● HASL & OSP
● Immersion Sliver & Tin
● ENIG & ENEPIG
Nowadays, with the development of technology, there are a number of surface finishes that are available for customers. Different surface finish has different characteristics in many aspects, such as cost and manufacture capability.
Here come the comments on different surface finish about its advantages and disadvantages.
HASL is the common method of surface finish at the beginning of PCB. And it can be divided into two types: HASL and HASL Lead Free.
Long storage time; High coverage of tin after soldering; Suitable for lead-free soldering; Low cost; Mature technology; Visual inspection and electrical testing are available
Limitations in SMT for surface toughness; Suitable for contacting switch design; Copper will melt in HASL; Limitation for boards with ultra thin or thick thickness
Smooth surface for lead-free soldering and SMT; Easy to rework and easy production; Hybrid treatment is available (like OSP+ENIG); Low cost; Environment-friendly
Limitation on reflow; Visual inspection and electrical testing are unavailable; Difficult to rework in SMT; High storage requirements
3. Immersion Sliver
Easy production and suitable for lead-free soldering and SMT; Smooth surface; Suitable for circuit with ultra narrow spacing; Low cost
High storage requirements and easy to be polluted; High soldering defect rate; Electro-migration
4. Immersion Tin
Suitable for production line manufacture and lead-free soldering; Suitable for circuit with ultra narrow spacing; Smooth surface for SMT
High storage requirements; Not suitable for contacting switch design; High requirements on soldermask foil;
ENIG is one of the surface finishes that wildly used in PCB manufacture.
Suitable for lead-free soldering; smooth surface for SMT; ENIG for through-hole is available; Suitable for contacting switch design; High reliability
ENEPIG is gradually applied in PCB industry, which was frequently used in semiconductor before.
Lower cost than ENIG; Suitable for lead-free soldering; Long storage time; Hybrid surface finish is available.
Complex manufacture; Short-term application in PCB