Circuit Building 101

Step 7 Trim the leads

Flush cutters are useful for trimming leads close to the surface. Regular diagonal cutters can work, also. Safety goggles are actually a good idea for this step as the leads can fly off quickly. We usually like to hold on to the lead while clipping.

Comments

[yusaku]

clinching should only be done if absolutely necessary, increases chance of lifting pads amongst other issues most parts can be tacked in place while holding the part in.

[spry981]

I have found that using a small fingernail clipper works quite well for most lead trimming. It's small and easy to maneuver when you have a lot of leads sticking up. Of course, safety glasses are a must!

[ac-dc]

I think there should be a step 8: Cleanup.

Assuming use of rosin core solder, take some alcohol (100% pure is nice, but a tiny bit of water won't hurt *most* components) and a toothbrush/etc and scrub off the excess flux. This also helps to remove stray solder balls, especially if solder paste was used. Next after scrubbing, rinse with alcohol and hang dry. Some people prefer to do the bulk of the cleaning before adding certain parts with inner cavities like POTs or switches, so they dont' have to be as concerned about the flux and alcohol getting inside where it may wash away grease or take longer to dry (but a quick scrub with only a little alcohol and quick rinse and shake will not get much alcohol inside, I've never had a problem doing it in moderation.

If one were to use the (some would call ill-advised) acid core solders, then instead of the alcohol scrub a strong warm detergent water solution would be used, then rinsed with water, shook off, and ideally final rinse with alcohol and shook off again. Note that the industry doesn't usually follow with the alcohol but in some cases it means close inspection of a PCB you would find a hazy film still on it which is generally not a problem but many DIYers want their end result to look prettier than a retail PCB would be.

[CuriousInventor.com]

I'll add a step sometime soon... the only bit I would add is that it's easier to clean rosin based residues sooner than later. That being said, I'm not convinced cleaning is necessary for most rosin-based fluxes (Kester's datasheet for aggressive RA flux says even it doesn't need to be cleaned) for hobby projects.

[ac-dc]

Agreed, mildly activated doesn't need cleaned, but more active rosin like Kester SP-44 will turn gummy with a fair amount of ambient humidity which is unsightly and a tiny bit more active. We also need to consider that hobby project can mean a lot of different things. Are hobbyists prevented from working with high speed fine pitched components? Maybe Kester assumes so but I'm not going to ask for permission?

[ac-dc]

I usually prefer thin-nosed very small diagonal cutters because you don't then have to focus on how far away from the board you're holding them, instead they automatically make a consistent ~ 1.3mm length to the leads by just holding them against the board. Of course with some parts the leads are too closely spaced to do this but usually not.