LED circuit-no R's, C's, T's, - ONLY A White GLOB??

[wokmajik]

I am wondering what the hard white glob is on the LED flashing circuit in my bicycle LED flasher. It seems to take place of the resistors, capacitors, and transistors in a traditional LED flasher. I am wanting to use this same technology for an idea that I have... I must also disclose that I am a caveman mechanical engineer...I know that there is some electrical engineer that would love to verbally kick me around in exchange for the information that I seek. Any help is greatly appreciated.

 

[automatic2]

It's likely as you've stated. The basic elements are photo masked and etched onto a substrate, then packaged with a big drop of resin. A crude (but cheap) method for basic functions.

 

[IRstuff]

The glob is there for structural and mechanical protection. If you managed to successfully remove the glob, you'll find the components you mentioned.

There may even be bare IC with bond wires visible.

TTFN

 

[buzzp]

I agree with IRstuff.
It is likely just some potting compound of sorts for protection from the elements. You could attempt to cut around it and you will likely find standard components underneath.

 

[BrianG]

If it's a flashing white LED then the "glob" may also be the phosphorescent material that makes it appear as a white light. "White" LEDs are usually made up from a blue wavelength LED which then excites a white-ish phosphor in close proximity to the chip.

 

[nbucska]

If the "glob" cowers the LED, BRIANG is right. Else
if it is larger than 1/2 inch, it covers discrete circuit
if smaller a "flip-chip" IC. ( An IC with BUMPS instead wires directly soldered to the PCB)

Most likely it is a special custom IC which is cheap to use
and expensive to develop.

Click on my name and send any info you are willing...



<nbucska@pcperipherals.com>