Study On Tungsten Carbide Production Technology For Micro PCB Drills

Printed circuit board(PCB)is the cornerstone of the development of the electronic communication information and electrical automation.With the upgrade of the industrial automation and the development of the artificial intelligence,PCB market is to be unlimited.At present,low-end products on the PCB market have serious homogeneity and fierce price competition,while high-end products pursue a smaller volume and a faster electrical signal transmission speed but with a higher processing difficulty and cost.Reducing the PCB processing cost becomes one of the key points for PCB manufacturers to enhance their market competitiveness.Drilling cost accounts for 30-40%of the whole PCB processing cost,since PCB holes,whose quality affect the electrical signal transmission stability,have high processing requirements,such as a high hole precision and a high hole wall quality.Meanwhile,PCB hole drilling tools have a higher cost than milling tools,and the drill pin life needs to be improved in order to reduce the processing costs.In the industrial applications,the substrate material of PCB drill pins generally selects the ultrafine-grained cemented carbide,which has a high hardness and abrasion resistance,and a high strength,bending resistance and breakage resistance.The smaller the drilling hole is,the more difficult the PCB machining is,and the higher requirement for the drill pin substrate material is.In addition,due to the small size and large production quantity of the bars for producing PCB drill pins,the low forming efficiency is the main factor that restricts the cost reduction of the bar production.This research expounds a kind of high efficient way to produce cemented carbide bars for high quality PCB drill pins.The main research progress are as follows:(1)Through the analysis of the physical and chemical indexes of the industrially used PCB drill pin materials,and in combination with the practical needs of the PCB pin clients,a cemented carbide substrate material with a high hardness,wear resistance and strength was developed;(2)Through the research on the working mechanism of the forming 'agents for the cemented carbide extrusion and on the mixing process for the extrusion,a forming agent formulation for the high-dimensional cemented carbide extrusion and the corresponding mixing process for extruding PCB drill pin bars with ?1.0-2.0 mm in one multi-hole mould were developed;(3)Through the study on the removal of the extrusion forming agents and on the effect of sintering process on the alloy properties,a special sintering process for PCB drill pin bars with ?1.0-2.0mm was developed.