Changxin Technology announced on the evening of September 28 that it plans to invest approximately 34.9 billion yuan in total to boost technology R&D and the back-end test capacity of memory wafers, of which 5 billion yuan will be invested in Phase II project of the new memory wafer back-end test base of Changxin Memory Products (Hefei). Continuous investment by major memory manufacturers in packaging and testing has significantly broadened the supporting market for packaging material processing equipment such as silver paste defoaming machines.

Memory chip testing is a critical link before delivery. The construction of testing and module production lines means the simultaneous capacity expansion of packaging materials and process equipment. Materials such as silver paste and underfill used in advanced packaging feature high solid content and high viscosity. If air bubbles are not completely removed before dispensing, voids will remain at the interconnection positions after curing, directly affecting the connection reliability between chips and substrates. With the expansion of back-end test and packaging production lines, the stability and efficiency of the silver paste processing step have become practical problems that packaging material enterprises must solve.

Solution Background

Take the silver paste mixing process of a packaging material supplier in East China as an example. Manual stirring plus static defoaming was adopted previously. A batch of about 300 grams of silver paste required several hours of static standing. The residual bubble rate fluctuated greatly, and the consistency of viscosity and gas content between batches was hard to guarantee, which directly affected customers' dispensing yield.

Processing Challenges

Silver paste has high viscosity and high silver content, so air bubbles can hardly be discharged naturally by gravity, resulting in a long static defoaming cycle. The amount of air bubbles introduced by manual stirring is unstable, and the fluctuation of gas content and viscosity between batches is obvious, which becomes a hidden danger to dispensing yield.

Why Choose SIENOX Equipment

SIENOX provides supporting solutions based on silver paste defoaming machines. The MIX60 model has a processing volume of 300ml and working vacuum degree of -98KPa with revolution speed of 2000rpm. It adopts planetary revolution and rotation stirring combined with vacuum defoaming, completing stirring and bubble removal in a closed vacuum environment and reducing manual intervention.

Processing Procedure

After the silver paste is loaded into the matched container, the equipment drives materials through planetary revolution and rotation motion under vacuum environment. The centrifugal force generated by revolution pushes air bubbles toward the liquid surface, and the shear force from rotation enables sufficient turnover of high-viscosity silver paste. Combined with vacuum negative pressure to promote bubble expansion and rupture for discharge. The whole process is controlled by equipment parameters, replacing manual stirring and static waiting.

Processing Results

The processing time of a single batch is shortened from several hours to minutes, and batch consistency is greatly improved. A temperature control module can be optionally equipped for scenarios requiring temperature control. This function is optional customization and not included in the standard configuration.

Judging from the industrial trend, the capacity expansion of memory packaging and testing is not an isolated action. It drives the re-matching of the whole chain including materials, equipment and processes. Changxin Technology’s investment of 34.9 billion yuan in R&D and back-end testing this time reflects the investment intensity of domestic memory enterprises during the production ramp-up phase. Once packaging and testing capacity is put into production, the defoaming demand for high-viscosity materials such as silver paste and underfill will be released alongside production line commissioning and mass production ramp-up, and the equipment verification window is concentrated at this stage.

The expansion cycle of memory packaging and testing has started, and the requirements for stability of packaging material processing are rising simultaneously. As the basic equipment to guarantee material consistency, silver paste defoaming equipment will see further growth in supporting demand during the expansion of memory packaging and testing. Equipment manufacturers with planetary vacuum mixing and defoaming capability will obtain more supporting opportunities.