Electronics > Manufacturing & Assembly

DIY PCB ink transfer


Some faxes use thermal transfer to print on paper. They have film coated with ink, which contacts the paper, and then heated - ink from fax transferred to paper.

It may be possible to modify this kind of fax to print directly on PCB instead of paper?

Some links describing how it works

So, in theory, it may be possible to print on anything, not just paper. The only consumable is the ribbon which is not very expensive. No transparencies, no photoresist, no UV. Print directly to PCB and it's ready for etching instantly.

Thermal labeling inks and many other products advertised as "BPA Free" can be dangerous because of a substance called Bisphenol S that acts as a synthetic female hormone, ("endocrine disruptor") confusing the body and causing intergenerational morbid obesity and cancers just like its better known cousin, BPA.

So be careful when handling it. Labels are printed with it. Its not toner.

For example, see :

http://ehp.niehs.nih.gov/121-a76/  or http://ehp.niehs.nih.gov/pdf-files/2013/Mar/ehp.121-a76_508.pdf

Thermal Reaction: The Spread of Bisphenol S via Paper Products

Lindsey Konkel

Lindsey Konkel is a Worcester, MA–based journalist who reports on science, health, and the environment. She writes frequently for Environmental Health News and The Daily Climate.

In January 2013 county executive Steve Bellone of Suffolk, New York, made history when he signed the “Safer Sales Slip Act,” a first-in-the-nation ban of thermal receipt paper coated with bisphenol A (BPA).1,2 BPA, used as a developer in thermal papers, has been linked in some animal studies to adverse reproductive and metabolic effects, while epidemiologic evidence shows an association with thyroid effects.3 But the safety of structurally similar bisphenol S (BPS), a widely used BPA replacement, has itself come under question, with one recent study indicating the compound disrupts cell signaling at extremely low doses.4 Although scientists are just beginning to analyze the safety of BPS, studies suggest this compound is already pervasive in the environment,5 in paper products,6 and in the human body.7

In a draft report released in July 2012, Design for the Environment, a research partnership program of the U.S. Environmental Protection Agency, assessed 19 chemical alternatives to BPA in receipt paper, including BPS.8 The preliminary report found no clear winners as far as human health and environmental end points go.

“It appears that BPS and BPA are equally problematic” in terms of toxicity, says Kurunthachalam Kannan, a research scientist at the New York State Department of Health in Albany and senior author of three recent BPS studies.

Kannan’s group reported in 2012 that 81% of 315 urine samples from men and women in the United States and seven Asian countries contained BPS.7 The highest average concentrations were found in urine samples from Japan, followed by samples from the United States. Japan banned BPA-coated thermal receipt papers in 2001.5,6,7 Appleton, a major U.S. manufacturer of thermal receipt paper, switched from BPA to BPS in 2006 due to growing concern about the safety of BPA, says corporate communications manager Bill Van Den Brandt.

Tagged luggage
Relatively high levels of BPS have been measured in thermal paper receipts, tickets, boarding passes, and luggage tags.
© Peter Titmuss/Alamy

In another 2012 study Kannan and colleagues analyzed 16 types of paper and estimated that receipt paper accounted for more than 88% of human BPS exposure from handling papers.6 They also found relatively high BPS concentrations in tickets, mailing envelopes, and airline boarding passes and luggage tags, which also are printed using thermal processes.6 Papers coated with BPS may contain up to 40% more compound than comparable papers coated with BPA, perhaps because BPS is a weaker developer than BPA, according to Frederick vom Saal, a biologist at the University of Missouri-Columbia’s Endocrine Disruptors Group.

Although thermal papers may contain a lot of BPA and BPS, it remains unclear how much of the chemicals makes it into the human body, according to Laura Vandenberg, a postdoctoral fellow at Tufts University. Studies estimate between 10% and 60% of BPA from receipt paper is absorbed through the skin.9 In one small sample of pregnant women, cashiers had higher urinary BPA levels than women in other occupations.10 There are no similar data for BPS. “Future studies for both chemicals must focus on how blood concentrations of the chemicals change before and after touching receipt paper,” Vandenberg says.

The detection of small quantities of BPS in paper products that are often made with recycled content—such as napkins, flyers, and magazines—suggests that BPS, like BPA, is transferred from thermal paper that has been recycled.6 According to a 2008 European Commission report, as much as 10% of thermal paper produced is recycled as scrap before it ever enters commerce, and an estimated 30% of used thermal paper also is recycled.11 The amount of BPA released during recycling can vary widely, depending on the processes used. Comparable information is unavailable for BPS, which may be more persistent in the environment than BPA.12

There are no studies testing how readily the body absorbs BPS or BPA from recycled paper goods. But Vandenberg points out that the chemicals in these products are mixed in with the paper rather than coated on top, so there may be less opportunity for dermal absorption. Still, she says, “Some recycled paper products, like facial and toilet tissues, come into contact with our mucous membranes and sometimes our food. We don’t want that paper to have chemicals that mimic hormones.”

