Printed Circuit Board Assembly
Printed circuit boards (PCBs) are found across many industrial and consumer electronics, used in products ranging from remote controls to military weaponry. The versatility of PCBs comes from their lightweight, compact, and flexible construction, which can be adapted to suit circuits of any complexity. Though PCBs are relatively commonplace, their complexity makes it critical to sourcing new circuit boards from reliable suppliers.
PGF Technology Group offers comprehensive PCB assembly services that help our customers fully realize their designs. We have extensive experience working with customers in a broad range of highly complex industries.
What is PCB Assembly?
PCBs themselves consist of a copper layer sandwiched between a non-conductive substrate. The Copper is etched away into intricate electrical pathways, allowing current to move between components on the board. During the PCB assembly process, electrical components get added to this board using either surface mounting or through-hole mounting.
- Surface mounting uses surface mount technology (SMT) to mount components into place on top of the board. This is the simplest way of installing electrical components, and it makes it easier to utilize both sides of the board.
- Through-hole mounting uses a pre-drilled hole in the board, through which a component can be inserted and soldered into place. Through-hole mounting is used for large components or any component otherwise incompatible with SMT.
Parts of the Printed Circuit Board
The PCB consists of four major components that can be combined in various ways depending on the circuit’s size and complexity.
- Copper layers. Every PCB contains one or more copper layers, which contain the etched pathways (traces) that form the circuit.
- Substrate. The substrate is a non-conductive material bound to the copper layers. It serves to insulate electrical traces from one another.
- Solder mask. The solder mask is responsible for a PCB’s characteristic green color. The mask is a thin polymer coating that protects the traces and prevents solder bridges.
- Silkscreen. The silkscreen is a screen-printed layer that provides assembly and reference information for the PCB. The silkscreen is usually white text on the green solder mask.
Types of Circuit Boards
PCBs come in numerous forms of varying complexity:
- Single-sided. The simplest and most affordable PCBs consist of one copper layer laminated to a non-conductive substrate layer. One side of the board contains all the necessary pathways and electrical components.
- Double-sided. A more versatile option, double-sided PCBs incorporate circuitry on both sides of the PCB. These boards have three total layers, consisting of two layers of copper on either side of a non-conductive substrate.
- Multi-layer. The most complex and expensive, multi-layer PCBs enable intricate circuitry that would be impossible to contain to one or two layers. Multi-layer boards use alternating layers of copper and substrate laminated together into one dense assembly. These boards allow for maximum component density by moving some traces to the interior of the board, freeing room for additional SMT components on the exterior.
Our PCB Assembly Capabilities
The majority of our PCB products are produced using surface mount technology (SMT), but we also make PCBs using through-hole assembly as well. Although the equipment, components, and mounting process vary greatly between these two assembly methods, we have extensive experience in both techniques. Additionally, we often combine SMT and through-hole technologies for mixed technology projects.
Production methods for PCBs vary depending on the electrical components required. Many PCBs use SMT primarily or exclusively, since surface mount assembly is fast and easy to automate. In general, PCBs undergo numerous production stages, such as:
- Screen Printing
- Solder Paste Inspection (SPI)
- Part placement (SMT or Through hole)
- Automated Optical Inspection (AOI)
PGF Technology Group can handle surface mount, through-hole, and mixed-technology applications using our state-of-the-art machinery. We also offer integrated electromechanical assembly services for customers seeking larger sub-assemblies or complete products. Electromechanical assembly combines the completed PCB with corresponding electronic components and harnesses to yield a functional product.
Using PGF Technology Group for one-stop, end-to-end assembly of PCBs will ultimately improve the overall quality of the circuit boards, shorten time-to-market, and reduce overall production costs. Our advanced capabilities adhere to the highest industry standards available.
We work with a wide array of PCB materials, including:
- FR-4 glass-reinforced epoxy laminate
- Mylar® film
- Phenolic laminates
- Polyimide (PI)
Printed Circuit Board Assembly Process
The PCB assembly process can look very different depending on the type of PCB and the volume of the order. Our PCB assembly process at PGF Technology may include any of the following steps, depending on the client’s needs:
- Automated assembly. Automated assembly is ideal for components that are difficult to solder by hand, as well as for high-volume production runs. Automated PCB assembly is the fastest and most efficient means of producing consistent circuit boards, so manual assembly is only used for extremely complex components or low-volume orders.
