Laserfiche WebLink
Services placed the 2041 Navy Drive site on the State Bond Expenditure Plan and issued a <br />'Remedial Action Order'. <br />On March 2, 1988, PHS-EHD signed a'Memorandum of Understanding' with the Department of <br />Health Services, (DHS), now known as Cal EPA/Department of Toxic Substances Control (Cal <br />EPA/DTSC), authorizing PHS-EHD to perform hazardous waste generator inspections in San <br />Joaquin County. <br />V. GENERAL DESCRIPTION OF FACILITY: <br />LIKA manufactures printed circuit boards of double sided and multilayer construction. The <br />customers consist of manufacturers of electronic equipment. These customers include computer, <br />telecommunications, medical, and other 'Hi -Tech" electronics manufactureg. LIKA is a 24 hour <br />operation and has 210 employees all of which are permanent and full time. <br />Briefly, the manufacturing process consists of the following: All circuit boards begin as a fiberglass <br />substrate covered in copper. For multilayered boards, they are laminated with a 'light sensitive`, <br />photopolymer dry film. The film displaying the circuitry pattern is exposed to UV light to image the <br />circuitry on the inner layer of the board. The board is then placed in a potassium carbonate bath <br />that dissolves the photopolymer, thus uncovering the exposed patterned copper. This is followed <br />by a 16% ammonia etchant solution that serves to etch the unexposed copper. The board then <br />goes through a series of baths for processing, including an acid soap cleaner to remove <br />contaminants. The board is then baked to remove all moisture, layered in 'books' using epoxy <br />to laminate, and pressed with 360 degrees heat and pressure. The single layer boards join the <br />multilayered boards at this point for drilling. The multilayered boards must then go through an <br />etchback process to remove smearing that occurs in drilling. All boards are then subjected to <br />an electroless copper plating process to facilitate conductivity. Another dry film procedure, <br />termed electrolytic copper process or "pattern plate', then takes place to image circuitry on the <br />outer layer of the board. This is followed by another etching, similar to the one described above. <br />Other plating materials, such as gold or nickel, can be utilized depending on the specifications <br />by a particular customer. <br />The entire board is sprayed with a protective coating called solder mask. This is a preventive <br />measure that deters possible shorting of the circuits due to dust build-up within the product or <br />during repair of the product. The board is then dipped in 250 degrees molten solder. The solder <br />serves two functions. First, to prevent oxidation of the copper, and second, to allow the <br />components to be more easily mounted to the board. Next, in fabrication the board is cut to the <br />required specification. Finally, the board goes through a series of testing in quality control to <br />prepare the final product for shipping. <br />LIKA also manages their own wastewater treatment operation in the rear of their facility. The <br />wastewater (including mop water from the production floor) is fed into a series of tanks where <br />sodium hydroxide is eventually added creating a metal hydroxide. This metal hydroxide is then <br />fed through a clarifier causing the metal hydroxide solution to precipitate. The 'metal free' <br />solution goes through a pH adjustment and is then discharged to the sanitary sewer. The metal <br />hydroxide particles are transferred to a filter press that performs mechanical dewatering. The <br />resulting liquid then returns to the beginning of the wastewater treatment system. The remaining <br />metal sludge is placed in a roll off bin and manifested off-site as hazardous waste. The <br />discharge process is under permit through Municipal Utilities who determines the allowable metal <br />concentration requirements in the effluent. Currently, LIKA is working with Cal EPA/DTSC to meet <br />tiered permitting requirements and obtain applicable permits for the wastewater treatment <br />operation. <br />2 <br />