There are two reasons to use copper rivets/eyelets on every through-hole lead for two-sided PCBs. First, it makes soldering so much easier. Second, well…. odds are that you will make use of it as a via.
(edit: I discovered that the proper name for these things are eyelets, not rivets.)
My DPCB system came with two sizes of eyelets. The small eyelets are used for vias. Drill 0.7mm holes for these eyelets that have an inner diameter of 0.4mm. Design your board with 28 millinch holes for the vias with a 38 millinch or larger pad.
Eyelets for the through-hole component leads have a 1.0mm (39 millinch) inside diameter which fits just about everything. Even a 0.025″ header pin has a diagonal measurement of 1.4 mm (29 millinch) so they fit well.
When you first start making DPCBs, your board design should plan on drilling 1.5mm or 1.6mm holes, with a pad diameter of at least 2.2mm (87 millinch). Your through-hole part probably has 2.54mm spacing (0.1 inch) so with 2.2mm (87 millinch) pad diameter you will have 0.34mm (13.3 millinch) clearance between the pads. Too often, however, when you stake the eyelets, the heads may expand until they short to the adjacent eyelet.
There are three ways to prevent shorts between eyelets.
- be extra cautious when staking the eyelet to keep head expansion to a minimum
- Use a sharp utility knife, such as an X-acto to cut the eyelet head a little narrower after staking.
- Alternate installation direction of the rivets. One inserted from the topside, the next inserted from the bottom side.
Method #3 was not my idea. But when I saw it posted here. I instantly thought “excellent idea, why didn’t I think of that.” Follow that link of a photograph of the method.
First install every other eyelet from the topside of the board and then stake them. Then install the eyelets from the bottom side of the board and stake them. You will have plenty of clearance between eyelets now.
That’s plenty of pad-to-pad clearance for now. That will not leave enough room to run traces between the through-hole leads, but as your progress with your DPCB skills you can modify your dimensions to allow such traces.