Abstract: In the present invention, the tin-silver-system alloy plating solution comprising following five fundamental ingredients (a)-(e): (a) a tin compound; (b) a silver compound; (c) at least one member selected from a group consisting of bismuth compounds and copper compounds; (d) a pyrophosphoric compound; and (e) an iodic compound. By the present invention, the tin-silver-system alloy layer, which can be employed instead of tin-lead solder alloy layer, can be formed without using harmful compounds: cyanide, lead compounds, etc..

Abstract: A tin-silver alloy plating solution having a tin compound, a silver compound, and a complexing agent including a pyrophosphoric compound and an iodic compound. The tin-silver alloy layer composition can achieve a high electric current efficiency without using harmful compounds such as cyanides. The plating solution is very stable, possesses adhesivability, and the solder-wettability of the tin-silver alloy layer is satisfactory. Also, the alloy is an advantageous alloy for solder plating.

Abstract: A setting machine for transplanting plugged seedlings of vegetables along predetermined transplantation ridges in a field used in combination with seedling culture trays made of synthetic resin and formed with cells as through-holes. The setting machine includes a taking-out device for supporting the seedling culture trays and for selectively taking the seedlings out of open bottoms of the cells successively. The taking-out device includes a selecting member adapted to be two-dimensionally positioned in a plane in parallel with the bottom surface of the seedling culture tray, and formed with selecting holes to be aligned with the cells of the seedling culture tray. The setting machine further includes a transfer device for forcibly transferring the seedlings taken out of the cells to a predetermined position by the action of negative pressure, and a transplanting device for transplanting the seedlings into the ground along predetermined transplantation ridges.