“Stick-it Flexible” Made of Cerac α®,
The Heat Dissipation Material of the
21st Century
Yuuichi Deushi
Masahiro Machida
Lighter, more compact, faster and more sophisticated
functions, are required of products in the field of electrical
and electronic devices in recent years. In order to respond
to such needs, further densification is taking place on
every level, including semiconductor chips, substrate
packaging and device mounting. Unfortunately, such
densification brought about an increase in heat generation
and the localized concentration of heat, which is causing
even more difficulty in terms of coping with heat.
Further, with the conversion of products into
household appliances and their personalization as well as
mobilization, demand for products with a better
appearance and less noise is on the rise. Very strict
limitations are being imposed on the designers, as they
deal with heat measures by hermetically sealing products,
quietening cooling fans or implementing heat measures
without cooling fans, in order to respond to such needs.
In such circumstances, there are cases when
conventional “heat conduction” heat dissipation products
(such as heat sinks) and “heat convection” heat
dissipation products (such as cooling fans) can no longer
offer any solution.
This paper will introduce the new innovative product,
“Stick-it Flexible”*1) made of Cerac α*2), which was
created with a focus on “radiation” heat dissipation.
Summary of “Stick-it Flexible”
This product is an environmentally friendly heat radiating
material that is prepared in thin sheets utilizing the
features of Cerac α, described below.
(1) The superior radiation characteristics of ceramics
converts heat into far infrared radiation (radiation ratio
of 0.96).
(2) The product can be formed into film with a thickness
of 50 to 150 µm.
(3) The product is friendly to the global environment
since it uses inorganic materials and does not contain
any specified regulated chemical substances.
Further, there are two types available in the new
lineup of “Stick-it Flexible”, the “Soft Sticker” and “Hard
Type” (Fig. 1). The “Soft Sticker” can easily be bent and
has a high tensile strength, yet it is flexible enough to be
cut with just a pair of scissors. The “Hard Type” contains
aluminum as a raw material that provides superior
thermodiffusion characteristics. Heat dissipation is
induced by the pasting of one of these “Stick-it Flexible”
products in the location where heat measures need to be
taken.
Mechanism of heat dissipation
The heat dissipation characteristics of the “Stick-it
Flexible”, is made possible by the radiation characteristic
of “Cerac α”, which coats its surface.
“Stick-it Flexible”, is a product that is based on the
technology of “Cerac α”, a heat-radiating liquid ceramic
paint that was developed by Oki Electric in collaboration
with Ceramission Co., Ltd.
(˚C)
Cerac α: Radiation ratio of 0.96.
Stainless steel (SUS304): Radiation ratio of 0.12.
Aluminum (A5052): Radiation ratio of 0.04.
160
150.4
140
133.6
Block temperature
120
105.3
100
66.7
Adhesive film
Peeling paper
<Cross section diagram>
<Cross section diagram>
Adhesive tape and peeling paper are optional.
Recommended adhesive: Product 9894FR10 manufactured by 3M.
"Stick-it Flexible"
Hard-type
50.3
40
Heat radiating material
Adhesive film
Peeling paper
"Stick-it Flexible"
Soft sticker
73.5
60.2
60
Heat radiating material
Base material (aluminum)
98.8
98.8
80
20
0
2W
5W
8W
Electric power input
Block of respective materials (40 x 40 x 16mm)
Heater
Fig. 1 Stick-it Flexible
*1) Stick-it Flexible is a registered trademark of Ceramission Co., Ltd.
*2) Cerac α is a registered trademark of Ceramission Co., Ltd.
22
Oki Technical Review
July 2004/Issue 199 Vol.71 No.3
Thermocouple (at core of block)
Fig. 2 Heat dissipation of Cerac α
Special Issue on Human Friendly Technologies
(˚C)
75
70.8
63.0
65
Ascending temperature of IC
59.6
57.2
59.4
53.1
55
54.2
[Applicable IC]
Dimensions: 30mm / t = 3.75mm
Type: 240-pin QFP
Electric power input: 1.5W
[Applicable housing]
Dimensions: 100 x 100 x 100mm
Thickness: 2mm
Material: Aluminum
[Heat sink]
The dimensions of the heat sink are
30 x 30 x 10mm.
