Wärmemangement_1_EN 29.10.12 17:41 Seite 1
S M A R T
HEAT
|
S O L U T I O N S
MANAGEMENT
|
|
|
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
Wärmemangement_1_EN 29.10.12 17:41 Seite 2
HiCu
Profile PCBHR
Metal
HiCu PCBHR
Inlay PCBHR
Heat Management
Metal
Wirelaid
Plate PCBHR
HiCu
Profile PCBHR
HiFrequency
PCBHR
HiCu PCBHR
HiDensity
PCBHR
Wirelaid
Optimised
Integration
High Speed
Metal
Plate PCBHR
HiDensity
PCBHR
High Current
SemiflexHR
HiCu
Profile PCBHR
Wirelaid
Heat Management
High temperatures act on printed circuit boards
The increasing compaction of performance in
not only when they are exposed to high ambient
electronics leads to rising temperatures develop-
temperature, for example on an engine block, in
ing on the circuit board. This as a result of heat
the exhaust gas train, or in the brake system of a
loss from high-performance components or inher-
vehicle.
ent warming of conductors due to the transmission of high currents. In line with maximum
assembly reliability, the heat generated must be
dissipated in such a way that critical temperatures
are not reached or exceeded. This is where modern heat management solutions that distribute
high temperatures uniformly across an area and
dissipate them at the surface or at the housing
can help to keep heat away from sensitive components. RUWEL International offers a large number of solution concepts for this.
2
SMART
SOLUTIONS
>
HEAT
MANAGEMENT
>
Wärmemangement_1_EN 29.10.12 17:41 Seite 3
HiCu PCBHR
Typical printed circuit board in thick-copper technology with a high copper content and deep etching channels
Current applications
Advantages of thick-copper PCBs compared
of HiCu PCBs
with punched-grid constructions
> Relay and fuse boxes (”junction boxes“),
> Significant cost reduction for
DC/DC converter (➜ eMobility)
the injection moulding tools
> Realisation of power and signal
> Punched-grid tools no longer required
➜ cost saving
circuits on one board
> Inverters for renewable energy sources
> Considerably fewer single parts
➜ easier mounting
> Planar transformers
> More compact construction
HiCu PCBs are employed in current applications,
➜ reduction in weight
in some cases to replace punched grids which
> Fewer plug-in connections through
have been used for many years to distribute
combination of power and control electronics
voltage and conduct current.
on one printed circuit board
> Considerably lower modification costs thanks
to fast and simple change possibilities
HiCu PCBs are a much more variable option in
every respect.
|
|
|
|
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
3
Wärmemangement_1_EN 29.10.12 17:41 Seite 4
HiCu PCBHR
Thick-copper product range
18µm
RUWEL International offers the following
35µm
thick-copper technologies:
> Double-sided PCB up to 210µm,
105µm
plated through
> Multilayers with inner layer Cu up to 400µm
> Semiflex PCBs in all variations
Combinations of thick-copper inner layers (IL) with
HDI technology (High Density Interconnection /
35µm
Laser-Via / blind via technique) are possible.
A great advantage of the HiCu PCBs is that
18µm
- with the appropriate choice of the printed
circuit board build-up - power and control
electronics can be combined in one board.
This can be realised by
different multilayer constructions, for example:
power electronics
➜
inner layers
control electronics
➜
outer layers.
Example: Sequential build-up of a thick-copper multilayer and a less expensive alternative
ML 6 Layers
4
210µm
35µm
SMART
SOLUTIONS
>
HEAT
Alternative
400µm
u
Prepreg
Cu
Core
Cu
Prepreg
Cu
Core
Cu
Core
Cu
MANAGEMENT
18µm
210µm
210µm
210µm
210µm
18µm
>
⎧
⎸
⎨
⎸
⎩
Only one press cycle required
Cu
210µm
1st press cycle
2nd press cycle
⎧
⎸ ⎧
⎨⎨
⎸ ⎩
⎩
35µm
Wärmemangement_1_EN 29.10.12 17:41 Seite 5
Base materials
RUWEL uses almost exclusively high-TG materials for these applications. This is necessitated
by rising demands made of temperature stability and thermal cycling strength. As a result of
the high copper thicknesses the material is subject to further, considerably higher requirements.
The base copper thicknesses used for outer and inner layers are 105µm, 140µm, 175µm, 210µm,
and for inner layers only 400µm too.
