Electronics Electroplating

Electronics Plating

Electronics metal finishing can be a challenging process that requires a finely honed expertise. With 90 years of metal finishing experience at our disposal, you can trust Sharretts Plating Company to provide the best metal finishing process for your electronics industry applications. Few electronics plating companies can match our mastery of plating on semiconductors, connectors, and other vital electronic parts and components. Learn more about our extensive capabilities when plating electronics with various metals.

It's hard to imagine living in a world without electronic products, gadgets or devices. Products such as computers, cellphones and televisions play a primary role in just about everyone’s lives. We use them at home, at work and even in our cars. Electronic systems now control the operation of automobiles, airplanes and other modes of transportation. Innovation in the electronics industry continues at a breakneck pace, and hardly a day goes by without the unveiling of a new product. It's safe to say that without electronics, the world would be a much different place.

Although electronic products have been with us throughout our lives, their development has been a relatively recent phenomenon. The electronics industry did not emerge until the early 20th century following the invention of electricity in the late 19th century. Some of the earliest electronic product innovations were the gramophone — a forerunner of the record player — the telephone and the radio. It wasn't until the 1950s that televisions became a staple in most American households. Personal computers did not gain widespread acceptance until the 1980s.

How important is the electronics industry to the United States economy? According to the Consumer Technology Association, revenues from U.S. shipments of consumer electronics products are expected to reach $222.7 billion in 2015 and $228.8 billion in 2016. This represents the continuation of an upward trend: 2011 revenues were $197.1 billion followed by $206.1 billion in 2012, $210.7 billion in 2013 and $217.6 billion in 2014.

Metal Plating Electronics

One of the most important processes in the manufacturing of electronic parts and components is electroplating, which involves the application of a metal coating via electrodeposition. This is done for a number of reasons such as improving corrosion resistance, enhancing electrical conductivity, increasing the solderability of the substrate and protecting against wear. Plating electronics can be a difficult process due to the delicate nature of many electronic components. Sharretts Plating Co. has developed expertise in the following area of metal finishing for electronics.

Gold Plating for Electronics

Gold is a precious metal that offers significant value in plating for electronics. When you think of gold, the first thing that probably comes to mind is its glittery appearance. However, gold is also commonly used in the plating of many different electronic components. Although relatively expensive, gold offers low and stable contact resistance and superior protection against corrosion. Gold plating is commonly used in the manufacturing of connectors, contacts, circuits and semiconductors.

Nickel is often used to provide an underlying coating when using gold to plate electronics. Nickel acts as an extra corrosion inhibitor by preventing rust from penetrating pores in the surface. Nickel also prevents the diffusion of other metals into the gold surface such as zinc or copper. What's more, nickel can increase the durability of the gold-plated surface.

The thickness of the coating is an important consideration when plating on electronics. As a general rule, the coating should be as thin as is absolutely necessary for the application. For instance, a 0.8 micron of hard gold over a 1.3 micron nickel coating will provide sufficient durability for the majority of connector manufacturing applications.

Silver Plating

Like gold, silver is a precious metal that offers numerous electronics manufacturing benefits. For one, silver is typically a less expensive alternative for metal finishing electronics. Silver also provides excellent electrical and thermal conductivity. Because of its low contact resistance, silver plating for electronics is often used to provide a coating on highly active copper parts.

Silver plating is also used in connector applications for contact finishes involving higher current power transmission and lower current separable power, and as a connector finish for higher normal force/lower durability signal applications. Silver also possesses strong solderability characteristics. One potential drawback when plating with silver is its tendency to tarnish. Immersion silver is sometimes used for applications requiring solderability, although the shelf life of immersion silver is somewhat limited.

The appropriate thickness of the silver coating is determined by factors such as the harshness of the environment, degree of durability and whether any surface treatments are applied. A thinner silver coating is required if a nickel undercoating is applied. A nickel undercoat can help to limit tarnish and prevent the formation of potentially harmful silver-copper intermetallics.

Platinum Electroplating for Electronics

Another precious metal used for electroplating is platinum. A member of the platinum group of elements — which also includes rhodium, palladium, osmium, iridium and ruthenium — platinum metal is relatively rare, adding to its high monetary value. Platinum metal is silvery-white in color and is known for its attractive, lustrous appearance. Platinum is more ductile than its gold and silver precious metal counterparts, and it's also extremely malleable. Platinum also offers excellent resistance against corrosion.

