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SMD Soldering without Soldermask? Answered

I'm working on a project and I needed to get a PCB made. I was planning on getting it from BatchPCB, but I ran into a little problem... I'm using a NAND Flash chip, which is TSSOP48; the footprint has 6mil spacing! (BatchPCB has a 8mil minimum) The next cheapest solution would be Barebones PCB, which makes prototype PCBs without soldermask & silkscreen. I'm worried about soldering on the Flash chip, and another LQFP48. Will the lack of a soldermask make it impossible to do?

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westfw

9 years ago

I find lack of soldermask a pain for SMT components. You are to some extent relying on the surface tension and adhesion of the solder to the pads to make up for impossible-to-hand-solder dimensions, and with no soldermask, the pads don't END...

yeah, but you don't NEED it, lol When possible it's nice, but many people do SMD soldering on homemade circuit boards I've only soldered on manufactured pcbs twice, and I will admit, it was NICE

I'm just really worried about these package sizes. I've done [the SMT Atmega168's (I can't recall the size) on both homeade & "real" pcbs, and I could feel the difference. The NAND Flash chip has 6mils between pads. It was hard on a "real" pcb... I wanted to know if it would be significantly harder on something like this. And even the best homeade pcbs (that I've seen) don't go down to 6mil.

I would consider a soldermask an important part of a commercially made board, and that it would make soldering fine-pitch stuff significantly easier. I'm not arguing that it's POSSIBLE to solder SMT without the mask, but it would certainly be harder. You should be able to find a PCB maker that does 6mil clearance AND soldermask in their prototype service...

Actually, I realized that AC's 33 each special w/ the student discount would end up being cheaper than their barebones service if I only get 1.

These are custom boards, that seems too expensive... I could probably get real prototype-quality boards for cheaper...

I got 2 samples (with amplifier chips!) for free, so I'm happy. I suppose they might get pricey

Ah, now that I'm looking at them, I understand it... I didn't see that you just buy it for a specific size, I thought it was like a PCB...

Actually it is like a pcb, thats just one version of it

nope, infact hobbiest don't even need soldermasks, the main purpose of a soldermask is for when big companies do wave soldering (where they pretty much dunk the board in molten solder). Another plus of a solder mask is that it prevents corrosion. as for SMD soldering, you do not need a solder mask.