Test Technician, Micron Custom Manufacturing Services

Why being a Test Technician was the best job ever for somebody like me when getting out of college.  These are some of the lessons learned from the job that influenced the rest of my career.

My First Few Months

My first few months at Micron was an immersion into the world of high tech manufacturing.  I was hired into a division that eventually got spun off as Micron Custom Manufacturing Services.   It was an exciting time due to Microns tremendous growth, which led to plenty of opportunities for those who wanted to take advantage them. I was one such individual.

My first few weeks on the job was learning how to test and manufacture printed circuit boards The main products were 256MB add in memory boards that took up a whole add in slot   Yeah I’m that old…  but I digress…

Learning how to manufacture a PCB was my introduction to what is commonly called a Process Flow, or a Workflow.  At the time we just called it The Recipe.

It was here where I learned how automated control, in each functional area of the manufacturing line effected, overall product outcome.  For example, when I first started the Printed Circuit Boards (PCBs) used through hole technology to solder the chip  to the board.  A marketed improvement in manufacturing efficiency came about when automated chip stuffers were installed replacing the people who hand stuffed those chips.  An even greater level of accuracy was reached when surface mount components started to appear. 

I also became aware of how issues that show up in the manufacturing process effect the overall cost of the product.   As a test technician I repaired printed circuit boards that didn’t pass initial testing.  When discussing the costs associated with manufacturing a PCB it was obvious that special handling of the product increased cost.  Therefore it was my job to minimize the amount of special handling each failed board received and to get them back into production as efficiently as possible.

My First Special Project

Because I was young, career driven, and didn’t have a life I stayed in school and was pursuing my Masters at BSU.  Actually Micron paid me to continue my education so I thought why not!  One day I was thinking about a Stats assignment when it dawned on me that nobody was really tracking the types of errors we were seeing in the technicians area.  I mentioned this to my boss who gave me the OK to figure out a way to track the errors.  I ended up learning a DOS based database application and started to track errors.

After a month of working on this thing I showed the results to a few of the process engineers.  We broke the report down by the most common type of failure by product line.  The main cause of a PCB failing the testing procedure was a lead on a microchip would get bent and not go through the hole in the PCB to be soldered in place.

Nine times out of ten a bent lead can be spotted with a visual inspection.  Management then put a couple of non-technical people in the test area.  If a PCB failed testing it would be visually inspected by cheaper labor.

The second most common cause of failure was non or improperly programmed PLD’s, programmable logic devices that looked like a microchip.  These devices had to be programmed and then placed into the PCB.  At first management decided to install sockets on the PCB’s because the cost of the socket was cheaper than re-working the PCB.  Eventually one of the test engineers decided to start testing the PLDs before they were approved for the manufacturing line.  This turned out to be another one of my special projects after I was promoted into Test Engineering.

The lesson I took from that experience was it’s easier to solve a problem when you first take the time to understand what works, what doesn’t work, and what can be improved.

The Bone Pile

As a Technician it was my job to repair PCB’s and I was pretty good at it.  I understood the schematics as well as how to use the main tools, an ocilloscope and volt-meter, to trouble shoot problems.  I got so good at it that for four hours each day I was assigned to the Bone Pile.  A wide and varried collection of PCBs that failed the manufacturing process.  Some boards went into an Atari system, some a PC, some were video boards, it was truly a hodge-podge of failed boards.  Or as I liked to call it a challenge!  I loved working the bone pile and everybody else hated it!

One day a test engineer brought a logic analyzer into the tech area for a project he was working on.  Jon and I were on good terms so I asked him how it worked and he showed me.  After his shift was over I asked if I could play with it for the rest of the evening.  I was working 3 to midnight at the time. He, of course, said yes!

So for the next few hours I went through the bone pile with a new toy at my disposal.  Learning how to use the logic analyszer was pretty straight forward and the data it provided was amazing!  One board in paticular had been vexing me for weeks so I decided to try another attempt on fixing it.  By this time I had replaced four or five chips on the board and it still wouldn’t work.  With help from the analyzer I was able to finally identify which of the 64 DRAMs soldered on this board was faulty.

It turned out to be a peice of anti-static foam, whose color and make up was that of a tiny peice of a black sponge, wedged between two leads on the DRAM.  The origin of the sponge was obvious, it covered every square inch of benchtops in the manufacturing line as well as the tech areas.  We used it everywhere!

I told Jon what I discovered the next afternoon.  Within a week all of the black anti-staatic foam was removed and replaced with a blue vynyl type of ant static matting.

This experience taught me several things.  First is the cost of manufacturing goes up when the failure is discovered in the manufacturing area.  If however, the error is discovered by the customer then the company lost money on that transaction.  Replacing the static foam at the cost of a few thousand dollars was completly outweighed by the enhancements in reliability that were gained by removing the sponge like material from the equation.

Another lesson I took from this experience was how the simple things can really mess up the big things.  “Pay attention” was a favorite cry of Chef Schroder when I was the Sues Chef at the Arid Club.  In the manufacturing environment detais were just as important.  Professionals always pay attention to the details.

Finally I learned that if there is an opportunity standing right in front of you take it.  By taking a few chances at Micron, and by being good at my job, I was promotted into Test Engineering with 18 mnths of getting out of school.

Final Analasys