Taizo Iwami

Large area electron beam direct imaging technology for printed wiring boards

An electron beam direct imaging system that can image electric circuit patterns directly on printed wiring boards (PWBs) from computer-aided design (CAD) data without using film masks has been developed. The system realizes beam deflection over a large field of 100 mm*100 mm. The deflection field can be imaged in less than 1 s with an accuracy of better than +or-30 mu m. The maximum deflection speed is 254 m/s, and the beam diameter in full width at half maximum is 40 mu m. This technology can use the same kinds of resists as those for conventional photolithography. It was shown that fine patterns with line widths less than 100 mu m can be imaged for PWBs 340 mm*400 mm in size by stitching deflection fields.<<ETX>>

Deflection data correction system of large areas electron beam direct imaging for printed wiring boards

A novel electron beam system for large-area patterning of printed wiring boards (PWBs) has been developed. The system features a large field deflection, high-scanning speed, and stably focused beam in the large field. In order to deflect electron beams in a large area with high precision, particular attention was paid to the construction of a deflection data correction system. Various errors originating from the optics are measured, and the data to correct for these errors are calculated and stored prior to imaging. These data are output to the optics column at a rate of up to 10 MHz during imaging. In addition, sensors provide the data to correct the position error originating from the height variations and warp of the PWB for each field. It is confirmed that the beam position precision is +or-12 mu m for a field of 52 mm*52 mm.<<ETX>>

Study on high-speed beam deflection for electron beam machining.

A frequency band required for an oscillation technique on an electron beam welding was discussed by analyzing vibration frequencies of molten metal. Lower limits of beam scanning velocity not melting surfaces of work-pieces were also discussed by calculating temperature rise. A high-speed beam deflecting device to satisfy above conditions was developed and some applications of high-speed beam deflection were studied.The conclusions obtained are summarized as follows:(1) The vibration frequencies of the molten metal are less than 10 kHz and a beam oscillation with higher frequencies than 10 kHz is necessary to control distribution of an input power to a work-piece regardless of molten metal vibration.(2) A beam scanning velocity of more than 10000 m/min is required not to melt a steel surface for a beam power of 10 kW(3) A cutoff frequency of 60 kHz (-3dB) in small signal region and a maximum scanning velocity of 23000 m/min (deflection distance 300 nun) are realized using a deflecting device newly developed.(4) The high-speed deflection technique is very effective for the new-field of electron beam application such as marking, patterning, simultaneous multi-beam welding, surface hardening, and so forth.