Electronics Forum | Fri Oct 22 11:37:38 EDT 1999 | Brett Gordon
Working DFM SMT issues with respect to a client's artwork together with a heavily modified solder stencil, I was able to reduce 0402 tombstoning from 80% across the board to 3%. I winged the aperture reductions, but are there any "rules" or guidelin
Electronics Forum | Fri Mar 09 05:06:09 EST 2012 | grahamcooper22
Is your solder paste deposit drying out? Or if the paste deposit is small or there is insufficient paste then the tack between the device and paste will be poor so it can easily come out of the paste during its placement or placement of other parts.
Electronics Forum | Thu Oct 12 11:08:20 EDT 2000 | Fraser
Dave, Why on earth would you want to use a stepped glue stencil?. If you print slightly off contact the hight of your glue deposition will be roughly half the width of your adhesive aperture width so if you want a 10mil high deposit use a 20 mil ape
Electronics Forum | Thu Oct 12 22:16:59 EDT 2000 | Dreamsniper
Hi Guys, I'd like to share this to all of you...you can start playing with the rests...Stated prices, if not indicated, are in Aussie $ or Singapore $. Stencil Printing Adhesive Pros a) Less Capital Equipment Cost (Short Term). In reality it is f
Electronics Forum | Thu Mar 25 19:07:22 EDT 2021 | llawrence
That is all a lot to take in, but thank you all for the recommendations. From what I understand, I'm going to start by ordering a new polished 0.1mm stencil with size reduced apertures and seeing if reduced paste deposit will help. As for the sten
Electronics Forum | Fri Oct 13 13:44:03 EDT 2000 | Mike McMonagle
You can achieve a wide range of dot heights when stencil printing by using a polyimide stencil along with a .040 snapoff. Loctite has a system for this that they call Varidot, by varying the size of the apertures in combination with the .040 snapoff
Electronics Forum | Thu Oct 21 14:02:32 EDT 1999 | Ron Costa
We are a contract manufacturer currently building a job with IBM CBGA-255 devices and 20mil QFP's that are close to each other. We use a 6 mil laser cut and electro polished stencil with one to one apertures on the BGA's. The customer is experiencing
Electronics Forum | Wed Mar 24 23:12:48 EDT 2021 | grahamcooper22
0.66 area aspect ratio...so for example...if the device is 0.5mm pitch QFP, the pcb pad may be 12 thou wide..make the aperture 9 to 10 thou wide...and reduce it's length by 10 % overall compared to the pcb pad.... Depending on device pitch, select ap
Electronics Forum | Tue Oct 03 20:35:23 EDT 2000 | Dave F
1. Throughput * Dispenser: Slower, may loose 70% of tact on fast chip shooters * Printer: Can be put in front of and use fast chip shooters effectively 2. Rework Rate ???? Deposition control???? * Dispenser - High control over amount paste - Coplan
Electronics Forum | Sat Nov 13 14:09:45 EST 1999 | se
First, let me say what I always say: a good chem-etched stencil will print fine pitch. Chem-etch brings trap to the side walls because its a physical by-product of the process. Because they are less expensive you can add electropolish and still save
