PCB Blogger-China PCB Factory,HOYOGO

HASL and immersion tin   are common surface treatment processes for PCB, both are used for lead-free soldering. Do you know the difference between the two?       1.  Technological Process HASL: Pretreatment → HASL → Testing → Profile → Visual Inspection. Immersion Tin: Testing → Chemical Treatment → Immersion Tin → Profile → Visual Inspection.     2.  Technological Principle HASL is mainly to immerse the PCB directly into the molten  tin paste .   After being leveled by hot air, a dense tin layer will be formed on the copper surface of the PCB.   The  immersion tin   mainly uses displacement reaction to form a very thin tin layer on the PCB surface.     3.  Physical Property The thickness of the HASL tin layer is about 1um-40um, the surface structure is relatively dense, the hardness is large, and it is not easy to scratch. HASL only uses pure tin in the production process, so the surface is easy to clean, i...

Blistering is one of the common quality defects in PCB production process, because of the complexity of PCB manufacturing process, some blisters will occur.   Do you know the causes of blistering on the PCB surface?       1. Some thinner substrates because  of its p oor rigidity, are not suitable for brushing with a brushing machine, so  please  pay attention to them during production and processing, So as not to cause the plate surface substrate copper foil and chemical copper between the poor bonding force caused by the surface blister.     2.  The board surface is caused by oil stains during drilling, lamination, milling and other processing processes, or other liquids contaminate the surface with dust, which will also cause blistering on the board surface .     3. PTH  electroplating has to go through a lot of chemical treatments, such as various acid-base inorganic, organic and other pharmaceutical solvents....