Hi PCB precision with Laser Printer

[goxy]

I want to ask can we improve resolution with better laser printer or resolution is limited with some others parametars like transparent foil, etch process or some other parametars.
Can we improve something with for example 1200dpi HP laser printer.
What's the best resolution with standard process?

 

[bomba]

What type of transference to the board are you using???

 

[Gorilla]

Like bomba says, what do you want, what goes wrong, ... ?

I use a HP LJ4000 to do 0,5 mm TQFP boards, without problems. Do you need to go smaller?

 

[goxy]

I'm looking for very precision design of MW filters and resonators, gap between two strips should be about 0.1 mm.

 

[Gorilla]

I think 0.1 mm will be very difficult to produce consistently using DIY techniques.

Theoretically, 1200 dpi means 4.7 dots for 0.1 mm; using 4 or 5 dots will already give you a 6-15% error.

But differences in the fusing (temperature), blackness percentage, dot adressing repeatablility, paper/film texture and stability etc. etc. will increase the error even further.

Frankly I think no laser printer will create a nice 0.1 mm gap between black areas.

And after all that, slight variations in exposure/etching times, chemical composition etc. won't make it any better.

A photo plotter offers the resolution, but then... 0.1 mm (4 mil) traces and home etching... It will be very diffucult...

You can always try though.

 

[pool_77]

I think that problem is not in resolution, 300dpi is nearly OK. bigger problem is in "linearity" of printing. If I print A4 PCB then printed size have tollerance about 1-1.5mm :-(. I tested LJ4,LJ6,,,, and each printting have different error.
photoplotting is OK

 

[flatulent]

photographic process

You can print your images at 2x or 3x size on paper and then have a professional photographic shop reduce them by 1/2x or 1/3x onto photographic film.

 

[FANT]

I have tried many times to reproduce filters PCB with home stuff, but all the times the filter must to be tuned.
The same filter, with a certified Er form the producer gave the correct center freqency, bandwidth, ecc.

So, home filters can be done, but for my experience only under say 500 MHz; above the response is not real o what expected.

Mandi

 

[goxy]

Thanks guys!

I'm also heard about laser printer linearity problem, maybe reason for this fault is paper heater specialy in transparent foil case.

I'll also try with inkjet printer and special inkjet transparent foil and like as flatulent said to reduce size in photographic shop (I hope they have machines with exactly reduce ratios)

FANT, what's problem with your home made filters, FR4 er constant or some other problem like etch process, printing quality...
I'll use PCB boards with certified er(Rodger Duroids or GIL type) so can I expect good results if my simulation is OK on 6GHz.



Between, I'm find some guys in my neighbourhood have very good engravir machine
( this one: https://www.rolanddg.com/products/egx300/spec.html ), very soon I'll try it

 

[KamW]

Have you ever tried to print two different layers of board on two sheets, and then fit it?
check topic **broken link removed**

regards
KamW

 

[goxy]

Thanks KamW :sm28: , 0.1 mm is excelent!!

What etch process are you use, with HCL+H2O2 or Ferric Chloride.
Does have any different for etching between this two for high precision?


Best

 

[KamW]

I use HCl + H2O2. With FeCl there were problems with family life - my wife do not like yellow points everywhere - especially on my new trousers;-). And you could believe me it is impossible to wash off !!!
HCl is better for etch because of room temperature. With a small dose of experience, (and a medium dropper for flush) you could controll speed of etching of different areas. Remember that oxides slow down etch processes, to speed up process you have to mix whole solution. By the other hand the places with closer tracks are etched faster, and empty places are etched slower. So to avoid over etch I am always flushing with dropper empty places of board, and then mix and etch places with tracks. So the most demanding areas are etched last, and over etches are minimal !!!
Additionally - except of good results of etch, use of dropper is very fun - before I've used dropper I didn't like the first stages of etching - before results could be seen. Now it is really fun.
Btw I use plastic, "single use" dropper of about 5 ccm volume, but I think a small pump could be better ??
I have tried some methods - air pumps, bubble, spraying etc. but in my oppinion manual etch is the best - of course for "home" scale technology.

regards
KamW

 

[pool_77]

I used HCL, but now I am using FECL2 because HCL make rusting all at my home and make gaps in carpet and other plastic material :-(

pool_77