But of greater concern than recycled products, says vom Saal, is the immediate consequence of touching thermal paper coated with free BPA or BPS. “You will spread that chemical onto everything you touch until you wash your hands,” he says.

1. Suffolk County (NY) Legislature. Introductory Resolution 2062. Resolution 1091. Adopting Local Law No. 8-2012, A Local Law to Reduce Exposure to Bisphenol A in Suffolk County (“The Safer Sales Slip Act”). Steven Stern, Sponsor. Adopted 4 Dec 2012, approved 3 Jan 2013. Available: http://legis.suffolkcountyny.gov/ressearch/ [accessed 20 Feb 2013].

2. Stern S. Legislator Steve Stern’s “Safer Sales Slip” Act Passes Legislature [press release]. Huntington, NY:Suffolk County Legislature (5 Dec 2012). Available: http://legis.suffolkcountyny.gov/press/do16/2012/do16pr_120512_salesslip.pdf [accessed 20 Feb 2013].

3. Bergman A, et al., eds. State of the Science of Endocrine Disrupting Chemicals 2012. Geneva, Switzerland:United Nations Environment Programme and World Health Organization (2013). Available: http://www.who.int/ceh/publications/endocrine/en/index.html [accessed 20 Feb 2013].

4. Viñas R, Watson CS. Bisphenol S disrupts estradiol-induced nongenomic signaling in a rat pituitary cell line: effects on cell function. Environ Health Perspect 121(3):352–358 (2013); http://dx.doi.org/10.1289/ehp.1205826.

5. Liao C, et al. Bisphenol analogues in sediments from industrialized areas in the United States, Japan, and Korea: spatial and temporal distributions. Environ Sci Technol 46(21):11558–11565 (2012); http://dx.doi.org/10.1021/es303191g.

6. Liao C, et al. Bisphenol S, a new bisphenol analogue in paper products and currency bills and its association with bisphenol A residues. Environ Sci Technol 46(12):6515–6522 (2012); http://dx.doi.org/10.1021/es300876n.

7. Liao C, et al. Bisphenol S in urine from the United States and seven Asian countries: occurrence and human exposures. Environ Sci Technol 46(12):6860–6866 (2012); http://dx.doi.org/10.1021/es301334j.

8. EPA. BPA Alternatives In Thermal Receipt Paper Partnership—About This Project [website]. Washington, DC:U.S. Environmental Protection Agency (updated 1 Feb 2013). Available: http://www.epa.gov/dfe/pubs/projects/bpa/about.htm [accessed 20 Feb 2013].

9. Mielke H, et al. The contribution of dermal exposure to the internal exposure of bisphenol A in man. Toxicol Lett 204(2-3):190–198 (2011); http://dx.doi.org/10.1016/j.toxlet.2011.04.032.

10. Braun JM, et al. Variability and predictors of urinary bisphenol A concentrations during pregnancy. Environ Health Persp 119(1):131–137 (2011); http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3018492/.

11. JRC-IHCP. European Union Risk Assessment Report. Environment Addendum of April 2008. 4,4’-Isopropylidenediphenol (Bisphenol-A). Part 1 Environment. Ispra, Italy:Joint Research Centre–Institute for Health and Consumer Protection (2010). Available: http://publications.jrc.ec.europa.eu/repository/handle/111111111/15063 [accessed 20 Feb 2013].

12. Danzl E, et al. Biodegradation of bisphenol A, bisphenol F and bisphenol S in seawater. Int J Environ Res Public Health 6(4):1472–1484 (2009); http://dx.doi.org/10.3390/ijerph6041472.

cdev, the mechanism you describe is not the same as the one knks described.

Your reference is to thermal roll products where the paper is coated with a material that reacts to direct heat.

The mechanism knks describes is a wax (or similar) coated film where heat is applied to the back of the film to transfer the wax to the target substrate.

Printers used to custom print identity cards/rfid cards/member ship cards use a similar mechanism in the cheaper versions.

As I have such a card printer, I might give this technique a try if I can source some 0.8mm blank PCB and cut it down to credit card size to fit.


[0] Message Index

There was an error while thanking
Go to full version