PCB Unlimited is able to offer low-cost quick turn prototype PCBs by combining multiple PCB orders on the same panels to reduce material and tooling costs. Prototype printed circuit boards with the same specs are placed on the same panel. The more boards per panel, the less the amount of material wasted. The more orders per panel, the lower the tooling cost per order.
To take advantage of this offer, your prototype PCBs must have the following specs:

High-Quality Standards

USA PCB manufacturers often adheres to standards like IPC Class 3, MIL-PRF-31032, and AS9100 for aerospace, military, and high-reliability applications. The strict quality control measures ensure that every board is inspected and tested thoroughly to prevent any defects, which is critical for high-performance applications such as aerospace and defense, medical devices, industrial control systems and telecommunications infrastructure.

Intellectual Property (IP) Protection

IP protection is one of the most important factors when choosing a U.S. PCB
manufacturer. The USA has some of the strongest intellectual property laws in the world, making it the safest option for companies that need to protect proprietary designs, especially for sensitive applications in defense or high technology.

Advanced Manufacturing Technologie

Manufacturers in the USA have invested heavily in the latest fabrication technologies, including laser drilling, micro-via production, controlled impedance, and advanced material handling. U.S. PCB manufacturers are leaders in high-tech, complex printed circuit board production, particularly for:

• Multilayer PCBs
• High-Density Interconnect (HDI) PCBs
• Rigid-flex and flexible PCBs
• RF/Microwave PCBs

Fast Turnaround Times

Quick prototyping services are usually available in the USA. Domestic
manufacturing means companies can often get prototype PCBs within days. This is particularly useful for startups or R&D departments working on rapid product development cycles.

Customization and Flexibility

U.S. manufacturers excel in producing customized PCB prototypes, especially for low-volume, high-complexity orders. They can work with specialized materials, offer unique design modifications, and provide detailed feedback during the prototype process, ensuring that each prototype printed circuit board meets exact design specifications.

Environmental and Safety Regulations

The USA enforces some of the strictest environmental and workplace safety
standards in the world, ensuring that printed circuit boards are produced with minimal environmental impact. PCB Manufacturers comply with regulations like RoHS, ISO 14001 and REACH to reduce harmful substances in their production processes.

Supply Chain Reliability

Domestic sourcing of materials and components often shortens lead times and ensures the use of high-quality parts. The U.S. supply chain for critical industries is tightly regulated, ensuring that components meet industry-specific standards.

Customer Support

Real-time support and close collaboration with U.S. PCB manufacturers lead to faster problem-solving, fewer miscommunications, and more direct access to technical experts. This helps to optimize the final product for both performance and manufacturability.

Cost Considerations

While the cost of prototyping in the USA is generally higher than in countries like China or Taiwan due to labor costs and regulatory overhead, the short lead times and value proposition often justifies the price, particularly for critical industries.

PCB Unlimited also offers prototype PCB assembly services, with rapid turn times and instant online quoting and ordering.

• SMT, Through Hole and Mixed Assembly
  
• Passive Down to 01005 Sizes
  
• Ball Grid Array (BGA)
  
• Ultra-Fine Ball Grid Array (uBGA)
• Quad Flat Pack No-Lead (QFN)
  
• Quad Flat Package (QFP)
  
• Plastic Leaded Chip Carrier (PLCC) 6. SOIC, Package-On-Package (PoP)
  
• Small Chip Packages (Pitch of 0.2 mm)
  

For a prototype PCB custom quote please email your Gerber files and bill of materials (BOM) to support@pcbunlimited.com.

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Design of Castellated Holes

Hole Shape, Size and Spacing: Castellated mounting holes typically have a round shape, but they can also be square or rectangular. The size of the holes should accommodate the screws or other fasteners being used for mounting. Spacing between the holes should be sufficient to prevent solder bridging and ensure proper electrical isolation between connections.

Castellation Depth and Width: The depth and width of the castellations depend on the thickness of the material being mounted and the size of the solder joint required. The castellations should be deep enough to ensure a strong solder joint but not so deep that they weaken the structural integrity of the mounting hole.

