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Surface
Heatsink
Area
Weight
Length “L”
Part Number
(in2/mm2)
(oz/g)
(mm)
C247-025
11 / 7,312
0.5 / 15
25
C247-050
23 / 14,858
1.1 / 31
50
C247-075
34 / 21,655
1.6 / 45
75
C264-030
13 / 8,774
0.7 / 19
30
C264-058
25 / 16,963
1.35 / 37
58
C264-085
37 / 24,861
1.97 / 54
85
C220-025
11 / 7,312
0.5 / 15
25
C220-050
23 / 14,858
1.1 / 31
50
C220-075
34 / 21,655
1.6 / 45
75
C126-025
10.2 / 6,559
0.45 / 12.7
25
C126-040
16.3 / 10,495 0.72 / 20.3
40
C126-050
20.4 / 13,119 0.90 / 25.4
50
C126-075
30.6 / 21,655 1.35 / 38.1
75
Ohmite introduces the C series (Pat. Pending). This
series offers high performance, low cost and a
compact heat sink with an integrated camming clip
system for TO-126, TO-220, TO-247 and TO-264
devices. This powerful heat sink provides tool and
fixture free assembly operation, largest surface areas
and smallest space occupation. It is the ideal type of
heat sink for high power density and small size (1U
or 2U) electronic packaging with forced convection
cooling.
FEA TURES
MinimumassemblycostandlaborSpringClips
make the mounting holes, fasteners, tools and
fixtures obsolete in assembly operations & reduce
costs.
MaximumThermalTransferMaximumsurfacearea
per unit volume, efficient cooling fins & consistent
mounting force reduces thermal resistance.
MaximumRepeatabilityConstantspringforceover
repeated assembly/disassembly.
MaximumReliabilityResilientspringactionlocks
electronic component in place. Fewer parts in
assembly and no fasteners and washers required.
Prevent short circuit by eliminating metal particles
generated from hardware or thread tapping.
DesignFlexibilityMaximumflexibilityfordynamic
device locations and power upgrading. “Configure-
to-Fit” gives designers total freedom to configure
heat sink needed to fit into a multitude design envi-
ronments.
C Series
TO-126, TO-247, TO-220
and TO-264 Package Heatsinks
C h ARACTER i ST i CS
Heat Sink Aluminum Alloy 6063-T5 or Equivalent
with either degreased or black anod-
ized finish.
Spring Clip Music Wire, Per ASTM A228 with
bright nickel plating
Solder Foot Cold-rolled Steel, Per ASTM A-366
with pure tin over copper strike. RoHS
compliant.
Interface
Thermal
Resistance
for improvement, use thermal joint
compound, 0.005 Grafoil (TGon 800
by Laird), or phase change material
(Hi-Flow by Bergquist)
Insulator (Optional) Sil-Pad 900-S, K6 800-S
and K10 by Bergquist
SER i ES SPEC i F i CAT i ONS
THERMAL
MANAGEMENT
HEATSINK
hEAT Di SS i P AT i ON
Case
Temp.
Rise
above
Ambient
(°
C)
Heat Dissipated, total for ALL devices (watts)
120
80
0
510
100
15
0
140
Thermal
Resistance
from
Mounting
Case
to
Ambient
(°
C/watts)
2
1
0
3
8
7
9
600
200
400
1000
60
40
20
5
6
4
Air Velocity (ft./min.)
800
C247-025-1AE (1 device)
C247-050-2AE (2 devices)
C247-075-3AE (3 devices)
HeatdissipationisthetotalforALLDEVICESattachedtoheatsink.
Average
Heat
Sink
Temp.
Rise
above
Ambient
(
C)
Total Heat Dissipated (watts)
36
32
22
6
7
8
9
10
34
2
3
4
5
38
Avg.
Thermal
Resistance
from
Mounting
Surface
to
Ambient
(
C/watts)
0
12
10
600
200
400
1000
30
28
24
26
6
8
4
Air Velocity (ft./min.)
800
TO-126/CE-S102 (25mm long)
one device w/Sil-pad 900s