Monday, 18 May 2015

Poor Man's Through-Hole PCB Rivet

First of all I have to thank Retromaster for his descriptions on how to do through-hole contact riveting. My double-sided prototype PCBs are done on a CNC Router but originally I was using just flexible wire soldered on both sides of the PCB. This method I found just created big solder bumps , not much good for surface mount IC's with through-hole contacts directly under them. So to remedy this situation I used a drill press with a 3mm stainless rod mounted in the Chuck. I put short pieces (approx 2.6mm long = thickness of PCB 1.6mm + Protrusion on each side of PCB 0.5mm X 2  ) of tinned copper wire whose diameter  matches closely the diameter of the via hole into the via for the through-hole connection. I positioned the 3mm rod in the chuck over the via to be riveted with the copper wire in the hole and gently rotated the drill press capstan. This pressed the copper wire into the hole. I relaxed the pressure on the PCB to allow the balancing of the head size of the rivet on both sides of the PCB. Below is a photo of some practice rivets and one via not riveted on a scrap PCB for practice, these rivets will have a light soldering using solder paste to ensure a good electrical connection. I am very pleased with this method of connecting vias on PCB prototypes.

Riveted through-hole connections

CNC 6040 Spindle Control

Note: This is only an on - off control there is no speed control due to limitations on the CNC control box , you set the speed using the pot...