The 621 and 623 Series low-profile flat back heat sinks are a general purpose but efficient heat dissipator for TO-3 and virtually all other styles of metal case power semiconductor package types, finding a wide variety of applications. The central channel between fins measures 1.300 in. (33.0) (min.) in width, accommodating many types of packages.
This catalog lists Wakefield's extruded heat‑sink series for power semiconductors, including low‑profile (621/623), compact stud‑mount (301/302/303), double‑surface (401/403), high‑performance (431/433, 441) and king‑size (490) families. All parts are made from aluminum alloy with a black anodized finish and are offered with a variety of mounting‑hole patterns for TO‑3, stud‑mount and hex‑type devices.
Each series entry provides mechanical dimensions, natural and forced‑convection thermal resistance, maximum power dissipation and weight. Optional accessories such as mounting hardware, thermal‑interface pads (SA suffix) and additional screws (M suffix) are also described, allowing designers to select the optimal solution for their power‑module applications.
| Material | Aluminum Alloy, Black Anodized |
|---|---|
| Thermal resistance (431K) | 0.40°C/W @ 250 LFM |
| Mounting hole pattern A | Predrilled for TO‑3 power semiconductor packages |
| Maximum power dissipation (490‑35K) | 84°C @ 200 W |
All heat sinks are fabricated from aluminum alloy with a black anodized finish.
Add the suffix “SA” to request factory‑applied Deltalink IV thermal interface material.