ZeptoBars - RSS feed http://zeptobars.com/en/ Microelectronics. Die-shots. Artificial intelligence. Lasers. en-us Tue, 10 Jun 2006 04:00:00 GMT Mon, 11 Dec 23 03:01:20 +0300 webmaster@zeptobars.com 120 10 <![CDATA[STMicroelectronics TS974IDT - quad CMOS opamp : weekend die-shot]]> http://zeptobars.com/en/read/STM-TS974IDT-quad-CMOS-opamp-R2R Look at that 4-way VCC split to improve channel-to-channel isolation!

Fri, 01 Dec 23 08:40:04 +0300
<![CDATA[Philips NE558N - quad 555 timer : weekend die-shot]]> http://zeptobars.com/en/read/Philips-NE558N-quad-555-timer Segnetics NE558N (Segnetics was acquired by Philips in 1975). Die size 2435x2408 µm.

Wed, 29 Nov 23 21:02:25 +0300
<![CDATA[Allegro A1304ELHLX - Linear Hall-Effect Sensor : weekend die-shot]]> http://zeptobars.com/en/read/Allegro-A1304-A1304ELHLX-Linear-Hall-Effect-Sensor

Wed, 01 Nov 23 04:19:27 +0300
<![CDATA[NXP PMBT2369 - supercomputer NPN BJT : weekend die-shot]]> http://zeptobars.com/en/read/NXP-PMBT2369-supercomputer-NPN-BJT-logic-resistor-logic deep dive by Tim was extremely interesting. Key to success here is not just multi-finger layout (which is quite common in high-frequency transistors) but also gold doping which dramatically reduce saturation recovery time without any additional circuitry. You can also see this Gold trick in Fast Recovery Diodes.

If you know other widely available yet inexpensive fast transistor for logic circuits - please let us know!

Die size 299x239 µm. That's probably the first transistor we've seen where there is small test BJT in every BJT.

Mon, 30 Oct 23 06:40:00 +0300
<![CDATA[AMD AM685DL - analog voltage comparator : weekend die-shot]]> http://zeptobars.com/en/read/AMD-AM685DL-analog-voltage-comparator-high-performance-schottky Die size 1319x767 µm.

Sun, 01 Oct 23 11:57:05 +0300
<![CDATA[Motorola MC14490 - CMOS button debouncer : weekend die-shot]]> http://zeptobars.com/en/read/Motorola-MC14490-CMOS-button-debouncer-Bounce-Eliminator Die size 2400x2048 µm.

Fri, 01 Sep 23 09:13:15 +0300
<![CDATA[TimesVano G170DM - transient overvoltage protection : weekend die-shot]]> http://zeptobars.com/en/read/TimesVano-G170DM-transient-overvoltage-protection-SLIC TimesVano G170DM can be found in wired phone line protection circuit. Can survive 350A current for 2µs, clamps both positive and negative voltage spikes.
Die size 3148x2292 µm.

Thu, 01 Jun 23 11:21:48 +0300
<![CDATA[TL432 - Shunt voltage reference : weekend die-shot]]> http://zeptobars.com/en/read/TL432-TL431-Precision-Programmable-Reference-shunt-regulator TL431 is pinout.
Die size 810x662 µm.

Mon, 29 May 23 12:35:27 +0300
<![CDATA[RCA CD4035A - CMOS Shift Register : weekend die-shot]]> http://zeptobars.com/en/read/RCA-CD4035A-CMOS-4-Stage-Parallel-in-out-Shift-Register Die size 1733x1804 µm.

Mon, 01 May 23 10:42:07 +0300
<![CDATA[Zeptolab upgrade - March 2023]]> http://zeptobars.com/en/read/zeptolab-upgrade-2 support of Zeptobars patrons - several vital hardware upgrades finally happened which will increase image quality and will make work more streamlined : custom wavelength RGB illuminator and 2-axis goniometer. Finally, we've also got Mastodon - @zeptobars@techhub.social - let's keep in touch there (just in case).

More details below:

First is custom RGB light source. I had to admit I've spent way too much on it due to fine-tuned wavelengths of the diodes.
My previous RGB light source that I used with old Chinese microscope used regular 450-520-620nm RGB leds. These do not match Bayer filter matrix in Sony imaging sensors very well (colors bleed into wrong channels reducing saturation and reducing efficiency of software correction of lateral chromatic aberration). So I decided to go for 440-545-660nm, which matches RGB filters and covers wider spectral range.

440nm is shortest wavelength that can be used on fluoride microscope lenses without significant quality degradation (they are designed for ~436nm and longer). Getting 440nm LED was straightforward - as it's just binning of commercially available GaN diodes. 5 batches from different suppliers was enough to nail down the wavelength.

660nm is the easiest. My very first batch was spot-on.

545nm diodes though are very challenging as they are in "green hole", where all LED semiconductors shows poorest quantum efficiency. In blue direction GaN starts working very well around 510-520nm. In yellow/red - multiple options starting at 580. I've tried to find extremely binned GaN diodes, and maybe 10 different batches gave me 530nm maximum. Phosphor-converted green LEDs have extremely wide spectrum, and definitely not suitable for this application. Finally, I've ordered GaP diodes from China, and in 4 batches one was perfect at 545nm. Surely, quantum efficiency is much lower, but I don't illuminate whole room anyways.

Per-channel adjustable current allows to set white balance to make sure gains of all RGB channels are 1.00 => lowest noise on the image. All extra capacitors (and inductors) - form CLC filter to ensure supply ripple does not introduce noise on progressive scan camera sensor.

LED light is side-coupled into 3mm optical fiber, which goes into microscope. I still want to build second version with the same LEDs with higher coupling efficiency. Otherwise I am already quite happy with it.

RGB illumination have 3 main benefits:
1) We work only on wavelength where lens shows highest quality,
2) RGB color channels are "independent", and correction of lateral chromatic aberration is much more efficient,
3) Color saturation is much higher without any special post-processing. See example below, exactly the same chip, similar post-processing but different light source:

White LED:


2-axis goniometer:
On the second upgrade - while ~80% of chips are flat enough to be photographed on regular XY stage, remaining ~20% are slightly tilted and became royal pain in the ass (typically in metal or metal-ceramic packages, due to uneven soldering or cases which impossible to lay flat). Dual-axis goniometer with micrometer adjustments from "ZY Automation" finally solves this issue.

You can also read previous article about how things worked in our lab in the past. ]]>
Mon, 06 Mar 23 02:50:12 +0300