Who is Gerber Labs?
With over 20 years in the Printed Circuit Board (PCB) industry, Gerber Labs has become a leading partner-in-design. We were built on a by you, for you foundation model, created by engineers, for engineers. Using best-in-class technology and innovative manufacturing processes, we work hard to provide you with exceptional PCB prototypes and components that are hassle-free and cost-effective. Our service-friendly site makes it easy for you to upload your Gerber PCB prototype design. As a trusted collaborator in PCB design spanning over two decades, we are here to guide you in securing the tools and resources you need for your STEM project to be successful.
Why You Need Gerber Labs as a Printed Circuit Board Manufacturer
Our extensive experience in the PCB industry gives us the knowledge needed to provide top-quality printed circuit board prototypes and customizable essential PCB components. We comprehend the prerequisites expected to give dependable PCBs rapidly and moderately.
Gerber Labs endeavors to become the main PCB supplier for both amateur and experienced electrical architects, furnishing our community of engineers with quality-built circuit boards at incredible costs. With our extensive knowledge of circuit boards, there is no room for faulty or ineffective PCBs. Your satisfaction and the functionality of your design are our main motivators. An engineer should never have to take risks on imperfections or workflow disruptions caused by poorly assembled PCBs.
Success the Gerber Labs Way
The success of our PCB design and assembly process hinges on us upholding our core principles. At Gerber Labs, we are a quality-first, integrity-driven leader in responsible service-led PCB manufacturing. Our community of innovative engineers thrives on all levels—from those of you just starting your engineer journeys at a school STEM program to advance innovators working on groundbreaking projects. In each case, we make it a point to provide exceptional service so our clients can focus on their vision. We embark on every design journey with the engineer in mind.
The extensive knowledge our electrical engineers possess, coupled with our commitment to perpetual learning, gives us an edge over our PCB manufacturer competitors. With Gerber Labs, the status quo does not exist. We customize each of our printed circuit boards according to the clients’ unique specifications and project goals.
Our design-to-assembly process is streamlined to ensure our clients can realize their project goals. From PCBs for simple IoT devices to complex electronic designs that require multilayer PCB boards, we are committed to helping you execute your design with precision.
Before the physical circuit board is created, it must be designed using PCB design CAD tools. This is divided into the schematic capture and the PCB layout.
First, the library CAD parts for the design are developed, which may include simulation models, footprints, schematic symbols, and step models. These are used to create a logical representation of the schematic circuitry. The tools are used to arrange all the symbols on a sheet and connect them to form the circuitry, ensuring that the physical layout will be functional.
A circuit simulation is used to verify that the components and routing are arranged properly to define electrical connectivity on the physical board. Once complete, the schematic tools can send connectivity to the layout tools.
In the layout part of the process, the schematic connectivity is established and processed as nets that tie the components together. The layout designer puts the component footprints in the designated locations on an outline of the board shape for optimal organization. The nets are connected by drawing the planes, all following the design rules built into the CAD tool. The designer can create manufacturing drawings from this layout to guide the manufacturer in building the PCB.
Done correctly, the PCB design will reflect exceptional functionality.
PCB Assembly Process
Parts of a PCB
A PCB has four main parts:
- Substrate: The most important part of the PCB is the substrate. Most substrates are constructed of fiberglass, which provides core strength to prevent breakage. The substrate forms the foundation for the design.
- Copper layer: Depending on the type of PCB, the copper layer may be a copper coating or copper foil. No matter the approach, the copper is used to transmit electrical signals to and from the board.
- Solder mask: The solder mask is a layer of polymer that protects the copper from short-circuiting.
- Silkscreen: The final part of the PCB is the silkscreen, which illustrates part numbers, symbol switch settings, logos, test points, and component references.
PCB assembly can have specific types, such as surface mount or through-hole, but the general steps are the same.
Solder Paste Stenciling
Solder paste stenciling is the foundational step of assembly. No matter the specific assembly type, this step will always be the same.
Much like screen-printing, a thin, stainless-steel stencil is placed over the circuit board to direct assemblers on where to place solder paste to secure the components on the finished PCB. The paste itself is a gray substance composed of solder, or small balls of tin, silver, and copper. Solder is mixed with a flux, which melts the metal and bonds it to a surface.
Soldering components to the board is a precise process – both the locations and the amounts must be exact. In professional manufacturing, a mechanical fixture is used to hold the PCB and solder stencil in place, then an applicator puts solder paste on the correct areas. A machine then distributes the solder paste across the stencil.
After removing the stencil, the solder paste is placed only in the areas intended for components.
Pick and Place
After solder pasting, the PCB assembly process moves to the pick and place machine. This robotic device places the surface mount components on the PCB and solders them onto the surface.
After removing the stencil, the solder paste is placed only in the areas intended for components. Machines are not only more accurate than humans, but they can work faster and without the need for breaks.
The mechanized system begins the pick and place process by gripping a PCB board with a vacuum and moving it to the station. The robotic device arranges the PCB and places the surface mount components on the surface, on top of the precise areas with solder paste.
