HEATSINK
D Series
Ohmite D Series heatsinks provide an innovative
solution for SMT compatible semiconductors and
resistors. The unique design (Patent Pending) com-
bines tin plated, solderable rods with an aluminum
extruded heat sink body. These rods (or “rollers”)
are mated mechanically to the heatsink by forging to
reduce the thermal resistance between the heatsink
body and the solderable feet.
Specifically designed for use with the increasingly
popular TO-252, TO-263 and TO-268 packages, the
D Series affords the user superior thermal perfor-
mance over the more common stamped aluminum
heatsinks. By eliminating the staking joint typically
used in stamped heatsinks, the resulting air gap and
thermal “bottle-neck” is also eliminated, while sur-
face area for cooling is maximized with the extruded
fins of the D Series body.
F e at u r e S
• Increased surface areas by 3 times therefore ther-
mal performance up to 300% over the aluminum
stamped heat sinks on markets
• Light weight aluminum construction allows faster
pick and place assembly reducing the manufactur-
ing cycle time
• Radius mounted “Rollers” are designed for maxi-
mizing heat transfer from the component and
avoiding the thermal “bottle-neck” seen in stamped
and staked heatsinks.
• Available in bulk packaging or tape & reel (250
units per reel
• RoHS Compliant
H e at D i S S i pat i o n
Air Velocity (ft./min.)
60
55
Case Temp. Rise above
Ambient ( C)
50
45
40
8
35
200
400
600
800
1000
14
50
Thermal Resistance from Mounting
Surface to Ambient ( C/watts)
200
Air Velocity (ft./min.)
400
600
800
1000
12
Thermal Resistance from Mounting
Surface to Ambient ( C/watts)
12
Case Temp. Rise above
Ambient ( C)
TO-252 (D)
TO-263 (D2)
101 & 201
45
TO-268 (D3)
101 & 201
10
10
40
8
Final thermal performance
is highly dependent on the
thermal characteristics of
the PCB. It is possible to see
a 50% drop in temp rise in
natural convection with a
thermally improved PCB.
35
6
301
30
25
2
4
6
8
Heat Dissipated (watts)
10
6
30
301
4
4
25
2
4
6
8
Heat Dissipated (watts)
10
2
DimenSionS
Style 10
TO-252 (D)
TO-263 (D2) TO-268 (D3)
1.02"
1.22"
25.91mm
31.0mm
Style 20
1.02"
25.9mm
Style 30
1.58"
40.2mm
0.50"
12.7mm
0.50"
0.50"
12.7mm
12.7mm
0.40"
10.16mm
0.27"
6.86mm
0.44"
(11.2mm)
0.56"
(14.2mm)
0.63"
(16.1mm)
0.75"
(19.1mm)
0.48"REF
12.1mm
0.26"
6.6mm
0.44"
11.1mm
0.56"
14.1mm
0.46"
11.6mm
0.09"
2.3mm
0.26"
6.6mm
0.64"
16.2mm
0.76"
19.2mm
0.15"
3.7mm
0.10"
2.54mm
TO-252 (D)
TO-263 (D2)
TO-268 (D3)
2
1-866-9-OHMITE • Int’l 1-847-258-0300 • Fax 1-847-574-7522 • www.ohmite.com • info@ohmite.com
THERMAL
MANAGEMENT
Heatsink For TO-252, TO-263
and TO-268 devices
OHMITE [ OHMITE MFG. CO. ]
