Micro-Cavity Machining of Semiconductor Encapsulation Molds – What Equipment Is Used? Application of Die-sinker EDM Machines in AI Chip Encapsulation Molds

In the field of AI chip manufacturing, the importance of the encapsulation stage is increasingly recognized. A high-performance AI chip, from wafer to finished product, must go through multiple stages: design, manufacturing, encapsulation, and testing. Encapsulation is the critical step that “protects“ the chip and provides the connection to the outside world.

With the rapid development of AI large-language models and HBM (High Bandwidth Memory), demand for advanced packaging is surging. Advanced packaging technologies such as CoWoS (Chip-on-Wafer-on-Substrate), 2.5D/3D packaging, and Chiplet impose extremely high requirements on encapsulation molds, driving the upgrading of processing equipment for semiconductor encapsulation molds.

What Special Requirements Does AI Chip Encapsulation Place on Mold Machining?

Unlike conventional semiconductor encapsulation, AI chip encapsulation faces several unique challenges:

Extremely high precision requirements. Dimensional tolerances for semiconductor encapsulation molds are typically required at the micron level.

High number of cavities and stringent consistency requirements. Taking a multi-cavity transfer mold as an example, a single mold may require simultaneous machining of hundreds of cavities. The dimensions, positions, and surface quality of each cavity must be highly consistent.

Special materials that are difficult to machine. Encapsulation molds typically use materials such as powder metallurgy tool steel, which achieve uniform carbide distribution through powder metallurgy processes and have high hardness – making them difficult for conventional cutting processes to handle.

Complex mold structures. Encapsulation molds often include complex cavity structures, micro-channels, fine textures, and more, requiring high-precision machining equipment.

When selecting encapsulation mold processing equipment, semiconductor manufacturers typically focus on the following aspects: whether machining accuracy can meet micron-level requirements, how consistency in multi-cavity machining is ensured, whether the equipment can machine high-hardness materials, and the long-term stability and reliability of the equipment.

What Role Does the Die-sinker EDM Machine Play in Semiconductor Encapsulation Mold Machining?

The precision CNC Die-sinker EDM Machine is the core equipment for cavity machining in semiconductor encapsulation molds. Its working principle involves pulsed electrical discharge between an electrode and the workpiece to erode material from the workpiece surface, independent of mechanical cutting force.

Advantage 1: Unaffected by material hardness. Encapsulation molds are hardened after heat treatment, making them difficult for conventional milling to machine. Die-sinker EDM Machines have no special requirements for material hardness and can machine directly. The AF Series, through its electrical discharge machining principle, removes material without being limited by material hardness.

Advantage 2: Capable of machining complex micro-structures. The cavities of encapsulation molds often have complex geometries and micro-features. Die-sinker EDM Machines can machine fine structures using precision electrodes. In general mold applications such as narrow slot machining, the AF Series achieves stable machining with a minimum corner radius of 0.03mm and a machining depth of 30mm.

Advantage 3: Excellent surface quality. Semiconductor encapsulation molds demand extremely high surface quality. The AF Series achieves optimal surface roughness of Ra < 0.1μm (copper electrode, S136 mirror steel) – entering the realm of mirror finishing. This means that the machined mold cavities require virtually no hand polishing and can be used directly for injection molding encapsulation.

Advantage 4: Controllable electrode wear. Semiconductor encapsulation molds require extremely high dimensional accuracy, and electrode wear directly affects machining accuracy. The AF Series features an intelligent discharge control system that automatically matches appropriate machining strategies at different stages, reducing electrode wear while maintaining machining efficiency and improving consistency in complex mold machining.

How Does the Die-sinker EDM Machine Ensure Consistency in Multi-Cavity Machining?

Multi-cavity is a typical characteristic of semiconductor encapsulation molds. A single mold may require machining dozens or even hundreds of cavities, with each cavity‘s dimensions, position, and surface quality needing to be highly consistent.

The AF Series ensures multi-cavity machining consistency through the following technical means:

The intelligent discharge control system precisely detects and controls each discharge pulse, maintaining consistent discharge status across all cavities.

The AC servo full closed-loop motion control system performs real-time detection, feedback, and correction of the position status of each motion axis, improving trajectory execution accuracy and long-term motion stability.

Leveraging 6axis CNC control with 5-axis simultaneous machining capability, the AF Series can complete complex spatial trajectories, multi-angle structures, and 3D curved surface machining – reducing error accumulation from repeated clamping.

Can Chinese Die-sinker EDM Machines Meet the Machining Requirements of Semiconductor Encapsulation Molds?

In the past, precision machining equipment for semiconductor encapsulation molds relied heavily on imports. However, in recent years, Chinese-made electrical discharge machining equipment has made significant progress in accuracy and stability.

Taking the Beijing NOVICK AF Series as an example, the AF Series precision CNC Die-sinker EDM Machines feature a high-rigidity Ram-type mechanical structure with a fixed worktable capable of handling maximum loads up to 2000kg – providing a stable foundation for large encapsulation mold machining. In terms of accuracy, the AF50 achieves bidirectional positioning accuracy of 0.008mm on the X/Y axes and 0.006mm on the Z-axis, with unidirectional repeat positioning accuracy of 0.004mm. Optimal surface roughness reaches Ra < 0.1μm.

What Advantages Does the NOVICK AF Series Offer in Semiconductor Encapsulation Mold Machining?

To address the high-precision machining requirements of semiconductor encapsulation molds, the NOVICK AF Series offers the following core capabilities:

High-rigidity Ram-type mechanical structure. The fixed worktable ensures that regardless of workpiece weight, motion axis accuracy remains unaffected. The AF70 can handle maximum workpiece weights up to 2000kg, making it suitable for stable machining of large encapsulation molds.

AC servo full closed-loop motion control system. Provides real-time detection, feedback, and correction of the position status of each motion axis, improving trajectory execution accuracy and long-term motion stability.

Intelligent discharge control system. Automatically matches appropriate machining strategies at different stages, maintaining stable discharge status during complex cavity, deep cavity, and narrow slot machining – balancing machining efficiency and surface quality.

Intelligent CNC system. Features a built-in intelligent process database for rapid recall of machining parameters based on different materials, machining targets, and process requirements – reducing operational difficulty and improving setup efficiency.

Flexible configuration. Supports optional C-axis rotary machining, linear scale feedback system, automatic tool changer, automation interface, and more – allowing flexible expansion based on semiconductor encapsulation mold machining requirements.

The rapid development of AI chips is driving continuous upgrading of advanced packaging technologies, placing higher demands on the machining accuracy and quality of semiconductor encapsulation molds. Precision cavity machining of encapsulation molds depends on Die-sinker EDM Machines – leveraging their advantages of being unaffected by material hardness, capable of machining complex micro-structures, offering excellent surface quality, and providing controllable electrode wear – making them indispensable key equipment in semiconductor encapsulation mold manufacturing.

The NOVICK AF Series precision CNC Die-sinker EDM Machines deliver corresponding performance in high-rigidity structure, positioning accuracy, mirror-finish machining, and control system intelligence – providing high-precision, high-reliability machining solutions for semiconductor encapsulation mold manufacturing.