In terms of electronics metal finishing, the platinum electroplating process is primarily used to apply a protective coating on low-voltage and low-energy contacts. In addition to preventing the formation of corrosion, a platinum electroplating solution can facilitate electrical conductivity. A platinum coating can range from 0.5 to 5 microns, although an electronics platinum electroplating process is typically designed to produce a coating toward the thicker end of the scale.

Rhodium Electroplating for Electronics

Like platinum, rhodium is silvery-white precious metal, although it is much whiter than platinum. Along with the other platinum group metals, rhodium can be found in platinum or nickel ores. Rhodium is also very hard and extremely durable — it will not form an oxide even under extreme temperatures. In fact, rhodium's melting point is higher than that of platinum. Another valuable rhodium property is its ability to ward off attacks from acid solutions.

A rhodium electroplating process is often used in electronics manufacturing due to rhodium's low electrical resistance. A rhodium electroplating solution will provide a protective coating on sliding electrical contacts as a means of reducing wear and tear. When applied to high-voltage or high-amperage electrical contacts, a rhodium plating solution will inhibit the formation of oxidation on the contact surface.

PLATING FOR ELECTRONICS USING Palladium and Palladium Alloys

Our electronics metal finishing services also include plating with palladium and alloys such as palladium-nickel and palladium-cobalt. Palladium is a somewhat rare, silvery-white metal that is a member of the platinum group. Palladium is frequently used in the manufacturing of connector plates in many types of consumer electronics products. A palladium-nickel alloy can offer the important advantage of low surface contact resistance. The emergence of a functional palladium-cobalt alloy in recent years has proved invaluable in the mass production of electronic components.

Palladium and palladium alloys are gaining acceptance as a more cost-effective alternative to gold in the plating of connectors used to link internal computer components. Because palladium is less dense than gold, palladium plating results in a lower weight of the finished product, while still providing a comparable coating thickness. Some manufacturers are also turning to palladium to coat the lead frames that connect integrated circuits to other electronic devices. Palladium offers a more environmentally friendly alternative to a tin-lead alloy when performing this function.

Copper Electroplating FOR ELECTRONICS

Most of us know that copper conducts electricity extremely well. It is a relatively soft metal that offers high thermal conductivity. Using copper for plating is also much less expensive than when plating with precious metals such as gold and silver. It's these properties that make copper highly valuable in plating for electronics parts and components. You'll find copper plating used widely in the production of semiconductors and circuits.

Copper can also be used as an underplate for other metals in the electroplating process. A coating of copper will enhance the electrical properties of the other metals and increase the corrosion resistance of the deposit. Copper will also increase the throwing power and provide greater deposit consistency.

PLATING ELECTRONICS WITH Tin and Tin Alloys

Tin plating is a relatively low-cost process that is favored by budget-conscious companies for many types of electronics industry manufacturing applications. One disadvantage of “tinning,” as it is widely known, is the formation of tiny metal protrusions called whiskers that can cause electrical shorts. SPC has developed a highly effective tin-lead alloy that can limit the occurrence of whiskers.

Using a tin-lead alloy in plating for electronics also offers a number of additional benefits besides preventing tin whiskers. Tin-lead provides excellent solderability, which is essential in so many electrical and electronics manufacturing applications. Tin-lead typically does not require an undercoating, which simplifies the plating process and minimizes costs. General thickness recommendations when plating on electronics with a tin-lead alloy ranges from 0.0003 to 0.0005 inches.

Plating on Plastic for Electrical Conductivity

While plating on plastics is primarily used in the automotive industry to metallize nonmetallic vehicle parts, many parts and components used in the electronics manufacturing industry are now comprised of plastic or other nonconductive material. Using plating to apply a coating of metal such as copper is a way to metallize these parts, which enables them to conduct electricity. Copper is an obvious choice for plating onto plastic electronic parts due to its excellent electrical conductivity and superior thermal properties. SPC is one of the few electronics plating companies in the world that has been able to master this extremely complex and challenging process.

