Factory life, consultants, graduates and analysis paralysis
I know we normally put technical issues and processes under the eyeglass, but for a change, I thought we might have a look and a chuckle at the expense of all these people who are put under pressure trying to resolve the PCB process problems and circuit board quality issues. (This includes yours truly).
In the dim and distant, we were a new circuit facility with all the gear and you guessed it. We found we were suffering from registration problems at drill so the holes were wandering off. One of our top engineers did an analysis of the 18 multi spindle CNC machines and after weeks of number churning and data analysis, called us all together and announced, “I can see a way forward, machine number 14 never produces the registration problems. I have done the research and can state that with no fear of contradiction.” We were all excited about improving the registration problem and getting the yields up to contribute to our annual bonus.
“What we should do, is strip the machine down totally and check every bearing, slideway, spindle collet and find out what is so good about this machine.”
It was agreed, overtime was put on at a weekend, measuring equipment made available, the machine released from production. I went down at tea break the day before and was talking to the operator who I vaguely knew. In the conversation, I explained what we were doing and why. “I can tell you why it doesn’t produce scrap drilled boards,” she announced. “I think this will be interesting,” she continued, “it is a routing machine used for profiling.”
Finishing my coffee, I went back up to my colleagues and broke the devastating news.
Lesson one, always consult at grass roots level, it has stayed with me forever.
It was decided we needed a new tooling system for photo mechanical imaging of the solder mask. A fresh outlook would be needed so we involved a local university. The bright eyed post grad student turned up and was briefed by me as to the requirement. After a couple of days, he came to me with a ‘seen the light’ expression and told me to give him a week and he would go through this sensational idea. I left him to it.
At the end of the week, I sat in a conference room with him and he got out all of his overheads and proceeded, “What we need is a flexible system away from the hard tooling pins which damage the artworks. What I propose is that we roll out the artworks onto the board and hold them in place with magnets.”
The conversation that followed was something like this.
Me “I like the concept but what do the magnets stick to?”
PG “The copper on the board… der”
Me “Copper is not magnetic”
PG “That is a joke, isn’t it?”
Lesson 2, get the basics right.
As technology moved on, the testing became more and more complex and some of the test fixtures had thousands of pins which were hand placed. The pins are like a nail with a head dropped down through several plates and held only by the top plate and the head. Some of these complex fixtures took days to pin. Our patient sharp eyed operators, no matter how vigilant, would occasionally miss a pin. One of the managers was chatting to the pinner one day who was explaining how difficult it had been to spot the missing pins on this particularly high density product being worked on.
“That’s easy,” said the manager hoisting the whole jig up to the light to see the holes with no pins in them. In one second, it was all of them as close on 10,000 carefully placed pins dropped onto the floor.
“Oops, well that didn’t work very well,” as he disappeared red faced.
Lesson 3, let those who know get on with it.
Factory life is wonderful and yields millions of stories, please feel free to share some of yours with us (Email me: Johnbarry@clarydon.com). I can tell you when I sat on a plating jig not realising that sulphuric acid rots denim, so when I was standing in the pub later with no backside in my jeans nobody chose to mention it.
Next month under the eyeglass will be about process control and documentation, unless someone can suggest a better topic.