Mold Chase Heating System

The Problem

In the Transfer molding process, mold chase heating is done to ensure the thermoset resin is liquid while flowing into the mold cavity.  In the Semiconductor Industry, mold chase assemblies need to be regularly changed on the Transfer Molding Machines to cater for production planning schedules which are based on the ever-changing market demand.

The mold chase heating can take up to two hours to reach operation temperatures.

As such the Manufacturing Line Down-Time is around 4 hours (including the change times and heat up time).  This is a significant cost impact on Semi-conductor Manufacturing Costs.

The Design Complexity

There is no standardized design among the numerous Transfer Molding Machines Makers.   All Mold Chase Assemblies come in different sizes with different assembly features.  The heating temperatures and heat transfer rates are also very specific to the machine.  The Hot Mold Chase Assemblies have to be moved as close as possible to the machine to reduce heat loss.

The Assembly Height for each machines are also different and the design has to cater for Top & Bottom Mold Chase Assemblies at the same time.

Mobility, Flexibility, Ease of Operation and Safety were critical design requirements.

The Mold Chase Heating Solution

Using our systematic and proven approach, we have integrated a scissors lift trolley with a custom-designed Electro-Mechanical Assembly.  Power Screw Drive mechanisms automatically center and adjust to the different sizes of the Mold Chase Assemblies.  Cartridge Heaters are inserted into a specially designed Hot Plate and heat it up to the desired temperature. This temperature is continuously monitored by a J-Type Thermocouple.  Based on the sensory feedback provided by the thermocouple, Temperature Controllers maintain the desired temperature on the Hot Plate by switching on/off the heaters thru SSRs (solid state relays).

The Hot Plate Assembly is mounted on a worm gear drive which moves the hot plate until it is in contact with Mold Chase Assembly.  A compliance feature ensures maximum contact between the Hot Plate and the Mold Chase Assembly to maximize heat transfer via conduction.  Slip Clutches and Shaft Locks fixed to the drive mechanisms prevent over-rotation of the drives.

The Result

After implementation on the Production Floor, clients have seen a 75%* reduction in down-time in Mold Chase Assembly Changes.

* based on consolidated production down-time information.