Nickel and nickel alloys are often used to plate on plastic items such as knobs and control buttons on personal computers and electric shavers. A shiny nickel coating can improve the appearance of the product and limit the impact of wear caused by frequent handling. It can also provide a decorative touch to the plastic trim on household appliances such as refrigerators and freezers. The development of more heat-resistant plastics has also led to the use of nickel plating for connector blocks, which facilitates direct soldering onto the surface. Nickel plating and plastics technology can also be combined to develop circuit systems with interconnecting paths.

ELECTROLESS PLATING Onto CERAMIC SUBSTRATES

Ceramics possess several unique electrical properties that are beneficial in the manufacturing of various electronic parts and components. Examples of the electrical properties exhibited by ceramic materials include:

• Semiconductor: Certain types of ceramic materials act as semiconductors that conduct electricity under some conditions. This makes them valuable for surge protection applications, particularly in electrical substations to protect against lightning strikes.
• Superconductivity: Some ceramics also exhibit superconductivity, which means they offer no electrical resistance when cooled below a specified critical temperature.
• Piezoelectricity: Numerous ceramic materials feature a property called piezoelectricity, which serves as a link between a mechanical and an electrical response. One example is the quartz that watch manufacturers use to measure time in watches and other electronic devices.

Additionally, many ceramics possess excellent thermal properties that enable the part or component to resist the extreme temperatures that are common in electronics applications.

Electroless Nickel Plating for Electronics

The metal coating of electronics can also be achieved without the use of electricity. A process known as electroless plating enables the coating of an electronic part or component via chemical reaction. This results in a more even, uniform coating that is able to coat areas on the substrate that are unreachable with typical electroplating methods.

A primary use of electroless nickel plating in electronics is in the manufacturing of semiconductors. The nickel coating makes the surface more receptive to soldering, brazing and welding than would be possible when plating with an electrical current. Nickel also provides excellent corrosion protection. Electroless nickel plating is also used in the production of zinc or copper heat sinks that keep the semiconductors cool during operation.

The Importance of Surface Preparation When Plating for Electronics

No electronics plating process will be successful without proper substrate preparation. A primary issue with plating on electronics is the deposition of ionic and nonionic residue that has a negative impact on electrical conductivity and can possibly prevent proper adhesion of the metal coating. This residue can also limit the effectiveness and performance of the finished product after it is sold and put into operation by the end user.

Surface preparation when plating for electronics has made significant strides in recent years. Instead of using organic solvent to remove ionic and nonionic residues – which did not offer an effective long-term cleaning solution and posed environmental hazards – newer, more efficient and environmentally friendly procedures have been developed. High-pressure water systems are now available that can remove both ionic and nonionic residues, while also offering a more eco-friendly surface preparation solution.

How to Choose the Right Metal for Plating Electronics

There are many different metals and metal plating processes to choose from, so how can you determine which is best for your electronics plating applications? The following information can help you make the best choice for your company:

• Substrate type/composition: Certain metals are more compatible with some substrate types than others. For instance, some metals will adhere more easily to plastic surfaces.
• Appearance: How important is the overall appearance of the finished product? A gold coating is likely to be more attractive than a copper or tin finish.
• Damage prevention: As mentioned, some methods of metal finishing for electronics could potentially damage the product, as in the case of tin whiskers. This can easily be avoided simply by using a different metal that can provide similar results without the risk of damage.
• Specifications: Does the finished product need to meet stringent ASTM, military or in-house specifications? A common example is ensuring the coating provides sufficient corrosion protection by complying with salt-spray testing guidelines.
• Lifespan: You'll want to be sure the coating of choice will last as long as the product itself and/or contribute to lengthening the product lifespan if required.
• Environmental considerations: The metal finishing industry is one of the most heavily regulated in terms of environmental compliance. It's important to select an eco-friendly electronics plating process/provider that is friendly to the environment.

SPC Can Handle All of Your Electronics Plating Needs

With more than 90 years of metal finishing experience, you can trust the experts at Sharretts Plating Company to help you select the best electronics plating process for your requirements and budget. We have a successful track record when it comes to plating for electronics – we serve companies of all types across a wide range of industries. We also go to great lengths to be good stewards of the environment. We've been able to achieve that sometimes delicate balance between efficient production and going green.