Abstract: The present invention provides an ink jet composition including a thermosetting epoxy resin, a monofunctional acrylate monomer, a polyfunctional acrylate monomer, a photoinitiator, and an amine synergist. The ink jet resin composition according to the present invention may improve heat resistance, chemical resistance and adhesion of a cured resin layer obtained by curing the composition. In particular, in contrast to the conventional ink jet resin composition, the resin composition may be easily discharged (jetted) from an ink jet printer without using a solvent but even when using a diluent, thereby forming a resin insulating layer without influencing the characteristics of a printed wiring board.

Abstract: The present invention relates to a resin composition for inkjet printing used to form a resin layer serving as an insulation layer of a printed wiring board by an inkjet printing method.

Abstract: The present invention provides a method of preparing an ink jet resin composition including preparing a liquid (a) including a thermosetting epoxy resin and a first non-volatile acryl compound, preparing a liquid (b) including a pigment and a second non-volatile acryl compound, preparing a liquid (c) including a photoinitiator and a third non-volatile acryl compound, and mixing the liquids (a), (b) and (c) and further including an amine synergist and a viscosity controlling agent to prepare a resin composition. According to the method of preparing an ink jet resin composition of the present invention, an ink jet resin composition may be easily prepared without using a volatile solvent but using acryl compounds as diluents, and the resin composition prepared thereby may have improved heat resistance, chemical resistance and adhesion.

Abstract: The present invention provides a method of preparing an ink jet resin composition including preparing a liquid (a) including a thermosetting epoxy resin and a first non-volatile acryl compound, preparing a liquid (b) including a pigment and a second non-volatile acryl compound, preparing a liquid (c) including a photoinitiator and a third non-volatile acryl compound, and mixing the liquids (a), (b) and (c) and further including an amine synergist and a viscosity controlling agent to prepare a resin composition. According to the method of preparing an ink jet resin composition of the present invention, an ink jet resin composition may be easily prepared without using a volatile solvent but using acryl compounds as diluents, and the resin composition prepared thereby may have improved heat resistance, chemical resistance and adhesion.

Abstract: The invention provides a method of apparatus for testing circuit boards which does not require any inner wide power plane so as to detect an open circuit defect and/or a short circuit defect in a conductor path network formed in the circuit board quickly and accurately. An apparatus for testing a circuit board according to the present invention includes a transmission unit (2) for transmitting electromagnetic (radio) wave signal by way of an antenna (1) to a circuit board (3) to be tested, a detecting unit (3) for detecting signal received by a conductor path (4) of the circuit board (3) by using the conductor path (4) as a receiving antenna, and compare unit (8) for determining whether or not there is an open circuit defect or a short circuit defect in the conductor path (4) by comparing the detected signal with reference data of corresponding to a conductor path not including any defect.

Abstract: The present invention provides an impedance measuring device for a printed wiring board. The device include an appropriate probe unit to locate measuring points on the printed wiring board. The probe unit has a probe with contact styli to be contacted with the measurement points. The probe is moved to make an arrangement of the contact styli matching the pattern of the measurement points.

Abstract: It is the object to automatically measure the characteristic impedance of a printed wiring circuit of a printed wiring substrate using a coaxial probe. The present invention provides an impedance measuring device for printed wiring boards that has a test probe driving means such as a coaxial probe which mounts a test probe unit that has a first contact stylus and a second contact stylus provided at a position apart from the first contact stylus by a certain distance with its tip facing the same direction as the first contact stylus. The impedance measuring device has the test probe unit moveable to any point on the board such that the first and second contact styli may be brought into contact with predetermined points of measurement on the board. The impedance measuring device is characterized by having a second contact stylus turning means turns the second contact stylus of the test probe unit mounted around the first contact stylus.