5 Common Mistakes in PCB Assembly that can cause PCB failure

By | Date posted: | Last updated: February 14, 2022
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An integral part of most electronic and electrical devices in play nowadays, Printed Circuit Boards (PCB’s) are essentially consists of layers of copper traces connecting together different components to create a complex maze of circuits. The importance of a PCB can be directly gauged by the fact that any errors in its design or assembly can affect the performance and output of the end product. Irrespective of whether you are fabricating PCB’s for a small electrical company or a global technology giant, there are a large number of complications and challenges that can arise during the PCB assembly process that can severely compromise the quality of the final product. Smooth collaboration is a must as far as PCB assembly is concerned, all stakeholders, including designers, engineers, manufacturers and fabricators need to work together to ensure the assembly process runs smoothly and is free of errors. A faulty PCB assembly can end up costing the organization dearly in terms of loss of reputation and returned delivery.

The potential for mistakes during the PCB assembly process exists during any of the process steps, it could be the result of flaws in the technical design itself or it could be the product of operational errors. While there can be any number or reasons for errors in the PCB assembly process, below are 5 of the most common errors mostly responsible for PCB failures.

Reasons for PCB Failure:

Cracking of Flex

Flex cracking is a term used when the excess stress on a ceramic chip capacitor causes the PCB to bend excessively when passed through it. Ceramic chip capacitors are designed to withstand a specific load, when the load generated by a PCB exceeds its maximum capacity, it causes stress on the ceramic chip capacitor which in turn causes the PCB to bend. It is important to use the same or similar load level ceramic chip capacitor during assembly as used during the design phase to ensure the capacitor does not come under stress and cause the PCB to bend or crack leading eventually to PCB performance failure.

Non-marked polarities

Assembling a PCB requires many different components like batteries and diodes which are characterized by polarities. Marking out the polarity of each individual component is very essential to make it easy for assembly engineers to differentiate between anodes and cathodes. In case the polarities are not marked clearly or are wrongly marked, there is very high likelihood of the wrong polarity getting connected to the wrong terminal during the PCB assembly process. Short circuits in PCB are very often caused by wrong connection between polarity and terminal and might even lead the circuit to blow up or at the very least cause some components on the PCB to be completely destroyed.

Inadequate Copper-to-Edge Clearance

Coppers high conductive properties make it an ideal metal for use in electrical and electronic PCB’s. However, as a metal, copper is also highly susceptible to corrosion which can happen if the copper layers get exposed to the environment. This is why copper used in PCB assembly is often coated with other materials like plastic to prevent corrosion. But sometimes during the process of trimming the printed circuit board, the copper coating also gets trimmed, causing the layers beneath to get exposed to the environment increasing the probability of corrosion and malfunctioning of the PCB. This mistake can easily be avoided by ensuring that the space between the edge of the board and the edge of the copper, also known as inner clearance or copper to edge clearance follows specific quality standards.

Plating gaps or voids

An important part of the PCB assembly process is the electroplating deposition process. This process is used to drill holes through the circuit board through which electricity can be carried from one end of the circuit board to the other. Once the holes are drilled, a thin electroless copper layer is added to the board and along the hole walls, which acts as a base for subsequent layers to be added for etching a printed circuit board. Errors during the deposition process can cause holes in copper plating which can prevent the passage of electricity through the hole causing the entire PCB to fail.

Component Misalignment

Each component on a printed circuit board has a specific landing place. Sometimes components shift from their target location during the soldering process by attaching themselves to the molten solder. A misaligned component can disrupt the proper flow of electricity through the circuit board causing the entire PCB to fail. There are only instances when an entire component gets missed during the assembly process leading to system malfunction.

Conclusion
PCB assembly requires skill and expertise, but even then there is scope for error unless you have put adequate quality controls in place at every stage of the PCB assembly process to ensure that one small error in assembly does not cause the entire product to malfunction.

TechnoTronix is one of the kingpins in delivering a well-defined and proven PCB layout and PCB assembly service to the electronics manufacturers. Our main strength lies in the extensive experience and skilled team of experts to provide error less and lead-free PCB assembly and manufacturing solution. You can drop an email to [email protected] or give us a call at 714/630-9200 to solve your queries or to get a quote.

What is the Need of Chemical-Free PCB Fabrication & PCB Assembly?

