Electrically Conductive Adhesive Transfer Tape 9707
Product Description
3M™ Electrically Conductive Adhesive Transfer Tape (ECATT) 9707 is a pressure sensitive adhesive (PSA) transfer
tape with isotropic electrical conductivity. The PSA matrix is filled with conductive fillers that allow interconnection
between substrates through the adhesive thickness (the “Z-axis”) and also provides electrical conductivity in the
plane of the adhesive (“X-Y Axis”).
3M ECATT 9707 and 9707K are ECATT products produced at different manufacturing locations. 3M ECATT 9707 and
9707K use similar base material types, however the ratios were adjusted slightly to achieve desired manufacturing
specification performance results as determined by 3M test methods.
Features and Benefits
• Good XYZ electrical conductivity performance with good adhesion
• Room temperature application and assembly
• Inherent EMI shielding capability can enhance existing shielding solutions, offer new design options and
improve Faraday cage designs
• Provides an electrical connection and adhesively bonds EMI/RFI shields and gaskets to metal frames and
enclosures
• Low contact resistance and tape construction for good EMI performance
• Can be applied as die cut parts or in roll form
• Can offer lower contact resistance to hard surfaces or surfaces with oxide layers, such as to stainless steel as
compared to 3M ECATT 9709
Construction
Property
Adhesive Type
Release Liner
Approximate Thickness
Adhesive
Liner(s)
Value
Filled Acrylic Pressure Sensitive
Std PET/PET Liners
2 mil (50 µm)
2 mil (50 µm) PET / 2 mil (50 µm) PET
3M
™
Electrically Conductive Adhesive Transfer Tape 9707
Typical Physical Properties and Performance Characteristics
Note:
The following technical information and data should be considered representative or typical only and should not be
used for specification purposes.
Adhesive Properties:
(Note 6)
Peel Adhesion to Stainless Steel:
(Test Method is based on a modified ASTM D3330, 12 ipm peel rate, 1 in. width, 2 mil PET backing, 180 degree)
Dwell Time @ Room Temperature
1 Hour
24 Hours
23°C
32.5 oz./in. (3.6 N/cm)
55 oz./in. (6.0 N/cm)
Note:
Peel values will often be higher than noted above when using a non-PET backing. Different backing types affect the backing
modulus, thickness and stiffness and these differences directly affect the peel test result value. As an example, a 2 mil aluminum
backing will change the test value of the peel adhesion. This is because the angle of the peel back at the interface will change due
to the backing stiffness. A 2 mil aluminum backing would generally increase the peel values.
Temperature Performance
Shelf Life and Storage
(Note 1)
Application Use Temperatures:
-40 to +85°C Varies with application design. See Note 1.
See also the Application section of this document
Tape in roll form: Shelf life 24 months from the date of manufacture when stored
in original cartons at 21°C (70°F) and 50% relative humidity.
Electrical Properties:
(Note 6)
Current Carrying Capacity
(Note 3)
Z-Axis Resistance @ 1 Hr dwell,
2mm x 5mm contact area
(Note 1,2,4,5)
Minimum Overlap Area
To be qualified by end use customer
<0.5 ohms
Application dependent
Thermal Performance:
(Note 6)
Apparent Thermal Conductivity
Note 1
0.6 - 0.7 W/mk
Application use temperature range of the 3M™ Electrically Conductive Adhesive Transfer Tape 9707 may be increased or have improved reliability with the
use of a mechanical clamping system as determined by the end use customer. The temperature use range is dictated by two primary items: Temperature
performance of the acrylic adhesive (generally in the range of -40°C to about 95°C depending on other environmental conditions) as it supports the conductive
particles in the adhesive/particle matrix and the potential movement of the conductive fillers in the adhesive system in an end use application design. Items
contributing to the good performance of the 3M ECATT 9707 for resistance level performance include, but are not limited to: assembled bond line force
(constant force present across the bond line after assembly and over the life of the product), types of substrates bonding, surface features in bonded area,
etc. (See section on mechanical clamping for added information).
Two wire resistance measurement (a 4 wire test would generally be lower). The Z axis test uses a test PCB with gold traces or pads that are 2mm wide.
The ECATT tape is laminated to a polyimide or PET flex with a gold plating. The ECATT is laminated to the flex to cover about 50% of the flex surface. The
flex/ECATT is bonded to the PCB gold pad and the opposite (non-ECATT end) is placed into contact with another gold PCB trace to make an electrical contact.
Contact R is measured between the two PCB pads of the flex to infer a relative contact R of the ECATT product based on this test method and surfaces used.
