What is Adhesive

By Bester PCBA

Last Updated: 2023-07-26

What is Adhesive

In the PCB industry, Adhesive, also known as Bonding Sheet, Sheet Adhesive, or Pure Adhesive, refers to an adhesive coated on release paper that is used to bond various components in the PCB manufacturing process. Adhesives in bonding sheets are used to bind metal foil to base materials to create laminates, bind layers of laminate material together in multi-layer FPCs, and bond flexible inner layers or rigid cap layers in multilayer lamination. They are also used to bond flexible circuits to rigid-flex boards during the fabrication of rigid-flex PCBs, as well as to bond stiffeners and heat sinks.

The most common adhesives used in FPC manufacturing include polyesters (PET), polyimides (PI), acrylics, and modified epoxies, each with its own advantages and disadvantages depending on the application. The properties of adhesives include peel strength, after soldering, low-temperature flex, adhesive flow, CTE, moisture absorption, chemical resistance, dielectric constant, electrical strength, and volume resistance. Adhesive thickness is chosen based on trace thickness and remaining copper rate to ensure that the adhesive in the selected bonding sheet can cover and bond the copper features fully. Bonding sheet is supplied on rolls or cut sheets and should be stored in the original packaging at temperatures of 4 – 29 °C (40 – 85 °F) and below 70% humidity.

Frequently Asked Questions

What Is the Best Adhesive for Electronic Components

When it comes to choosing the best adhesive for electronic components, the selection depends on the specific application. Epoxy resins are considered to be the most versatile option, while UV-curing acrylics are ideal for SMD bonding. Additionally, cyanoacrylates are commonly used for wire tacking purposes.

Is Adhesive Bonding the Same as Soldering

Soldering involves melting a special metal called “solder” to bond different types of metals together. On the other hand, adhesive bonding involves using specific materials known as adhesives to create a smooth bond between two surfaces.

Can You Hot Glue PCB

To securely attach delicate wiring to a motherboard or other fragile circuit board, it is advisable to use a hot glue adhesive. This process, also known as potting or overmolding, ensures that the component is held firmly in place without compromising the overall quality or functionality of the electronics.

Can I Use Glue Gun Instead of Solder

Certainly, a glue gun can be used as an alternative to soldering, but it requires precision to ensure that it is applied in the same location as the original solder and that no short circuits occur. It’s worth noting that beginners in soldering often use excessive amounts of solder.

Is Solder Paste an Adhesive

Solder paste functions as a bonding agent, linking surface components to the board’s pads while also establishing electrical and thermal connections. By using solder paste, the requirement for solder wire is eliminated.

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