Preparation Printed circuit boards

These patents discuss various adhesive formulations and techniques which may be employed to prepare printed circuit boards. Laminates are electrolessly plated with copper to produce these heat resistant boards. As an example, a Toshiba patent describes hot pressing prepregs with films coated with adhesives to make such laminates (Table 18). 

This type of coil was prepared from copper cladded printed circuit board material by applying photolithographic techniques. The p.c. board material is available with difierent copper thicknesses and with either a stiff or a flexible carrier. The flexible material offers the opportunity to adapt the planar coil to a curved three dimensional test object. In our turbine blade application this is a major advantage. The thickness of the copper layer was chosen to be 17 pm The period of the coil was 100 pm The coils were patterned by wet etching, A major advantage of this approach is the parallel processing with narrow tolerances, resulting in many identical Eddy current probes. An example of such a probe is shown in fig. 10. 

Blends have also been prepared by dissolving DMPPO in a monomer and then polymerizing the monomer. An example is an epoxy—DMPPO blend prepared by curing a solution of DMPPO in Epon 828 at 85°C with an alurninum—tetramethylguariidine catalyst. Some copolymer formation is observed. The solutions can be appHed to glass cloth before curing to produce prepregs for composites in appHcations such as printed circuit boards (67). 

A.dhesiveslCements Sealants j Coatings. Excellent adhesives of high strength and high oil resistance can be prepared using nitnle mbber (25). Many references have discussed the use of nitnle mbber—phenoHc and nitnle mbber—epoxy adhesives for printed circuit boards. 

The preparation of flame-retardant epoxy resins is accompanied by inclusion of tetrabromobisphenol A [79-94-7] in the advancement process (see Flame retardants). Products containing ca 20 wt % Br are extensively employed in the printed circuit board industry. 

The 40 CFR part 433 does not apply to (a) metallic platemaking and gravure cylinder preparation conducted within or for printing and publishing facilities and (b) existing indirect discharging job shops and independent printed circuit board manufacturers which are covered by 40 CFR part 413. 

DHS. June 1987. Waste Audit Study Printed Circuit Board Manufacturers. California Department of Health Services, Toxic Substances Control Division, Alternative Technology Section. Prepared by Planning Research Corporation, San Jose, CA. 

USEPA. 1989. Guide to Waste Minimization in the Printed Circuit Board Industry. Prepared by Jacobs Engineering Group, Inc., Pasadena, CA for the U.S. Environmental Protection Agency (In Process). 

Resins prepared by Timberlake [1] consisting of benzoguanamine-modified phenol-formaldehyde or melamine-phenol-formaldehyde resins were treated with tris(4-methoxy- phenyl)phosphine oxide to prepare coatings in printed circuit boards. Isomeric mixtures of tris(2-hydroxyphenyl)-phosphine oxide compounds were also converted into resins by Brennan [2] by reacting with tris(4-methoxy-phenyl)phos-phine oxide derivatives. 

Matsuwaki [5] prepared polyimide films, (V), having molecular orientation in the machine direction that were used in high-density mounting of flexible printed circuit boards. 

An aqueous etching solution containing 8.8% KI is to be prepared to etch gold in printed circuit boards. The desired solution is to be formed by combining a strong solution (12% KI and 3% I2 in H2O) with a weak solution (2.5% KI and 0.625% I2). 

Also known are poly(ester-imide)s prepared from 3,3, 4,4f-benzophenonetet-racarboxylic dianhydride (12) (Fig. 5). They were claimed to have excellent thermal properties [60], excellent refrigeration medium resistance [61] or to be useful for making high performance printed circuit boards [62]. 

Aromatic Polyesters Engineering thermoplastics prepared by polymerization of aromatic polyol with aromatic dicarboxylic anhydride. They are tough with somewhat low chemical resistance. Processed by injection and blow-molding, extrusion, andftiermoforming. Drying is required. Used in automotive housings and trim, electrical wire j acketing, printed circuit boards, and appliance enclosures. 

CAS 1189-08-8 EINECS/ELINCS 214-711-0 Uses Crosslinking monomer for preparation of inks, photoresists for printed circuit boards, photopolymer printing plates, wire and cable coalings reactive diluent for PVC plastisols, rubber crosslinking, glass reinforc plastics, adhesives, sealants, impregnated wood composites, and other surf, coatings... 

After 3 years of development, including 2 years of practical testing in the industry up to a commercial scale, we can report (text written in 1998) an interesting new application the preparation of the surface finish of printed circuit boards. The places where the diodes, resistors, etc., have to be mounted and connected to copper-based printed circuits have to be solderable for a period of at least 1 year in... 

In fabrication of printed circuit boards (Goh 1994), a resin formula is prepared and impregnated with fibreglass and other particles. This is baked to form a panel or a board. Lamination involves metallic copper being bonded to the board in (sandwiched) layers. Each side of the laminate is cleaned, photoprinted and etched to form the electrical circuits. Solder plating is done, and the boards are drilled and cut to the required sizes. Finally, the boards are marked and tested. 

Many types of Clark sensor have been prepared. An example of a small flow-through sensor fabricated from a printed circuit board is shown in Fig. 9. The gelatin layer contains a depolarizer (KCl) for the reference electrode and polystyrene functions as a gas permeating membrane [126]. 

The large number of patents issued in recent years testifies to the current interest in high-temperature polymers for various applications in the electronics industry. Printed circuit boards for engine control panels on the Mirage 2000 aircraft withstand service temperatures of 260°C. To achieve this the boards are prepared from multilayer woven glass laminates impregnated with a polyimide resin. ... 

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