Estimated. Customers are required to qualify the maximum current capability for their application. Added compression in bond line suggested for any current
carrying application to improve reliability. See also Note 1
Minimum suggested conductor overlap area (pad area) in the interconnection of individual circuit lines to ensure Z-Axis conduction must be optimized for
each application and environmental and mechanical design conditions.
Z & XY conductivity end use and testing results will vary based on many factors such as, but not limited to: End use design, environmental conditions, aging
environment, test methods, interface material types & compatibility, product lot to lot & with-in lot variability, XY span, surface features & topagraphy, area,
surface preparation, etc.
3M ECATT 9707 and 9707K are ECATT products produced at different manufacturing locations. 3M ECATT 9707 and 9707K products use similar base material
types, however the ratios were adjusted slightly to achieve desired manufacturing specification performance results as determined by 3M test methods.
Note 2
Note 3
Note 4
Note 5
Note 6
Available Sizes
Slit Tape Width
1.0 to 12 inch
(25 mm to 354 mm)
Normal Slitting Tolerance
(2)
Standard Length
36 yds.
(32.9 m)
0.065 in.
(0.8 mm)
Maximum Length
108 yds.
(98.8 m)
3M
™
Electrically Conductive Adhesive Transfer Tape 9707
Application Techniques
Note:
As each application is unique, it is important for users of the 3M ECATT products to evaluate which will work best
for their product design. In some designs,
3M™ Electrically Conductive Adhesive Transfer Tape (ECATT)
9709 may
perform as effectively as
3M ECATT 9707
for EMI shielding when a final design is tested for electromagnetic interference
compatibility (EMC).
3M ECATT 9707 is a more surface aggressive ECATT on many substrates, which will allow for a higher level of adhesion
build (as measured by a peel adhesion test method and as compared to the 3M ECATT 9709S). Because 3M ECATT 9707
is a more surface aggressive ECATT tape, it is generally not compatible with Indium Tin Oxide (ITO) coating or other easily
corroded surfaces.
As with all conductive PSA applications, stable electrical performance in any electrical connection application may require
added mechanical reinforcement (clamping or compressing) in the bond area.
Bonding
• To obtain maximum adhesion, the bonding surfaces must be clean and dry.
• Pressure must be applied to the bond line after assembly to wet the substrates with 3M ECATT 9707 and to engage the
conductive particles with the substrates to make electrical connection. Mechanical pressure (roller, metal bar) or finger
pressure at 5 to 15 psi (0.03 to 0.10 Mpa) is suggested at 20°C (68°F) to 25°C (77°F). The end user may find through
testing that a higher pressure could be more effective in their end-use design to meet their specific design criteria.
Heat may be applied simultaneously to improve wetting and final bond strength.
See Note A.
• 3M ECATT 9707 is suggested to be applied at a maximum temperature range not to exceed 15°C - 70°C (60°F - 158°F).
Tape application below 10°C (50°F) is not suggested because the adhesive will be too firm to wet the surface of the
substrate, resulting in low adhesion.
See Note A.
• Adhesion builds with time. Up to 24 to 72 hours may be required to reach final adhesion values.
Note A)
Regarding the application of Temperature, Pressure and Time (T-P-T) during assembly and/or lamination: Care
must be taken by the end user during assembly as the modulus of the tape will be reduced with the application of heat.
- An application method with ranges of not more than: 5-15 psi @ 15-70°C for 2-30 seconds is suggested as a set of initial
evaluation ranges. An example of initial T-P-T that may be evaluated is: 8 psi applied via an assembly fixture using an air actuated
pressure pad (pad is a medium firm elastomer) for 5 seconds @ 23°C. The end user may find assembly T-P-T outside these limits
works well in their unique application. The noted T-P-T is a suggested starting point of tape bonding criteria and will be influenced
by 3M ECATT 9707 part size, substrate types, substrate modulus, surface features, flatness, assembly fixtures, etc.
- Final bond strength and conductive performance will be impacted by “Temperature-Pressure-Time” interactions in an end use
assembly method to the desired substrates.
- Care must be used to minimize excessive “Temperature-Pressure-Time” assembly methods so the conductive filler/acrylic
adhesive matrix is not damaged, leading to poor performance (ie: excessive squeeze-out of tape, filler-interface damage,
minimize over compression and conductive filler/adhesive matrix damage.)
- A Design of Experiments (DOE) is suggested to establish the optimum bonding conditions for each application assembly.
