Well as some of you may of guessed i've been trying to build an xml light, all was going well until i came to soldering the emitter.
First i scraped of the white squares to reveal the copper underneath then i added a small amount of flux and tried to tin the board but no matter how hard i try i can't get the solder to stick. what am i doing wrong ?
What you need is a much hotter iron. at least a 60-80+ watter. Get it nice and hot and do it quick, before the head can get drawn out. How thick is the wire your soldering? Try to pre-tin and then pre-heat the wire and emitter, bit of heat from a second (smaller iron is fine), then when your happy, use the big really hot iron and reflow the 2 together.
Slow and not enough heat just wont work in your situation. Yeah, its great to see the heatsink working really well!