917 m³ Cold Storage Project for Semiconductor Materials, Taizhou

Project Background

Mingxin Microelectronics is a local Taizhou manufacturer specializing in power semiconductor packaging and testing. Its core operations include wafer thinning, plastic encapsulation and finished product testing, with products widely adopted in industrial control and consumer electronics. Following the launch of its new packaging production line in 2024, the company’s consumption of materials such as photoresists, electronic-grade epoxy resin and low-temperature storage conductive silver paste surged by 120% year-on-year.

These semiconductor materials have extremely stringent storage environment requirements. Any temperature fluctuation beyond permissible limits or excessive airborne particles will degrade material performance and directly reduce the yield of packaged components. The company’s original ordinary low-temperature warehouse suffered insufficient storage capacity and failed to meet cleanroom classification standards for production. Critical raw materials had to be circulated via third-party cold chain warehouses, which brought high logistics costs, long material delivery lead times and complicated batch traceability. To address these pain points, the enterprise decided to build an on-site clean cold storage complying with semiconductor industry standards for centralized low-temperature material storage and standardized management.

Key Challenges

Challenge 1: Integrated Delivery of Cleanroom & Refrigeration Systems Within a Tight Timeline

The overall project timeline is limited to only 45 days, requiring simultaneous construction of the cleanroom enclosure, installation of refrigeration equipment, and deployment of electrical and monitoring systems. Cross-working of multiple processes demands highly sophisticated construction scheduling. Cleanroom panel installation has strict limits on on-site dust and humidity, while refrigeration pipe brazing and equipment hoisting tend to generate airborne dust. Poor process coordination will not only delay the schedule but also compromise the airtightness and cleanliness of the finished clean cold storage.

Challenge 2: Compatibility Between Low-Temperature Operation & ISO Class 8 Cleanliness Standards

Conventional cleanrooms mostly operate at ambient temperature, whereas this warehouse maintains a minimum temperature of -10°C, greatly raising difficulties in air distribution and contamination control under cryogenic conditions. Air supply from cooling units can disrupt laminar clean airflow. In addition, water droplets and frost particles generated from defrosting evaporator fins act as particle contaminants. Large temperature differentials between the interior and exterior of return air ducts also cause condensation and blockages, preventing compliance with cleanliness specifications.

Challenge 3: Independent Precise Temperature Regulation & Minimal Temperature Drift Across Multiple Zones

The project requires independently adjustable temperature zones ranging from -10°C to 0°C, and semiconductor materials mandate temperature fluctuation held within ±0.5°C. Significant heat load discrepancies exist between different temperature zones, which easily trigger temperature overshoot during regulation. Heat ingress from frequent door opening and closing also creates short-term temperature deviations. Standard cold storage temperature control algorithms cannot deliver the required precision.

Challenge 4: Cold Bridge Elimination & Anti-Condensation Design for Low-Temperature Clean Storage

Cold bridges tend to form at joints of 150mm polyurethane insulated panels, pipe wall penetrations and door frames. The maximum temperature difference between indoor and outdoor sides can exceed 30°C, leading to condensation and water seepage on exterior cold bridge surfaces. This not only elevates refrigeration energy consumption but also introduces moisture that impairs warehouse cleanliness. Sealing solutions used for ordinary cold storage fail to satisfy both thermal insulation and cleanroom requirements simultaneously.