Problem

Solution

Higher frequencies require optimized

grounding and Faraday Cage design

Inherent bond line thickness

Poor “through tape” EMI Shielding leads to

lower EMI SE at High Frequencies.

Standard electrically conductive tape leads to

EMI leakage through bond line tape thickness.

3M ECATT 9709SL

60dB EMI Shielding

0.1mHz

50mHz

10Hz

60db

3500 µm

35 µm

1000mHZ

(1GHz)

10000mHZ

(10GHz)

Grounding Surface (R OK)

Grounding Surface (Lower Contact R)

Flex Circuit (FPC)

Flex Circuit (FPC)

Grounding Surface (R OK)

Grounding Surface (Lower Contact R)

Flex Circuit (FPC)

Flex Circuit (FPC)

3M ECATT with inherent EMI shielding at the bond line provides significantly reduced crosstalk,

stray EMI, noise in circuit, antennae effects, FPC susceptibility and spurious emissions.

At High Frequencies, the effect of “through the tape thickness”

EMI gaps or EMI slits is to allow EMI leakage. If the effective

EMI gap/slit does not = “0”, EMI energy at high frequency can

pass through a “standard conductive adhesive tape material” via

the gap related to the adhesive thickness. The “Tape Bond Line

Gap/Slit leakage effect” leads to poor EMI Shielding, cross-talk,

degraded Signal-to-Noise ratio, etc.

4

Mobile Handheld & Tablet EMI/EMC Solutions

3M ECATT 9707, 9709S

ECG-7050/ECG-8055/MSG-6100

3M Multi-functional EMI Shielding,

Grounding and Heat Spreading Solutions.

Hot device heat spreading & grounding, LED

heat spreading and attachment. EMI and

thermal management materials.

Flex Printed Circuit

Flex

3M ECATT 9709SL

Grounding Surface

Substrate Layer

3M Electrically Conductive Adhesive Transfer Tape

9709SL used for FPC grounding and EMI Shielding

As frequency increases, is the “bond line gap” leading to stray EMI?

(Cross talk, spurious EMI, signal degradation and noise.)