PCB-mounted contacts for 9V battery

Do you guys know where to order (or even what name to find them by) the little contacts (clips?) that the 9V battery plugs into, but in a PCB-mounted version. I've seen them on some boards, positive and negative terminals as separate parts, positioned 90 degrees to the board (so the battery is parallel to the board) and I'd be interested in those, too, but my immediate need is something that I can solder flush with the board so that the battery stands on its contacts on the PCB. I realize it's not very secure that way but it should work for me.

I've seen TONS of pre-cabled contacts with both positive and negative terminals but I'm looking for something that's solderable and does not include parting out a connectorized contact.

Thanks!

Reply to
passerby
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Keystone has these in a couple of versions. The first one requires something else (usually the enclosure) to keep the battery pushed into the contacts:

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The second one looks just like the contacts on the top of the 9V battery; it will stay reasonably "plugged into" the clips by itself:

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Digi-Key and Mouser stock at least the "plug in" style.

Standard disclaimers apply; I don't get money or other consideration from any companies mentioned.

Matt Roberds

Reply to
mroberds

Keystone has several variations. 968 and 967 seem to be closest to what you want:

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The "90 degree" style comes in a couple of versions. The first one requires something else (usually the enclosure) to keep the battery pushed into the contacts:

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The second version looks just like the contacts on the top of the 9V battery; it will stay reasonably "plugged into" the clips by itself:

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Digi-Key and Mouser stock at least some of these contacts.

Standard disclaimers apply; I don't get money or other consideration from any companies mentioned.

Matt Roberds

Reply to
mroberds

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Reply to
krw

Thank you for your input! Looks like Keystone is the way to go. I also see the exact version I needed - just the snap-on socket and the snap-on stud (and now I know how they're called!) as separate components. I will still need to figure out how to mount them on the board because they aren't solderable - the mount type is shown as "custom" and I believe they are meant to be held in place by some sort of a rivet.

So, that's going to become my next question then - how do you deign a board for the .125" rivet? Do you make a .125" hole for it or larger? Will it damage the FR board material when it gets squished if the hole is the exact size? Does this need to be a plated hole? Do you solder it over after you installed the rivet (from the back side, of course)?

Thanks in advance for all input you can provide on the rivet mounts!

Reply to
passerby

Keystone part numbers 261 and 269?

I think the rivet problem is why Keystone part numbers 967 and 968 exist. They install the rivet for you, and the rivet has a PC pin coming out of the bottom. You just need to provide two 0.086" holes on an 0.5" center in the board. Note that the insulator will sit not quite flat on the PC board, due to the rivets on the bottom side of the insulator. Keystone does not specify the gap, but it looks to be on the order of 0.010" to

0.020" in
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.

Look closely at Keystone's catalog. The contacts that have an 0.125" hole are marked as "Senior" size (262 and 270), which is the wrong size for a 9 V battery. The "junior" size (261 and 269), for a 9 V battery, have a smaller hole.

There is a single page from an older catalog at

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which shows an 0.093" hole on the stud and no data on the socket. Their complete current catalog, available from
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, shows an 0.097" hole on the stud and an 0.096" hole on the socket on paper page 30 / PDF page 37. So, you need a rivet that is smaller than the hole.

The eyelets and rivets they have are on PDF page 141 / paper page 134 of the complete catalog. Eyelet part numbers 22-27 and 33-37 have a narrow enough shank to fit through the hole in the contacts. The length you need depends on how thick your board is; remember that some of the length will be used up when you round it off when installing. I can't tell from the information given whether you want the 22-27 eyelets or

33-37 eyelets; the eyelet head has to fit inside the battery contact.

The 3381-3383 and 3384-3387 rivets may also work; their heads will stick up more than the eyelets and may not fit as well in the contacts. Again, I'm not sure which series you need.

You pick the size based on the outside diameter of the eyelet or rivet you are using. Keystone has recommendations for the eyelets and rivets they sell; in general the hole is a little bit bigger than the outside diameter of the eyelet or rivet. For instance, for an 0.089" diameter eyelet, they call for an 0.093" diameter hole.

You have to be a little bit careful when you set (squish) the rivet. If you set it too hard, then you may damage the board. I think you are more likely to damage the board surface or trace than the inside of the hole.

Only if there will be traces connecting to the battery on the same side as the battery snaps. If all the traces are on the other side of the board from the battery snaps, they don't have to be plated holes.

I would. Before plated-through holes existed, at least one TV manufacturer tried to use rivets to join the traces on one side of the circuit board to the other. They were soldered at the factory, but it apparently didn't always work that well:

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This might be a good job for a 100 W or so "gun" soldering iron, rather than a lower-rated "pencil" iron; there's a lot of metal to heat up.

You will also need some kind of tool to set the rivets; Keystone sells them.

Advice: If you are only making one or a few of this device, the 967 or

968 clips will be a lot easier to deal with; two PC board holes, two pins to solder, done. (You or your PC board assembler will also find this easier; you/they *know* how to solder things to a board.) If you are making lots of this device, then it may make more sense to use the rivet-on contacts. In this case, it might pay to get a sheet of unetched circuit board material the same as what you will use in production, order a few each of different sized rivets, and try attaching the contacts. Then you know what you need before you order a bunch, and you can talk to your board assembler about the correct rivet technique. Also, if you are making lots of this device, it might be worth an email to Keystone to see what they recommend.

Matt Roberds

Reply to
mroberds

Delco tried them in their car radios & called them Gripletts. They were hard to doled in a solder wave machine & not get cold joints.

Reply to
Michael A. Terrell

Thank you for the incredibly detailed answer, Matt. I think I understand the situation much better now than when I started! It looks like the 967 clips are the way to go for me - the rivets may be doable but require very careful consideration but the pre-mounted ones only add less than 2mm to the height and I think (need to see one up close first) I can route traces under the contacts themselves because they are raised on the fiber insulator - will be handy on what should be a very small board. I'll get myself a few to try and go from there. Thanks again!

Reply to
passerby

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Using rivets for electrical contacts isn't too reliable if your board is likely to see temperature cycling. The FR4 expands more than the rivet at higher temperatures, so the FR4 gets squashed and cold-flows a bit to relieve the stress. When the temperature comes down again, the preload on the rivet has been reduced by the cold flow. There's nothing that tends to make it flow back again, so repeated temperature cycles will eventually reduce the preload to zero. It doesn't necessarily stop there, either--the rivet can pull the copper away from the board and crack it, making an open or intermittent contact.

So rivets are OK for mechanical mounting, but you need soldered joints for higher reliability.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
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Reply to
Phil Hobbs

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I've seen a few brass rivets used to join 9 volt battery terminals to PCBs which all hardened and cracked over time. Thermal cycling should not have been an issue for a device that just ran a few LEDs either.

Little bit of solder fix those things up.

Reply to
Cydrome Leader

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