Design rules
A
B
layout
conductive
pattern
base material
base copper thickness
marking
105µm Cu
175µm Cu
210µm Cu
400µm Cu
A
layout track width
min. 200µm
min. 350µm
min. 500µm
min. 800µm
B
layout track space
min. 250µm
min. 400µm
min. 400µm
min. 400µm
C
copper thickness
105µm ± 10%
175µm ± 10%
210µm ± 10%
400µm ± 5%
(+DK Cu*)
(+DK Cu*)
(+DK Cu*)
D
track width (top)
F-C
F-C
F-C
F-C
E
track space (top)
G+C
G+C
G+C
G+C
F
track width (bottom)
A ± 60µm
A ± 80µm
A ± 100µm
A ± 100µm
G
track space (bottom)
B ± 60µm
B ± 80µm
B ± 100µm
B ± 100µm
* on outer layers
|
|
|
|
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
5
Wärmemangement_1_EN 29.10.12 17:41 Seite 6
HiCu PCBHR
Heating of thick-copper conductors (measured on the RUWEL test build-up)
Comparison 210µm/400µm track width 5mm
Temperature increase (K)
120
100
80
60
40
20
Current (A)
40
20
210µm OL
60
80
400µm OL
100
210µm IL
120
140
400µm IL
OL = outer layer / IL = inner layer
Thanks to our high-current measuring station we are able to test new materials and technologies
up to a maximum current intensity of 1,500A.
High-performance power supply unit with a possible total power of 45kW
6
SMART
SOLUTIONS
>
HEAT
MANAGEMENT
>
Wärmemangement_1_EN 29.10.12 17:41 Seite 7
The analysis (temperature curve and distribution)
is conducted using a thermographic camera.
Know-How
> Large connected copper areas should
be avoided for the layout because they may
provoke mechanical tensions.
> The drilling time increases considerably due to
the thick copper; i.e. special drilling parameters and drill bits must be used. This means
also that higher expenditure
for drilling influences the costs directly.
> It may be necessary to apply a double coating
of solder resist in order to achieve sufficient
edge coverage.
> HAL may be used as surface finish.
For thick-copper printed circuit boards,
however, applying chemical surface finishes
is recommended (electroless Ni/Au,
electroless Sn → no thermal stress).
> Measurements are possible in our own
measuring laboratory.
We generally recommend that you contact our
product management already before designing
your HiCu PCBHR to discuss the requirements
on the printed circuit board in detail.
This makes it possible to lay the foundations for
an optimal and cost-efficient solution in advance.
Thermographic analysis using a thermographic camera
|
|
|
|
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
7
Wärmemangement_1_EN 29.10.12 17:41 Seite 8
HiCu Profile PCBHR
An alternative for partial currents up to 1,000A
In HiCu Profile Technology massive
This technology can often be an inexpensive
copper elements are inserted in the inner cores
alternative to conventional thick-copper
of multilayer printed circuit boards and
technology as regards current-carrying capacity
then laminated into the PCB. In this way
and heat dissipation.
the copper cross-section is partially increased but only where the high current-carrying capacity
(up to 1,000A) is required.
8
SMART
The copper profiles used are between 0.5 and
2.0mm thick.
SOLUTIONS
>
HEAT
MANAGEMENT
>
Wärmemangement_1_EN 29.10.12 17:41 Seite 9
2
1
The copper profiles are then placed in the recess.
First the appropriate contour is established
by milling or punching a recess in the inner
layer core.
3
4
Then the prepregs and copper foils are laid up.
After lamination of the multilayer
the usual process steps follow to finish
the printed circuit board.
copper profile
copper foil
A great advantage of HiCu Profile PCBHR is the
easy combination of control electronics (outer /
inner layer) and power section (in the inner layer
core) on one printed circuit board. Because the
outer layers are plane, even fine structures - for
ex. HDI - can be realised there.
inner layer
|
|
prepreg
|
|
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
9
Wärmemangement_1_EN 29.10.12 17:41 Seite 10
HiCu Profile PCBHR
FR4
Cu
400µm
FR4
FR4
Cu
400µm
Cu
1.0mm
FR4
FR4
Cu
1.0mm
Cu
400µm
FR4
FR4
Cu
400µm
FR4
As shown in the above figures, even a number of inner layers can be equipped with
copper profiles. HiCu profile technology can also provide an important cost advantage
where it permits replacement of thick-copper layers with a copper thickness of 210µm
or 400µm. In this specific application four inner layers each with 400µm copper could
be replaced by two inserts of 1mm each. This reduces the overall thickness of the
printed circuit board by approx. 0.5mm.
