A glass cover had to be bonded precisely and permanently to a printed circuit board—tightly, partially opaque, and reliably. However, the liner adhered too strongly, the molded parts slipped, and the positioning pins stuck to the adhesive.

INNO TAPE developed a solution with a split removable liner, inner liner protrusions for clean placement, and additional positioning aids for precise assembly. 

The result 

Error-free, stable series processes and a clean appearance. Find out in our case study how small changes can bring big process advantages.

A supplier of climate control systems faced a complex challenge: the glass cover of a control device had to be bonded to a circuit board over its entire surface, permanently and with a flawless appearance—without visible inclusions, without misalignment, and without compromising the functionality of the overall system. The bond had to be not only mechanically stable, but also visually appealing and durable over the long term.

Challenges

• flat bonding with suitable adhesive tape thickness
• high holding force and tightness
• blockout function (light shielding in confined areas)
• semi-automatic further processing without slipping
• excessive liner adhesion – tape shifted when removed
• positioning pins on the device got caught on the adhesive edge
• very tight tolerances for component fit

Objective

The company was looking for a full-surface, durable, and visually clean bond between the glass cover and the circuit board that would not only ensure high holding forces but also reliably meet additional functional requirements. The bond had to be mechanically resilient, remain permanently stable, and show no weaknesses even under demanding environmental conditions.

In addition, the solution had to be cream-resistant, light-tight, and completely sealed in order to reliably protect sensitive components from external influences. Neither moisture, dust, nor chemical effects were allowed to impair its function. At the same time, a uniform, bubble-free appearance was required, as visual quality also played a central role.

The challenge was therefore to develop an adhesive solution that combined mechanical stability, protective function, and aesthetic requirements in a single, process-reliable, integrable system.

Together with the customer, we developed a solution that is impressive in terms of both materials and processes.

Material selection 

The tape was selected in an optimal thickness to ensure full-surface adhesion and complete sealing. The black design also gives the material a light-blocking function—especially in narrow bridge areas and between internal recesses.

Process optimization 

The ideal design for the molded part was developed in several test runs. The tape was given several grip tabs and integrated positioning aids to enable easy and secure installation.

The liner was designed to be split so that the tape can be exposed section by section, keeping the molded part stable during processing and preventing it from slipping. A new liner with lower adhesion also ensures controlled, even removal.

Inner liner protrusions were integrated to prevent the positioning pins of the mounting device from coming into contact with the adhesive edge.

At a glance

• clean, tension-free bonding
• no slipping when removing the liner
• highest fitting accuracy in the fixture
• better ergonomics for employees thanks to easy handling
• stable series processes with consistent quality