- Reflow. Reflow soldering is the most common method used for efficiently soldering SMT mounted components. The process uses a reflow oven to melt solder onto a pre-heated and pre-soaked PCB.
- Wave solder. Wave soldering is another efficient method that involves applying flux to an entire PCB surface, heating the board, and then applying molten solder to the entire heated board.
- Selective solder. Selective solder is a more precise variation of wave soldering used to apply flux locally rather than to the entire PCB. Instead of using a “wave” of molten solder, it instead uses nozzles to apply solder exactly where it is needed.
- Hand insertion and soldering. Hand insertion and soldering may be used when project constraints require manual through-mounting.
- Point-to-point wiring. Point-to-point wiring is a labor-intensive manual assembly method that involves hand-mounting and soldering all components on a circuit board. This process is used as an alternative to PCBs in certain applications, including repairs to vintage electronics.
- Automated Optical Inspection (AOI). This automated inspection process uses cameras to scan the PCB for defects and quality issues.
- Solder Paste Inspection (SPI). The SPI process closely inspects solder paste deposition prior to part placement.
These additional services represent one of our biggest advantages over our competitors. Many companies are unable to provide the x-ray capabilities or ionograph testing necessary for industries requiring extremely clean boards. For example, our medical clients leverage our ability to measure contamination down to ppm on a single square centimeter.
Ball Grid Arrays (BGA)
Ball grid arrays are used on highly complex PCBs as a means to mount microprocessors and other integrated circuit components. BGAs provide a higher number of interconnection pins to facilitate faster and more reliable component connections. While BGAs and micro-BGAs provide superior performance, they are also exceedingly difficult to solder. Incorporating BGAs and micro-BGAs into your PCB assembly requires partnering with an expert EMS provider such as PGF Technology Group.
Printed Circuit Board Assembly Applications & Industries
PCB assembly is used across virtually every industry. Consumer electronics such as computers and televisions use PCBs, as do drones used by the military, CNC machinery used in the manufacturing industry, and imaging equipment used in hospitals. A sampling of the industries that rely on PCB assembly include:
- Laser technology
- Material Handling
Where You Might Find PCBs Assembled by PGF Technology Group
We’ve worked with an expansive range of industries to assemble highly complex PCBs. Examples of our PCBs out in the world include:
- Aerospace: You can find PGF products and assemblies in sonar systems, satellite tracking devices, and collision avoidance products.
- Automotive: Many of our assemblies are strategically built into assembly plant robotic cells, nut running systems, heavy duty machinery and controls, seating, testing and countless applications around cars and mobility products.
- Medical: Our assemblies are used in operating rooms, simple medical devices, endoscopy application, pathology station, instrumentation, and myriad other medical products.
- Logistics and manufacturing: PGF assemblies help to operate machine tools, material handling equipment, laser technology, and vision systems used in logistics and manufacturing applications.
- Research and development: PGF is always on the cutting edge, working closely with university labs and R&D centers to create the next generation of technology. Whether creating the PCR cameras to identify the existence of COVID-19 or finding new ways to accurately position tools in 3D modeling, PGF is a leader and partner that can be relied on.
- Mobility: The rise of electric vehicles created a demand for longer battery life. PGF is at the forefront of the manufacturing and assembly of new generation of products that will speed the charging time as well as prolong the battery life cycle for many mobility applications.
- After market products: We help our customers develop innovate products for the aftermarket sector. You will see PGF assemblies in many product improvements currently used on the market across industries.
Premium PCB Services at PGF Technology Group
At PGF Technology Group, we consider ourselves to be a partner and specialist, not just a supplier. We work tirelessly to customize every aspect of the PCB manufacturing and assembly process. We support all assemblies with comprehensive testing services to ensure that every product we ship is of premium quality.
To learn more about our full-service assembly capabilities, contact PGF today.
Key Considerations for Medical PCB Assembly
Download our eBook, Key Considerations for Medical PCB Assembly, for an overview of the important considerations for designing and assembling these small yet dense layouts.Get Your eBook Now