Toner Transfer PCB Etch Resist Release Paper

Making Toner Release Paper

"CashSales" says:

Materials: Kiwi Camp Dry spray (says 13% silicone), dextrin solution as thick as you can make it by reducing over burner, glossy laser paper like Staples brand or other, rubber roller, and a clean Teflon cookie sheet.

In the cookie sheet, place a sheet of paper, spray with silicone. Saturate it good on both sides. The paper should be translucent without any spots missed. Squeegee out all you can with the roller, flip and do it again.

Use a paper towel to wipe down the sheet so as to remove any excess silicone on either side. Set aside to dry - the paper will look about normal when the drying is complete and will have no wrinkling or warping whatsoever. Do this for however many sheets you will be making in the batch.

Clean the tray with soapy water and dry thoroughly.

Drop in a dried piece of paper from the first step and sprinkle a few drops of dextrin solution on the top side. Use a rubber roller and lots of downward pressure to spread the solution evenly over the surface. Keep rolling it until it begins to feel tacky, but not so sticky that the roller peals it up off the tray. Let the sheet sit in the tray for a few seconds (not longer or it will stick to the tray) and remove to dry somewhere. It will be dry to the touch within a few seconds, but should not be used for at least 10-15 min.

Print your board design on the dextrin side and fuse this to your PCB using an iron or laminater. You will need to use soapy water to release the dextrin from the paper because of the silicone resisting water penetration. When the paper is translucent from the soapy water it should slide off on its own and 100% of the toner will be transferred to the PCB.

Materials:

• (1) 16 Oz box of 100% Cornstarch
• A stove with top burners as well as an oven capable of 400'F
• Oven Mitt
• A timer for up to 20 minutes.
• (1) spray can of "Camp Kiwi Heavy Duty Silicone Water Repellent." Look in camping footware
• (1) Teflon coated cookie sheet at least 10"x12"
• (1) Teflon coated pot
• (1) High temperature plastic stirring/serving spoon (don't use metal on teflon)
• (1) High temperature plastic spatula
• (1) Measuring cup
• (2) 16 Oz or larger food storage containers with lid
• (1) Roll of Paper Towels
• (1) Ream glossy (brochure type) letter size (8.5"x11") laser printer paper
• (1) 4" soft rubber pain roller. Look in craft department. Speedball is a common brand name.

Method:

Making Dextrin: Preheat oven to 400'F. In a convection oven, 375'F may be better. Spread entire box of cornstarch on cookie sheet and bake on top rack, stirring every 20 minute, for a total 160 minutes or until all the white specks cornstarch are gone. Let cool and store in food storage container.

Making Dextrin glue: Reduce a 10% solution of Dextrin in water to the consistency of glue by bringing it to a boil while stirring until most of the water is gone. In small batches this will be 2 cups of water with 3 tablespoons of Dextrin or in one large batch use 8 cups water with all 16 Oz (approx 12 tablespoons) of Dextrin. Store in food storage container.

Making Waterproof Paper: Prepare paper by saturating it with silicone water repellent in a clean cookie sheet. Ensure the repellent is evenly spread on both sides of the paper by rolling over it with a rubber roller. The paper is properly saturated when it appears evenly translucent over the entire sheet. Wipe away excess repellent and set paper on a flat surface to dry.

Making Toner Release Paper: Spread several drops of Dextrin glue at a time evenly on dried, waterproofed paper by rolling over it with a rubber roller while it lays on a teflon coated cookie sheet. Stop when the roller starts to slightly stick to the paper. Let the paper set in the tray for a minute, then transfer to a flat surface to dry. Drying time: 30 minutes.

Other Release Materials:

Pentel "roll'n glue"

Helmar Professional Acid-Free Glue

"envelope gum" http://www.crafterscompanion.com/Envelope-Gum_p_32.html

"Paper Gum" http://www.miyartcrafts.com.au/Craft-Smart-Paper-Gum.html

See also:

• /techref/tonertransfer.htm Toner Transfer+
• http://www.pulsarprofx.com/ PCB FAB in a box.
   
  The "green' film is a standard heat transfer foil. You have probably seen the gold version used to hot stamp stamp jewelry boxes. If you remember the early days of laser printers, before inkjets came out, you could buy (and still can buy) "laser foil" to add metallic colors to certificate.
  
  The release paper is Dextrin coated stock.Dextrin is a starch used in papermaking as a sizing / coating on paper to bind it together and make the surface smoother.
  
• http://forums.makezine.com/comments.php?DiscussionID=1825 There is a link here to a PDF by a Triston J. Taylor that gives a very nice pictorial step by step on making release paper.

Comments:

• I tried making Dextrin coated paper and it works.
  Some things to make it easier: When mixing the Dextring glue, there is no need to "reduce" it much at all. To make 4.5 oz, just put 5 oz of water and 3 level TBSP of dextrin in a pan, bring to a boil while wisking. Boil and wisk for about 5 minutes till all is dissolved and lumps gone. It should be thin. Easy! Make sure to use the waterproofer on the paper and let it dry overnight before coating it. Pour a bit of dextrin glue into a tray, use a foam trim roller (Home Depot) to quickly coat a page (I used HP Laser Broshure paper) did about 10 pages. Does not dry perfectly flat. I cut a piece and taped it to white paper, printed my design, cut out the images for 2 sides, aligned with a light, taped 2 sides, laminated. After soaking 15 minutes in warm water the paper just falls off... The design was perfect. It did take a long time to etch but could have been my etchant and was using 2 oz copper (for a driver board). Used down to 10 mil lines. Thanks for the ideas!+

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