Eaton in Adv. A process is disclosed for applying a preformed photopolymerizable solder mask film and a photosensitive liquid to a printed circuit substrate containing a plurality of holes wherein reduced failure is obtained in photopolymerized areas of the solder mask film above the holes as determined after a soldering operation. In another embodiment a layer of curable, percent solids liquid of predetermined thickness is employed as the adhesive layer. The process of claim 12 wherein the liquid plasticizer is taken from the group consisting of butyl benzyl phthlate, dibutyl phthalate, tricresylphosphate, glyceryl triacetate, and mixtures thereof. Both sides of the laminated panel are then uniformly exposed to radiation from watt high pressure mercury lamps except areas along the edges of the panel are not exposed.
TB Water Cleaning OA Fluxes After Wave Soldering · TB Handling and Safety Considerations for the VACREL® Solder Mask Curing Process. Finally, tape along.
Chip capacitor 1 2 3 4 Figure A typical wave-soldering thermal Apply adhesive Place SMCs Cure adhesive Turn PCB over Wave soldering Clean flux Figure Assembly processes for type III surface mount boards, (a) THC inserted For the wave soldering process, a solder mask with a smooth finish is found to. Print solder paste Place SMCs Reflow Clean flux residue Insert THCs Turn PCB adhesive Place SMCs Cure adhesive Turn PCB over Wave soldering Clean flux Assembly processes for type III surface mount boards, (a) THC inserted wave soldering process, a solder mask with a smooth finish is found to cause.
Preferably, the panel is processed immediately.
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Latest E. Film Adhesion Promotor When the photopolymerizable layer is used as a photoresist, a heterocyclic or mercaptan compound typically is added to improve adhesion of the coating to the metal required during processing.
The pad contacts one side of the panel surface and forces photopolymerizable liquid through the through-holes while the counterpoised idler roller maintains the alignment of the panel path. In this instance, the reverse side of laminated panel is masked with an opaque cover to prevent exposure Alternatively lamps on a single side of the panel can be used. Liquid A produced high yields with the 1 mil film but there was moderate sized internal voids, and feather cracking in holes.
Preferred are those wherein at least one and preferably most of such linkages are conjugated with a double bonded carbon, including carbon double bonded to carbon and to such heteroatoms as nitrogen, oxygen and sulfur.
The longer you can resist consuming it, the finer it will become. Solder mask on a printed circuit board cari lead to many process problems it tr11cc of, thesc nulzsks were cured uISing both ai tiucrinal curIc and1(an1 nit ra'.
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The process of claim 1 wherein the transmitted portion of the actinic radiation in the first spectral region has wavelengths longer than the wavelengths of the actinic radiation in the second spectral region. Justia Patents Material Deposition Only US Patent for Lamination of a photopolymerizable solder mask layer to a substate containing holes using an intermediate photopolymerizable liquid layer Patent Patent 5, Lamination of a photopolymerizable solder mask layer to a substate containing holes using an intermediate photopolymerizable liquid layer.
In the use of this system, the panel is first cleaned and then sprayed with a dye penetrant solution containing low boiling catalytic reformer fractionater distillates CASisobutane, normal C.
Preferably the plug should be 30 mils long or longer. For liquids A and N which have very high yields, the average plug depth is at least 31 mils or greater which is more than half the barrel depth of the holes, and a factor of 3 or more deeper than the average plug depth for liquid X containing no matched initiator system.
Video: Solder mask curing process cannabis PCB Prototyping Part 2: Solder Mask, Assembly and Testing (Dry Film Soldermask)
The exposure is adjusted so that 11 to 12 steps on a 21 step Stouffer.
A commercial process for lamination of liquid/solder mask film onto a printed observed after thermal curing and/or soldering wherein cracks are formed in the surface of the tent above the barrel of the hole. . 3,, and Weed, U.S. Pat. Acommercial process for lamination of liquid/solder mask film onto a printed board substrate is marketed mal curing and/or soldering wherein cracks are formed in the surface of the . Patent 3,, and Weed, U.S. Patent 4, 6.
The dry panel is then wiped with a cloth to remove excess dye and is then sprayed with a developer which contains methyl chloroform, chlorodifluoromethane, calcium carbonate, ethoxylated nonylphenol CASamorphous silica, magnesium stearate, methalal, and tert-butyl alcohol and allowed to dry.
Film Plasticizer The photopolymerizable layer may also contain a plasticizer to modify adhesion, flexibility, hardness, solubility, and other mechanical or chemical properties required during its processing. Suitable plasticizers include triethylene glycol, triethylene glycol diacetate, triethylene glycol dipropionate, triethylene glycol dicaprylate, triethylene glycol dimethyl ether, triethylene glycol bis 2-ethylhexanoatetetraethylene glycol diheptanoate, poly ethylene glycolpoly ethylene glycol methyl ether, isopropylnaphthalene, diisopropylnaphthalene, poly propylene glycolglyceryl tributyrate, diethyl adipate, diethyl sebacate, dibutyl suberate, phthalate esters such as dioctyl phthalate, tributyl phosphate, tris 2-ethylhexyl phosphate, Brij.
The photopolymerizable compositions used in the photoresist layer typically contains at least one nongaseous ethylenically unsaturated compound having a boiling point above A photoinitiating system listed for use in the film could be employed in the liquid provided the film uses a different initiator system wherein different spectral sensitizers are utilized and the film allows actinic radiation to pass and photopolymerize the liquid.
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|Preferred photopolymerizable compositions contain mono or polyfunctional acrylates or methacrylates and particularly preferred are such compositions containing monomers with two, three or more acrylate or methacrylate groups to allow concurrent crosslinking during the photopolymerization process.
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For preformed photopolymerizable film having a spectral window in the nm region, initiators such as 2-benzyldimethylamino[4- 4-morpholinyl phenyl]butanone, ethyl dimethylamino benzoate and mixtures thereof are useful as initiating systems for the photopolymerizable liquid.
Useful photoinitiator systems may contain a sensitizer that extends spectral response into the near ultraviolet, visible, and near infrared spectral regions provided that the resulting photopolymerizable layer absorbs only a portion of actinic radiation in the first spectral region. This dye penetrant method is equivalent to the optical method supra for detecting cracks and is substantially faster.
At the end of the input section is a pair of vertical, undriven, heated, laminating rolls and two webs of dry film photopolymerizable solder mask typically consisting of a 0. A suitable class of monomers include an alkylene or a polyalkylene glycol diacrylate prepared from an alkylene glycol of 2 to 15 carbons or a polyalkylene ether glycol of 1 to 10 ether linkages, and those disclosed in U.