By | Date posted: | Last updated: February 14, 2022
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Commonly referred to as PCBA, printed circuit board assembly refers to the process of rigidly mounting electronic components onto a printed circuit board. It is essentially a mechanical assembly process of soldering or assembling disparate electronic components onto one printed circuit board in a manner that enables packaging. A fully functioning PCB is by no means a finished product; it needs to be connected to a power source as well as a display monitor for displaying information. PCB assembly is not generic; they are assembled as per detailed specifications related to the placement of connectors, mounting boards, etc. In many specifications the specifications are detailed enough to require a drawing of the exact location and dimensions of each external component, for instance specifications related to height or keep out areas need to be defined and designed before the fabrication and assembly process itself.

It is common to confuse PCB assembly with PCB manufacturing; the two are completely different and distinctive from each other. Manufacturing PCB’s requires Making and prototyping before actual production while assembly requires soldering of electronic components onto the circuit board for use in a variety of gadgets and equipment. There are many materials required in PCB fabrication and assembly, the primary ones being:

  • Printed Circuit Board
  • Electronic components
  • Soldering materials, including solder wire, solder paste, solder bar, solder preforms (depending on the type of soldering to be done)
  • Soldering flux
  • Soldering equipments including soldering station, wave soldering machine, SMT equipment, inspection and testing equipment etc.

By the late 1900’s, the threat to the earth’s ozone layer posed by emissions from CFC based defluxing solvents like Freon and Trichloroethylene brought about a renewed focus on the need to reduce the use of chemicals in manufacturing. The increased clamoring led many organizations to abandon CFC based defluxing solvent sin favor of aqueous based defluxing as well as no clean fluxes. The standards of defining green technology have evolved considerably since then, also because of regulatory directives which have made it imperative for companies to adopt cleaner chemical free PCB fabrication and assembly. Organizations are increasingly looking to adopt methods that reduce product liability as well as environmental liability as a means of bringing down their carbon footprints.

Taking care of the environment

Environmental concerns aside, safety in the workplace also becomes paramount not only during process operations, but also with regards to performing routine cleaning and maintenance functions, which are why many environmentally committed organizations have started adopting lead free soldering, even though it sells at a 200-300% premium. It is not just workers in factories where PCB assembly takes place that are susceptible to exposure from toxins released during the process, but even the end consumer purchasing these products.

Environment friendly PCB cleaning processes

It is in the cleaning process of PCB assembly that chemicals are chiefly used, although there are many industries that require use a no-clean process. However, industries like aeronautics, automotive and medical industry do require post assembly cleaning of solder reside paste. It is these industries that have demanded that manufacturers of PCB fabricators and assembly adhere to chemically reliable cleaning solutions that are also environmentally friendly. The European Union already has strict guidelines regarding chemical free fabrication and assembly of PCB’s. The ROHS directive is very clear in its stipulations that, from July 2006 onwards, member states are required to ensure that new electrical and electronic equipment released in the market should be free of lead, mercury, cadmium, hexavalent chromium, PBB or PDBE. Since the ROHS Circuit Board guidelines are a product based initiative, the responsibility for compliance lies with the manufacturer. This means that from an environmental perspective, flux and solders paste residues commonly used for high reliability and long lifecycle PCB assembly products need to be compatible with solvents and detergents required to clean them.

The normal environment that we live in is already rich in pollutants which are why it has become even more imperative to ensure that we do not add to the contamination by adopting manufacturing and assembly processes that do away with using any kind of harmful chemicals. While there is no regulatory body in the US for testing of PCB Fabrication and Assembly processes, the government has come out with initiatives that make it mandatory for organizations to use non lead based products in their fabrication and assembly process. Apart from the government based initiatives there is an increasingly active role played by nongovernmental environmental agencies to raise awareness about the safety hazards posed to workers and consumers by the use of chemicals in PCB fabrication and assembly without sacrificing on quality or reliability. Even organizations now prefer working with PCB assembly suppliers who are committed to implementing advanced processes and using high quality raw materials that reduce environmental contamination and provide an increased level of health and safety to workers and consumers.

TechnoTronix is one of the kingpins in delivering a Chemical-Free PCB Fabrication & PCB Assembly service to the electronics manufacturers. Our main strength lies in the extensive experience and skilled team of experts to provide tailored electronic design and manufacturing solution. You can drop an email to [email protected] or give us a call at 714/630-9200 to solve your queries or to get a quote.

