hehehehe
I thought about the Hot oil thing some weeks ago but never gave the oven bag any consideration at all ... thank God for the cooking tools in the kitchen !
certainly I have had some mixed results with different sized PCB's being Hot or too Hot and how much pressure to apply, I never really thought about it much until now ... so here goes, damn I hope I got this right boys !
a quick and dirty calculation about the amount of pressure for different size PCB's and the downward force that is being exerted onto the PCB.
(some assumption here for the Iron and the PCB and both are 20sq" in Area and square)
1: if there was 20lbs force being applied and the PCB had a surface area of 20sq" then that = 1PSI
2: ok so now you have a PCB that's 10sq" and apply 20lbs that's now = 2PSI, that's a 100% increase ! hardly repeatable conditions imo.
what I am getting at here (my logic) is wouldn't the Oven bag with a set vacuum applied have the same PSI irrespective of what the PCB size is inside it, or am I wrong on this ?? (that would be approx 14.7 PSI at sea level with a 30" Hg vacuum)
say it like this if 14.7 PSI was being applied from the Iron to the PCB and had an area of 20sq" that's means 294lbs would be needed...... I reckon that would trash most ironing boards... well certainly this nice wooden one :-(
Therefore :
30"Hg will apply 14.7PSI
then
30/14.7 = 2.04"Hg will yeild 1PSI onto the copper
find the vacuum setting that applies the correct pressure without squishing the tracks all to hell when you deep fry it and you've got "homebrew PCB QC".
Thomas :-) ..... hit send
----- Original Message -----
From: Earl T. Hackett, Jr.
To: Homebrew_PCBs@yahoogroups.com
Sent: Wednesday, October 20, 2004 10:02 AM
Subject: Re: [Homebrew_PCBs] Re: Questions about toner transfer method. Deep Fried
I like the way this guy thinks. Deep Fried Toner Transfer Technology. It sounds really cool.
----- Original Message -----
From: Thomas
To: Homebrew_PCBs@yahoogroups.com
Sent: Tuesday, October 19, 2004 8:54 PM
Subject: Re: [Homebrew_PCBs] Re: Questions about toner transfer method. Deep Fried
Hi Gents
I thought that I read somewhere that the applied pressure with the iron was checked with a set of scales and it was either 15 or 25 so Lbs, cant find it know !! its not a lot but should be within the range and capabilities of the Oven bag and Mums Hoover, then drop this assy into hot Cooking Oil at the right temp.... even pressure and even temperature !
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