Good Semiconductor IC / Bad semiconductor IC?

Sure!

You'll probably find that the absolute cheapest memory you can buy doesn't last as long or perform as well as the more expensive stuff.

Back in school, some classmates and I went on a tour of NEC in Roseville. The tour guide (a former chemical engineering student) mentioned, in front of a neat laser that processed memory chips, that NEC's chips have redundant wires, so if one wire fails, the chip can still work. You might not find that feature on cheaper chips.

This is probably bad advice. One of the more important influences on the price of a chip is the volume being produced. More expensive chips remain available largely because it is cheaper to keep on using a more expensive chip than it is to redesign and re-layout a printed circuit board to take advantage of a chip that didn't go into production until after the board was designed.

So the equation of higher price with better quality is rarely - if ever - valid.

And NEC was spending money on putting in redundant connections because a significant proportion of the chips coming off the end of their production line didn't work, and some of those non-working chips could be made to work by using one of the "redundant" connections.

Once they'd got their production process under better control, most of the chips produced would have worked first time, and they'd have stopped wasting money on the redundant connections (which never did a thing for the end-user anyway).

-- Bill Sloman, Nijmegen

A company that wants to stay in business TESTS its products before shipping them.

If an item does not meet all specifications at Final Test, that item is rejected. If a pattern of failure is detected, a cause in the manufacturing process is sought.

Companies that consistantly don't meet their published specs are soon exposed and rapidly lose business.

Learn something new everyday... thanks!

This NEC tour was back in '98 or so. Were redundant connections more commonly needed back then?

Michael