Help identify the IC manufacturer: is it really possible that these ICs from the 60's just made a comeback (К155ИД1)?

Question

So we've been manufacturing Nixie Clock kits for the last few years, and for the multiplexers we used 74141 ICs, or their Soviet clones (К155ИД1). The latter were easier to find on ebay and were used more commonly. These chips have a date code like "8910" which I assume to mean year 1989, week 10.

Since this is all NOS (New Old Stock), I've made a 74141 tester to verify incoming batches.

I received the latest batch of chips yesterday and to my surprise about 1/3 of them failed the tests. Then I noticed that these new chips were visibly different: the plastic package is more edgy, there's some sort of manufacturer logo, and their date code is "1814"!

Compared to an old one at the bottom right:

I later verified that the new chips work on actual nixie clocks, but my tester rejects them for some minor reason (probably the new ones are a bit more sensitive to supply voltage, they also seem to be consuming a tad more current).

Questions:

1. Which manufacturer is this?
2. Is it really possible that these ICs from the sixties have just made a comeback?

The practical upside of this is that we'd be curious to contact the new manufacturer directly, to cut the ebay middlemen.

Answer 1

The chips that you have are made in Belarus by a company named Integral.

• К155ИД1 1814 :- This is a recently manufactured chip. (i.e. 14th week of 2018).
• К155ИД1 8910 :- This chip is very old (i.e 10th week of 1989).

Link to the site of manufacturer.

Yes, it might be possible that the manufacturer is using a slightly modified architecture based on the previous one for the manufacturing of these new chips

Answer 2

You have К155ИД1 1814 chips made in Belarus see this. Company name is Integral.

К155ИД1 8910 is a very old chip made in 1989. Unfortunately, these old chips are hard to find. The Soviet Union made excellent chips; now you need to carefully verify the modern versions.

Answer 3

Consider the possibility that the chips inside these packages are NOS, from 1989 or whenever, but had been stored as bare dies, and have been bonded and packaged in 2018. Which would make a lot of sense if somebody has a stash of bare dies - you could put them in ROHS-compliant packaging. Coincidentally, the pin finish on these does look rather matte, typical of lead-free components...

Alternatively, the parts might be old stock that someone retested, refurbished, remarked and remarketed in 2018.... there might be the more sinister possibility that they have been just remarked, in order to avoid ROHS-related suspicion :)