This is a high-speed SIP resistor network processing machine. The operator loads tinned strips of SIP resistor networks into magazines, which are loaded onto a rotary index table. The machine removes the top strip from the rotary table, and places it into a straightening die, to repair any bend leads. The first half of the machine cuts the individual SIP packages free from the carrier while trimming the leads to a pre-set length. This dimension is referenced from the standoff bump, shown in the pictures above and is held to a tolerance of +/- 0.005″. Once the SIP’s are separated, they are fed by vibratory inline feeders to the second half of the machine in two rows.
Where they are tested electrically, vision inspected, and straightened at over 200 parts per minute. The second half of the machine is almost entirely cam driven, to ensure correct timing at these speeds. The inspection of the laser marking described below is done on the fly, using a strobe light. The finished parts are then loaded into tubes, either side by side, or end to end for shipping.
INSPECTION – Each SIP is electronically tested for the proper resistance value. The vision system inspects both the location, and completeness of the laser marking (one row on the edge of three rows on the face), verifies the content of the part number, and verifies the true position and length of the pins.
CONTROLS – This machine is controlled by GE 90/30 PLC using a custom relay ladder logic program. The operator interface is provided by an Intel 486 based PC, with a touch screen monitor, running custom Man Machine Interface program written in Microsoft Basic. The vision inspection functions are performed by a pair of PPT Scout PC-based vision systems with a total of 7 CCD cameras. The MMI computer and the two PPT systems are connected together to an Ethernet network and netDDE is used to communicate between the three systems.
CYCLE RATE – Two lines of parts running through the machine at 6,000 parts per hour for a production rate of 12,000 parts per hour.
PARTS CONFIGURATION – This machine can accommodate various body widths and numbers of leads with minimal changeover.