LINQTAPE PIT1S has a backing thickness of 1mil (25 micron) and the adhesive layer adds another 1.5 mil (36micron) for an overall thickness of 2.5mil (60 micron). The new PIT0.5S has a backing thickness of 0.5mil (13 micron) + 1mil (25 micron) adhesive layer for an overall thickness of 1.5 mil (38 micron).

This product is only available to registered users (customers can be added manually after registration) but the price is the same as LINQTAPE PIT1S.

To prepare a tape with an overall thickness of 25 micron could be possible, but the minimum order quantity would be one master roll of 20″ (510mm) width or the equivalent of about 20 rolls of 1 inch (25.4mm) tape.

For more information about polyimide tapes or any other of our products, visit us or contact us for more details.

• Sputtering metals on silicon wafers
• Study the inter-metallic layers formed during metal deposition
• Study the metal-polyimide interface
• Carry out X-ray photoelectron spectroscopy

The first test is to determine the thermal robustness of the CAPLINQ LINQTAPE PIT1SD and PIT2SD (double-sided, polyimide tape with silicone adhesive; 1mil and 2mil thick backing respectively). For the purpose of wafer metal deposition, Dr. Markus Lützelschwab, an R&D Engineer in the Optics & Packaging department of CSEM (Centre Suisse d’Electronic et de Microtechnique SA) carried out this test in Switzerland. He did some preliminary tests by sticking the PIT1SD and PIT2SD onto a glass container and heating the assembly using a hot-air solder tool. Using this test, he demonstrated that it showed the same thermal robustness as [single-sided] Kapton tape.

After this step, Dr. Lützelschwab sent the wafer with the LINQTAPE polyimide tape for a sputtering process. The LINQTAPE withstood easily the externally conducted sputtering process of Titanium and Gold. Attached is the picture of one corner of the LINQTAPE polyimde tape after sputtering.

For more information about polyimide tapes or any other of our products, visit us or contact us for more details.

Q1. What’s the minimum polyimide film thickness?
A1. Our thinnest standard material is 1mil (0.025mm).  We can produce thinner, but there would be minimum order quantities associated.

Q2. Could we provide free samples of PIT1A?
A2. As you can imagine, CAPLINQ receives many, many requests for “free samples”.  The manual entries, paperwork and ultimately costs that resulted from working outside our current workflow system (ensuring correct ship-to addresses, price quotes, samples lists, follow-up, etc.) was not in line with the low-cost model that we try to bring to our customers.  As such, we have done away with minimum order quantities and implemented a way to order single units instead of shipping free samples.

Q3. What is the heat resistance? We require it above 200C for 1-2 hours.
A3. The temperature resistance depends on the application.  The polyimide film itself can withstand temperatures of 450 °F (~230 °C) and for short periods, can withstand temperatures as high as 900 °F (~480 °C).  The weak point is the adhesive system.  The silicone adhesive (PIT1S-Series) can maintain adhesion above 200C, as well as short (2-3 minutes) periods at 260C.  Above this temperature, adhesion drops off quickly.  Acrylic-adhesives (PIT1A-Series) have a lower temperature resistance, but at lower temperatures (Room temperature) have a higher adhesion than silicones.  Depending on the application (namely masking), it is quite reasonable that the PIT1S could withstand 200C for 2 hours.

Q4. Under a certain degree of temperature an pressure, would the glue be coming out from the edge?
A4.  It is imaginable that under pressure at high temperature that the adhesive layer is compressed.  Whether and how far it would come out from under the polyimide backing, we have no data for.

Q5. What is the lowest thickness that can be produced, and will the thickness influence its heat resistance ability?
A5. I need to check with production what the minimum thickness is, but no, heat resistance is independent of the film thickness.

CAPLINQ offers this service and can even supply this for fairly low volume applications. For example, the image shown is a 3mil (0.003″ or 0.075mm) polyimide film with a custom-shape with maximum outside dimensions of 19.4mm x 9.4mm.

