How to Attach Ring Terminal Crimps to PCB? - Page 1
Forum section: electronics / beginners

author: sean0118
author_rank: Frequent Contributor
timestamp: June 14, 2015, 09:25:03 am
content: Hi everyone,What's the correct way to attach crimped ring terminals (Is that the right name?) to a PCB? For high-current, low-voltage applications a lot of the terminal blocks are physically oversized as they are often rated for 1kV.Is it acceptable to bolt the ring terminals with some washers directly to a pad on the PCB? Or is there a large danger of the copper stripping off the board?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 14, 2015, 09:29:38 am
content: An issue is that PCB will cold-flow over time, reducing contact pressure.use something like thishttp://www.toby.co.uk/content/catalogue/products.aspx?series=PCB-11-xxx

author: RobertHolcombe
author_rank: Frequent Contributor
timestamp: June 14, 2015, 09:30:08 am
content: I've not seen ring terminals used in the way you suggest, rather spade terminals are used as there are PCB mount male spade terminals.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: June 14, 2015, 09:34:58 am
content: I've done it before, but as Mike says, PCB will shift. Be sure to use cone (Belleville) or wave washers rated for a good amount of spring force. Multiple in a stack if necessary.Tim

author: sean0118
author_rank: Frequent Contributor
timestamp: June 14, 2015, 09:41:57 am
content: Ok, thanks guys, I'll play it safe and use one of the terminals Mike linked to.Quote from: RobertHolcombe on June 14, 2015, 09:30:08 amHey, I'm not sure exactly which terminals you're referring to? Is it the quick connect crimp terminals you see in consumer electronics etc?

author: nanofrog
author_rank: Super Contributor
timestamp: June 14, 2015, 10:21:16 am
content: TheAMP/Tyco 63849-1would be an example of a PTH Quick Disconnect.

author: sean0118
author_rank: Frequent Contributor
timestamp: June 14, 2015, 10:49:07 am
content: Ok thanks, those are the type of terminal I thought he was referring to.Something else I just thought of, which of the two terminals mentioned in this thread have the lowest risk of shorting to another terminal? This is for a battery charger so I really do not want a short across the output terminals. Maybe, I should also use an inline fuse to protect against such a fault (as opposed to PCB mounted fuse)?

author: cs.dk
author_rank: Unknown
timestamp: June 14, 2015, 10:58:33 am
content: At work we use some like these;http://www.digikey.com/product-detail/en/7461383/732-3216-ND/2682507You can get them in female thread to;http://www.digikey.com/product-detail/en/7460307/732-3201-ND/2682492They seem to be fairly strong and reliable.

author: nanofrog
author_rank: Super Contributor
timestamp: June 14, 2015, 11:15:59 am
content: Quote from: sean0118 on June 14, 2015, 10:49:07 amWhy not use fully insulated female spade terminals on your wiring then?

author: sean0118
author_rank: Frequent Contributor
timestamp: June 14, 2015, 11:38:27 am
content: Yeah I think I might, those screw terminals (and my original idea) look pretty susceptible to shorting.

author: woodchips
author_rank: Frequent Contributor
timestamp: June 14, 2015, 05:46:10 pm
content: As mentioned, the cold flow of the PCB is a killer, but it is worse than that. If you just screw the terminal to the board, and the PCB will prevent the correct torque being applied then the joint will get warm. At 120 deg C the PCB passes its glass transition temperature when it becomes like a stiff paste. This will not help the long term reliability of the joint.If you screw terminals to a PCB always use Belville washers. Flat, crinkle and all types of shakeproof washers are a waste of time.How do I know? Repairing and scrapping all types of electronics.