PCB Photoresist Searching in India

[shiveni]

Re: PCB Photoresist

are you heat the copper clad?

I have used hot water(around 80 C) for laminating the flim. after lamination i am using hair dryer to heat the PCB with lamination to 1 to 2 mins. Ensured that the PCB is not wet and limination is intact.

Should i try increasing the exposure distance to 7inchs and exposure time to 1min?.

What do you think adbout the trail PCBs above?...

I am now going out to get some Na2Co3 for developer.

Will post addtional results.

 

[badrinath_ks]

Re: PCB Photoresist

Hi Rajdup,

Can u help me in getting the photo resist in small quantity. I checked with Idea factory, they sell only in bulk.

regards,
badri

 

[shiveni]

Re: PCB Photoresist

Hi Rajdup,

The distance is now 7 inches & exposure time is 90 seconds.

The result is excellent. Tried 5 sample PCBs and the result is consistent and perfect.

Here we go......

Sample 1 - SMD track SSOP.

 

[shiveni]

Re: PCB Photoresist

Sample 2 - test mark track is <= 0.1 mm

 

[shiveni]

Re: PCB Photoresist

Sample 3 - mask test

 

[shiveni]

Re: PCB Photoresist

Sample 4 - text different font size.

 

[shiveni]

Re: PCB Photoresist

Dear Raju,

Thanks once again. You are that man behind our success.

As of now we are getting pcb track negative film through photographic shop. We are giving the positive print out to them and they are providing negative film for the same.

Can you please provide us some light in making our own negative film from the printed circuit.

We are confident DRY film process. where can we order bulk Qty.


Shiveni....

Microkid.....

 

[rajudp]

PCB Photoresist

you can make negative using lith film . just make printout to normal paper(positive) . cut the film a little bigger than the required size and keep the positive above the lith film . i normally keep a black paper below the film. keep a glass sheet above the positive ( better use a thick glass i am using 5mm ) keep a 60w Incandescent bulb about 1 meter above the positive. just on and off the bulb very fast for 2 to 5 times ( exposure ). keep the film in lith A B developer. watch carefully for the development of image. the tracks will come in white color and the remaining will turn black. when it is clear white remove and put in hypo solution then the white parts will become transparent. all the above should done in dark room ( i don't have a dark room i was doing it in night). you can keep a red zero watt bulb in the room( i have seen some people are using 20w tube with some filter film covered). after that you can wash the film in running water and allow to dry.

now i am using UV lith film, just print the positive to a transparent sheet ( a good quality tracing sheet will do) and expose with UV light for about 5 to 10 sec. all the remaining procedure are same. in this process a small light won't make any problem. but it is not working for paper positive for me. i bought metal halide lamp hoping it will work with paper i was not assembled it.

Added after 6 minutes:

i bought the film from Bangalore

Added after 38 minutes:

you better make all process in a tutorial and post it

 

[barrybear]

Re: PCB Photoresist

I use photographic paper and then a very hot iorn to transfer the black toner from the paper to the plain copper board . For me this is a simplar method as it realy only takes one action befor the copper sulphate emersion.

 

[piscrevathi]

PCB Photoresist

Dear Barrybear ,
Oh no.........Photographic paper,very hot iron,toner transfer etc...................... I think u r far behind the lattest development in PCB fabrication. People clarify their doubts on dryfilm photoresist PCB fabrication( Mr rajudp doing a very smart work. I expect a lot from him. Thank You raju ). But you are in old stone age. Come on , Come and join with us and share your knowledge with us

 

[rajudp]

Re: PCB Photoresist

in ebay they are selling photo resist go for www.ebay.com and search for photoresist the price is little high but ok for small volume buyers. around 9.5US$ for A5 size 10 sheets. postage is free

 

[shiveni]

Re: PCB Photoresist

in ebay they are selling photo resist go for www.ebay.com and search for photoresist the price is little high but ok for small volume buyers. around 9.5US$ for A5 size 10 sheets. postage is free

Thanks man,

I have the account in ebay.
I have placed the order in ebay. delivery is expected in 10days.

I have a queary in lith film method.

Whether i can use normal tube light for expose or 60w filament lamp.

hypo is in crytal form.at what ratio should we mix it with water.

Shiveni....

 

[rajudp]

PCB Photoresist

you can use normal 60w lamp keep it about 1 meter above the unit. i will add only a small qty oh hypo to water but i think you can keep the solution for more than 1 day( i am not keeping it )

shiveni:

you asked for bulk qty. look your edaboard inbox . i have a pm for you.

 

[shiveni]

Re: PCB Photoresist

you can use normal 60w lamp keep it about 1 meter above the unit. i will add only a small qty oh hypo to water but i think you can keep the solution for more than 1 day( i am not keeping it )

shiveni:

you asked for bulk qty. look your edaboard inbox . i have a pm for you.

Dear Raju,

i have tried lith film method as directed.

The initial result is - in negative the transparent area is ok. But the full dark area is not full dark but 70% dark.

