The choice of surface finish is crucial in determining electronics components and devices’ durability, functionality, and aesthetics. Some surface finishes enhance a material’s surface properties and aesthetics and help improve its physical, mechanical, and chemical properties.
This article explores ten of the most common surface finishings used in the electronic industry to improve components and parts. Read ahead!
Common Surface Finishes Used in the Electronics Industry
Below, we briefly overview the ten most common surfaces used in the electronic industry.
Painting
Painting
Painting is a readily available surface finish for various electronic parts and components. The process involves coating the product’s surface with liquid paints or lacquers to improve its aesthetics and resistance to environmental factors, making it more durable. The finish uses distinct or combined colors and textures, making it ideal for brand differentiation and improving user interface design. Though not as durable as some other finishes, painting is an economical surface finish and can be easily touched up when necessary to enhance the product further.
Anodizing
Unlike painting, anodizing is an electrochemical process. It involves coating the surface of the electrical part with a durable, corrosion-resistant, anodic oxide finish. This surface treatment is particularly useful for aluminum anodized parts in electronics, enhancing their wear and corrosion resistance. The finish allows coating the material with a protective oxide while allowing distinct color customization through dyeing, enhancing aesthetics. Anodizing also improves surface emissivity, contributing to thermal management in electronic components.
Anodized metal parts
Electroplating
Electroplating is another electrochemical process. But while anodizing coats the metal surface with its oxide, electroplating adds a thin layer of another metal to the surface, usually a more resistant or aesthetically appealing metal. This finish helps to enhance the mechanical and chemical features of the metal, making it more conductive and resistant to corrosion and abrasion. The go-to metals for electroplating include gold, silver, nickel, and copper, which are crucial in electrical connectivity and performance in the electronics industry.
Brushing
Brushing is a mechanical surface finish that involves using an abrasive brush to enhance the surface property, particularly the appearance and texture of metal surfaces. The finish often creates a unidirectional satin finish by polishing the metal surface with abrasives. It helps enhance the aesthetic appeal of the electronic product while also masking the appearance of fingerprints, scratches, and other potential defects. Therefore, brushing helps make the product more suitable for consumer electronic components.
Brushing
Laser Engraving
Laser engraving involves using a laser beam to remove material from the surface of a material while creating an inscription, mark, or design. The finish offers precise and permanent marking options for electronic parts, creating high-resolution graphics, barcodes, and serial numbers on surfaces without inks or cutting tools. Laser engraving is one of the go-to techniques for traceability and branding, as it does not compromise the part’s integrity.
Polishing
Polishing is a surface finishing technique that smoothens and shines a surface to improve its appearance and texture. It uses abrasive materials, such as polishing compounds or abrasive pads, along with a polishing tool or device. The resulting finish is a smooth, mirror-like surface on metals, enhancing the visual appeal and corrosion resistance by removing oxidation layers. Its use in electronics is primarily for aesthetics or in components where electrical and thermal conductivity is essential.
Powder Coating
Powder coating is similar to painting. However, while the latter uses liquid paints or lacquers, the former coats the metal surface with dry, free-flowing powder before curing under heat to form a skin-like polymer layer. Powder coating offers excellent durability and resistance to chipping, scratching, fading, and corrosion, making it suitable for protective casings in electronics.
Silk Screen
Silk screening, also known as screen printing, is a printing technique that applies ink to a surface through a fine mesh screen, except in areas made impermeable to the ink by a blocking stencil. This process allows the creation of precise, vibrant, multi-colored designs, patterns, or logos on electronic enclosures and panels, regardless of whether they are made of plastics or metals.
Bead Blasting
Bead blasting involves propelling fine glass beads at a high speed and pressure onto a surface to create a clean or smooth surface while ridding it of blemishes or imperfections. This process produces a uniform matte finish through mechanical abrading of the surface with the impact of the beads. The process may suit surface preparation for coating or painting, as well as achieving a consistent texture on metal and plastic parts.
Black oxide
Black oxide surface finish is a conversion coating for ferrous metals featuring black iron oxide produced through a chemical reaction. It is also known as blackening or bluing, as it coats the surface of the material with black iron oxides. The process offers minimal corrosion resistance but is used to reduce light glare, improve lubrication properties, or for aesthetic purposes in electronic components.
