The Role of Lasers in Circuit Technology
Of all the modern inventions that have impacted circuit board manufacturing, lasers have arguably been the most influential.
Lasers make the circuit board manufacturing process both more efficient and more precise. They can create the exact type of circuit a company needs, even circuits with tiny and intricate patterns. Lasers can even speed up the manufacturing process and reduce the total cost.
Let’s take a closer look at the many roles lasers play in the circuit manufacturing process.
Types of Lasers Used in Circuit Technology
First, let’s examine two common types of lasers that are crucial for circuit manufacturing.
A UV laser is a unique tool because it doesn’t burn the material it targets. Instead, it shines UV light, causing the molecular bonds on an object’s surface to break up. This means that the laser can impact needed areas on a circuit board without damaging other parts of the circuit board.
UV lasers are crucial for a part of the circuit manufacturing process called photolithography. Photolithography creates the minuscule patterns on printed circuit boards.
The use of UV lasers for photolithography was first demonstrated in 1982 at IBM. At that time, engineers used mercury-xenon lamps for lithography. Engineers quickly realized that UV lasers could create smaller features than mercury-xenon lamps. In fact, UV lasers reduced circuit features from 800 nanometers to 10 nanometers. Plus, UV lasers produced faster and denser circuits and produced them at a more rapid pace.
The CO2 laser was first used by Bell Labs in 1964.
A CO2 laser is filled with a mixture of carbon dioxide, nitrogen, hydrogen, xenon, and helium. The interaction between molecules produces a beam of infrared light. This infrared light has lower energy and a longer wavelength than other types of light. These features give the light a higher atmospheric transmission, meaning that more radiation enters the circuit board to make necessary changes.
When it comes to circuits, manufacturers use CO2 lasers to perform many functions, including cutting, welding, and engraving. Along with their use in circuit manufacturing, CO2lasers are also used in laser surgery, spectroscopy, and even military range finding.
Specific Uses for Lasers in Circuit Technology
Circuit manufacturing is a complex process, and lasers play an important part in many steps of the process.
The substrate is the middle layer and base of the circuit. Lasers play an important role in processing this substrate.
Through photolithography, the laser creates the desired pattern in the substrate. Lasers are a sought-after tool because they can create a pattern in the exact size and shape manufacturers need, even if the pattern is smaller than a nanometer. Lasers can also create a pattern that covers the substrate’s entire surface.
Flexible Electronic Assembly
Lasers help assemble a specific circuit type called flexible electronics, or flex circuits. Like their name implies, they are more flexible than traditional rigid circuits. Flex circuits are used for various technologies with dynamic requirements, including rockets and folding cell phones.
To assemble flexible electronics, manufacturers connect the various electrical components to a flexible plastic base.
Lasers also play an important role in drilling vias. Vias are miniature holes that connect the various layers of a circuit board. These vias are often too tiny for regular drilling, so manufacturers use UV lasers to create the vias.
Lasers perform two types of drilling: blind via drilling and through via drilling. Blind via drilling connects outer layers of the circuit board to inner layers. Through via drilling connects vias through the entire board. Both types of drilling are important for creating a complete circuit board.
Skiving is the process of removing specific materials from the circuit’s outer layer without damaging the circuit’s inner layers. Skiving can change the patterns on the circuit’s surface and can expose specific parts of the circuit.
Laser skiving is the most advanced and effective skiving method. Lasers create patterns of uniform appearance and depth while other types of skiving tools create more random patterns.
A coverlay goes over the circuit to protect it from environmental damage. Before attaching the coverlay, manufacturers use lasers to rout the coverlay. Routing the coverlay means to create specific features in the coverlay that match the features of the circuit. Coverlay routing ensures that the coverlay can align perfectly with the circuit.
Lasers are the best choice for coverlay routing because they can create much smaller openings than mechanical drilling can.
Clearly, lasers have changed the world of printed circuit manufacturing for the better. When it comes to manufacturing circuits, lasers are the most precise and effective technology available.
If you want the highest-level printed circuit manufacturing, turn to Streamline Circuits. We have advanced laser equipment, including UV laser and CO2 laser technology. Request a quote for advanced printed circuit boards today.