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I don't get it. If you need 0.1mm accuracy, all the machining, on plastic, mind you, must be done to say 0.05mm accuracy, both in position and size. And, it a
by aj7 8y ago
I don't get it. If you need 0.1mm accuracy, all the machining, on plastic, mind you, must be done to say 0.05mm accuracy, both in position and size. And, it appears that one of the parts registers to the edge of the pc board, which is inaccurate. Since you got it to work, what am I missing here?
- jdietrich 8y agoThe routed edges of a PCB are generally +/-0.1mm. Most laser cutters will match or exceed that tolerance, even on acrylic. In the worst case this jig will be 0.2mm out, but it's a lot easier to nudge a package from almost aligned to perfectly aligned than to place it purely by eye.
- aj7 8y agoOk I get it, it’s a manual aid and it gets you close enough to nudge, plus you can correct the fixture cheaply by remaking it.
- gh02t 8y agoFor reflow soldering they really don't have to be that precise. Capillary action pulls the part into place and aligns it as long as it's somewhat close when the solder wets, it's really neat. Even QFN packages the author mentions don't really need to be that precise, for those it's more important to get the right amount of solder paste dispensed so that you don't have bridging of pads.