Guten Wienerschnitzel, netters,
challenge for an IBM-guy if he reads (no, of course he doesn't, big Blue too big) , maybe my mate and competitor Bev can rise his eyebrow and move his finger to the keyboard. Topic: multilayer 3D "boards" with IBMs liftoff and PI dielectric. Reactive Ion etch (O2/He RIE) through mask for removing PI, followed by WSiN sputter for biting and low current electroplating for first step making the vias. Vias are finally O2 plasma, SF6 RIE'd. Now, most seems maybe familiar to you, but, the problem is that the conductors are only 4um wide and the vias 1um in diameter. Test "board" consists of single to two layers with very short conductors, daysichained, let's say a hundred such strips. See it in front of you: gold, under is the via, via goes  horizontally some um, goes up to next gold, .. up, down, up down, like chaining an ordinarey PWB, but one decade smaller. And, PI is the dielectric, approx 2um thick. Now, palomas, the Q:
when these "boards" are temcycled we get interrupts somewhere in the daisychain, seen as RF signal anomalies. How on earth do we analyse? Ordinary SEM of surface tells nothing of what's under the conductor. Finefocus Xray has unsufficient resolution for finding microcracks. Sonoscan, no. Cross-sectioning, no, weeks of job, little chanse of finding rupture. Reactive etching will heat and possibly take both Gold and PI. Wet etching, e.g. KaC? Takes Au, but what do you do with the W under Au? Agree, more like semiconductor techs.

Oftenly when we have to do with the japs, we describe with hands, paper, mail, photos and words, and they reply 'yes', 'yes', which is oftenly of little help. So, Bev (I'm sure you have a recipe in your pocket) and like, what do I do with the drunken saylor?
Aussilek, give up, you can't be specialist on everything, you must have some limitation, please, tell that you are a human and not a Cray. (on that isle you may say crayfish, I don' t know).

Cu?

Ingemar Hernefjord
Ericsson Microwave Systems

PS. With HISTACK, I mean that our test samples remind of this EU-thing, but does not belong to EU at all.

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