Why so few transparent ICs?


TSL230R is transparent mainly because it needs light to work.


I believe it is for optical mouse so naturally it'd need transparent portion to read reflected light to calculate movement.

And Motorola had some:

they were made available in the early 90s for teaching people how it works.

But there are so few transparent IC that it's almost crazy. There's been transparent game systems, transparent computers, etc but I have not seen a transparent CPU, transparent 7400's, etc. Obviously light can affect the electronics but I would think at low frequency like Arduino, light wouldn't be an issue.

Light does effect the electrical conduction in I.C.s

You could always go and grab some old EPROMS or some of the old 8751 types that had the clear windows on them so you could erase them. They were fun to look at under a microscope.

Exposure to light can indeed influence semiconductors. The existance of UV erasable EPROMs should give you a hint here.

Besides, transparent materials are more expensive than black plastic. It would have a large impact on costs - and have no real functional purpose

In fact, I can't think of any reasons to make a transparent IC unless it's doing something with optics and needs to, or like the motorola one, as an educational aid.

...transparent materials are more expensive than black plastic...

Is epoxy naturally black?

Einstein won his Nobel Prize for the photoelectric effect ya know, not relativity.

:wink:

From the "real world" the Raspberry Pi model 2B has a known issue with unintended photoelectric effect:

No. but IC bodies are deliberately opaque because all semiconductor devices are affected
by light. A photodiode is just a diode with an anti-reflection coating and the pn-junction
close to one surface really.

The fundamental things that happen in semiconductor devices are drift, diffusion, recombination and
generation. Generation of electron-hole pairs can be thermal or optical.

I refer to the great Raspberry Pi flashgun debarcle:

wilykat:
But there are so few transparent IC that it's almost crazy.

No there are so few transparent IC that it just makes sense.

Stop thinking that you know anything about electronics.