You ever see a DIP-40 like this one? - Page 1
Forum section: electronics / projects

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 18, 2016, 10:42:28 pm
content: From Wikihttps://en.wikipedia.org/wiki/Intel_8086#/media/File:KL_USSR_KP1810BM86.jpgPretty bizarre but oddly appealing.

author: ataradov
author_rank: Super Contributor
timestamp: May 18, 2016, 11:19:00 pm
content: Yes, I did. There is also a version with oval-shaped holes, which are molded from both sides, so metal traces that go to pins are fully exposed and hanging in the air.And here is another design -http://cdn.cpu-world.com/CPUs/8086/L_USSR-KR1810VM86%20(Kvazar)%20(with%20traces).jpgCan't find a picture with the molding holes on both sides, but they basically looked like this -http://i.ebayimg.com/00/s/MTIwMFgxNjAw/z/n-YAAOSwe-FU5Kwt/$_1.JPG, but with completely transparent holes.

author: robertbaruch
author_rank: Regular Contributor
timestamp: May 18, 2016, 11:47:01 pm
content: Yep, all the 40-pin chips from my USSR-era calculators look like that.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 19, 2016, 01:06:08 am
content: Haha, awesome, just bought one of those on eBay. I enjoy these oddities. My parents threw out my XT years ago ... grrr....

author: TerraHertz
author_rank: Super Contributor
timestamp: May 19, 2016, 01:06:29 am
content: Looks like you are supposed to eat it in three bytes.Or snap it along the perforated lines for lower power versions.

author: Cubdriver
author_rank: Unknown
timestamp: May 19, 2016, 04:43:52 am
content: Quote from: TerraHertz on May 19, 2016, 01:06:29 amResulting in three 2-2/3 bit processors?-Pat

author: Circlotron
author_rank: Super Contributor
timestamp: May 19, 2016, 05:39:40 am
content: Quote from: TerraHertz on May 19, 2016, 01:06:29 amYeah, I was going to say it looks like it ought to be made of chocolate.

author: Fungus
author_rank: Super Contributor
timestamp: May 19, 2016, 07:44:25 am
content: Quote from: ataradov on May 18, 2016, 11:19:00 pmStylish - exactly what every computer-chip-based movie plot needs!(Seriously though: I can't think of any reason to do that other than it looks nice)Quote from: TerraHertz on May 19, 2016, 01:06:29 amDefinitely looks like you're supposed to be able to snap it.There's no reason they couldn't make chips like that. eg. Imagine an Atmel AVR chip that could be made smaller if you don't need all the I/O pins for a project.

author: Circlotron
author_rank: Super Contributor
timestamp: May 19, 2016, 08:07:14 am
content: Like that old saying - if you can't hide it, make a feature of it.

author: mikerj
author_rank: Super Contributor
timestamp: May 19, 2016, 11:29:04 am
content: So what's the actual reason for this? The only thing I can think of is that the slots cut into the package either side of the die would tend to remove bending stress from the die (e.g. during installation) which could be significant on such a long package.

author: tggzzz
author_rank: Super Contributor
timestamp: May 19, 2016, 11:46:38 am
content: Quote from: Cubdriver on May 19, 2016, 04:43:52 amIntel did, of course, make 2-bit wide devices, i.e.http://www.cpu-world.com/CPUs/3002/

author: senso
author_rank: Frequent Contributor
timestamp: May 19, 2016, 12:56:58 pm
content: Those wire frames look to be punched out to un-short each pair of pins, some ESD protection during potting?

author: bson
author_rank: Unknown
timestamp: May 19, 2016, 01:09:02 pm
content: Looks like the cutouts are there to provide access to test points. Maybe they didn't have the means to test prior to or during bonding, and this turned out to be economically advantageous over using the DIP pins for testing? Either that or the bonding itself had non-zero defect rates? Either way, it looks like a packaging hack to work around some manufacturing limitation.

