility of the silver paste and bonding strength between the silver paste and a PCB are greatly improved, and defects such as bubbles and cracks are not likely to generate in the silver paste printing process.

Description

technical field [0001] The invention belongs to the technical field of electronic paste, in particular to a conductive silver paste for a PCB circuit board and a preparation method thereof. Background technique [0002] In the modern microelectronics industry, people have higher and higher requirements for electronic components, and the production is mostly carried out by process and standardization to reduce costs. The printed circuit board (PCB) was born to meet the needs of the microelectronics industry. Correspondingly, conduct research on new conductive pastes to match electronic pastes such as conductive pastes, electrode pastes, dielectric pastes, resistor pastes, and hole filling pastes with printed circuit boards (PCBs) that require new requirements. It is imperative. [0003] Generally speaking, the main components of electronic paste include functional phases such as metal, noble metal powder, etc., inorganic binders such as glass powder, oxide powder, etc., orga...

AI Technical Summary

Problems solved by technology

[0005] The binder in the conductive silver paste has a great influence on the yield of circuit printing, such as viscosity, cohesiveness, adhesion, leveling, film formation, solvent volatility, etc. will affect the printing performance of the circuit , there are pores, open circuits, etc., and sometimes the glass phase has not yet begun to melt after the organic matter has volatilized, resulting in the phenomenon that the conductive line falls off from the substrate, and the conductive line is scrapped. Therefore, the performance of the organic binder needs to be improved.

[0006] At present, many inorganic binders use glass powder. Glass powder is made of metal oxides, silicon oxide and other materials. If the melting point is too high, the glass phase has not yet started to melt after the volatilization of organic matter is completed, resulting in conductive lines obtained from conductive silver paste. The phenomenon of falling off from the substrate makes the conductive circuit scrapped; and many of the current glass powders contain harmful substances such as lead, which is not good for the environment, so it is necessary to develop glass powders with better performance