Views: 752 Author: Site Editor Publish Time: 2026-09-20 Origin: Site
IGBT and SiC power modules serve as the core switching components of electric drive inverters for new energy vehicles. With the rapid upgrading of automotive electronic architectures, 800V high-voltage platforms and third-generation semiconductor technologies are widely adopted, pushing power modules toward higher voltage, greater power density and stricter thermal cycling resistance. In high-frequency switching, high-current heating and extreme temperature fluctuation working scenarios, packaging quality directly determines the service life, operational stability and safety of vehicle electric control systems.
Vacuum potting is the most critical process in power module packaging. High-performance potting compounds fully encapsulate internal chips, bond wires, DBC substrates and electrode terminals to achieve four core protective functions:
Dielectric Insulation: Eliminates air gaps between electronic components, enhances overall dielectric strength and suppresses partial discharge under high-voltage conditions.
Thermal Conduction & Heat Dissipation: Builds stable thermal conduction pathways between heat-generating chips and housing structures to effectively reduce junction temperature.
Environmental Isolation: Shields internal precision structures from moisture, salt spray, dust and corrosive ions to prevent electrochemical migration and component corrosion.
Stress Buffering: Absorbs thermal stress and mechanical vibration during vehicle operation, protecting bond wires and welding layers from fatigue damage and cracking.
Automotive-grade power modules generally adopt high-filler thermally conductive epoxy and silicone gel materials with high viscosity and strong abrasiveness. Tiny internal gaps and complex cavity structures make traditional potting processes prone to residual bubbles, uneven filling and inconsistent curing. Air voids cause insulation weaknesses and local overheating, eventually leading to partial discharge, breakdown failure and premature module scrappage. It is widely recognized in the industry that chip performance determines the upper limit of power module capability, while vacuum potting quality controls the lower limit of mass production consistency and long-term reliability.
To solve automotive-grade manufacturing pain points, HOLS provides modular, standardized full-turnkey vacuum potting production lines dedicated to IGBT and SiC power modules. The integrated line realizes fully unmanned production from automatic loading, precision processing to finished product unloading, with an ultimate working vacuum of 2 mbar, dispensing accuracy within ±2%, and full compliance with Class 1000 cleanroom production standards. The modular design supports flexible configuration according to product specifications and tact time requirements, adapting to diversified mass production demands.
HOLS integrated vacuum potting production line adopts streamlined process layout, covering the complete manufacturing chain of power module encapsulation. The standardized workflow ensures stable, repeatable and traceable automotive-grade production:
Automatic Loading → Preheating → Dust & Particle Cleaning → Precision Vacuum Potting → High-Temperature Curing → Cooling → Height & Hardness Testing → Capping Assembly → Finished Product Unloading
Pre-Cleaning & Dust Removal: Removes surface and internal particulate contaminants in a Class 1000 clean environment to avoid impurity mixing and ensure pure potting medium.
Preheating Treatment: Optimizes material fluidity and wettability, enabling full penetration and filling of micro gaps inside complex module cavities.
High-Precision Vacuum Potting: Core encapsulation process completed in a fully closed vacuum chamber. Supports point, linear, contour and segmented potting modes for uniform filling, flat surface and zero dead-angle encapsulation.
Multi-Stage Curing & Cooling: Adopts multi-layer tunnel curing ovens to execute customized temperature curve curing, followed by rapid constant-temperature cooling to stabilize material cross-linking performance.
Online Quality Inspection: Real-time detection of potting height, curing hardness and glue volume consistency to intercept insufficient filling, deviation and incomplete curing defects.
Automatic Capping & Unloading: Finishes precise cover plate assembly and automatic offline output, seamlessly connecting with downstream assembly and testing processes.
The entire production line integrates automatic conveying, precision dispensing, thermal curing, inline inspection, automatic assembly and full-process data acquisition system, realizing fully intelligent and unmanned batch production.
HOLS vacuum potting system delivers industry-leading precision and stability, fully matching strict power semiconductor manufacturing standards:
Parameter Item | Technical Index |
|---|---|
Ultimate Working Vacuum | 2 mbar |
Vacuum Pump Pumping Speed | ≥100 m³/h |
Material Flow Rate | 0.5–10 g/s |
Dispensing Accuracy | ≤±2% |
Mixing Ratio Accuracy | ≤±3% |
Chamber Structure | Single-chamber / Three-chamber optional |
Potting Modes | Point, linear, contour, segmented potting |
Real-Time Monitoring Items | Dispensing volume, motion trajectory, mixing ratio, vacuum degree |
Three-Chamber Vacuum Potting Technology: The three-stage chamber structure realizes parallel cyclic operation of pre-vacuumizing, vacuum encapsulation and gradual pressure relief. The core potting process is always completed in a stable vacuum environment, eliminating waiting time for repeated vacuumizing and pressure relief in single-chamber equipment, greatly optimizing production tact time and improving mass production capacity while guaranteeing void-free quality.