author: SeanB
author_rank: Super Contributor
timestamp: May 19, 2016, 04:15:59 pm
content: I used to fix stuff with an Intersil ADC which came in a purple ceramic package. Interesting to have an ADC which was 18 bits, stable over the full military temperature range ( well, at least the reference and the ADC drifted at the same rate and direction, so the inputs were all stable as it cooked up from cold) and all the ADC and the 20 odd logic chips and Jfet switches ( none of this rubbish CMOS analogue switching, only JFET switches with oddball supply voltages like -21V, 17V and -9V, along with a standard TTL 5V supply and the obligatory opamp +-15V rails) were all on one plug in card. The multiplexing for the inputs lived on the next card, along with the 741 opamps used for signal conditioning and the synchronous rectifiers. Sampled all 8 400Hz signals in a single cycle, and then the next 3 cycles sampled all the arithmetic constants ( set by another board with a whole load of Vishay 0.05% resistors giving assorted selections of the main reference voltage) used in the calculations it did. Output was digital, a single bit delivered via a relay.

author: TerraHertz
author_rank: Super Contributor
timestamp: May 20, 2016, 10:43:39 am
content: I don't suppose these ICs with exposed leadframes could have more than one die in the package?Because then making leads going between the dies accessible for testing would make sense.

author: wraper
author_rank: Unknown
timestamp: May 20, 2016, 10:48:17 am
content: I guess this could be done to hold a big lead frame in the stable position while molding the package.

author: EEVblog
author_rank: Unknown
timestamp: May 20, 2016, 10:49:40 am
content: Quote from: Alex Eisenhut on May 18, 2016, 10:42:28 pmMmm, chocolate...

author: Cubdriver
author_rank: Unknown
timestamp: May 20, 2016, 01:44:44 pm
content: Quote from: wraper on May 20, 2016, 10:48:17 amThat makes sense. And some of the other images appear to have small drill spots between the conductors which could have been reinforcing bridges that were removed after encapsulation.-Pat

author: LazyJack
author_rank: Frequent Contributor
timestamp: May 20, 2016, 01:53:26 pm
content: Also, don't forget that at least for a period of time, ICs made in the USSR were converted to metric sizes. Meaning that the 2.54mm (0,1inch) lead spacing was converted to 2.5mm. This was not really a problem on a DIP14, but a DIP40 was a different thing, the pins were pretty much off if you wanted to put it into a capitalist PCB or socket. This was especially interesting with copies of existing chips, like the 8085 etc.

author: djQUAN
author_rank: Frequent Contributor
timestamp: May 20, 2016, 04:03:09 pm
content: Quote from: Fungus on May 19, 2016, 07:44:25 amHow about saving on the amount needed of encapsulating material?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: June 04, 2016, 12:38:03 pm
content: Quote from: LazyJack on May 20, 2016, 01:53:26 pmJust got the chip, and indeed the pins don't line up to a capitalist 40 pin DIP. 0.76mm off if my math is right. Can't be bothered to measure it. Gotta go find an XT or something like it to plug it into.

author: jitter
author_rank: Frequent Contributor
timestamp: June 04, 2016, 04:23:39 pm
content: I was wondering what? ?? means... of course... MADE IN USSR...That reminds me when I was a boy my parents bought a Lada 2105GL, and with it came quite a comprehensive toolkit which had a spanner in it that said "Made in USSR". Obviously that was for the export model going to the evil capitalist countries.Edit: huh, the preview showed me the Cyrillian characters just fine, but they've turned into emoticons after posting?!

author: ataradov
author_rank: Super Contributor
timestamp: June 04, 2016, 04:26:05 pm
content: Not capitalist. They were going to Cuba and other countries like that.This forum does not like Russian.

author: jitter
author_rank: Frequent Contributor
timestamp: June 04, 2016, 04:28:01 pm
content: ...and to the West.We had one of these Soviet beauties in the eighties:

author: JacobPilsen
author_rank: Regular Contributor
timestamp: June 04, 2016, 07:49:03 pm
content: Designed as Fiat 124 by Dante Giacosa in 1960'...(We had one with more saturated red color.)