10
SMART
SOLUTIONS
>
HEAT
MANAGEMENT
>
Wärmemangement_1_EN 29.10.12 17:41 Seite 11
Design notes
C
B
E
A
D
Characteristics
Symbol
min. value
Copper profiles thickness
A
0.5mm
Transmittable current
max. value
2.0mm
1.000A
Copper thickness on core where profiles are inserted
B
Overall thickness of the printed circuit board
Distance of copper profiles from next Cu layer
C
TG (only filled materials)
18µm
105µm
0,8mm
3.2mm
100µm
150°C
Distance between two copper profiles
D
5.0mm
Distance conductor (inner layer) to copper profiles
E
500µm
Advantages of HiCu ProfilePCB:
> High current-carrying capacity (up to 1,000A)
layer 1 - Ø: 0.35mm
> Excellent heat dissipation; direct connection of
the component to the copper profiles possible
30.9µm
(e.g. through cavities or blind via-holes)
> Planar surface
28.8µm
> Combination of fine structures with
34.1µm
high currents on one printed circuit board
> Higher tracking resistance
(solder resist only has to cover planar surfaces)
> Combinable with other technologies
Copper profile connected by blind via to the outer layer
(e.g. thick copper, HDI, SemiflexHR etc.)
> Weight saving and/or reduction
of thickness possible
|
|
|
|
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
11
Wärmemangement_1_EN 29.10.12 17:41 Seite 12
Metal Inlay PCBHR
1.
heat flow
2
3.
4.
5.
1. chip 2. solder 3. metal inlay
4. heat-conducting adhesive or similar 5. heat-sink or housing
In Metal Inlay Technology a massive copper
element (inlay) is pressed into the printed circuit
board and serves to dissipate the heat of
an electronic component through the printed
circuit board. The heat-emitting component
(heat source) can be connected directly to the
metal inlay. Copper inlays with a minimum
diameter of 5mm and a thickness of 0.8-2.5mm
are used primarily for this. Depending on their
shape and dimensions, the metal inlays are
inserted fully or semi-automatically.
The use of metal inlays allows substantial
Any shape can be chosen for the metal inlays
improvement of the thermal conductivity
(square, round). The required recesses in the
(through the printed circuit board) compared
printed circuit board are produced by milling or
with conventional thermal vias.
drilling. Mounting holes up to a diameter of
6.35mm can be produced during the first drilling
procedure and are therefore cost-efficient.
12
SMART
SOLUTIONS
>
HEAT
MANAGEMENT
>
Wärmemangement_1_EN 29.10.12 17:41 Seite 13
Design notes for metal inlays
D
Inlay thickness
0,8-2,5mm ±20µm
U
Inlay dimensions
min. 5mm (diameter)
A
Distance to holes or layout
> 1mm
Z
Inlay - inlay distance
min. 2 x material thickness
VL
Inlay position to preferred layer
0-50µm standard
RL
Inlay position to rear side
depending on PCB and inlay design
Metal inlays can also be inserted in the inner layer core of a multilayer (e.g. sequential build-up).
In this case they are called “embedded metal inlays“. The contact to the inlays is established here by
lasered or mechanically drilled blind vias.
Example 4-layer multilayer with “embedded metal inlay“
Metal Inlay
Blind vias (lasered or mechanically drilled)
|
|
|
|
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
13
Wärmemangement_1_EN 29.10.12 17:41 Seite 14
Metal Inlay PCBHR
Fully automatic mounting of round metal inlays
Reliability tests
Test
Test method
Result
Thermal storage
1000h/125°C
3
Soldering
2x reflow
3
Thermal cycling
>1,000 cycles -40°C /+140°C
3
Delamination test
Pre-treatment 72h 40°C 92% r.h.