HOLS configures differentiated volumetric metering and feeding systems according to material viscosity, filler content and flow requirements, solving various potting material processing challenges:
VS Series High-Flow Screw Valve: Adopts volumetric screw metering principle, flow range 1.2–600 ml/min, dispensing accuracy ±1%. Features low shear and low pulsation, perfectly suitable for continuous large-flow potting of high-filler thermal conductive glue and encapsulation compounds, working stably within 10–100℃.
Plunger Metering System: Customized for ultra-high viscosity and high-filler materials. The fixed stroke volumetric metering mode ensures dispensing volume is unaffected by viscosity drift, temperature change and feeding pressure fluctuation. Supports adjustable mixing ratio from 1:1 to 10:1, maximum stroke accuracy ＜0.3%, CPK＞1.67, realizing ultra-stable batch consistency.
Gear Pump & Micro Screw Metering: Covers variable flow of 0.6–2.4 ml/s and ultra-precision micro dispensing up to 0.00025 ml, meeting precision sealing and coating requirements for auxiliary processes of power modules.
SP Vacuum Pressure Plate Feeding System: Vacuum-assisted sealed feeding for barreled high-viscosity materials, effectively reducing air entrainment. Equipped with liquid level monitoring and low-level alarm functions, maximum feeding pressure up to 100 bar, compatible with single-component and two-component materials.
MIF Vacuum Defoaming & Stirring System: Integrates vacuum defoaming, stirring, heating and circulating functions with an ultimate vacuum of 2 mbar, thoroughly removing internal air bubbles from materials before feeding to achieve source-level bubble control.
Supporting a temperature range of 40–250℃ (customizable higher temperature), the curing oven achieves ±1℃ temperature fluctuation and ±2.5% temperature uniformity. It supports independent multi-segment temperature curve programming to match the curing characteristics of epoxy, silicone and polyurethane materials. Equipped with SUS304 mirror stainless steel liner, 80mm thick insulation layer, Fuji PID temperature controller and PT100 high-precision sensors, it realizes real-time temperature monitoring, automatic data recording and equipment networking. The multi-layer compact structure saves factory floor space while ensuring continuous and consistent curing effects for mass production.
Tiny gaps inside IGBT modules and air entrainment during material mixing easily cause residual bubbles, leading to partial discharge and insulation breakdown under high voltage. HOLS builds a full-chain bubble control system: MIF vacuum defoaming removes material bubbles at the source; SP vacuum pressure plate feeding realizes low-air-entrainment material supply; 2 mbar ultra-high vacuum potting promotes full infiltration of colloids into micro gaps; graded slow pressure relief avoids secondary air intake, achieving 100% void-free encapsulation.
High-thermal-conductivity potting compounds contain a large number of abrasive fillers, which easily cause ratio drift and volume deviation affected by temperature and viscosity changes. HOLS volumetric metering technology completely isolates external interference: plunger metering ensures fixed stroke and fixed volume with CPK＞1.67; high-flow screw valves maintain long-term stable precision. Wear-resistant wetted parts are configured according to material characteristics, controlling overall mixing ratio accuracy within ±3%.
Traditional single-chamber vacuum equipment wastes massive time on vacuumizing and pressure relief, restricting production capacity. HOLS three-chamber parallel structure separates pre-vacuumizing, potting and pressure relief processes, realizing non-stop cyclic production. Combined with automatic loading/unloading and continuous tunnel curing, the line flexibly matches high-volume automotive-grade mass production tact time while ensuring zero-compromise potting quality.
Traditional processes lack effective monitoring of curing curves and potting parameters, leading to hidden batch quality risks. HOLS system realizes full-process digital management: curing temperature curves are monitored and recorded in real time; post-potting height and hardness online testing screen defective products one by one; all parameters including vacuum degree, dispensing volume, mixing ratio and curing data are stored and traceable, fully meeting automotive-grade quality management system requirements.
Beyond standalone equipment supply, HOLS provides one-stop full-cycle technical support. We supply vacuum potting platforms and three-axis dispensing platforms for pre-production sampling, material adaptation, trajectory programming and parameter verification, solidifying optimal process parameters before mass production launch. The modular line design supports rapid layout adjustment, fast model changeover and functional expansion, allowing optional integration of plasma cleaning, vision inspection and other process modules to shorten equipment commissioning and capacity ramp-up cycle.
At present, HOLS vacuum potting solutions have been widely applied in automotive electronics and power semiconductor industries, covering IGBT/SiC power modules, motor stators, actuators, ECUs, OBCs and various high-reliability sensor encapsulation scenarios.
Headquartered in Suzhou, China, HOLS is a global intelligent manufacturing solution provider focusing on automotive, semiconductor and new energy automation fields. Integrating R&D, manufacturing, delivery and after-sales services, we operate overseas service centers in North America and Europe. With decades of experience in precision dispensing and vacuum potting technology and mature turnkey project delivery capabilities, HOLS empowers global customers with stable, high-yield and automotive-grade intelligent manufacturing solutions.
