In today’s high-tech world, electronics play a vital role in daily industrial and consumer operations. If a circuit board fails, machine downtime can be costly not to mention inconvenient. Although industrial tapes generally act as a processing aid in electronics applications, their performance can be crucial to keeping equipment running on schedule.

Masking printed circuit boards during the solder strip bath and precious metal plating process utilizes both self-wound tapes and tapes supplied on a liner for selective masking. In either case, the tapes used must exhibit abrasion, solvent and temperature resistance for sufficient protection of the board in-process.

When selecting a plating tape, the adhesive, backing and product configuration are important factors to consider. Dielectric Polymers manufactures plating tapes with polyester and polyimide backings, offered with and without a liner. Our polyester tapes are constructed with low shrink film that offers high tensile strength to resist tearing. Our polyimide tapes provide resistance to corrosion and punctures in addition to continuous temperature resistance of 500°F.

Our line of electronics tapes stand out due to the benefits of silicone pressure-sensitive adhesives. Not only do silicone adhesives provide long-term, high performance properties, the unique adhesive formulation anchors well to the film backing to resist undercutting. This reduces labor on rejects and rework, resulting in increased operating efficiency and cost savings. Silicone adhesive also offers excellent conformability to irregular surfaces, making it ideal for masking printed circuit boards as well as clean removal after the plating process is completed.

In the manufacture of printed circuit boards, a chemically resistant pre-mask has many uses. Our NT-590 Series self-wound polyimide tapes provide secure protection when masking gold fingers on printed circuit boards during wave soldering. In plating applications where gold connectors are located in the central area of the board, NT-590DL can be die cut to protect the gold contacts through tin plating and wave soldering. This linered tape is also useful for selective masking of connectors and other key areas of the board when applying conformal coatings.

Silicone transfer adhesives, such as Dielectric Polymers’ TRANS-SILâ, are sometimes required in the production of printed circuit boards. TRANS-SILâ is used to mount components and devices on circuit boards that collect and dissipate heat from the board. This adhesive, which exhibits temperature resistance to 500°F and low outgassing, also performs well in electrical applications as a temporary hold in connectors where elevated temperatures are present. Membrane switch applications often incorporate silicone rubber touch pads and require heat stable materials. TRANS-SILâ is used to adhere the graphic overlay to the touch pad and to bond the touch pad to the switch mechanism. Even electronic security mechanisms present in airports contain a disposable filter device that utilizes TRANS-SILâ as a laminating material.

Product identification in the electronics industry is another application that requires high performance adhesive materials. Since identification labels supply lot numbers and other symbols used for product tracking, they can be critical in isolating a manufacturing problem. Therefore, the label stock used must be able to perform in extremely harsh operating environments.
Our NT-490 thermal transfer imprintable polyimide label stock is designed for use as a bar code label substrate for printed circuit boards during wave soldering. NT-490 meets the American National Standards Institute (ANSI) standards for print contrast signals and minimum reflectance ratios for bar code print quality. In addition, abrasion and solvent resistance as well as continuous temperature resistance of 395°F assure that labels produced with NT-490 label stock will be clear and readable over time.

Since we rely heavily on electronics in everyday life, the components that actually comprise these devices or play a role in their manufacture are key. They must provide reliable performance, day in and day out, to keep our lives and our production schedules on track.

Like Dielectric Polymers, Nelco is a subsidiary of Park Electrochemical Corporation. Park/Nelco is a leading global designer and producer of electronic materials including laminates and prepegs used to fabricate complex multilayer printed circuit boards. For more information on Nelco, please visit www.parknelco.com.

Plating Tapes

• NT-580, 582, 583: silicone adhesive on a one mil polyester film backing with temperature resistance to 350°F (177°C).
• NT-590, 590-2: solder mask for printed circuit boards constructed of silicone adhesive on a one and two mil polyimide film backing with continuous temperature resistance to 500°F (260°C).

• NT-581, 7411-5: one and .5 mil silicone on a one mil polyester film backing for protection of printed circuit boards during the plating process. Temperature resistance to 350°F (177°C).
• NT-4500 Series, 5000 Series: low tack acrylic adhesive on 1.5 mil and two mil polyester film for protection of printed circuit boards against splash and fumes during the plating process.

• NT-590DL: solder mask constructed with 1.5 mil silicone on a one mil polyimide film backing laminated to a clear polyester release liner for die cutting. Continuous temperature resistance to 500°F (260°C).

• TRANS-SILâ NT-1001, 1005: two and five mil silicone transfer adhesives protected by two clear polyester release liners offer high performance in electronics applications. Maintain bond strength at temperatures of -300°F to 500°F (-185°C to 260°C).

• NT-490: one mil high temperature acrylic adhesive on two mil thermal transfer imprintable polyimide film for use as bar code labels on printed circuit boards during wave soldering. Meets American National Standards Institute (ANSI) standards for print contrast signals and minimum reflectance ratios for bar code print quality. Continuous temperature resistance to 395°F (202°C).