3
Solder shock 20sec. 288°C
in accordance to DIN 5008
Solderability test
DIN IEC 60326 T.2, Pt. 8.2 Test 14a
3
Surface cleanliness (by ionograph)
< 0.7µg/cm2 NaCl equivalent
3
Press-out forces
> 50N
3
Application fields for metal inlay technology include
> E-Mobility & automotive:
Motor controls (ECU), ABS, ESP, start-stop systems
> Industrial electronics:
Inverter and rectifier, power electronics, control electronics
> Lighting technology:
LED lighting, special projectors and cinema technology
14
SMART
SOLUTIONS
>
HEAT
MANAGEMENT
>
Wärmemangement_1_EN 29.10.12 17:42 Seite 15
Possible applications
> control electronics (automotive)
> high-power LED
> control electronics (industry)
> control electronics (automotive)
Technical features / know-how
> Optimal heat dissipation through direct connection of the component to the metal inlay
(soldering, gluing etc.)
> Optimal heat conduction through the printed circuit board: the continuous copper path
enables excellent conduction from the heat source to the heat-sink
> Combination with other technologies possible, e.g. heat-sink, Semiflex etc.
> Electrical connection of the metal inlays possible - also to the inner layers
> Freedom to choose the geometry of the metal inlays
> Fully automatic mounting of round metal inlays, semi-automatic mounting for other shapes
> Very good planarity of the inlay to the reference layer (component or heat-sink side).
The planarity on the opposite side depends on the design
|
|
|
|
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
15
Wärmemangement_1_EN 29.10.12 17:42 Seite 16
Metal Plate PCBHR
Aluminium heat-sink
printed circuit board
composite material
heat-sink
The increasing power density of electronic
components, ever more compact sizes of
electronic assemblies and higher temperature
requirements generally result in increased
heat production by the individual assemblies.
With maximum reliability and service life of the
assemblies in mind, the heat produced needs to
Rth-reduction by
Rth-reduction by
be dissipated in order to reliably prevent critical
reduced layer thicknesses
thermal vias
temperatures and to operate the assembly under
all environmental conditions within the admissible
temperature limits.
RUWEL offers heat-sink technology under the
One extremely efficient way of dissipating heat
product designation Metal PlateHR. In this technol-
from an electronic assembly is to conduct the
ogy heat-sinks in the form of sheet metal (prefer-
heat from its source through the printed circuit
ably copper or aluminium) are applied on the
board to a defined heat-sink. This heat-sink,
printed circuit board for better heat dissipation /
in turn, can be part of the housing concept.
distribution.
16
SMART
SOLUTIONS
>
HEAT
MANAGEMENT
>
Wärmemangement_1_EN 29.10.12 17:42 Seite 17
Copper heat-sink
Copper
Aluminium
Cu-ETP
EN-AW 1050A
CW004A
EN-AW 1060
Typical layer thickness
min. 200µm
min. 200µm
Thermal conductivity
~ 400
pressure-sensitive adhesive films. Other compos-
Type of adhesive
pressure-sensitive
ites (e.g. Prepreg) are also possible.
Typical adhesive thickness ~ 125µm
The thermal resistance (Rth) can be reduced by
Material
thin layers - thin printed circuit boards - or alternatively by copper paths through the printed circuit board, such as for example thermal vias or
Metal InlayHR.
W
m·K
> 180
W
m·K
The heat-sink is normally connected to the
printed circuit board by temperature-resistant
|
|
|
|
Thermal conductivity
> 0.35
Dielectric strength
>5
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
W
m·K
kV
mm
17
Wärmemangement_1_EN 29.10.12 17:42 Seite 18
Metal Plate PCBHR
RUWEL has automatic equipment (pick & place
Features of the automatic mounting and
and pressing) for assembling heat-sinks with
assembly facility using a pressure-sensitive
pressure-sensitive adhesive. This guarantees that
adhesive:
even large quantities can be assembled with accurate placement in a controlled process at a con-
> Accurate placement and pressing are
guaranteed (location tolerance: ±0.2mm)
sistently high quality level.
> Registration by CCD camera
> Variable heat-sink geometry,
as individually programmable
> Highly automated processing
➜ reduced process costs
> Pressure-sensitive adhesive
= no thermal stress on the printed circuit board
> The different expansion coefficients of PCB and
heat-sink can be partially compensated by the
modulus of elasticity of the adhesive
> Thickness of the heat-sinks from 200 to 500µm
(deviating thicknesses are processed semi-automatically)
18
SMART
SOLUTIONS
>
HEAT
MANAGEMENT
>
Wärmemangement_1_EN 29.10.12 17:42 Seite 19
Feeding of heat-sinks on rolls for automatic mounting
A possible alternative to Metal Plate PCB HR is the
printing of a heat-sink paste.