I have compared the commercially produced film and mine. The dark area in my film is 30 to 40% less compared to the commercial one.

I used 60w bulb in 60cm and exposed to light rapidly 5 times as directed.

Then i put it in A&B developer for about 30seconds till i get the tracks coming in white color.

Then i put it to hypo solution for about 20 secs then rinsed in water.

Do you have any suggestion?.. how can we improve the black level to 100%.

Note :
1. If i level the film in A&B developer for more time to get full black the tracks are started to shrink.

Added after 3 minutes:

you can use normal 60w lamp keep it about 1 meter above the unit. i will add only a small qty oh hypo to water but i think you can keep the solution for more than 1 day( i am not keeping it )

shiveni:

you asked for bulk qty. look your edaboard inbox . i have a pm for you.

Dear Raju,

i have tried lith film method as directed.

The initial result is - in negative the transparent area is ok. But the full dark area is not full dark but 70% dark.

I have compared the commercially produced film and mine. The dark area in my film is 30 to 40% less compared to the commercial one.

I used 60w bulb in 60cm and exposed to light rapidly 5 times as directed.

Then i put it in A&B developer for about 30seconds till i get the tracks coming in white color.

Then i put it to hypo solution for about 20 secs then rinsed in water.

Do you have any suggestion?.. how can we improve the black level to 100%.

Note :
1. If i level the film in A&B developer for more time to get full black the tracks are started to shrink.

Where can i get UV lith film. Here in erode no store is having this UV lith film.

Do you have any web site links about lith film usage. I have googled for the past two days about lith film. No fruitful informations so far.

 

[rajudp]

PCB Photoresist

while developing take the film and check to the light source( red zero watt bulb ) if you can see the bulb through dark region put in developer again. if it is not working try changing the exposure time. i am not using any timing for developer. if i think it is very fast i will add a little water to it to slow the process.

the UV film is called as DAYLIGHT negative film. the film normaly come in 22" x 30' roll. for small qty you can ask any local polymer stamp makers/ suppliers. they will sell in A4 size. i bought in the roll form madras ( they give the best rate) but i think if you dont have that much use better go for small qty. if you have a dark room then the lith film is good i think. even lith film is cheaper than daylight film.

 

[danibilabibah]

Re: PCB Photoresist

Dear Barrybear ,
Oh no.........Photographic paper,very hot iron,toner transfer etc...................... I think u r far behind the lattest development in PCB fabrication. People clarify their doubts on dryfilm photoresist PCB fabrication( Mr rajudp doing a very smart work. I expect a lot from him. Thank You raju ). But you are in old stone age. Come on , Come and join with us and share your knowledge with us

i think that is quite simple for developing custom pcb, but not for a large quantity PCB fabrication. i have a tutorial for developing small quantity pcb at my blog(indonesian language). it can transfer 0,1mm thick of the trace, just need 3-10 min to transfer from photo papper to pcb, and 10-15 min for etching.

 

[shiveni]

Re: PCB Photoresist

while developing take the film and check to the light source( red zero watt bulb ) if you can see the bulb through dark region put in developer again. if it is not working try changing the exposure time. i am not using any timing for developer. if i think it is very fast i will add a little water to it to slow the process.

the UV film is called as DAYLIGHT negative film. the film normaly come in 22" x 30' roll. for small qty you can ask any local polymer stamp makers/ suppliers. they will sell in A4 size. i bought in the roll form madras ( they give the best rate) but i think if you dont have that much use better go for small qty. if you have a dark room then the lith film is good i think. even lith film is cheaper than daylight film.

Hi Raju,

Got DAYLIGHT film in local store and the result is excellent. It works very well even in day time. Planning to do a full size fine track PCB for complete process testing this week. After that i will submit the tutorial in PDF.

 

[rajudp]

PCB Photoresist

please check any way to make daylight film negative from normal paper printout. what you used for positive.
for me the lith film given good results with paper printouts

 

[shiveni]

Re: PCB Photoresist

please check any way to make daylight film negative from normal paper printout. what you used for positive.
for me the lith film given good results with paper printouts

The lith film is very sensitive and is able to manage with normal white sheet prints. Daylight film is UV sensitive hence suffecient light source is required.

There are two option we found.

1. Tracing sheet printout (almost all tracing sheets are usable. The sheet specific to offset printing gives excellent sharp prints through laser printer.)

2.The dirty and cheap way is using oil over normal paper printouts to make it transperent.

 

[shiveni]

Re: PCB Photoresist

please check any way to make daylight film negative from normal paper printout. what you used for positive.
for me the lith film given good results with paper printouts

The lith film is very sensitive and is able to manage with normal white sheet prints. Daylight film is UV sensitive hence suffecient light source is required.

There are two option we found.

1. Tracing sheet printout (almost all tracing sheets are usable. The sheet specific to offset printing gives excellent sharp prints through laser printer.)

2.The dirty and cheap way is using oil over normal paper printouts to make it transperent.

Gusy,

Sorry. The second method Oil over normal sheet is not working. I am now trying polymer sheet used for offset printing.

Will post the results.