Ball mask stencil, also known as solder ball mask, is a key precision template for micro solder ball placement in advanced semiconductor packaging. It is mounted on automatic ball placement equipment to constrain the position of tiny solder balls, guiding balls to fall onto the corresponding pads of IC substrates, avoiding ball offset, missing balls, bridging and other common packaging defects.

Two mainstream manufacturing technologies are available for ball mask stencils:

1. Photo Chemical Etching Ball MaskLow cost and fast prototyping. No mechanical stress on the metal sheet, burr-free aperture edge. Suitable for BGA packages with relatively larger pitch, ideal for R&D verification and small batch trial production.
2. Electroformed Nickel Ball MaskThe preferred option for ultra-fine pitch high-density packaging. Electroformed nickel stencils feature ultra-smooth inner hole walls, excellent dimensional stability and high aspect ratio performance. It greatly reduces solder ball jamming and flux residue, perfectly matching FCBGA, HBM and other high-end chip packaging requirements.

Core Features

1. Micron-level positional accuracy, custom aperture size, array layout and thickness based on Gerber files.
2. Stress-free & burr-free metal sheet, low thermal expansion to prevent alignment deviation.
3. Custom fiducial marks for CCD automatic alignment on high-speed packaging production lines.
4. Optional nano surface coating to enhance flux release and extend service life.
5. Support quick-turn prototyping and mass production.

Typical Applications

• FCBGA / Flip Chip BGA packaging
• HBM high bandwidth memory packaging
• Consumer & automotive IC carrier board ball placement
• High-performance computing chip packaging
• Custom micro solder ball positioning for advanced IC packages

Process Advantages

Compared with laser cutting, chemical etching and electroforming produce micro holes without heat-affected zone. There is no extra tooling cost when modifying design files, which is friendly for packaging iterative development and flexible volume production.