Apple Tests Samsung Electro-Mechanics Glass Substrates for ‘Baltra’ AI Chip
Apple is intensifying its pursuit of custom AI hardware by testing advanced glass substrates for its upcoming in-house AI server chip, code-named “Baltra.” By partnering with Samsung Electro-Mechanics for these samples, Apple is signaling a strategic shift toward tighter control over the packaging and design of its high-performance silicon.
The Shift from Organic to Glass Substrates
In traditional semiconductor packaging, flip chip ball grid array (FC-BGA) substrates use organic core materials. However, as AI chips grow in size and complexity to meet performance demands, these organic materials face significant limitations. Glass substrates are emerging as the next-generation solution to these engineering hurdles.
Glass offers several critical advantages over organic materials:
- Superior Flatness: Glass provides a higher surface flatness, which allows for the creation of finer, more precise circuit patterns.
- Thermal Stability: It has a lower coefficient of thermal expansion, which reduces “warpage”—the bending or distorting of the substrate caused by temperature differences between the chip and the base.
- Reliability for Chiplets: Because the Baltra chip is expected to use a chiplet-based design—where different modules handle separate tasks—the stability of glass is essential for maintaining connections between multiple chiplets in one package.
Samsung Electro-Mechanics’ Strategic Expansion
Samsung Electro-Mechanics has been supplying glass substrate samples to Apple since last year, expanding its potential customer base beyond its work with Broadcom, a leading custom AI chip designer. This move positions the company to capture a significant share of the emerging glass substrate market.
To support this transition, Samsung Electro-Mechanics is taking several concrete steps toward commercialization:
- Pilot Production: The company is currently operating a glass substrate pilot line at its Sejong facility in South Chungcheong Province.
- Strategic Partnerships: In November of last year, Samsung Electro-Mechanics signed a memorandum of understanding (MOU) with Japan’s Sumitomo Chemical Group to establish a joint venture for manufacturing “Glass Core,” the essential material for these substrates.
- Mass Production Timeline: The company is targeting mass production of glass substrates starting after 2027.
The ‘Baltra’ Chip and the Apple-Broadcom Synergy
The “Baltra” AI server chip represents Apple’s effort to develop in-house AI hardware. Even as Apple is collaborating with Broadcom on the chip’s development and expects it to be manufactured by TSMC using an advanced 3nm process, the decision to directly test glass substrates suggests Apple wants more autonomy over packaging decisions.
Broadcom is already a key partner for Samsung Electro-Mechanics, as the chip designer works with major tech firms like Meta, Google, and OpenAI. By supplying samples to both Broadcom and Apple, Samsung Electro-Mechanics is embedding itself into the primary supply chain for the next generation of AI server hardware.
Key Takeaways
| Feature | Organic Substrates | Glass Substrates |
|---|---|---|
| Surface Flatness | Lower | Higher (Enables finer circuits) |
| Thermal Expansion | Higher (Prone to warpage) | Lower (Increased stability) |
| Primary Use Case | Standard FC-BGA | Large-scale AI chips & Chiplets |
Frequently Asked Questions
What is the “Baltra” chip?
Baltra is the code name for Apple’s upcoming in-house AI server chip, which is being developed in collaboration with Broadcom and is expected to be manufactured by TSMC.
Why is Apple testing glass substrates now?
As AI chips increase in size and complexity, traditional organic materials are more likely to warp. Glass substrates provide the thermal stability and flatness necessary for the chiplet-based architecture Apple is pursuing.
When will glass substrates be mass-produced?
Samsung Electro-Mechanics is targeting the start of mass production for glass substrates from 2027 onward.
Looking Ahead
The transition to glass substrates marks a pivotal moment in AI hardware evolution. As Apple seeks more direct control over its packaging and Samsung Electro-Mechanics scales its production capabilities through its joint venture with Sumitomo Chemical, the industry is moving toward a future where hardware packaging is as critical to AI performance as the silicon itself.