The components of a PCB must be secure, meaning the solder needs to be set in a process called “reflow.” After pick and place, the PCB is moved to a conveyor belt that travels through a reflow oven. This oven has a collection of heaters that reach temperatures of 480 degrees Fahrenheit (250 degrees Celsius) and melts the solder paste.
After high heating, the board is moved through a collection of cooler heats, which cool the melted solder and solidify it in a smooth, consistent manner for a permanent solder joint.
In two-side PCB assembly, the stencil and reflow process must take place on both sides. Typically, the side with the smaller parts is stenciled and reflowed first, followed by the more complex side.
After the reflow process, the assembled PCB is tested for functionality. If any component moves, it can impact the connection quality of the finished board. Poorly placed components can also connect the wrong parts of the circuit.
Several inspection methods are used, including:
- Manual inspection: Though much of the assembly process is automated, the human eye is still a crucial part of inspection for many manufacturers. For small batches, developers or designers often perform a visual inspection to ensure the board is assembled properly and functions well. In large batches, however, this can be challenging for the human workforce and leads to fatigue and eye strain.
- Automatic optical inspection: For large batches, automatic optical inspection is the better choice. An automatic optical machine uses high-powered cameras to view the solder connections. This sophisticated technology can detect low-quality solder based on the way different connections reflect the light. The main benefit of automatic optical inspection is speed, especially compared to manual inspection.
- X-ray inspection: Though rare, x-ray inspection can be helpful for inspecting layered or complicated PCBs. The x-ray penetrates the layers and visualizes each component to identify problems or poorly constructed areas.
After a visual inspection, the PCB must be tested to ensure functionality. Each component is tested for connection and quality.
Through-Hole Technology Assembly Process
The through-hole mountain process is a combination of manual and automated systems.
Typically manual, the components placement step is done by engineers. They precisely place components in the appropriate positions, based on the PCB design and the operational standards of the through-hole mounting process. This can be challenging, since engineers have to ensure the correct polarity, orientation, and component placement for high-quality products. Engineers often wear anti-static wristbands to maintain the integrity of static-sensitive components.
Once all of the components are set and placed, the board is put in a matching transport frame for inspection. Each component is plugged in to determine if they’re placed correctly. If there are any issues, the engineers can correct them before they’re soldered.
The inspection ensures the components are placed accurately and ready for the soldering process. Using a wave soldering system, the PCB moves over a wave of liquid solder at about 500 degrees Fahrenheit to secure the components to the board.
Surface Mount Technology Assembly Process
Surface mount technology assembly is one of the most efficient processes for a specialized board. Each step is automated for improved speed and accuracy.
Solder Paste Printing
Solder paste is added to the board using a specialized printer and template. Like stenciling, this ensures the paste is only placed in the appropriate places for component mounting. Once the solder paste is applied, a visual inspection is conducted for accuracy.
Like conventional assembly, the next step of this process is the pick and place. The PCB goes through the pick and place machine to have the components mounted in the correct positions. Each component is mounted using component reels, which are similar to film reels. The rotating reels allow multiple components to be placed at the same time for better efficiency.
Once the components are placed, the PCB passes through a reflow oven that reaches temperatures of 500 degrees Fahrenheit. The solder is liquified, then cooled to solidify, securing the components to the board.
Mixed technology PCBs combine components from different types of boards, such as through-hole components. These can be more challenging to assemble, since they have so many elements.
Mixed boards can be approached with the following methods:
- Single-side mixed assembly: This type of assembly follows solder paste printing, parts placement, reflow soldering, component placing, and wave soldering.
- One-side through-hole or surface-mount assembly: This type of assembly begins with the surface mount process, solidification, then flipping for through-hole component placement and wave soldering. This assembly procedure is less than ideal, however, since the multilayer process can cause soldering issues.
- Double-side mixed assembly: This assembly method may involve the application of adhesives and requires three heating steps, making it less efficient. The assembly process starts with solder paste printing and surface-mount placement, followed by reflow. The board is then flipped and the process is repeated for surface-mount placement on the other side, then flipped again for through-hole component placement and wave soldering.
Post-PCB Assembly Quality Control
The PCB assembly process is dirty. Boards may have oils or dirt from human touch, flux from soldering paste, or other unsightly residue. This goes beyond appearance, since leftover flux and human skin oils can damage solder joints or leave an odor. Because of this, cleaning the board is an important part of the process.
PCBs are cleaned using a steel, high-pressure washing machine with deionized water. This effectively removes the residue without harming any of the components or circuits. Once washed, the board is dried with compressed air before packaging and shipment.
Quality PCB Assembly
PCB assembly can be a complex and technical process with many considerations. Small mistakes can lead to significant quality defects or cost changes. When you choose a PCBA company, it’s important to choose a manufacturer with the skills and quality benchmarks to bring your project to life.
At Gerber Labs, we play an instrumental role in ensuring our customers succeed. From designing concepts and laying out prototypes to manufacturing and testing the safety of your PCB, Gerber Labs is here to partner with you on every endeavor.