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.

About Chris Perabo

Chris is an energetic and enthusiastic engineer and entrepreneur. He is always interested in taking highly technical subjects and distilling these to their essence so that even the layman can understand. He loves to get into the technical details of an issue and then understand how it can be useful for specific customers and applications. Chris is currently the Director of Business Development at CAPLINQ.

7 thoughts on “How is Polyimide Pressure Sensitive Tape Made?

  1. We have an appli­ca­tion where we need to store a Li bat­tery under sea­wa­ter. We use a lam­i­nate pouch with an Al bar­ri­er lay­er and a Mylar (PET) coat­ing on the out­side. In time the sea­wa­ter cor­rodes away the Al along the edges of the pouch ulti­mate­ly caus­ing the pouch to fail. We have found Kap­ton tape placed on the edges helps pre­vent the pouch from fail­ing but I was won­der­ing if you had infor­ma­tion as to the best type Kap­ton to use to adhere to Mylar in a sea­wa­ter envi­ron­men that would hold up the longest. What are your recomen­da­tions?
    Thanky­ou
    Art

  2. Sil­i­cone adhe­sive backed poly­imide (Kap­ton) tapes have far supe­ri­or resis­tance to water, includ­ing salt water and sea water. Sil­i­cones are nat­u­ral­ly more resis­tant than acrylics to water (click here to read arti­cle com­par­ing acrylics to sil­i­cones to rub­bers).

    Though acrylic adhe­sives have the high­est adhe­sion to low-sur­face ener­gy plas­tics, in my expe­ri­ence, the thin bond­edge of acrylic adhe­sives slow­ly erodes when exposed for long peri­ods of water.

    They may start out stronger, but giv­en time, sil­i­cone-based adhe­sives for Poly­imide (kap­ton) tape are a bet­ter suit­ed to this appli­ca­tion. Con­tact us today for more infor­ma­tion or to place an order.

  3. Chris,
    In the arti­cle above, it states: “Poly­imide film … cre­ates excel­lent phys­i­cal, chem­i­cal, and elec­tri­cal prop­er­ties, as well as atom­ic radi­a­tion resis­tance, sol­vent resis­tance and low & high tem­per­a­ture resis­tance. ” and “Poly­imide Sil­i­cone Adhe­sive Tape … offers excel­lent prop­er­ties of heat resis­tance, elec­tri­cal insu­la­tion, sol­vent resis­tance and radi­a­tion pro­tec­tion. ”
    Please quan­ti­fy the radi­a­tion resis­tance and pro­tec­tion in terms of rad© using gam­ma (Co-60) irra­di­a­tion.
    Thanks

  4. Joe,

    You make a very good point. While it’s true that our poly­imide tapes and films have excel­lent radi­a­tion resis­tance, these val­ues should be quan­ti­fied. This has been giv­en to one of our engi­neers and the site will be updat­ed when the infor­ma­tion becomes avail­able.

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