Below is CAPLINQ’s pricing for such a request:
#1 A one-time tooling charge of USD$150

#2 Price per part is volume dependent. Lower prices are available for even higher-volumes:
a) 500 Pieces: USD $1.50 /each
b) 1000 Pieces: USD $1.10/each
c) 2000 Pieces: USD $1.00/each

For your no-obligation quote or more information about polyimide tapes or any other of our products, visit us or contact us for more details.

PIT2SD, a 2-mil double-sided polyimide tape is often used to mount wafers on a carrier for through wafer etching and it works very well.

For more information about polyimide tapes or any other of our products, visit us or contact us for more details.

What customers do not always realize though is that UL classification must be tested for every unique film backing, thickness and adhesive combination, and the cost for any single combination is approx. $1000 + cost of material + delivery charges. It is difficult to justify the expense for the certification for each product without a significant customer request.

CAPLINQ does, however, work with an independent testing facility who can carry out this the UL Certification, but then CAPLINQ normally requests either a commitment for a certain order quantity (ie. 100 rolls), or that the customer pay for the testing. In order to share the burden of testing, we offer to pay for all the material, administration and shipping charges if the customer pays $1000 toward the testing.

For more information of UL classification or polyimide tapes, visit us or contact us for more details.

Silicone-based adhesives are certainly more standard, but sometimes the customer needs acrylic because they cannot have silicone in their systems, need higher adhesion at mid-range temperatures or other specific reasons.

The Usual Suspects

Generally speaking, manufacturers use three different adhesive types in combination with the backing material to produce a final “tape” product. Though these adhesive types can be subdivided into subgroups, the main categories are as follows:

1. Silicone
2. Acrylic
3. Rubber

Each of these adhesive types have advantages and disadvantages which make them more or less suitable for particular applications. Here we will draw the major lines outlining these differences.

Silicone adhesives

Silicones have been used to formulate adhesive products for decades due to their flexibility, temperature cycling resistance, chemical resistance, and wide range of possible material properties.

Silicone adhesives have the following general characteristics:

• High flexibility (low modulus) at sub-ambient temperature
• Consistent performance over wide temperature range (a reason they work so well with Polyimide Tapes)
• Excellent ageing and UV resistance (a reason they work so well in LED applications)
• High temperature resistance
• Good resistance to polar solvents

Compared to acrylic and rubber adhesives, they are significantly more expensive, but due to their excellent high temperature performance they are very well suited to splicing tapes, masking tapes and polyimide (Kapton) tapes.

Acrylic Adhesives

Acrylic adhesives can either be water-based (this is also referred to as emulsion or dispersion) or solvent-based. Water-based are slower drying compared to solvent-based systems but generally solvent-based acrylic systems have better resistance to other solvents, chemicals and water. Comparatively, water-based systems are less expensive than their solvent-based counter parts.

Acrylic adhesives are generally divided into two subgroups: Pure and Modified

Pure acrylic
Pure acrylic adhesives share the following characteristics:

• Reasonable adhesion to a wide range of substrates (see modified acrylics below)
• Good ageing, transmittance and UV resistance (a reason they are often used in fiberoptic applications
• Reasonable temperature resistance; between silicones (high resistance) and rubber (low resistance)

Pure acrylics have a lower tack (“stickyness when dry” for the layman) and less adhesion on hard-to-bond plastics such as high- and low-density polyethylene (HDPE & LDPE) and polypropylene (PP) than modified acrylic or rubber adhesives. Pure acrylic adhesives are mainly used on tapes whose applications are bonding, sealing or surface protection.

Modified acrylic
For all intents and purposes, modified acrylics have the same characteristics as pure acrylics, but have superior adhesion to the hard-to-bond-plastics mentioned above. Generally, these are more expensive than pure acrylics and are used for plastic bonding (including vinyl and linoleum), lamination and splicing.

