Aehr vs. Cohu: Specialized Power Chips vs. Diversified Semiconductor Testing

Investors seeking exposure to the semiconductor equipment sector are currently weighing two distinct paths to growth: the specialized precision of Aehr Test Systems (AEHR) and the broad diversification of Cohu Inc (COHU).

Both companies operate in the critical testing and handling phase of semiconductor manufacturing, but they target different market segments. Aehr Test Systems specializes in wafer-level burn-in (WLBI) testing, a process essential for ensuring the reliability of silicon carbide (SiC) and gallium nitride (GaN) power semiconductors. These wide-bandgap materials are primarily used in electric vehicles (EVs) and industrial applications. In contrast, Cohu Inc provides a wider array of semiconductor test handlers, inspection systems, and automation software designed for a diversified range of chip types.

The Strategic Divide

The current semiconductor landscape is defined by a split between legacy demand and high-growth sectors. Aehr’s business model is heavily tied to the adoption of SiC and GaN technologies. Because these materials allow power electronics to operate at higher voltages and temperatures, they are foundational to the efficiency of EV powertrains. Consequently, Aehr's performance is closely linked to the acceleration of green energy infrastructure and the global transition to electric mobility.

Cohu operates as a more diversified player in the back-end manufacturing process. Rather than betting on a single material science trend, Cohu serves a broader spectrum of the industry. This makes the company more sensitive to general market cycles and the growth of AI-driven infrastructure, such as the processors required for massive data center expansions. While Aehr focuses on the power electronics niche, Cohu captures the broader recovery of the semiconductor market across multiple verticals.

Market Implications

Choosing between these two stocks represents a fundamental bet on different growth drivers. Aehr is effectively a high-beta play on the wide-bandgap semiconductor market. If EV adoption accelerates and the demand for high-efficiency power chips surges, Aehr is positioned to capture that specific momentum. However, this specialization also exposes the company to the volatility of the EV sector.

Cohu offers a more stable, diversified approach. By providing tools for a wide array of chips, it mitigates the risk associated with any single industry vertical. For investors, Cohu is a play on the general recovery of semiconductor demand and the overarching trend of industrial automation.

Looking Ahead

As the industry navigates a volatile cycle, the primary factor to watch will be the pace of EV infrastructure deployment versus the scale of AI hardware investment. While Aehr remains the primary vehicle for those betting on the power semiconductor revolution, Cohu remains the steadier option for those tracking the broader semiconductor ecosystem. Whether the market rewards specialized dominance or diversified stability will depend on which of these growth engines fires first.