circuitnet
Sponsor
Essegi Automation
Scaling SMT Traceability
High-mix electronics manufacturing requires precise material control. This whitepaper explains how Tecnimaster improved traceability, inventory accuracy and picking efficiency through integrated automated storage and reel-level tracking.
Essegi Automation
Quick-Turn PCB Assemly
Sponsor
AIM Solder
Viscosity Does Not Equal Rheology: What Solder Paste Measurements Really Tell You
Viscosity is a useful solder paste quality control measurement, but rheology provides a more complete understanding of how paste will roll, fill, release, recover, and remain stable during stencil printing.
AIM Solder
Ask the Experts
QUESTIONS
  
SUBMIT
  
MEMBERS
  
JOIN
November 19, 2007 - Updated
November 19, 2007 - Originally Posted

Pros and cons of HASL, OSP and Immersion Gold

What are the pros and cons of HASL, OSP and Immersion gold surface finishes?
T. M.
Expert Panel Responses
A very interesting question and the answers could go on forever. HASL ( Hot Air Solder Leveling) replaced Electroplated Tin/Lead and became SMOBC (Solder Mask over Bare Copper) with HASL. Good for through hole components, helped with weak knees or the wetting at the knees of the plated through holes. Problems not very flat and problems developed with the introduction of surface mount in the early 80s. OSP, Organic Solder Protective coating, eliminated one thermal cycle from the board processing process, was flat so it accepted surface mount components relatively easy. Vaporize pretty easily so if the product was double sided, soldering on the second side could be problematic. This was reduced quite a bit with the use of water soluble fluxes in the solder paste. Immersion Gold, or ENIG, Electroless Nickel, Immersion Gold. Again a flat surface and good for all surface mount components especially BGA components. The soldering was ok, but the board shops had to watch the chemistry involved in the plating process. If the plating process went bad, the opportunity to have black pad existed and when this happen the solder joints could not be made. This has been resolved in the industry but once in a while it happens, so everyone needs to be on the look out for this condition.

Leo Lambert
Leo Lambert
Vice President, Technical Director, EPTAC Corporation
At EPTAC Corporation, Mr. Lambert oversees content of course offerings, IPC Certification programs and provides customers with expert consultation in electronics manufacturing, including RoHS/WEEE and lead free issues. Leo is also the IPC General Chairman for the Assembly/Joining Process Committee.
Submit A Comment
Comments are reviewed prior to posting. You must include your full name to have your comments posted. We will not post your email address.

Your Name


Your Company
Your E-mail


Your Country
Your Comments



Free Newsletter Subscription
Circuitnet is built for professionals who bear the responsibility of looking ahead, imagining the future, and preparing for it.

Insert Your Email Address

Sponsor
SCHUNK
Gripping Systems from micro assembly to heavy lifting
The first industrial-suited grippers from SCHUNK were a milestone. Since then we have brought countless newly and further developments to market.
SCHUNK
Ultrasonic Stencil and Pallet Cleaner