Stud-mounted SCR hardware In a stud-mounted SCR package, the stud is electrically connected to which terminal?

Introduction / Context:
Mechanical packaging of power devices affects thermal design and electrical connections. Stud-mounted SCRs attach the device to a heat sink via a threaded stud that is also an electrical terminal.

Given Data / Assumptions:

• Standard stud-mounted SCR package.
• Conventional polarity conventions: anode (top), cathode (stud).

Concept / Approach:
Most stud-mounted SCRs bring the cathode out through the stud to simplify mounting and to keep the heat sink at cathode potential. The anode and gate are provided as separate top connections.

Step-by-Step Solution:
Inspect package drawings: stud threaded base connects internally to the cathode layer stack.Anode is the top terminal, gate is a small auxiliary terminal.Therefore, the stud = cathode.

Verification / Alternative check:
Manufacturer datasheets consistently mark the stud as K (cathode) for typical SCRs.

Why Other Options Are Wrong:

• Anode: not used for stud in standard SCR packages.
• Gate: always a separate low-power lead.
• Selectable: not in standard devices.
• Floating: contradicted by design.

Common Pitfalls:

• Assuming TRIAC packages follow the same convention; check datasheets.

Final Answer:
Cathode