Current Issue An Independent Journal Dedicated to the Advancement of Chip - Scale Electronics March 2001 Email the editor

Jerry Secrest Contributing Editor

In most packaging operations, there is not enough capacity to meet market demand. Moreoever, there is a long leadtime on new equipment delivery that delays the addition of capacity.

For a vertically integrated semiconductor maker or contract assembler, inadequate capacity means business lost, or at least deferred. Alternatively, finding a way to increase capacity from the same equipment allows expansion of billings and satisfying customers.

Bump Up Capacity

One way to bump up capacity is to employ the SECS/GEM communications interface on the equipment to automate equipment setup. (SECS is SEMI's Equipment Communications Standard and is available on equipment from many assembly equipment suppliers.) Simply put, automating equipment setup can increase equipment use, thereby increasing capacity. Typical changes that increase utilization are:

• Decreasing the setup time on change-over: Automating the product change-over means automatically selecting and loading the right program for the next product, which saves time for looking up the program.

• Decreasing the setup verification time: Verification of the equipment set-up means up-loading the equipment variables to the factory computer for checking against the "golden" values stored in the engineering database.

• Decreasing the time to respond to equipment alarms: Automatic collection of equipment alarms to a central maintenance dispatch system allows maintenance technicians to know what repair is needed prior to arriving at the equipment.

Raising capacity from the same equipment base offers a double benefit. First, it increases the manufacturing output, which increases sales. Second, the output is increased from the same equipment base, thereby de-creasing CSP cost. The chart shows a 15 percent gain from the use of SECS on the equipment. This gain is in the appropriate range for a factory SECS implementation.

While automating manufacturing can produce capacity/throughput increases, data automation of all equipment in packaging may not always be cost effective.

For example, the equipment at the bottleneck determines the capacity for the manufacturing line. Although auto-mation at the bottleneck increases overall capacity, increasing equipment use at other manufacturing steps does not.

The largest gain from the investment in automation requires preceeding implementation with a study to define:

• Capacity limit by manufacturing step

• Data automation solutions to increase utilization

• Cost of the implementation solution

Is the gain in utilization through data automation real? Amkor Technology Inc., presented its results with SECS at the SEMI TAP integration conference in February 1999.

As illustrated, automation with the SECS protocol capacity can substantially increase output.

Setup Time Cut

Amkor was able to reduce setup time, combined with bond verification on wire bonders, by 18 minutes. In our analysis this represents a 5 percent increase in wirebond capacity. It is a larger savings in capacity when product changeovers are made more often than at shift change.

Implementing SECS to improve capacity is not plug-and-play. But, there are services and products to ease the implementation. Engineering services are available for the analysis, design and installation. There are also pre-configured software and hardware computer products for SECS communications.

Most assembly and packaging operations already have a Manufacturing Execution System in place for process program management. Management needs to make the decision to either stay with the same method and results or to make the investment for bumping-up capacity.