Pcb pre-assembly inspection (or incoming material inspection)

- Sep 11, 2019-

Incoming material inspection is the primary condition for ensuring the quality of pcb assembly。Because the quality of the components,PCB ,PCB assembled material is difficult or impossible to solve in the later process. The incoming material inspection items are as follows:


Incoming material

Inspection items

General   requirements

Detection method

components

Solderability

235℃±5℃,2s or 0.2s or 230℃±5℃,3s±0.5s,Weld end 90% Dipped tin (lead-free250~255℃)

Wetting method   and impregnation test

Solderability

Reflow soldering:235℃±5℃,10~15s
  (lead-free 265~270℃,10~15s)

Immersion test

Lead coplanarity


Optical plane and   placement machine coplanarity inspection

performance


Sampling,   instrument inspection

PCB

Size and   appearance

Eye inspection

Warpage

Plane measurement

Solderability

Rotary dipping,   etc.

Solder mask   adhesion

Thermal stress   test

Process material

Solder paste

Percentage of   metal

Heated weighing   method

Solder ball size

Measuring   microscope

Metal powder   oxygen content


Viscosity,   processability

Rotary   viscometer, printing, dispensing

Binder

Bond strength

Pull force,   torque meter

Craftability

Printing,   dripping test

Rod solder

Impurity content

Spectral analysis

Flux

active

Bronze mirror,   welding

density

Densitometer

No wash or   washability

Eye inspection

detergent

Cleaning ability


Harmful to people   and the environment or not

Chemical   composition analysis


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