How pcb layout and PCB assembly is setting a new trend of electric vehicle charging stations

By | Date posted: | Last updated: April 9, 2021
PCB Design

With the Electric vehicles (EV) becoming a recent buzz in the UK, new modifications in the vehicle charging stations come up every other day to reap the advantages of the saving fuel. People are also staying conscious about the environmental protection and using Eco friendly products and gadgets as much as possible. To derive innovations in car charging stations, an exact pcb layout and PCB manufacturing solution is the key success factor. This article drives you to the basics of vehicle charging station and the printed circuit board used in its manufacturing and installation. It also outlines the current modifications seen on charging stations.

As more and more people choose to opt for a plug-in hybrid vehicle or an electric car, it is vital to first get a short brief about the PEV’s. The battery electric vehicles operate through the an electric motor. While the plug in hybrid electric vehicles has both, an electric motor and gasoline engine. The PEV’s need to be charged on a regular basis to get high efficiency in the average miles. This has made the researchers forecast the increased use of PEV’s will drop down the number of conventional fuel stations than that of electric car charging station with making the electricity to be a propulsive dominance for vehicles, especially in the UK. The issue of car charging station is heading the electronic industry to come up with far reaching unique solutions.

With this, the tipping point for the modified charging station is grounded on the PCB Assembly manufacturing to come up with an improved electric design and manufacturing solution. In order to increase the potential of EV’s, the issues pertaining to the lack of charging station in every zone be it a free vehicle recharge or a ‘pay to charge’ option becomes a prime concern.

Giving a dynamic arena to the PEV’s, many charging stations are now installed in the UK, but still there is many more developments to be made with up-gradation of technology. The high tech PCB prototypes to design and manufacture the charging stations, be it charging point for homes, commercial or public use is taking a next step in enhancement that has multi functionality features. Also modifications are addressed in getting customized solution for wall mounted type of charging station or a pedestal structure or a ball top/curve top style of the charging station.

To manufacture an entry level commercial charging unit or robust vandal resistance EV charger that has a versatility in 1 way or 2 way plug in with custom fast charging versions or to discover a heavy vehicle charging station needs an effective electronic and design solution. With the help of flexible PCB, technology has made it possible to come up with security innovations that includes c/w hatch lock and overload protection with fault current security. For the manufacturer of charging stations, it proves challenging to also have well defined charging test equipments.

A device that has automatic charging capabilities with auto plug-in and payment facilities is a challenge to the electronic manufacturers. The use of an embedded controller in the system gives NFC and internet capabilities for mobile payment. The major challenge here is on the electronic manufacturers to reduce the cost of production with high efficiency grounded on the systems installed in the charging station.

The EV control center is also high in trend that offer both the options- pay to use Or free to use car charging service. With a single control panel it manages the multiple local EV charging points. The driver has to simply park the car in EV charging point which automatically initiates the charging procedure.

The customized PCB assembly with state-of-the-art techniques of production like the Surface Mount Technique (SMT), Through-Hole Technique and many others are highly in use to get a compact and multi feature printed circuit board used in automobile industry. To get a complete turnkey PCB Assembly for the high-tech control system used in EV’s, it requires an effective PCB assembly and also a consultation of a PCB expert.

Technotronix provides a tailored electronic and layout solution for the manufacturer and designer of vehicle charging stations. Having an experienced team of technical experts, we provide customization in PCB assembly and derive a tech savvy pcb layout for your project by providing a consigned and complete turnkey solution. Our main strength lies in the extensive experience and offering quality electronic design and manufacturing solution. You can drop an email to [email protected] or give us a call at 714/630-9200 to solve your queries or to get a quote. To get more insights into the PCB assembly, Check out our PCB Assembly Services!!

Solder Bridges becoming a major challenge during PCB assembly

By | Date posted: | Last updated: February 14, 2022
pcb-assembly

The next generation Mantra is to provide uniqueness in the electronic solution raising the level of innovation in this modern world of electronics. The main innovation grounding the electronic manufacturing mechanism is the printed circuit boards. With this, it is important for the electronics manufacturer and OEM’s to update on the major challenges in pcb layout and assembly. Solder Bridges during PCB assembly are becoming a tough challenge for both the PCB manufacturers and the customers. This article is a brief guide for all the Original Equipment Manufacturer (OEM’s) to know the importance of solder mask during PCB assembly and pcb layout to prevent solder bridges. It also takes you to the root cause and preventive measures to avoid solder bridges during PCB assembly and avoid damage to the components and circuit board resulting into a PCB rework.