(3)
3M
™
Electrically Conductive Adhesive Transfer Tape 9707
Application Techniques
(continued)
Mechanical Clamping
To assure electrical resistance stability of
3M™ Electrically Conductive Adhesive Transfer Tape (ECATT) 9707
in any
flexible circuit interconnection application, or grounding application between various types of substrates, a mechanical
clamp or other compressive force (i.e. foam strip held in compression over bond area) should be considered in the design
of the application. Any stress inherent in the assembly design (i.e. tensile, shear, cleavage) or temperature excursions
(encountered through normal product use) applied to the bond area could result in an electrical open in the bonded
circuit over time. A well designed mechanical clamp will reduce the environmental stress on the bond line, improve the
electrical reliability of the bond, and improve the temperature operating range for the adhesive, helping to ensure the
conducting particles in the 3M ECATT 9707 maintain electrical contact. Several types of mechanical clamps have been
used successfully including foam strips attached to lids or cases and screw-attached plastic clamps. Contact your 3M
Technical Service Engineer for further information about mechanical clamping.
Temperature Performance
The electrical performance of 3M ECATT 9707 is more sensitive to environmental changes than is the peel adhesion
performance. Contact resistance performance may be compromised, even if holding power is not significantly affected.
See Note 1 in “Electrical Properties” section. The user is responsible for the environmental performance qualification of
3M ECATT 9707 in their design.
Rework
Mechanically separate the parts using torque (for rigid parts) and peel (for flexible parts). Remove the adhesive by rubbing
it off with a Scotch-Brite™ Hand Pad, clean up the site, and apply new adhesive. Heating the adhesive to 70°C - 100°C
(158°F - 212°F) or using solvents can soften the adhesive and reduce the force needed to separate the parts.*
*Note:
When using solvents, be sure to follow the manufacturer’s precautions and directions for use when handling such
materials.
(4)
3M
™
Electrically Conductive Adhesive Transfer Tape 9707
General Application Guide
3M has a broad line of Electrically Conductive Adhesive Transfer Tapes (ECATT) that vary in conductive filler types, filler
loading design, adhesive chemistry, storage modulus of the conductive tape, adhesion to various surface types, thickness,
conformability, etc. 3M provides a variety of tape products to allow end-users more options to optimize grounding, EMI
shielding and interconnects based on product attributes.
As each end use application has many variables unique to the design, it is suggested that 2 or more products be tested
in a Design of Experiments (DOE) to identify the best performing product for the application along with the optimum
assembly means (pressure, time, temperature, assembly fixtures, etc.) and final design configuration for desired end
use performance.
End-use substrate surfaces, final assembly design specifications, design configurations, assembly methods and end use
environmental conditions will vary. For example:
a)
When evaluating 3M ECATTs, note that the surface energy of the design substrates to be evaluated will vary in surface
energy, which can impact the adhesion strength of the tape to the surfaces (i.e. stainless steel vs. polyimide vs. gold
vs. nickel plating, etc.).
b)
Substrate surface hardness and inherent conductivity can affect potential filler/surface contact resistance (i.e. stainless
steel vs. polyimide vs. gold vs. silver epoxy ink vs. plated surfaces, etc.).
c)
Modulus or flexibility of the substrates can affect substrate interaction with the 3M ECATTs and environmental aging
performance (i.e. rigid PCB vs. flex circuit vs. metals vs. substrate thickness, etc.).
d)
Contact area for grounding on a substrate can impact the effective contact resistance level achieved in a design (Total
contact area [3mm
2
, 25mm
2
, 100mm
2
, etc.] and discrete sizes of individual contact areas [3mm
2
, 10mm
2
, 30mm
2
, etc.].)
e)
Substrate surface topography or surface features can impact how the tape can “gap fill” or “conform to irregularities”
and provide adhesion and conductivity between substrates.
f)
Bond line stress in the form of a tensile, cleavage, compression and shear can all affect 3M ECATT performance in an
application (i.e. rigid to rigid substrates, multi-layer flex to rigid, thin flex to rigid, etc.).
g)
Method of assembly and size of finished parts can affect tape selection (ease of converting and assembly based on
die cut part shape and final assembly).
h)
Desired contact resistance level varies. For example, some applications specification may indicate a contact R <100ohms
or R < 10ohms or R <1.0ohms target. Each design has its own resistance specification, and within a design, each area
can have a different resistance level need.
i)
Environmental conditions vary (i.e. minimum and maximum temperatures, cycling, humidity, etc.).
j)
Assembly methods affect final performance of the tape with the given substrates (tooling, fixtures, assembly pressure-
temperature-time).
k)
Final assembly configuration will also vary (i.e. inherent bond line compression, clamping, stand-alone assembly, etc.).
The above end use application variables make it difficult to predict which 3M ECATT will best achieve the desired level of
performance in an application. Thus, 3M has a broad and unique line of conductive tapes to provide a blend of performance
京公网安备 11010802033920号
EEWORLD
