Electronics Forum | Mon Aug 13 16:07:08 EDT 2007 | dyoungquist
We run double sided surface mount boards through our Heller oven without any parts falling off the bottom side unless they are too big/heavy. The trick we use is to set the bottom side temperature in the final 3 heat zones 10C-20C lower than the top
Electronics Forum | Tue Aug 14 10:01:32 EDT 2007 | gmoritz
I have posted earlier on a UIC Radial inserter machine. We have the machine running after repair of the CnC head. However, I now have a process problem with a board that has 256x3 LED parts (768 LEDs in three colors) where only 50% of the LEDs can b
Electronics Forum | Tue Aug 14 16:26:21 EDT 2007 | slthomas
So it's a C-n-C clearance issue? Could you go with the other cutnclinch unit...which ever you have, get the other one (one's right angled, one's offset at 45�)? Yeah, I know, they're not cheap. Other than that, hand place some of the SMT in chip bon
Electronics Forum | Thu Feb 21 04:41:37 EST 2008 | mun4o
hi,Toni, we use only FR4.Some of PCB we order in China and Taiwan.With these PCBs we can't any problem.Other PCB we order here in Bulgaria.The problems with voids start last year - we have voids only in PCBs from Bulgarian factory.The process is sam
Electronics Forum | Thu Sep 27 10:53:59 EDT 2007 | gregoryyork
Joris, > > Yep, very common to have those small > blow holes in lead-free alloys. We used to get > them very consistently on white-tin finished > boards, and less frequently with gold finished > boards, for what ever that is worth. > > IPC-6
Electronics Forum | Fri Sep 07 09:13:21 EDT 2007 | smtirl
Folks, we've recently upgraded to Heller MKIII reflow ovens with Gen 9 cooling units. We're running N2 atmosphere at 1000ppm O2 and Kester256 solder paste. We're seeing a big problem with flux residues building up in the cooling section of the
Electronics Forum | Tue Sep 11 22:40:26 EDT 2007 | philip_yam
We are testing SAC paste for thru-hole components in the 2nd reflow process. The solder joint is alright but some problem encountered in FR1 or CAM2 PCB after multiple times of reflow due to the temperature. We are very interested in Zn or Bi-based l
Electronics Forum | Fri Sep 14 09:30:29 EDT 2007 | russ
That is inherent issue with lead free, you may want to ask your customer to reconsider this specification, It was probably initiated during the pb days when an exposed pad could signify a reflow issue. Overprinting will give you solderballs and unle
Electronics Forum | Mon Oct 01 11:54:56 EDT 2007 | dyoungquist
Last I heard the Mydata MY500 jet printer was in the $275k-$325k range. If it does all they claim, I would love to have one. However, we only buy 45-50 screens each year and have only a small amount of rework due to paste errors that the MY500 woul
Electronics Forum | Thu Sep 27 17:25:33 EDT 2007 | chef
The short answer is immediately after reflow the problem occurs. To be more exact, what you are describing is not "rust". Rust occurs in iron. The oxidation that occurs in Tin-Lead has been sometimes called "white rust". Either way, oxidation occur
