TSMC is reportedly planning to build five additional advanced packaging plants in Phase III of Chiayi Science Park. If the plan is implemented, the number of its advanced packaging plants in Chiayi will rise from five to ten. AI chips keep driving the growing demand for advanced packaging technologies such as CoWoS. The processing precision of packaging materials has become a key focus of production lines. As front-end processing equipment for packaging materials, silver paste defoaming machines are gaining rising supporting demand.

Solution Background

In advanced packaging processes, silver paste (conductive silver adhesive) is applied in chip mounting and conductive interconnection. It is a high-value and high-viscosity material. Silver paste tends to trap air bubbles during sub-packaging, transportation and pre-use processing. Residual bubbles will cause packaging defects such as voids and open circuits, directly affecting device yield. Against the background of packaging line expansion, defoaming treatment before silver paste application has become a standard process.

Processing Challenges

Silver paste contains precious metal fillers with high material cost, so material loss during processing should be minimized. It features high viscosity and obvious thixotropy, and is sensitive to stirring modes and defoaming efficiency. In addition, the batch dosage of silver paste is usually small. The equipment needs to maintain stable defoaming performance under small processing volume and avoid damaging filler structure caused by excessive stirring.

Why Choose SIENOX Equipment

SIENOX vacuum defoaming mixer adopts planetary revolution and rotation combined with vacuum mode. Materials are mixed and defoamed inside a sealed tank without blade intervention, reducing material loss and cross-contamination. This solution selects the MIX60 model with a processing volume of 300ml, matching the small-batch and high-value characteristics of silver paste. It achieves a vacuum degree of -98KPa and rotation speed of 2000rpm. Process parameters can be adjusted according to silver paste formulas. A temperature control module is available as customization for temperature-sensitive scenarios.

Processing Procedure

Take a packaging material supplier as an example. Its silver paste needs to be treated tube by tube before use to eliminate bubbles generated during transportation and sub-packaging. Manual centrifugation and static standing were adopted previously, featuring long processing time and unstable consistency. After switching to MIX60, silver paste is loaded into a dedicated container, and the equipment runs according to preset parameters. Air bubbles are quickly extracted under vacuum environment, greatly shortening the processing time per tube.

Processing Results

The void rate of silver paste after defoaming becomes more stable, mounting and bonding defects during packaging are reduced, and the material loss rate declines. The supplier has incorporated the defoaming step into the standard incoming material handling workflow, and the MIX60 is deployed as regular equipment for small-batch silver paste processing.

The expansion of advanced packaging capacity brings refined requirements for packaging material processing. Defoaming treatment for high-value materials like silver paste is evolving from an optional process into standard production line configuration. Compact size, stable performance and low material loss have become key indicators for equipment selection.