A technical blog by John Barry, providing insight in to the PCB manufacturing and assembly industry.
There are lots of views on testing circuits from both the PCB manufacturer and the user. As a user, a well worn phrase is ‘’they don’t need testing if you can guarantee they are right.’’ As a manufacturer, you can’t guarantee they are right without a test so the ball is back in that side […]
It seems an obvious statement that once a board is finished, it needs to be shaped to suit enclosures but as usual in the manufacturing of any product, there are options which can impact heavily on the cost. The cheapest and most cost effective shape is a rectangle and this is because it fits on […]
So, why do we need a solder mask? Well, when we first used circuits to interconnect components the majority of the work was hand processed using soldering irons. The heat was applied to local areas and the chance of shorts was small. As volume use increased, the PCB industry moved on to wave soldering and […]
In the early days of circuit boards, life was simple. You made a silk screen image in negative of your tracks, screen printed them onto copper clad laminate using an etch resist ink, cured the ink, etched the exposed copper off, stripped the ink and hey presto, basically your circuit board. Then came the requirement […]
Thank you for your emails and memories of good old solder finishes but I opened up a question by mentioning undercut and a few of you have asked for a bit of background. Undercut is relatively easy to explain in that when a copper sheet is chemically etched, it is done with a bank of […]
For those of us who can, let us cast our mind back to the days when 12 thou gap and track was still a technological challenge and there was a rumour someone could drill and plate 0.6mm diameter holes. Surface finish was simple in those days. You had roller tin for single sided complete with […]
I have been involved in Automatic Optical Inspection (AOI) for close on 30 years during which time the technology has moved on dramatically, but I am still amazed, as I was then, why a system as sophisticated as this is abused by its owners. That may sound harsh judgement but I still see people using […]
