Printed Circuit Boards Multilayered PCB 

Multilayered PCB  For fabricating multilayer PCB, we have to first fabricate corresponding number of double sided PCBs. For a 4 layered PCB, we have to first fabricate two double layered PCBs, and for 6 layered, 3 double layered PCBs. These double layered PCBs are sandwiched one over another exactly with oxidizing agent between them. Then the sandwiched board inserted in the multilayer press machine. It has a control unit for all pressure supply, press plates and heaters.  The large loading door that allows quick and easy access to the pressure part is security switch protected. The unit is controlled by two digital and adjustable thermostats, one digital timer as well as a pressure valve with pressure meter. Two strong air ventilators are activated automatically during cooling cycle. After complete curing and cooling, the sandwitched multilayed PCB is taken out from the press machine is subjected to masking, legend printing as per requirement The PCB lab. has a variety of chemicals in the store for PCB fabrication process. The lab. has facility for producing deionized water which is used in plating purpose It has got the facility of inspection of photo films and PCBs under a table lamp with a microscope a leading PCB Manufacturer started in 2001 China, provides PCB manufacturing, assembly, turn-key services with low price high quality, please visit their web site , to get a high quality pcb manufacturing in china services

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Thick Copper Design

Thick Copper Design

A CTE Mismatch Between Copper And FR- – 4 Exists • Copper = 18ppm • FR-4 = 15-16ppm • As Copper Gets Thicker, It Has Greater And Greater Influence Over Post Lamination Dimensions Of The Resulting Substrate Rolled , Annealed Copper Reacts Differently Than ED Copper • Design Influences On Net Shrinkage Become Far More Significant Standard Scaling Factors (That Compensate Net Shrinkage Effects) Do […]

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Component Issues – Decreasing Pitch

Component Issues – Decreasing Pitch

Component Issues – Decreasing Pitch Potential Issues: – Paste Volume Control – Component/PCB Flatness • Internal Split Plane • NFP Removal Impacts – Component/PCB Warpage LGA/QFN Package Assembly Trace Routing Under Component Create Localized Height Variations – Standoff Height Variation Leadless Devices Are More Sensitive To PCB/Component Flatness/Warpage – Received Condition – In-process Condition (During Reflow/Rework Solder Process) Solder wicking around NSMD pads produce significantly […]

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Root Cause Failure Analysis of Printed Circuit Board Assemblies Part 1

Root Cause Failure Analysis of Printed Circuit Board Assemblies Part 1

What do you mean 0% first pass yield? My process is in control , so what happened? Today’s Electronic Designs Component Packages Are Getting Smaller 0603 > 0402 > 0201>01005 BGA > CSP > WL-CSP > Assembly Design Density Is Increasing Tighter Component to Component Spacing Spacing Smaller Than 0.020” Common Smaller Copper (Pad) Interconnections Assembly Process Margins Are Tighter Thermal Balance @ Pad Level […]

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