4 ms·

Wow, I always assumed that the actual "live" part of the chips were most of the packaging - the second picture makes it look like the chip is 99% epoxy packagin

Wow, I always assumed that the actual "live" part of the chips were most of the packaging - the second picture makes it look like the chip is 99% epoxy packaging and 1% silicon. Is that right? Is that typical? Is the packaging that big to separate the pins from each other or just to make it something humans can handle/keep track of?

andyjohnson0 5y ago
> Is the packaging that big to separate the pins from each other Yes. DIP packages have standard pin spacings. https://en.wikipedia.org/wiki/Dual_in-line_package https://en.wikipedia.org/wiki/Dual_in-line_package
jaywalk 5y ago
This holds true even on current CPUs, although they're obviously not packaged in the same way.
kens 5y ago
Back then, printed circuit board technology wasn't as advanced so chips usually had 0.1" spacing so there was room for the PCB traces. The chip's package was much larger than the silicon. Nowadays, in something like a phone, you want the packages to be as small as possible. You can now get a 555 timer in a package that is 1.4mm on a side, which is not a lot bigger than the silicon die, but still limited by the spacing of the solder balls.
- TillE 5y ago
  I'm curious about why the DIP packages still exist. As a hobbyist I'm glad they do, but I can't imagine the hobby/education market is big enough to support a wide variety of ICs being made in the oversized breadboardable format. Are there any major commercial users?
  - mastax 5y ago
    Lots of high volume electronics, especially power electronics, still use through hole parts. They can use a cheap single-sided phenolic board with a single wave soldering pass. DIP packages are (usually) more expensive than SMT ones, but larger parts (power transistors, electrolytic caps, connectors) are usually cheaper and more robust in THT.
  - elihu 5y ago
    You probably wouldn't use DIP packages in most modern designs unless it's a low-volume part that you don't mind hand-soldering. However, DIP packages have been used for so long in so many things that the most common DIP ICs are going to continue to be manufactured for a very long time I think. It would be interesting to know what the statistics are for the global production of various DIP package ICs. Presumably the production of the DIP variants of 555, TL074, and similar ICs peaked at some point and started to decline, but maybe not. Apparently it's still economical to produce fairly specialized DIP chips, like reproductions of the 3340 [1] voltage controlled oscillator chip used in a lot of synthesizers. Low volume specialty chips tend to be more expensive, though, which I suppose justifies the costs associated with manufacturing. [1] https://aisynthesis.com/product/alfa-3340-vco-ic/ https://aisynthesis.com/product/alfa-3340-vco-ic/
spear 5y ago
Sometimes, the silicon die itself may be "pad-limited", ie. the minimum size is determined by the number of I/O pads on the die, which have their own spacing requirements.
jacquesm 5y ago
The connections can take up the bulk of the package.

andyjohnson0 5y ago

> Is the packaging that big to separate the pins from each other Yes. DIP packages have standard pin spacings. https://en.wikipedia.org/wiki/Dual_in-line_package https://en.wikipedia.org/wiki/Dual_in-line_package

jaywalk 5y ago

This holds true even on current CPUs, although they're obviously not packaged in the same way.

kens 5y ago

Back then, printed circuit board technology wasn't as advanced so chips usually had 0.1" spacing so there was room for the PCB traces. The chip's package was much larger than the silicon. Nowadays, in something like a phone, you want the packages to be as small as possible. You can now get a 555 timer in a package that is 1.4mm on a side, which is not a lot bigger than the silicon die, but still limited by the spacing of the solder balls.

TillE 5y ago
I'm curious about why the DIP packages still exist. As a hobbyist I'm glad they do, but I can't imagine the hobby/education market is big enough to support a wide variety of ICs being made in the oversized breadboardable format. Are there any major commercial users?
- mastax 5y ago
  Lots of high volume electronics, especially power electronics, still use through hole parts. They can use a cheap single-sided phenolic board with a single wave soldering pass. DIP packages are (usually) more expensive than SMT ones, but larger parts (power transistors, electrolytic caps, connectors) are usually cheaper and more robust in THT.
- elihu 5y ago
  You probably wouldn't use DIP packages in most modern designs unless it's a low-volume part that you don't mind hand-soldering. However, DIP packages have been used for so long in so many things that the most common DIP ICs are going to continue to be manufactured for a very long time I think. It would be interesting to know what the statistics are for the global production of various DIP package ICs. Presumably the production of the DIP variants of 555, TL074, and similar ICs peaked at some point and started to decline, but maybe not. Apparently it's still economical to produce fairly specialized DIP chips, like reproductions of the 3340 [1] voltage controlled oscillator chip used in a lot of synthesizers. Low volume specialty chips tend to be more expensive, though, which I suppose justifies the costs associated with manufacturing. [1] https://aisynthesis.com/product/alfa-3340-vco-ic/ https://aisynthesis.com/product/alfa-3340-vco-ic/

spear 5y ago

Sometimes, the silicon die itself may be "pad-limited", ie. the minimum size is determined by the number of I/O pads on the die, which have their own spacing requirements.

jacquesm 5y ago

The connections can take up the bulk of the package.