Screen-stencil

Other Printing Applications. There are a number of lower volume applications of photopolymer chemistry to the printing industry. Some of these include the production of tactile images (raised Braille patterns) (47) and screen stencil resists... 

Fig. 1. Diagram to show preparation of screen-printed electrodes. (A) Polyester card support, (B) screen-stencil, (C) ink suspension, and (D) squeegee (this is a variation after Fig. 3 in ref. 7).

Screen, stencil printing Surface mount, hybrid, or MCM/ stencil or screen printer Fast, multiple dot size. Dots as small as 3-mils diameter on 5-mil pitch can be printed Stencil printing requires a new stencil per design complex cleaning procedures for small aperture stencils cannot be used with other components on boards... 

In etching technology, where a surface resist stencil is produced from photoresist imaging, screen stencil, or maskant cutting, chemical attack can occur into the body of the substrate, and once a sidewall has been formed, the etchant can attack beneath the stencil to form what is known as undercut (U) where U = 0.5 (B-A) (see Fig. 2). Normally the etch factor (DAJ) is required to be as high as possible so that smaller holes can be etched into thicker materials. 

Screen-printed electrode An electrode prepared by forced screen printing of a powder-based ink through a screen stencil typically on a plastic sheet or foil, or ceramic plate, as a single or set of film electrodes [66],... 

PEG-20 oleamine PEG-35 tallowamine cleaner, polymeric residues Diethyl oxalate Dimethyl adipate N-Methyl-2-pyrrolidone cleaner, precision Dichlorofluoroethane cleaner, printed circuit boards 2-Ethyl-1-butanol cleaner, scouring powders Trisodium phosphate, chlorinated cleaner, semiconductors Nitrogen trifluoride cleaner, silicon wafer industry Dimethyl hexynol cleaner, silk screen stencils Periodic acid Sodium m-periodate cleaner, solvent... 

This is a clever modification of flat silk screen printing. The paste adhesive is fed in the center of a rotary perforated drum, it is pumped through a hollow doctor blade into the rotating screen stencil and then through the holes in the drum and applied onto a web or fabric (Fig. 64). The web or fabric is running over a counter roller coated with rubber. 

Valieia Process. A decorating process for tableware. A table has a recess to receive the article to be decorated, alongside a silk-screen stencil which can slide into a predetermined position above a rubber sheet. This is on a panel hinged to superimpose it on to the curved surface of the ware, where it is forced down by compressed air to transfer the decoration. (J. Valieia and Interpace Corp, USA, Br. Pat. 746,100 1956). 

Various adhesive application methods are available (dispensing, pin transfer and screen/stencil printing) and different adhesive rheologies are required in each case. 

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