To come up with a perfect PCB prototype, The pcb layout and PCB assembly stage play a vital role in deriving a proper electronic manufacturing and design solution. Be it a PCB used in aerospace, defense, military, renewable energy, transportation, telecommunication or any other industries, the PCB manufacturers need a well defined PCB manufacturing process that uses quality raw materials and comes up with an exact pcb layout that prevents solder bridges or PCB rework with giving highly durable and effective solution in turn saving time and money for the electronic manufacturers.

To get insights into the things to be taken care of at the time of PCB assembly, all the electronic manufacturers should first understand the common major problems to be considered. Among all, solder bridges are the main blunder to be taken into consideration. With this, it is significant to understand the solder bridges at the prima facie.

Solder Bridges:

A solder bridge is an unwanted and unintended electric connection occurring between the conductors due to a small blob of solder. They are also known as “shorts” in PCB terminology. Detecting solder bridges are a difficult when there is involvement of fine pitch components. If it is kept unresolved, it can lend up causing a damage to the other components and the circuit board as well. The solder mask (ie) a thin layer of polymer applied to the copper traces on the printed circuit board to protect it from oxidation and avoid solder bridges forming between the solder pads. This solder mask is necessary for the mass production of the PCB but it is of less use in case of hand soldered PCB assemblies. For the circuit boards to be soldered automatically, Solder bath and Reflow techniques are high in trend. To avoid the solder bridges during the PCB assembly, it is first needed to decide a proper type solder mask to be used during the PCB assembly. This becomes a sensitive point of consideration while deriving a proper pcb layout and type of PCB for your project.

The electronics manufacturer should investigate thoroughly the merits and demerits of each type of solder mask and then decide whether to opt for Epoxy Liquid, Liquid Photoimageable Solder Mask (LPSM) or a Dry Film Photoimageable Solder Mask (DFSM). They can even take help of PCB manufactures to get a consultation and to go for a perfect type of PCB assembly with well defined techniques and flow of PCB production. For all the electronics manufacturers, though the prevention of the solder bridges can cause additional investment of time and money, but it can help you to derive a significant long term payback.

Causes of Solder Bridges:

The root cause of the solder bridges is the inappropriate pcb layout. Less than the idea package size of their components and also inadequate use of material melds has increased with the requirements of introducing more compact and faster technology. This is a big challenge for the OEM’s to go for a perfect and adequate layout of the printed circuit board. They usually end up compromising on the PCB layout to launch a new product in the market.

Other causes of solder bridges include the lack of solder resistance in-between the pads on the circuit board. The insufficient layer of polymer on the copper traces of a PCB usually known as a solder mask also acts an issue leading to solder bridges. When the device pitch is 0.5 mm or less, the inappropriate pad to gap ratio also becomes the cause of the solder bridges. The incorrect stencil specification can lead to excessive solder paste thus causing the solder bridges. The uneven distribution of the solder paste due to the inappropriate sealing between the PCB and the solder stencil, inappropriate stencil thickness, errors in the Surface Mount Component Placement or compared to the PCB-the solder screen has a poor registration, these are the common issues leading to solder bridges during the PCB assembly.

Remove Solder Bridge

To verify that the solder resist is applied between each lead and if it is not possible due to tight tolerances, then it accounts for a design change around that particular component. Also the recommended solder stencil of 0.127 mm thickness, stainless steel stencil with a laser cut works well for a device pitch of 0.5mm. These are the preventive measures to avoid solder bridges and to get a perfect PCB assembly solution. Checks out handy tips on PCB Solder mask.

TechnoTronix is one of the kingpin in delivering a well defined and proven pcb layout and PCB assembly service to the electronics manufacturers. Our main strength lies in the extensive experience and skilled team of experts to provide tailored electronic design and manufacturing solution. You can drop an email to [email protected] or give us a call at 714/630-9200 to solve your queries or to get a quote. To get more insights into the PCB assembly, layout and prototyping services, visit www.technotronix.us