How is Polyimide Pressure Sensitive Tape Made?

Poly­imide pres­sure sen­si­tive adhe­sive (PSA) tape is actu­al­ly made up of two sep­a­rate steps. The first is the man­u­fac­ture of the poly­imide film itself (the gener­ic name of of DuPon­t’s trade­name Kap­ton®), and the sec­ond is apply­ing an adhe­sive back­ing depend­ing on the intend­ed application.

Poly­imide Tape is made up of two sep­a­rate steps. First is the man­u­fac­ture of the poly­imide film itself and the sec­ond is the appli­ca­tion of the adhe­sive backing.

The Polyimide Film Manufacturing Process

Poly­imide film, the gener­ic name of of DuPon­t’s trade­name Kap­ton®, is syn­the­sized by poly­mer­iz­ing PMDA and ODA in strong polar sol­vents through the process of form­ing film and imine treat­ment at high tem­per­a­ture. This syn­the­sis cre­ates excel­lent phys­i­cal, chem­i­cal, and elec­tri­cal prop­er­ties, as well as atom­ic radi­a­tion resis­tance, sol­vent resis­tance and low & high tem­per­a­ture resis­tance. It per­forms well in a wide range of tem­per­a­tures as low as ‑452°F (-269°C) and as high as +500°F(+260°). Because of these char­ac­ter­is­tics, it is unique­ly suit­able for spe­cif­ic for many high tem­per­a­ture applications.

Manufacturing Polyimide Silicone PSA Tapes

Poly­imide Sil­i­cone Adhe­sive Tape is made by first tak­ing poly­imide film and coat­ing it with a heat-resis­tant sil­i­cone adhe­sive. Due to its sta­ble pres­sure-sen­si­tive macro­mol­e­cule adhe­sive lay­er at high tem­per­a­ture, the tape offers excel­lent prop­er­ties of heat resis­tance, elec­tri­cal insu­la­tion, sol­vent resis­tance and radi­a­tion pro­tec­tion. Being sil­i­cone, it offers bet­ter elon­ga­tion at break, and is used for elec­tri­cal insu­la­tion of elec­tri­cal equip­ment and high tem­per­a­ture insu­la­tion. It offers the high­est heat resis­tance among film adhe­sive tapes, so it can also be applied for insu­la­tion in high-end elec­tron­ic equip­ment, motors, and Lithi­um (Li) bat­ter­ies. Oth­er appli­ca­tions include the pro­tec­tion of the gold fin­gers on Print­ed Cir­cuit Boards (PCBs) dur­ing wave sol­der­ing, as lead-free sol­ders often require reflow tem­per­a­tures up to 260°C — an oper­at­ing tem­per­a­ture for which poly­imide tape is unique­ly suit­ed — leav­ing no adhe­sive film once the tape is removed. Final­ly (though the true list of appli­ca­tions is near­ly end­less), it can be used for shield­ing in high tem­per­a­ture applications.

Manufacturing Polyimide Acrylic PSA Tapes

Poly­imide Acrylic Tape is made using the same process as the sil­i­cone process described above, but though the acrylic is typ­i­cal­ly a heat-resis­tant acrylic, it still can­not with­stand the high tem­per­a­ture range of the sil­i­cone PSA described above. Also, acrylics tend to be more brit­tle, so the low­er tem­per­a­ture range is also some­what more lim­it­ed as the adhe­sive can crack at extreme­ly low tem­per­a­tures. How­ev­er, since the poly­imide acrylic tape still uses a base of poly­imide, the film itself is still able to with­stand a wide tem­per­a­ture range and can still be used in many of the same high-tem­per­a­ture appli­ca­tions; it is just that the adhe­sion prop­er­ties of the film become more lim­it­ed with an acrylic adhe­sive. Acrylic chemistries are typ­i­cal­ly cheap­er mate­ri­als also, so the final sell­ing price of acrylic-based poly­imide tapes are gen­er­al­ly low­er. Though CAPLINQ offers both acrylic-based and sil­i­cone-based tapes; giv­en the mar­gin­al price dif­fer­ence and the wider range of appli­ca­tions, the most pop­u­lar tapes remain the sil­i­cone-based poly­imide tapes.