Abstract: A test unit to test a board having an area array package mounted therein includes the board, the area array package having an electronic component, a plurality of package pins including a plurality of contact pins connected with the electronic component and a plurality of no-contact pins not connected with the electronic component, and a plurality of contact members respectively provided on the plurality of contact pins and the plurality of no-contact pins to connect the plurality of package pins with the board, a plurality of board contact parts provided on the board and connected with the plurality of contact members to be connected with the plurality of package pins, at least one first connection part provided in the area array package to electrically connect the plurality of no-contact pins with each other in pairs, at least one second connection part provided on the board to electrically connect the plurality of board contact parts with each other in pairs to form a circuit line arranged alternately with

Abstract: A test unit to test a board having an area array package mounted therein includes the board, the area array package having an electronic component, a plurality of package pins including a plurality of contact pins connected with the electronic component and a plurality of no-contact pins not connected with the electronic component, and a plurality of contact members respectively provided on the plurality of contact pins and the plurality of no-contact pins to connect the plurality of package pins with the board, a plurality of board contact parts provided on the board and connected with the plurality of contact members to be connected with the plurality of package pins, at least one first connection part provided in the area array package to electrically connect the plurality of no-contact pins with each other in pairs, at least one second connection part provided on the board to electrically connect the plurality of board contact parts with each other in pairs to form a circuit line arranged alternately with

Abstract: An improved method for mounting tape carrier package type integrated circuits on printed circuit boards. In the method, some of leads of the integrated circuit are preliminarily soldered with corresponding lead pattern on the printed circuit board after the integrated circuit is aligned on the printed circuit board so that the integrated circuit is prevented from being disordered while the printed circuit board including the integrated circuit aligned thereon is transferred to a soldering apparatus.

Abstract: Disclosed is a method of preventing a gold plate connector of a printed circuit board (PCB) from being contaminated during a soldering process. The disclosed method prevents the gold plate connector coupled with the printed circuit board from being contaminated during wave soldering of the printed circuit board after spreading flux over the printed circuit board on which electronic components are mounted, and the method includes the steps of: forming a strip mask in a form of a membrane by solidifying a masking solution after spreading the masking solution capable of being solidified over the gold plate connector of the printed circuit board, performing the spreading of the masking solution before the spreading of the flux; and removing the strip mask from the gold plate connector after performing the wave soldering. As a result, it is not necessary to perform a washing operation of the gold plate connector. The washing operation can be troublesome, time-consuming, and inconvenient.

Abstract: Any one of at least two holding blocks loaded in a holding block storing portion is picked up and moved to cover an IC on a PCB of a PCB array. A light beam is applied to the whole surface of the PCB. The holding block is moved from the PCB to the holding block storing portion and cooled. It is then determined whether any other PCB to be soldered exists in the PCB array. If it is determined that any other PCB to be soldered exists in the PCB array, another holding block is picked up from the holding block storing portion and moved to cover an IC on the PCB of the PCB array. The above steps are repeated until all the PCBs of the PCB array to be soldered are completely soldered. If it is determined that any other PCB to be soldered does not exist in the PCB array, the PCB array is transferred to a subsequent process.

Abstract: An apparatus to clean gold plated contact surfaces on printed circuit boards uses a printed circuit board guide and cleaning units in contact with the printed circuit board guide. A guide rail on the printed circuit board guide is adapted to guide the printed circuit board having contaminated gold plated contact surfaces. The cleaning units include grindstones to abrade the gold plated contact surfaces and rub off the contaminants. Embodiments are capable of achieving cleaning uniformity, reducing failure rate, and enhancing the quality of the products. The effectiveness of the invention permits operators to carry out other operations during the cleaning process. Practice of the present invention also provides improved operating conditions without problems such as those due to the presence of waste eraser particles.

Abstract: A method for washing metal masks using a cleaning liquid includes the steps of washing the metal masks before a solder printing process on printed circuit boards, washing the metal masks at least once during the solder printing process and washing the metal masks after completing the last solder printing process. The washing liquid has a composition consisting of from 1 to 5% by weight of a fluorine-based surfactant and from 95 to 99% by weight of isopropyl alcohol, the some of the constituents being 100% by weight. More preferably, the cleaning liquid is a composition consisting of 2% by weight of the fluorine-based surfactant and 98% by weight of isopropyl alcohol, the some of the constituents being 100% by weight.