Apparatus and process for mounting conductor balls on terminal pads of semiconductor devices

An apparatus for mounting conductor balls on terminal pads of semiconductor devices or other electronic devices on a semiconductor wafer or other substrate, stepwise, for divisions of the substrate that include different numbers of the devices, the apparatus including an adsorbing unit which comprises:

• an adsorbing head;
• an adsorbing plate attached to the head and having adsorbing holes for adsorbing the conductor balls, the adsorbing holes being arranged corresponding in number and position to the terminal pads present in one of the divisions that includes a largest number of the devices;
• a vessel for containing the conductor balls and having an open end for allowing the conductor balls to enter and exit the vessel;
• a mask plate attached to the open end of the vessel and having an opening conformed in shape and size to an area of the substrate occupied by a group of the devices included in a selected one of the divisions;
• and
• a means for moving the head to bring the adsorbing plate into close contact with, or away from, the mask plate so that the conductor balls are only adsorbed by the adsorbing holes corresponding in position to the terminal pads of the devices of the group in the selected one division when the head is moved to bring the adsorbing plate into close contact with the mask.