Board manufacture

Printed circuit boards manufacture is aided by the use of KMnO. Alkaline permanganate solution is used to remove resin smeared on the interior hole wall of multilayered printed circuit boards. Additionally the hole wall is etched, resulting in a surface with excellent adhesion characteristics, for electrodeless copper (250). The alkaline permanganate etchback system containing >60 g/L KMnO and 40-80 g/L NaOH at 70—80°C, is effective for difunctional, tetrafiinctional, and polyimide resin substrates, where the level of etchback is direcdy proportional to the immersion time (10—20 min) (251). 

Poly(vinyl alcohol) is employed as a modifier of thermosetting resins used as adhesives in plywood and particle board manufacture (314,315). The polymer is added to urea-formaldehyde or urea—melamine—formaldehyde resins to improve initial grab, to increase viscosity, and, in general, to improve the characteristics of the board. 

Trichloroethane and other chlorinated solvents are used for vapor degreasing (84—90). Other uses include cold metal cleaning, printed ckcuit board cleaning, and as a solvent for inks, coatings, adhesives, and aerosols. 1,1,1-Trichloroethane is an excellent solvent for development of photoresist polymers used in printed ckcuit board manufacture (see Integrated circuits Photoconductivepolymers). 

The DfE partnership will develop information to improve the understanding of the environmental and human health impacts of new and current materials that can be used to meet the fire safety requirements for circuit boards. Project partners include electronics manufacturers, component and board manufacturers, chemical companies, trade associations, environmental groups, universities and governments. The project will consider environmental and human health impacts that can occur throughout the life cycle of a material, from development and manufacture, through product use and end of life of the material or product. Stakeholders have expressed a particular interest in understanding the combustion products that could be formed during certain end of life scenarios. The list of active partners includes ... 

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. 

U.S. PSES for All Metal Finishing Plants Except Job Shops and Independent Printed Circuit Board Manufacturers... 

The term independent printed circuit board manufacturer shall mean a facility that manufactures printed circuit boards principally for sale to other companies. 

In a presentation [14] on the occasion of a FPT workshop organised by PTS in 2010 the subject Migration of mineral oils in the paper circuit , model calculations showed how any separation of the RCP cycles to avoid in medium term the input of newspapers as raw material for board manufacturing for food packaging affected the mineral oil contamination of the board. However, the authors concluded that under economic, qualitative and ecological aspects a reasonable solution of the problem can lie only in the reduction of the mineral oil load at the source . 

Printed circuit board materials, 17 843 Printed circuit board manufacture,... 

The analysis of tetramethylammonium hydroxide (TMAH) solutions manufactured by SACHEM Inc. of Cleburne, Texas, includes the determination of trace elements. These elements cause less-than-optimum performance of integrated circuit boards manufactured by SACHEM s customers that use these solutions in their processes. Alkali and alkaline earth metals (e.g., Li, Na, K, Mg, Ca, and Ba) can reduce the oxide breakdown voltage of the devices. In addition, transition and heavy metal elements (e.g., Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Au, and Pb) can produce higher dark current. Doping elements (e.g., B, Al, Si, P, As, and Sn) can alter the operating characteristics of the devices. In SACHEM s quality control laboratory, ICP coupled to mass spectrometry is used to simultaneously analyze multiple trace elements in one sample in just 1 to 4 min. This ICP-MS instrument is a state-of-the-art instrument that can provide high throughput and low detection Emits at the parts per thousand level. Trace elemental determination at the parts per thousand level must be performed in a clean room so that trace elemental contamination from airborne particles can be minimized. 

SACHEM Inc., located in Cleburne, Texas, is a producer of high-purity bulk chemicals for companies that have high-purity requirements in their chemical processing. As stated in Workplace Scene 1.2, one of their products is tetramethylammonium hydroxide (TMAH), which is sold to semiconductor industries. The analysis of TMAH for trace anions such as chloride, nitrate, nitrite, and carbonate is critical for SACHEM s quality control laboratory. If these ions are present on the integrated circuit boards manufactured by one of their semiconductor customers, they may cause corrosion severe enough to affect the functionality and performance of the electronic devices in which the circuit boards are used. In SACHEM s quality control laboratory, ion chromatography procedures have been developed to measure the anion concentrations in TMAH. Because the concentration levels are trace levels, a clean room environment, like that described in Workplace Scene 1.2, is used. A special procedure for carbonate analysis is required so that the absorption of carbon dioxide from the atmosphere can be minimized. 

Before the invention of the planar transistor, many photoresist processes were developed for the manufacture of circuit boards. Experience gained in this area was rapidly transferred to silicon processing, and much of the early work in integrated circuit lithography can be traced directly to circuit board manufacturing. 

Maryland Supeifund Site Natural attenuation enabled new development at 70-acre Superfund site approximately 20 miles northwest of Baltimore, Maryland. This property had been contaminated by a printed circuit board manufacturing company. According to a manager, the pump-and-treat remediation system failed to meet groundwater treatment goals, though it cost over 1 million to construct and more than 200,000 a year to operate. It was estimated that this approach could cost as much as 5 million over 10 years and would still not achieve the cleanup objectives of the Maryland Department of Environment (D17452R). 

Adhesive Formulation. Adhesives for testing consisted of 100 parts resin, 10 parts wheat flour as extender, 4 parts commercial additive, and 2 parts water. This formulation is recommended by Japanese board manufacturers. Adhesives without wheat flour were also formulated to examine the bond strength of the neat lignin based resins. 

MSA and other lower alkanesulfonic acids are useful for plating of lead, nickel, cadmium, silver, and zinc (409). MSA also finds use in plating of tin, copper, lead, and other metals. It is also used in printed circuit board manufacture. In metal finishing the metal coating can be stripped chemically or electrolytically with MSA. MSA also finds use in polymers and as a polymer solvent and as a catalyst for polymerization of monomers such as acrylonitrile. MSA also finds use in ion-exchange resin regeneration because of the high solubility of many metal salts in aqueous solutions. 

Raw materials for PC board manufacture that contain metals include the following o Copper foil (encasing the board) o Etchants chromic acid, cupric chloride, ferric chloride o Catalysts stannous tin, palladium chloride o Electroless copper bath copper sulfate... 

Waste reduction methods of specific interest to PC board manufacture are discussed below 11.1.3 SOURCE REDUCTION 11.1.3.1 Metal Complexes... 

WASTE MANAGEMENT FOR PRINTED CIRCUIT BOARD MANUFACTURE... 

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. 

Also, as part of the WRAP Program, the EPA in cooperation with the California Department of Health Services is producing a series of industry specific manuals that address waste minimization opportunities in a variety of industries. These manuals are in various stages of development but are expected to be available by the Fall of 1989. The industries addressed in the series include (1) paint shops, (2) pesticides, (3) commercial printing, (4) metal fabricators, (5) circuit board manufacturing, (6) hospitals and (7) research and educational institutions. 

Sellers, Veronica R. 19B6. "Waste Management Alternatives for Electroplating and Printed Circuit Board Manufacturing Operations." 4th Massachusetts Hazardous Waste Source Reduction Conference Proceedings. Massachusetts Department of Environmental Management, Boston, Massachusetts. 

WTI currently has ARO systems operating in three categories of metal finishing -Electronic parts and circuit board manufacture, functional (cyanide) plating and aluminum coating and finishing. 

Circuit Board Manufacturer "B" produces 125 gallons/day of waste cyanide solutions. Every 90 days they pay a licensed transportation and disposal company 4.75/Gal. to remove 11,250 gallons of cyanide waste. 

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