Meco's Solution for High Speed Spot Plating with Exceptional Flexibility

Meco's internationally patented spot-wheel technology with its modular construction provides the best solution for high speed selective silverspot plating in today's market. Meco originally developed the patented spot tool system to plate leadframes on a continuous basis. This lead to a number of advantages over the traditional step and repeat plating systems.

Today's leadframe market is rapidly moving towards more diversity in IC-packaging with variable spot patterns. Besides the trend towards lead-less packages (like CSP, BGA), matrix leadframes are more and more required. Meco's spot technology is well prepared to handle variable spot patterns such as single-spot, minispot, ring-spot, matrix-spot and stripes. All these diverse products can be handled with the same selective spot equipment by simple and easy exchange of the product specific spot-tooling.

Meco's Spot Technology

The spot wheel technology is based on a continuously moving product onto a rotating spot wheel (spot-tool) in combination with a stationary jet and integrated anode (sparger). The plating solution is pumped through the anodes and slots of the sparger on the rotating spot-tool, onto the moving product. Accurate positioning of the spots is ensured by pilot pins on the spot-tool and matching pilot holes in the leadframe. Both the spot-tool and sparger can be easily exchanged when changing to a different product set-up.

Spot-Tool and Sparger Configuration

Variable spot patterns require variable solutions. Therefore, Meco supplies several spot-tool configurations such as spot-wheel, stripe-wheel, "chain" spot-wheel and combinations of it. For silverspot plating we commonly use "chain" spot-wheels as shown, which gives the best spot tolerance.
Main purpose of the sparger is providing high agitation. Therefore, the sparger configuration is dependent on product and spot-tool. We supply several sparger types, such as length-slotted, cross-slotted or with small holes. The cross-slotted as shown is commonly used for matrix products.

Good Distribution

As with all Meco technologies, the continuous nature of the spot plating reduces individual spot distribution characteristics to fall well within the industries standards and ensures repeatability from spot to spot.

High Speed Plating

Meco's spot technology makes high plating speeds possible (roughly 3 times faster than for step and repeat systems). Because the leadframe moves continuously around and engages with the spot-tool, there is no "dead" time as seen in the step and repeat system. For high-speed silver spot plating you can reach up to 156 micron per minute based on 250 A/dm2, depending on spot configuration. In most high-speed silver spot lines with line speeds up to 12 m/min a tandem spot unit is sufficient to reach the common silver specification of 4 microns.

Low Product Change-Over Time

With the Meco spot-tool and sparger concept, low conversion times can be reached. Converting to a new product will take approx. 4 hours by a well trained operator. For a product within the same product family it can be done within an hour by a well trained operator.

Minimum Drag-Over

The high drag-over values seen in step and repeat machines are dramatically reduced in the Meco RTR Ag line, whilst overall output is much faster. The drag-over caused by the step and repeat rapid advancement motion is eliminated in the Meco's continuous operation.