Multichip Diode Array
The existing line produces various configurations of multiple diodes mounted on a silver spot plated copper substrate. The final product comes out in different options like a dual-in-line or a single-in-line through hole board insertions or a small outline surface mounted package.
Diode mounting is normally done on automatic ASM die bonders using silver-filled conductive adhesive specified for high-speed die bonding operations.
Depending on the product design configuration and depending on how many different sizes of diodes are to be mounted the machine is programmed for the desired number of pick and place sequence.
For some array layouts where the automatic machine cannot be programmed to perform a required process sequence, innovative operator-dependent techniques come into play. For instance, silk screen can be used to dispense epoxy dots at selected locations with just one sweeping move from one end to the other end of a leadframe substrate. Adhesive topping for multi-layer connections is manually applied from precision-controlled syringe dispensers.
Diodes to diode or diode to substrates connections are done with gold wires on Kaijo automatic thermosonic gold wire bonders. Other than wire bonding, the alternative process is called clip attach. This method uses a strip of Kovar material which is held firmly in place at the top surface of the diode by means of silver paste. This process is unique to specific modules where the “mother” diode is connected to a “daughter” diode.
The completed package undergo parametric testing at customer specified test conditions.