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68 The PCB Magazine • September 2014 dan: What about people? Are people going to need to be better trained in the future? Will E-test get more difficult for the non-technical people to use? Todd: Yes, we are seeing some of this today. It has been the misnomer in the past that any- one can run a test machine and in some sense that is true; but today there is much more to the equation. Many times historically there is a su- pervisor (expert) on the floor that sets product up and the operator then just pushes buttons. This is not efficient in today's environment. Operators need to understand prints/drawings, set up their own machine and understand what the machine is telling them. This makes the operation more efficient, reduces delays due to false calls from the testers and allows the floor supervisors to focus on higher level issues. Ef- ficient training is absolutely critical. dan: I know that in some instances when independent test service companies are actu- ally going to take over the test departments of board shops. In the spirit of full-disclosure here, I know that you're company is doing some of this already, so do you think there will be more of what I call embedded services, in the future? Todd: I think this is inevitable. The sheer cost of capital equipment, staff and understand- ing specification requirements is making this function cost prohibitive within the individual manufacturing plant. All manufacturers have their FA department to review the final product for dimensional, finish, copper thickness and all other physical attributes. However, the dif- ficulty is fully making sure all the electrical at- tributes are covered. We take that worry away from the manufacturer. We know the specifica- tions; we understand the prints and customer electrical requirements. dan: Can you talk a little bit about new and more sophisticated types of testing will be done in the future? Todd: There have always been more inten- sive tests available but in recent times we are seeing the design shops call on these tests. This includes IR (insulation resistance) testing, se- lective high-voltage testing, which is not to be confused with hi-pot dielectric withstanding testing. Designers are reducing the size of the PCB and this has reduced internal core thick- nesses. Cores that are .002" (80 µm) and below cannot withstand the standard high-voltage hi- pot parameters that originally were called out by IPC-TM-650, so awareness and care must be taken when testing these designs. Buried pas- sive testing is now more common and this can be both resistive and capacitive. The test depart- ment must be able to identify these character- istics and provide the optimal and correct test solution. dan: Let's look into that proverbial crystal ball; where do you see E-test in five or 10 years? Todd: That is a difficult one. Technology is advancing so quickly that one could make an argument that the standard grid test machines in North America could very well be obsolete in the next five years or less. Although bed-of- nails test in North America remains stable at this point they will have to evolve in the near future. Asia has already made this leap and bed of nails machines of quad density are the norm, if not the requirement. Flying probes will cov- er the solution in the interim period but there will be the need for quad and ultimately, octal- density test machines. The other option is the return to dedicated fixturing and dedicated ma- chines which use wired technology fixtures and can provide the density requirements of these new and emerging designs. dan: Thanks Todd, very interesting and in- formative, as always. PCB todd Kolmodin is the vice president of quality for gardien services usa, and an expert in electrical test and reliability issues. to read past columns, or to contact Kolmodin, click here. WHERE DO WE GO FROM HERE? continues