Comprehensive table of alternative packages names - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: April 13, 2022, 08:35:46 pm
content: Hi,through the years I compiled a small list of alternative names for ICs packaging (i.e. SC−75 = SOT−416, etc). But form time to time I come across some names which I need to look up what other alternative names it has.There must be a a full list available somewhere without having to Google or Wikipedia the name whenever you look for an alternative name.Where can I find it?Thank you

author: exmadscientist
author_rank: Frequent Contributor
timestamp: April 14, 2022, 07:38:37 am
content: No, there is not any such list. At least not that I've ever found! topline.tv is helpful but not all-encompassing.I do have an internal one that I've put together over multiple employers. (Actually, it's three lists: passives, diodes, and SOT23-ish things. The bigger ICs are close enough to standardized that all you really need are the JEDEC documents.) There are weeks, maybe months, of time invested in it. I'm not particularly interested in sharing it for a few reasons. One, some proprietary information has accumulated over the years (which would be easy if tedious to strip out). More importantly, it's not all rigidly correct: some of it is "yeah, these are close enough" or personal shorthand or what-have-you. The kind of stuff that's no problem to work with if the guy who made the list is next to you, but that can easily ruin a clueless internet rando's day. Removing that isn't really feasible, and so it must remain private. I will say though that if there's a good place to put it, a table for the SOT23/323/523-3/5/6 stuff would probably be very helpful to everyone, and I have most of that table so I should probably just do it....

author: ricko_uk
author_rank: Super Contributor
timestamp: April 14, 2022, 03:37:37 pm
content: Thank you exmadscientistYes, if you could make one and perhaps ask the moderators to pin it at the top like some other posts that would be nice and of great use to everybody!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 14, 2022, 05:04:57 pm
content: Designation is irrelevant: they can call it whatever they want. Even when they call it "SOT-23" (or some modifier thereof), there are variations in body width and length, leads, gull wing vs. flat, etc. Sometimes these fall within the JEDEC dimensions, sometimes they're just different enough to deserve a new footprint.So, the drawing is king. Call it whatever you like internally; IPC generated names aren't terrible -- if ugly and verbose, but I mean, that's going to be part of the tradeoff.Tim

author: ricko_uk
author_rank: Super Contributor
timestamp: April 15, 2022, 02:30:19 am
content: Thank you Tim

author: exmadscientist
author_rank: Frequent Contributor
timestamp: April 15, 2022, 09:21:37 am
content: I could hardly disagree more. We have found that the most effective thing to do, in general, is to draw as few footprints as possible and draw them to the standards (JEDEC, JEITA, EIA, etc.). Nobody changes their 0603 resistor footprint when they change suppliers from Vishay to Yageo. So why should you change out your SOIC-8 op-amp footprint? Most parts really are standard packages, so a small library containing stuff drawn to standards will cover a vast number of manufacturer packages. And it is much easier to check and maintain a small number of footprints. I know, when I put down a standard SOT-323, that it is going to work because we've built dozens of boards using that exact footprint and multiple assemblers have successfully used it without issue. I just don't have to worry about it. All I have to do is pick the correct standard footprint for my part. And if I pick wrong, it will probably (1) be so far off it's obvious and (2) there's a good chance of finding another part in the marketplace that does exactly fit what I put down!And the IPC namesareterrible. They tell you what the footprint was drawn to be. They don't tell you what it wassupposedto be! We have had errors where someone checked the footprint against the description, but not the description against the part. Partly because the verbosity of the IPC naming format makes it really, really hard to actually do that check. That verbosity also makes it just about impossible to check for reuse: you basically have to draw it over again for every part, or at least every manufacturer package code. Which is not really sustainable.I wish I had time to clean up and publish the tables I have. But they're big: the SOT23-type table, the smallest one, is 147 rows covering 28 package styles. And some of those 28 styles have the same land patterns (compare SOT23-3 to TSOT23-3... it's thinner!) or are so rare as to be skippable, so there is further economy to be had. Better than 5:1 reduction is pretty nice!

author: jpanhalt
author_rank: Super Contributor
timestamp: April 15, 2022, 11:02:00 am
content: Nice you mention the "SOIC-8." I have limited experience, but in that time I have used a generic SOIC-8 footprint and found others that didn't fit. I don't recall off hand which two manufacturers were involved. I learned my lesson, and didn't repeat that error.Just consider the Microchip offerings in similar footprints (it does not show an SOIC in EAGLE). The only safe way is to look at the datasheet (or manufacturer's footprints if in a different source) and check.