From consumer electronics, IoT, automotive, industrial control, healthcare, communication systems to aerospace; printed circuit boards (PCBs) plays a vital role as the backbone of electronic circuits providing the mechanical support and electrical connections between varied components. The advent of AI coupled with IoT and wireless technology has accelerated growth in PCB fabrication and assembly. In this article we look at Bittele Electronics, their PCB assembly process and why they are relied on by major companies in various sectors for turnkey PCB assembly services.
Before we can go further, it is important to define the difference between PCB fabrication and PCB assembly: PCB Fabrication can be defined as the process of laminating the dielectric and conductive layers and forming the copper circuit pattern, producing a bare circuit board. The bare boards also undergo a surface finish for oxidation protection and solderability enhancement, on the other hand, PCB assembly or printed circuit board assembly refers to the process of soldering electronic components onto a printed circuit board (PCB) to create a complete operational electronic device. PCB assembly is an essential process in electronics manufacturing, since it ensures that components are correctly placed, connected and soldered to the board.
Over the years Bittele electronics has established itself as a leader in turnkey PCB Assembly, working with businesses in various sectors such as consumer electronics, and healthcare, automotive as well as technological sector. Developers and engineers working on tech systems where innovations are ever taking place, require fast and reliable solutions to ensure they meet their products’ goals; this is one of the areas where Bittele turnkey PCB assembly services which includes PCB fabrication, parts procurement and PCB assembly, has built a reputation as a dependable service provider.
PCB Assembly Process
Generally PCB assembly process at Bittele Electronics can be summarized into the following stages:
Design for Manufacturing (DFM)/Design for Assembly (DFA) Check
When the client’s turnkey PCB assembly order is released to production team, the design is first validated through a thorough (DFM) and (DFA) check process. These checks include verification of consistency across different design documents (i.e. BoM, Centroid, Gerbers, etc.), part spacing, footprint accuracy, and clear orientation markings. The main aim here being to minimize the potential for design errors affecting the finished product avoiding the additional time and cost involved with board-level redo.
PCB Fabrication
After the initial DFM/DFA check is complete, the order then proceeds to the PCB fabrication stage. At this stage, the bare PCB is formed through several stages of material lamination, drilling and copper deposition/etching, depending upon the design requirements; the stencil for solder paste screening is also created during this stage. The solder mask and surface finish, which aid in PCB assembly, are then added to the board, and finally, the silkscreen is printed over all.
When the boards are fully formed, electrical testing is conducted against client’s Netlist file, to verify 100% conformance with design requirements. Finally, tab routing or V-Scoring defines the profile of each individual PCB within the fabricated panel, providing for ease of separation after PCB assembly is completed.
Incoming Material Inspection
The parts procurement team works simultaneously with the PCB fabrication team to ensure that all assembly materials are ready for use when the bare PCBs are ready for assembly.
The quality control team conducts a thorough inspection of parts being received, before warehousing any particular material or component. Inspections in this case include sample operational testing as well as date code verification and entry into a software material management system.
All these efforts by both the quality control and parts procurement teams ensures all parts employed in the PCB assembly are of highest quality to meet the clients’ expectations.
Surface Mount Technology (SMT) Solder Paste Screening
The application of solder paste to the bare PCBs is in fact the first step in the actual PCB assembly process. Here the stainless-steel stencil that was created during PCB fabrication is fit over the bare board, leaving only the pads for assembly of surface-mount components uncovered. The stencil is held in place by a mechanical fixture, and an applicator moves over the surface of the board to meticulously distribute solder paste over those uncovered spaces. The quality control team then performs a careful inspection to ensure that the solder has only been applied to the required areas, and that all pads are covered with a sufficient amount of paste. This process will need to be performed individually for each side for double-sided SMT boards.
Machine Placement
Once solder paste has been applied to the bare PCBs, they are moved to automated pick and place machines for the actual mounting of components on their associated pads. Part placement is 100% machine automated for maximum accuracy and efficiency and employs the project’s centroid file for component coordinates and rotation data. The boards are once more inspected after components have been mounted to ensure all placements are accurate before the soldering process starts.
Depending upon the specifics of a given project, this stage may need to be performed multiple times. Double-sided SMT boards require one round of placement for the top and one for the bottom. Projects that require wave soldering due to a high number of through-hole parts have their components machine-placed too.
Reflow Soldering
Presently, this is the most common method for PCB assembly in the industry because it is much more flexible in terms of PCB layout requirements compared with wave or manual soldering.
Generally, Bittele employs reflow soldering for a majority of the components on a board, and then passes the mostly-assembled boards the highly skilled manual soldering team for the final few connectors.
For a double-sided SMT, PCBs are reflowed separately for each side. An appropriate adhesive is applied beneath the parts that were soldered during the first production run to avoid having them loosen and separate from the PCB when the solder is re-heated.
X-Ray Inspection
Once reflow soldering has been performed, any boards including BGN, QFN, or other lead-less package types are send for X-Ray Inspection.
X-rays penetrate the silicon of an IC package and reflect from the metal connections underneath, forming an image of the solder joints themselves that can be analyzed by advanced image processing software such as automated optical inspection (AOI). Higher-density features in the captured area create a darker resulting image, allowing for quantitative analysis to determine the quality of the solder joints and compare against industry standards.
In addition to detection of likely issues in the PCB assembly, the analysis of the X-ray image can assist in the determination of the root cause of a given defect, such as insufficient solder paste, skewed part placement, or improper reflow profile.
Wave Soldering
This is a technique of PCB assembly that involves sending boards on a conveyor through a “wave” of molten solder. The solder bonds together exposed component pads and leads while wicking off the bodies of components and the solder masked bulk of the board. Though popular in the past, wave soldering is infrequently used nowadays. Reflow soldering is the top choice for most PCB projects.
Manual Soldering
Generally, manual soldering is used when PCB design includes some parts that are not suitable for either reflow or wave soldering. Bittele has a staff of highly skilled manual soldering specialists to work on such designs.
Final Inspection
The final inspections include visual inspection by the quality assurance team, and automated optical inspection (AOI) for complex or high-volume projects. Functional Circuit Testing (FCT) and In-Circuit Testing (ICT) can be performed upon client request.
Reasons to Consider Bittele Electronics Turnkey PCB Assembly Services for your PCB Projects
Having been in business for some time and built a reputation as turnkey PCB Assembly Company for prototype and low-to-mid volume PCB fabrication and assembly services, Bittele Electronics is a first choice for many industries looking for a reliable service provider with proven track record for their PCB fabrication and assembly needs.
Their facility in Canada ensures low cost, one-stop PCB assembly services for their customers in United States and Canada. Their facilities in Malaysia and China also helps in serving clients worldwide, their locations in particular allows for competitive pricing, quick turnaround times and high-quality production standards, regardless of your project size.
To ensure high quality is maintained and comply with standards, Bittele applies several schemes in quality management and process control. Strict testing standards are adhered to verify the reliability and quality of assembled PCBs.
The value-added services provided to the clients that includes Design for Manufacturing (DFM) and Design for Assembly (DFA), checks for every order that ensure that clients’ designs are optimized for production, minimizing the risk of errors and delays.
You are able to work with industry leading PCB assembly experts, ready to handle design and requirements of your PCB project.
Their excellent customer support aids in faultless implementation of your PCB project. Every concern you may have is dealt with swiftly.
Lastly, they provide an online ordering service that is user friendly, built to simplify the process of PCB fabrication and assembly for the customers. You can quickly get quotes, place orders, and track your projects from inception to completion, on the online platform.
Related content: How Artificial Intelligence is Revolutionizing PCBs
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