Electronics Forum | Tue Jul 25 14:30:04 EDT 2017 | emeto
Looks like you have a great wetting of your paste :). Once body has been in contact with molten solder, the package could suffer damages on the body(outside and inside) and on the circuitry inside. It is considered a defect. I have seen that before a
Electronics Forum | Wed Aug 09 11:59:19 EDT 2017 | dleeper
As you already know, it depends on the paste. There isn't really a rule of thumb, but less time exposed it better. The issue is the flux exposure to the air and ambient conditions. The flux can evaporate or absorb moisture from the air. If the paste
Electronics Forum | Thu Sep 07 07:36:57 EDT 2017 | tsvetan
we use 0.12 mm stencil with 0.3 mm apretures for 0.5mm step FBGA153 memory without problems the solder paste is SAC305 Class4 http://www.olimex.com/Products/Components/Soldering/SOLDER-PASTE-SAC305-CLASS4/
Electronics Forum | Thu Sep 07 08:45:02 EDT 2017 | dleeper
In my experience with similar sized parts, the nano coatings (or what ever your supplier might call them) do help with repeatable paste release. How are you cleaning your stencils? A big red flag to me is that your stencil worked fine for the first
Electronics Forum | Thu Oct 05 07:11:35 EDT 2017 | emeto
Now you are putting your assembly to vibrate with frequency of 30-60kHz. What kind of flux/paste are you using? If it is NC there is no reason to clean. If it is water wash, you should consider a proper way of cleaning it according to your paste/flux
Electronics Forum | Mon Oct 09 15:03:08 EDT 2017 | emeto
From what I know from people using it - it is a great machine. Allows you to have unique shape and amount of paste for every single pad. Great for small volumes, prototyping series and a great replacement for step stencils and any other occasions, wh
Electronics Forum | Fri Dec 01 13:55:44 EST 2017 | emeto
Brikainis, it looks like these vias are not plated and closed. I would say that thickness of your paste is lifting the part. Are you willing to try another stencil with ground pad apertures matching the via holes? It is probably worth trying. Anothe
Electronics Forum | Thu Nov 23 20:01:05 EST 2017 | myke03o
Hi to all experts, Can anyone advice us what solder alloy to use for thermal cycling products. We are facing a lot of issues using normal solder paste SAC305. After thermal cycling the solder is cracking. Any suggestion is welcome. Thanks in advanc
Electronics Forum | Thu Feb 01 05:06:46 EST 2018 | ameenullakhan
Hi Rob, Thanks for your reply. Our customer don't need any pin hole in his board. Attached is the image for your reference. The issue is minimized for us with hot profile ( 80 - 100 sec in between 170 to 180 deg C ) For leaded paste. Lead free pa
Electronics Forum | Sun Jan 07 07:40:31 EST 2018 | mohammad
Hi everybody. I'm new at SMT soldering. I'm using a stencil to print solder paste on PCB. and my board has 0402 components that it make assembling process long so I can't complete a set of board in a day and I have to continue in the next day. what
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