[Measuring conditions]
25˚C room temperature (dead calm environment).
45
35
~
~
0
IC
(heat generating side)
None
Housing
(heat receiving side)
Distance btw. IC
& housing
Heat dissipating
material weight
"Hard Type"
30mm
50mm
Heat sink
30mm
"Hard Type"
30mm
50mm
"Soft Sticker"
90mm
90mm
None
20mm
0 (g)
12 (g)
"Hard Type"
50mm
distribution, but since the “Hard Type” is made of
aluminum raw material, its thermodiffusion and soaking
characteristics effectively dissipate heat. Further, by
mounting a “Hard Type” with a surface area larger than
that of the heating element, it is possible to improve the
heat dissipating effects even further.
On the other hand, the application of a “Soft Sticker”
is extremely effective as a heat dissipation measure for
housings (heat receiving surface), due to its flexibility,
light weight and thin characteristics.
The effective heat characteristics of “Stick-it Flexible”
contributes toward the miniaturization, weight reduction,
noise reduction, life extension, energy conservation and
cost reduction of parts, components and devices.
3(g)
Conclusion
10mm
7 (g)
6 (g)
10 (g)
10 (g)
Distance between the IC
and the housing
Image diagram
Fig. 3 Heat dissipating characteristics of the Stick-it Flexible
By radiation we mean a transfer of energy by
converting heat into far infrared radiation. It is quite a
different type of heat transfer from that of conduction or
convection methods. In general, the power of radiation is
expressed in terms of a radiation ratio. The radiation ratio
and heat dissipating characteristics of various
substances are shown in Fig. 2. The radiation ratio of
Cerac a is extremely high, with superior heat dissipating
characteristics.
Further, the heat dissipating features of Cerac a
include its capacity to absorb and transfer heat as well as
release and transfer heat.
Heat dissipation and the advantages of
Stick-it Flexible
“Stick-it Flexible”, with its “radiation” heat dissipating
method that is also environmentally friendly, is certainly
the heat dissipating material of the 21st century.
It is believed that the importance of this product will
grow as a heat reduction measure and that it will become
a defacto standard for heat reduction measures in the
future.
We intend to continue striving for the best in
improvements and the development of future products
with the release of more Cerac α application products.
References
1) Naoki Kunimine, Complete Introduction to Thermal
Design for Electronics, Nikkan Kogyo Shimbun, 2003.
Authors
Yuuichi Deushi: Manufacturing Service Company, EMS
Business Div., Cerac Business Planning Dept.
Masahiro Machida: Manufacturing Service Company,
EMS Business Div., Cerac Business Planning Dept.
In general, electrical and electronic devices are
structures that contain a heating element covered by a
housing. In conventional equipment design, the heat
dissipation of a heating element inside a housing was
realized with the installation of cooling fans or openings in
the form of ventilation holes. In recent years, however, the
tendency has been to avoid the use of cooling fans due to
their noise and the accumulation of debris and dust that
enter through the ventilation holes, which becomes the
source of degradation for the value of the equipment as
well as the equipment's reliability. Further, whether a
cooling fan or ventilation holes are used or not, a heat
sink is mounted on the heating element as a means to
dissipate heat.
“Stick-it Flexible” is thinner and much lighter than
these heat sinks with a comparable heat dissipating
capacity. As a result, it became possible to increase the
mounting volume of the device and reduce its weight.
Further, by using the “Soft Sticker” and “Hard Type” in
conjunction, the heat dissipating characteristics were
improved even more (Fig. 3).
It is especially effective when the “Hard Type” is
attached to the heating element, while the “Soft Sticker”
is applied to the housing (heat receiving surface).
Heating elements often have an uneven temperature
Oki Technical Review
July 2004/Issue 199 Vol.71 No.3
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