Re: Automotive HID Projector Lamp Exposing a PCB?
- From: D from BC <myrealaddress@xxxxxxxxx>
- Date: Wed, 19 Dec 2007 09:47:38 -0800
On Wed, 19 Dec 2007 08:55:34 -0800, John Larkin
<jjlarkin@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
On Wed, 19 Dec 2007 00:14:10 -0800, D from BC
<myrealaddress@xxxxxxxxx> wrote:
I expose pcbs with a cheapo 500W halogen work lamp.
Exposure time ~30 minutes..
Could I reduce the exp time with an auto HID projector lamp? (Scrap
yard. BMWs I think. Who hasn't been blinded by those suckers.)
I see blue light from those HID lamps.
If there's more blue end, than perhaps there's more UV too?
It's probably not a big spectral span from blue to the UV band.
A point light source is supposed to be best for exposing circuit
boards..
A projector makes a nice spot.
UV tubes radiate radially.
I have no idea how this difference in directionally has on the
exposure quality.
Anybody seen a spectral graph for those automotive HID lamps?
I tried to Google up a spectrum.. Nothing yet.
Note: UV tubes are not easily found around here but I'm surrounded by
scrap yards.. :)
D from BC
I've used warehouse-type mercury vapor lamps to expose pcb's. A 175
watt lamp, about 3 feet above the board, is close to a point source
and exposes a KPR-coated board in 3-5 minutes. I removed the reflector
from the fixture, mounted it so that the tube is horizontal, and
silvered the top of the tube with a piece of aluminum foil, all of
which directs the light down and keeps the source size small. It casts
nice sharp shadows.
I don't understand why so many people want to make light boxes, which
have terrible optics. I guess they enjoy carpentry.
John
Speaking of light boxes...
I had the crazy idea of turning a school overhead projector into a
sort of light box. I think that would make a nice spot with low angle
light (coherent I think is the word).
The light source would be replaced with something with sufficient UV
such as halogen, mercury vapor or perhaps UV tubes..
D from BC
.
- References:
- Automotive HID Projector Lamp Exposing a PCB?
- From: D from BC
- Re: Automotive HID Projector Lamp Exposing a PCB?
- From: John Larkin
- Automotive HID Projector Lamp Exposing a PCB?
- Prev by Date: Re: How to quickly turn on/off N-FET switching high side of 55V?
- Next by Date: Re: Yet another new battery breakthrough
- Previous by thread: Re: Automotive HID Projector Lamp Exposing a PCB?
- Next by thread: Re: Automotive HID Projector Lamp Exposing a PCB?
- Index(es):
Relevant Pages
|