Rubber Adhesives

Just from looking at the roll, it is very hard to tell what type of rubber is used on the tape. Look at the figure to the right, and this same picture can be used to describe every type of rubber-tape below. The key is to ask the supplier what type of rubber adhesive is used. Like acrylics, rubber adhesives can be divided into two subgroups: Natural and Synthetic

Natural rubber
These adhesive have higher tack (again “stickyness when dry” for the layman) than acrylic adhesives as well as higher shear strength but they have limited UV resistance. These are used in the cheapest tapes on the market, but have limited applications. Natural rubber adhesives are used in duct tapes, low-temperature masking tapes and surface protection tapes (think of the tape you get on your new fridge or stove).

Synthetic rubber
As the name implies, synthetic rubber is “formulated rubber” – think coming from the lab, not coming from the tree. Synthetic rubber can broken into three subgroups: Hot-melt, Solvent and Butyl rubber.

Hot-melt rubber

Hot-melt is a low-temperature melting plastic, which makes this adhesive have low temperature resistance. It also ages poorly (becoming brittle) and has low UV resistance. This rubber is used for low- to medium-duty carton sealing, low-temperature splicing as well as paper core starting applications.

Solvent rubber

Solvent-rubber based adhesives have better temperature and aging performance but still poor UV resistance. It is used for electrical and foam tapes.

Butyl rubber

Butyl rubber based tapes have excellent UV and aging resistance but lower mechanical strength. These tapes are used in foam tape applications and construction and plumbing applications such as pipe joints.

Visit CAPLINQ.com today or ask us how we can help you select the right tape for your application.
tapes are mainly used for sealing applications in the building and construction industry. T

Each layer has a thickness and the sum of these thicknesses makes up the total tape thickness.

What is often misunderstood by customers is what exactly “1-mil thick” polyimide tape implies. Customers are not sure whether “1-mil” (25µm) thick polyimide tape refers to the polyimide film thickness or the total thickness, since ultimately polyimide tape is made up of both the polyimide film layer plus the silicone adhesive layer (read more about why we believe in silicone-based tapes here).

As can be seen in the photo (click to enlarge), polyimide tape is madeup of two distinct layers:

1. The polyimide (kapton) film layer
2. The adhesive (silicone) layer

Each layer has a thickness and the sum of these thicknesses makes up the total tape thickness.

The Polyimide (Kapton) Film Layer

This is the layer that is specified in the product description. For example, 1-mil tape (referred to as LINQTAPE PIT1 by CAPLINQ) has a polyimide film layer of 1 mil (25µm). Similarly, 2-mil tape has a polyimide film layer of 2 mil (50µm), 3-mil tape has a polyimide film layer of 3 mil (75µm) and so on. This is in fact the layer that determines the thickness used in the description.

The Adhesive (Silicone) Layer

This is the layer of silicone adhesive applied to the backside of the polyimide (kapton) film. Though this layer thickness can vary, the standard average thickness is 1.6 mil (40um). Of course, there is some variation in this adhesive thickness and the thickness can actually range between 35µm – 45µm (1.4 – 1.8 mil) though historical data suggests that the actual range is betweeen 40µm – 45µm (1.6 – 1.8 mil). For all intents and purposes, 1.6 mil (40µm) can be used as the silicone adhesive layer thickness.

Of course, this assumes single sided polyimide (Kapton) tape. Since CAPLINQ also supplies double-sided Polyimide (Kapton) Tape (referred to as LINQTAPE PITD2 by CAPLINQ) this tape would have adhesive layers on both sides of the polyimide film layer in fact doubling the adhesive thickness of the double-side polyimide tape from 1.6 mil (40µm) to 3.2 mil (80µm).

The total thickness is then the sum of these two layers. For example, as can be inferred by the name, LINQTAPE PITD1 is 1-mil double-sided polyimide (kapton) tape that has a polyimide film layer of 1 mil (25µm) and two adhesive layers of 1.6 mil (40µm) each for a total thickness of 4.1 mil (25µm + 40µm + 40µm = 105µm) . Likewise, 1-mil (LINQTAPE PIT1) tape has a total thickness of 2.6 mil (65µm), 2-mil (LINQTAPE PIT2) tape has a total thickness of 3.5 mil (90µm), and so on.

Contact us or visit us at www.caplinq.com today for more information on these or other products.

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.