For this we use for example the heat-sink paste
HSP-2741 (from Lackwerke Peters),
a one-component system based on epoxy resin
Heat-sink paste
(conducts heat, but not current!).
Parameters of the paste:
Thermal conductivity λ = 2
W
m·k
Dielectric strength: 10 kV
mm
TG = 65 °C
Colour: black
Density: 2,05±0,05
|
|
|
|
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
g
cm3
19
Wärmemangement_1_EN 29.10.12 17:42 Seite 20
Wirelaid Technology
An alternative for partial currents up to 100 A
Preceding WIRELAID ® process steps
1
1st Welding
2
3
Cut
2nd Welding
Wire
Cu foil
Standard PCB manufacturing
4
5
6
7
Wire on
Cu foil
(treatmentside)
Multilayer stack-up
lamination
Multilayer
laminated
Wirelaid is a patented printed circuit board
technology used by RUWEL as licensee.
In Wirelaid Technology copper wires are applied
to the treatment side of a copper foil
(thickness 35-105µm) by micro resistance
welding. The wires used are round wires with a
Microsection with embedded flat wires
diameter of 300µm and flat wires with
dimensions of 250µm x 800µm or
350µm x 1400µm in any length. During the manufacturing of multilayers these wires are embedded in the resin of the respective printed circuit
board construction.
20
SMART
SOLUTIONS
>
HEAT
MANAGEMENT
>
Wärmemangement_1_EN 29.10.12 17:42 Seite 21
The position of the wires:
Wirelaid Technology can be an alternative and
cost-efficient solution in cases where
a high copper cross-section is only partially
required within a printed circuit board. Here basic
copper in standard thicknesses (35µm-105µm)
can be used, reinforced in the specified areas by
appropriate wires. By combining different wire
geometries and varying the number of wires,
the current load capacity can be increased while
reducing conductor warming at the same time.
The total copper component is lower than that in
thick copper technology, which also has positive
effects for instance on the soldering process.
In addition, a lower consumption of etchants and
shorter etching times help to reduce costs.
on inner layers
on inner and outer layers
on outer layers
Advantage: Only one lamination step
|
|
|
|
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
21
Wärmemangement_1_EN 29.10.12 17:42 Seite 22
Wirelaid Technology
Photo: Jumatech GmbH
Compared with other processes, in Wirelaid
Technology the wires are laid, welded and cut
automatically using cutting-edge CNC equipment.
Application possibilities
> Heat dissipation in critical areas by partial
increase of the copper cross-section
> Combination of power and control electronics
in or on a printed circuit board
> High-current applications (up to 100A)
where a higher wire cross-section is only
partially required.
> To a certain extent mountings can also be
optimised by special V-scoring.
Detail of a layout with “reinforcement” by wires
(green: wires / red: Cu layout)
22
SMART
SOLUTIONS
>
HEAT
MANAGEMENT
>
Wärmemangement_1_EN 29.10.12 17:42 Seite 23
Applications
Switch unit (red: position of the wires)
Power supply for servo drive control (partial 70 A on
105µm Cu foil & wires / red: position of the wires)
Photos: Jumatech GmbH
Processor-controlled drive control
LED helical lamp (red: position of the wires
(red: position of the wires)
Technical features
> The wires are laid by a CNC-controlled machine
> The surface is planar as the wires are laid inside the printed circuit board
> Significant gain in surface space, the actual layout structure itself is scarcely affected
> Enhanced heat dissipation at hot spots, similar to that of thick copper
> Layer count in multilayer PCBs can be reduced
> Reduction of copper thickness ➜ costs reduction
> Combination of power and control electronics on one layer
> Many common printed circuit technologies can be combined with Wirelaid
|
|
|
|
HiCu PCBHR HiCu Profile PCBHR Metal Inlay PCBHR Metal Plate PCBHR Wirelaid
23
Wärmemangement_1_EN 29.10.12 17:42 Seite 24
RUWEL International GmbH
Am Holländer See 70
D-47608 Geldern
Tel. + 49 (0) 28 31 - 3 94-0
www.ruwel.com