How to Distinguish the Surface Finishes Treatment in the Electronics Industry
We have already examined ten of the most common surface finishes used in the electronics industry. The table below gives a distinction for each finish, indicating the variations based on color and texture.
| Surface Finish | Color | Texture |
| Painting | Almost any form of color available | Smooth may vary based on the painting methods and intended applications |
| Anodizing | Various color options | Matte finish with a slight, smooth texture |
| Electroplating | Different colors, depending on the substrate metal | Smooth, though, may vary based on the metal substrate |
| Brushing | Various patterns and designs | Uniform, satin-like consistent finish |
| Laser Engraving | Offers diverse designs and patterns, depending on the application | Smooth, with precise engraved patterns |
| Polishing | Various color options, depending on the choice of polish | Smooth, mirror-like |
| Powder Coating | Different color options | Uniform, slightly textured surface |
| Silk Screen | Different color options | Smooth, with precise printed designs |
| Bead Blasting | Various color options depending on the beads | Matte finish with a uniform texture |
| Black Oxide | Black | Matte, with a uniform black color |
Considerations for Choosing the Suitable Surface Finishes
Besides understanding the different surface finishes, it is important to know the other factors to consider before selecting an appropriate finish for your fabrication. Below, we discuss those criteria you need to consider before choosing the appropriate one for your project.
Materials
The type of material used in the electronic component is an important criterion before selecting a suitable finish. Metals, plastics, and polymers each have specific mechanical properties that influence their compatibility with different finishing processes. For example, finishes like anodizing and electroplating are specific to metal surfaces.
Cost
Costing may vary significantly between surface finishing techniques, often influenced by factors like process complexity, materials used, production volume, and the finish itself. When budget constraints exist, it is important to carefully weigh the finish that’ll best suit your application, balancing cost and required finish quality.
Appearance
The choice of finish is important for the final aesthetics of your end product. Factors to consider include desired color, texture, and reflectivity, which must align with the product’s design specifications and brand identity. Most surface treatments and finishes enhance the appearance of the material; you just have to select the one that best suits your application.
Performance
Besides appearance, most surface finishing tends to improve the general properties of the material, increasing durability. However, how they affect these properties and the performance of the product may differ. While some may enhance electrical conductivity, others may improve corrosion resistance and wear resistance. Therefore, the OEM needs to select a finish that meets the operational demands.
Maintenance
Some finishes require more maintenance than others to retain their properties and appearance. Choose finishes that align with the expected maintenance capabilities and intervals of the product’s end-use environment.
Environment
The operating environment of the finished product also influences the choice of surface finish. Different finishes offer specific resistance to various environmental factors. Therefore, conditions like temperature, humidity, and exposure to chemicals, corrosives, or UV light should guide the selection to ensure longevity and functionality.
Process Complexity
The complexity of applying a surface finish impacts its feasibility and cost. Many people prefer simpler finishes, especially for high-volume or cost-sensitive projects. However, if the fabrication calls for a more complex finish, you should engage it.
Safety
Machinists and OEMs must consider the safety implications of each finishing process, including the potential for toxic emissions or residues. Worker safety and end-user considerations should guide the selection process of appropriate surface finishes.
Sustainability
With increasing awareness of conservation and sustainability, eco-friendly surface finishing options are becoming more important. To support sustainability goals, consider finishes that use less toxic materials, reduce waste, or are more energy-efficient.
Regulations and Standards
Besides all the considerations discussed thus far, compliance with industry regulations and standards is vital. Ensure that a suitable surface finish meets all relevant specifications to avoid costly rework or legal issues.
Conclusion
The selection of surface finishes in the electronics industry is a critical decision, as the selected finish may impact the performance, appearance, and longevity of electronic components. Therefore, it is important to understand what property you need to enhance in your manufacturing material before selecting them. Whether prioritizing corrosion resistance, aesthetic appeal, or environmental sustainability, manufacturers must carefully consider the unique properties and requirements of each surface finish.