PCB Prototyping Unit Conversion Chart 



























Data based on Kepro's chemical supplies, DRY FILM PROCESS 



























Developer DFD12G 

Sodium Carbonate 

Water 


Sq Ft of Board Developed 






250 
mL 
2.3 
grams 
250 
mL 

0.7 
sq ft 





500 
mL 
4.6 
grams 
500 
mL 

1.3 
sq ft 





1000 
mL 
9.2 
grams 
1000 
mL 

2.7 
sq ft 





1500 
mL 
13.7 
grams 
1500 
mL 

4.0 
sq ft 





2000 
mL 
18.3 
grams 
2000 
mL 

5.4 
sq ft 





3000 
mL 
27.5 
grams 
3000 
mL 

8.1 
sq ft 





3875 
mL 
35.5 
grams 
3875 
mL 

10.4 
sq ft 





Mix at Temperature 3238 deg C (90100 deg F) 













Develop at temperature 3843 deg C (100110 deg F) 



























Etchant SP1G w CAT1G 

Sodium Persulfate 

Water 


Catalyst 

Catalyst Maintenance 

Copper Capability 











every (12hours etch) 

Sq Ft (1oz) 
Sq Ft (2oz) 
Sq Ft (4oz) 
250 
mL 
58.5 
grams 
213 
mL 

1.9 
mL 
0.13 
mL 



500 
mL 
117 
grams 
426 
mL 

3.81 
mL 
0.26 
mL 



1000 
mL 
234 
grams 
852 
mL 

7.61 
mL 
0.52 
mL 



1500 
mL 
351 
grams 
1277 
mL 

11.4 
mL 
0.77 
mL 



2000 
mL 
468 
grams 
1703 
mL 

15.2 
mL 
1.03 
mL 



3000 
mL 
702 
grams 
2555 
mL 

22.8 
mL 
1.55 
mL 



3875 
mL 
907 
grams 
3300 
mL 

29.5 
mL 
2.00 
mL 



Bath Temperature 3843 deg C (100110 deg F) 








Note: Copper Capacity is per sq ft of copper single sided 




Copper Capacity 45oz/gallon 



























Note( If you expect to run more than just a few boards, the SP12G or SP20G is 













much more economical due to the Hazmat fees. The etchant has very long shelf life 













until mixed, then it is only 3 weeks. 



























Premix the etchant 24 hours prior to use to allow the PH to stabilize. You can 













accelerate PH stabilization by shocking the solution by adding some spent 













Sodium Persulfate solution see www.kepro.com for details 



























Exposure Times 













BTX200A 

3045 seconds 











PE2 Photoflood 

46 minutes at 1012 inches 











BX101 or GE FT15BL single 

23 minutes at 1012 inches 











BX101 or GE FT15BL double 

12 minutes at 1012 inches 











I have a BTX200A, so I can't validate the other numbers and they are from Kepro 



























Be sure to let the exposed pcb sit for 15 minutes after exposure to allow the phototesist to harden properly 













Develop time is 4560 seconds up to 90 seconds 













Etching time depends on a lot of issues, see www.kepro.com for details 



























Dispose of used solution safely, follow your venues recommendations, do not put in household drain 













Precipitation and Evaporation are 2 methods. 



























If you want a more environmentally sound procedure, see Think and Tinkers greencircuit.com 



























Copyright Ron Amundson KB0PAX 2002 












