HP4401A - die pictures of hybrids - Page 1
Forum section: electronics / testgear

author: Noopy
author_rank: Super Contributor
timestamp: May 01, 2020, 09:36:52 pm
content: Hi all,are you interested in the HP4401A? It´s a plug-in-card for the HP3852A Acquisition system.The HP4401A contains the "HP Multi-Slope II conversion technique" which is also used in the HP3457A, HP3468A and HP3478A. Because of that it contains a lot of similar components.HP used a nice shielding foil for isolation of analog and digital parts.I´m sure many of you realize the circuits.…Too many pictures! You have to visit my Website:https://www.richis-lab.de/HP44701A.htmGerman as usual but ask me in here whatever you want to know.In my view the most interesting facts are:- It seems they used different "key-pictures" for different dies.- In my view the slope switch would be able to support seven steps.- They integrated a strange overvoltage protection in the second hybrid...

author: Hydron
author_rank: Super Contributor
timestamp: May 01, 2020, 10:24:20 pm
content: Very interesting as usual, thanks!

author: TiN
author_rank: Super Contributor
timestamp: May 02, 2020, 08:52:45 pm
content: Amazing pictures as always. My only wish is for higher-resolution/unresized photos, so we can put them on big monitor wallpapers tooAre those resistance networks chips covered in pink epoxy on top? Is the epoxy soft? Or is it transparent (quartz?) substrate with resistor stuctures?Do you have ability to measure resistors, maybe probe them with some superfine tip, with broken connections to active chip?

author: Noopy
author_rank: Super Contributor
timestamp: May 02, 2020, 09:53:14 pm
content: Thanks!Well I enlarged the standard pictures to max. 1400px width and max. height 1000px, isn´t that enough?To be honest often the pictures aren´t good enough for 4K. After all it´s only a modified SLR camera. I do overview pictures and detailed pictures. To get nice 4k-pictures I would have to do a lot of detailed pictures. With my low-tech equipment that´sa lotof work.Furthermore the current size doesn´t consume too much webspace…If you need a special detail I can try to supply you with more pixels.It seems like the pink material is kind of a glue and only shines through the transparent resistor array. On the tilted picture I don´t see any sealing. I assume the substrate is glass or a special plastic.I have some good multimeter tips but no special micromanipulator. I can try to do measurements but often sitting in front of the part you realize how small the pads really are.

author: TiN
author_rank: Super Contributor
timestamp: May 02, 2020, 11:06:11 pm
content: It's not about how small parts are, it's about how steady hands are.1400px width are my previews size for siteI always upload images in full resolution on click, so pixel-peepers like myself can enjoy and salivate.Obviosuly having own physical server makes that possible, as I have zero concern about webspace. Currently site weights about 900GB , not including video content (which is meh quality, to be honest). If you need gigabytes of free webspace, just give me a hint

author: Noopy
author_rank: Super Contributor
timestamp: May 03, 2020, 10:02:04 pm
content: Quote from: TiN on May 02, 2020, 11:06:11 pmI just looked at the pads… No, I won´t be able to contact these small pads, sorry...Quote from: TiN on May 02, 2020, 11:06:11 pmIn principle you are right… Finally storage isn´t really expensive...But you definitely should uploadnewpictures!