Paint Removal

Learn how lasers are used for paint removal and surface removal (the process that peels the film or plating from a target).

Basic principles of paint peeling using laser markers

Laser removal involves removing the surface coating of a plastic in order to expose the base material or coating underneath.

In the shift lever processing example below, the black coating on the plastic was removed to allow light to pass through to the colored material underneath. Laser-based paint removal is useful for exposing multiple layers of plastics (such as black, red and green coatings).

Shift lever paint peeling
Shift lever paint peeling
Shift lever paint peeling

Paint peeling example — On-board instrument panel switch coating removal

Application Explanation

Creating contrast on vehicles switches is usually done one of two ways: either the desired contents are printed on top, or the paint is removed with a chemical or removal agent. However, the former method requires custom printing plates for each mark, while the latter method involves expensive chemical consumables. Laser markers make this application simple because they can simply peel the paint off the part via laser irradiation.

Cars with illuminated switches are becoming much more common. As a result, laser markers are being rapidly adopted thanks to their ease-of-use.

On-board instrument panel switch paint peeling
On-board instrument panel switch paint peeling

YVO4 laser markers have a high peak power and short pulses, which enables momentary, high-energy irradiation of a target. This allows for detailed finishing edges without any heat being applied around the processing location. As a result, high-quality processing is possible even on design surfaces.

High-quality processing is possible for design surfaces with detailed edges.
High-quality processing is possible for design surfaces with detailed edges.

Basic principles of surface peeling using laser markers

Surface removal is a process in which the coating, plating, or other surface layer of a target is peeled in order to expose the underlying material.

In reference to paint removal—where the film coating is removed—any application where plating or other coatings are removed can also be referred to as surface removal. As shown in the figure below, a grounding point is created by removing the alumite surface layer (insulating layer).

Alumite layer peeling

Surface peeling example 1 — ITO film removal

Application Explanation

Attaching ITO film (transparent conductive film) to a glass substrate is an essential step in manufacturing flat panel displays. Chemicals are generally used for wet etching patterns. However, using such chemicals can require equipment investments and running costs. Laser markers can perform the same job with no overhead costs (in this case removing film around a circuit).

Touch panel patterning

High peak-power, short-pulse YVO4 laser markers can perform surface removal without damaging glass/film and with no increase in turbidity.

Since no chemicals were used for this process either, running costs can be kept low and any expansion/contraction of the film due to moisture can be prevented. Compared with wet etching, laser processing is an inexpensive alternative that does not require a lot of space. Capital investment can therefore be determined by production quantity.

ITO film removal

Surface peeling example 2 — Peeling off gold plating from connector terminals

Lasers can also be used to peel gold plating off of connector terminals.

The goal of this process is to prevent the solder from rising up. Connectors used to require masks in order to prevent unnecessary plating, but the connectors themselves continued to get smaller and fine-pitched. Eventually, post-processing via laser markers became a popular alternative.

Nickel barrier
Preventing solder absorption

Creating a nickel barrier is a technique that creates an area with low solder wettability between the PCB mounting and contact points. The creation of this area prevents solder rise up and reductions in joint strength.

Laser light / Ni barrier layer

Advantages of laser processing

Reduced running costs and improved processing takt

Eliminating the need for printing plates and chemical release agents (removers) associated with conventional methods results in drastic reductions in running costs. In addition, conventional methods required changing printing plates for every design change. Laser markers make it possible to change the design by simply importing the new data to the software, thereby shortening processing takt time.

Support for complex 3D shapes through 3-axis control

KEYENCE's Marking Builder software makes it possible to import the 3D CAD data (STL format) of a marking target and use it as the base of a program layout. This enables users to perform laser etching on targets with complicated profiles that cannot be expressed with basic shapes (such as cylinders and step height changes).

Support for complex 3D shapes through 3-axis control

Recommended models for surface peeling, organized by material