Leadless HASL or ENIG - Page 1
Forum section: electronics / general

author: PartialDischarge
author_rank: Super Contributor
timestamp: October 21, 2020, 12:45:41 pm
content: I have to order a lot of boards (all SMDs, smallest is 0603s and a DNF-8), can't decide if go for leadless HASL or ENIG. I'm biased towards HASLBesides what would be the best solderpaste for each in your experience?

author: SMTech
author_rank: Frequent Contributor
timestamp: October 21, 2020, 01:10:14 pm
content: ENIG because its reliably properly flat (certainly doesn't hurt when you have DFN/QFNs), decent shelf life a bonus.Solder paste choice shouldn't be affected really, use one you like and you can get hold of. GC-10 seems to be a popular globally available choice

author: PartialDischarge
author_rank: Super Contributor
timestamp: October 21, 2020, 03:17:29 pm
content: Quote from: SMTech on October 21, 2020, 01:10:14 pmThanks, I was somewhat afraid of it after reading of black pads and gold leachng into solder

author: SMTech
author_rank: Frequent Contributor
timestamp: October 21, 2020, 03:28:54 pm
content: Heard of but not seen black pad, I don't think you should worry on that front. Where clients care to bother, they typically specify ENIG these days, its pretty standard. I don't believe there is enough gold in ENIG plating to be an issue w.r.t weakening or embrittlement.

author: Nauris
author_rank: Regular Contributor
timestamp: October 21, 2020, 06:08:22 pm
content: Have you considered immersion silver? That should also offer good planarity and no risks from gold/nickel. Some say it has low shelf-life but I have had some sitting in my drawer for 10 years. Ones in in their original plastic wrap still look good, the loose ones are tarnished here and there.

author: PartialDischarge
author_rank: Super Contributor
timestamp: October 21, 2020, 07:00:03 pm
content: Quote from: Nauris on October 21, 2020, 06:08:22 pmThat would automatically disqualify it, besides the higher cost compared to ENIG

author: Niklas
author_rank: Frequent Contributor
timestamp: October 21, 2020, 08:55:02 pm
content: We have good experience with lead free HASL, no ENIG due to customer demand. Packages on the boards: 0402, 0603, 0805, SOD523, SOT23-8, VSSOP8, TQFP48, 1212-8 (MOSFET similar to DFN). Solder paste is either 63/37 leaded solder or SAC387, both with ROL0 flux. For some of our newer project we are using OSP instead of HASL and the solder paste is GC10.

author: Rat_Patrol
author_rank: Frequent Contributor
timestamp: October 21, 2020, 09:37:31 pm
content: If you are running larger components like SOIC and such, I prefer HASL.For fine stuff like TSSOP or other fine pitch components, ENIG gives easier assembly to deal due to its flatness, especially if you hand solder any of the components.

author: ANTALIFE
author_rank: Frequent Contributor
timestamp: October 21, 2020, 11:05:58 pm
content: Definitely ENIG for something like DNF-8, if you are afraid of black pads (which I have only seen once during my lifetime) you could ask for immersion silverhttps://studylib.net/doc/18116674/viasystems-surface-finishes

author: Nauris
author_rank: Regular Contributor
timestamp: October 23, 2020, 06:25:25 pm
content: Quote from: MasterTech on October 21, 2020, 07:00:03 pmOnly the improperly stored boards gone bad, boards in unopened factory packaking still looked good. I don't think it is much of an issue and ten years is a long time anyway. I think it should not be more expensive than ENIG, at least these boards were not, but that of course depends on board house.