EEVblog #730 - Thin Film Resistor Networks

How ceramic backed precision thin film resistor networks are constructed and laser trimmed.
Examples come from the resistor networks in the 7.5 digit Keithley DMM7510 Multimeter, manufactured by Fluke.

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[albessat]

Hello Dave,
This is an amazing video. I have extensive background in laser material processing in the medical field.That being said, I wanted to point out that the reason for the clear glass cover is for final precision trimming. The clean trim lines have been made with open substrate before the glass he been installed to rough in the values to a closer range than after the glass is installed the network could recieve the final absolute tune in as laser can still travel through the glass with minimal distortion. You can tell by the evident burning marks trapped behined the glass which is soot from the laser vaporized material that would not be possible to evcuate after sealed. I would l also point out the that final triming process could also be done in circuit after board assembly.
that is the difference between a $$$ precision device and a $$$$ precision device.
Cheers.

[ian-c.]

This was actually a lot more interesting than I expected, thanks Dave !

[DJignyte]

Cheers for all your work, Dave! these close up photos are simply mind-blowing!

[kenatnip]

I know next to nothing about electronics but your videos are changing that. Thank you sir for taking the time to share your knowledge with others.

[mikeselectricstuff]

I wonder if the 2 different colour materials have opposite tempcos to get an overall near-zero tempco.

[Demyanych]

Very interesting video! I worked in  laboratory sputtering thin-film resistors for hybrid integrated circuits crystal oscillators. We sputtered alloy resistive silicon-nickel-ferrum (RS-1004) on substrates from Sital.
Earlier sputtering was performed by the explosion - of a resistive alloy powder poured out of the bunker on a hot plate of tungsten and evaporated in it, then we have modernized, instal a magnetron, and started sputtering target resistive alloy.

Sorry for my illiterate English.

[OneBiOzZ]

I have dealt with what we called CPA (ceramic precision arrays is just what we called them in house) and i think you hit the nail right on the head here! great work as always!

[Tangobaldy]

Watched this on my smart tv. Amazing quality!

[sallowsandy]

Thank you Dave, a bit thumbs up to you - you deserve a lot for your effots.

[helgirudd]

Surfing the edge of the tangible and the microscopic... beautiful, love your work :)

[timmgiles]

Great video Dave, I always wondered what high precision resistors looked like and now I know

[adamwolfram]

I enjoyed this very much. Component technology is extremely fascinating!

[GoldSrc_]

Resistors just got a lot more respect from me, amazing, thanks Dave.

[didaloca]

I don't know why, but I always get excited when I see components that I recognize! Like the 2n3906 transistor! :)

[lejink]

I never get more than a few minutes into these videos before the video ends up in the background and I'm off Googling things Dave is talking about

[lasersbee]

It seems I learn something new every day... Thanks again Dave. :thumbsup:

[nrdesign]

I recently had to deal with ESD materials at work, and didn't know much about the Ohms per square. Thanks for clearing that up!

[nowt]

Dave, this was really interesting! I enjoyed learning about the ladders especially. Thanks for this! Very, very interesting indeed.

[mike]

Good work Dave. Very interesting indeed.

[nickclark]

These are widely used in the automotive industry, in components such as : engine management computers, air flow meters, , lambda probes (oxygen sensors ), electronic throttle units, pressure sensors of all types, . also electronic accellerator pedals which are quite comp!ex variable resistors. Each sensor individually laser trimmed to give the desired accuracy. So when you buy a non genuine part which is half the cost you get problems !