3M anisotropic conductive film adhesive 7313 tech bulletin 用户手册

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The purpose of this document is to provide information about 3M™ Anisotropic
Conductive Film (ACF) Adhesive 7313 that can be used as a starting point in
developing the bonding process. For additional information on this product, consult
the 3M™ Anisotropic Conductive Film Adhesive 7313 Technical Data Page.

The information presented in this report should be considered representative or
typical and should not be used for specification purposes. The user is responsible for
evaluating ACF 7313 under actual conditions of use and with the substrates for the
intended application that are necessary to determine whether the product is suitable
for a particular application and assembly method.

The reliability of any interconnection will depend upon many factors including but
not limited to substrates to be bonded, plating metallurgy, bonding conditions, pitch,
and circuit design.

ACF 7313 is a thermoplastic adhesive matrix randomly loaded with conductive
particles. The ACF 7313 adhesive is used to join together two circuits to provide an
electrical and mechanical connection. The method used to join the circuits together
is the bonding process. 

The purpose of the bonding process is to apply simultaneously heat and pressure to
melt the crystalline regions of the thermoplastic thus allowing the thermoplastic to
flow bringing the connecting pads into contact with the conductive particles. The
thermoplastic again recrystallizes upon cooling below the melting temperature
range thus providing an electrically and mechanically stable bond. The use of
relatively large conductive particles, coupled with a thermoplastic matrix, enables
very short bonding times. Figure 1 shows the dynamic mechanical properties of
ACF 7313. The storage modulus exhibits relatively stable values below the
maximum use temperature (about 80°C). The crystalline melt temperature (where
the modulus approaches a minimum value) is at about 115°C.

Effective bonding requires that the bond-line temperature be high enough that the
applied pressure is sufficient to achieve the necessary flow in the time allowed.
Certain precautions should be observed for optimal use of ACF 7313 in a given
application. An interrelation among temperature, pressure, and time must be
tailored toward the uniqueness of individual applications. As a starting point in
developing a bonding process, bonding pressure should be applied throughout the
steps of ramping to bonding temperature, holding at a bond-line temperature of
between 135-150°C maintained for 5 seconds, followed by cooling to a bond-line
temperature below 90°C. The typical pressure is 200 to 250 psi over the bond-line.
Note, if the pressure is too low, the adhesive will not flow sufficiently for the
substrates to contact the particles; if the pressure is too high, damage to the
substrate or circuits can occur.