Spacing and Alignment: Ensure proper spacing and alignment between the castellations to facilitate soldering and assembly. The castellations should be evenly spaced around the perimeter of the mounting hole to provide uniform support.

Thermal and Mechanical Factors: Depending on the application, you may need to consider thermal and mechanical factors. For applications subjected to high temperatures or mechanical stress, may need to use thicker material, or increase the size of the castellations to ensure proper stability and reliability.

Benefits of Castellated Mounting Holes

Space-saving – Castellated holes eliminate the need for additional connectors or headers, allowing for more compact printed circuit board designs.

Simplified Assembly – Castellated mounting holes simplify the assembly process, reduce assembly time and labor costs by providing an easy way for soldering components directly onto another surface, such as a larger printed circuit board or another module.

Increase Stability and Reliability – Castellated mounting holes, with notches or gaps around the perimeter, provide strong mechanical connections between components. This guarantees stability and reliability in applications subjected to vibration or mechanical stress.

Improved Electrical Connection – Castellated holes provide robust electrical connection between components thus minimizing signal loss and ensuring consistent electrical performance.

Modular Design – Castellated mounting holes enable a modular design approach, which enhances flexibility, scalability, and ease of upgrades or repairs.

Lower Assembly Cost – By eliminating the need for additional connectors or mounting hardware between components.

Disadvantages of Castellated Mounting Holes

Complexity in PCB Design: Integrating castellated mounting holes into a printed circuit board design can add complexity. Proper placement and sizing of the holes are critical to ensure alignment and compatibility with other components.

Increase Manufacturing Costs: Fabricating printed circuit boards with castellated mounting holes require specialized equipment and technique to ensure precise cutting and plating of the holes.

Increase Risk of Solder Bridges: The design of castellated mounting holes may increase the risk of solder bridges forming between adjacent pads during the soldering process.

Limited Reusability: Once components are soldered onto a surface using castellated mounting holes, they may be difficult to remove or reuse without causing damage to the printed circuit board or the components themselves.

Assembly Complexity: While castellated mounting holes can introduce additional complexity, particularly in hand soldering operations or when working with automated assembly equipment.

Interference with Signal Traces: The presence of castellated mounting holes on a printed circuit board may interfere with nearby signal traces. Designers need to carefully consider the placement of these holes to avoid signal integrity issues.

Despite these disadvantages, castellated mounting holes remain a valuable option in many electronic hardware designs.

Applications of Castellated Mounting Holes

Castellated mounting holes offer versatility, reliability, and space-saving benefits, making them suitable for a wide range of applications such as:

Wireless Communication Modules: Castellated mounting holes are often used in radio frequency (RF) modules, such as Wi-Fi modules, Bluetooth modules, and RF transceivers.

Internet of Things (IoT) Devices: Castellated mounting holes facilitate the integration of multiple components, sensors, and communication modules onto a single printed circuit board, enabling compact and robust designs.
Embedded Systems: In embedded systems, where space is limited, castellated mounting holes are used to attach small modules to the main PCB.

Wearable Technology: Wearable devices benefit from the space-saving nature of castellated mounting holes.

Industrial Control Systems: Castellated mounting holes are used in devices like industrial controllers, data acquisition systems, and automation equipment. They provide secure connections and withstand harsh environmental conditions.

Consumer Electronics: Consumer electronic devices, such as gaming consoles, media players, and smart home devices, use castellated mounting holes for integrating additional features or expanding functionality.

Future Evolution

The future of castellated mounting holes in electronic hardware design is likely to be influenced by several factors:

• Miniaturization Trends
• Advanced Manufacturing Techniques
• Integration with Emerging Technologies
• Innovations in Assembly Processes
• Material Advancements

PCB Unlimited offers PCB fabrication services and PCB assembly services. You can get an online quote for USA Quickturn PCBs, Taiwan PCBs and China PCBs, request a custom quote by simply email your design files to support@pcbunlimited.com.

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Spacing Is Everything

The first thing you should do is start designing your PCB, whether it’s by hand or by using software. The most important thing during the PCB design process is remembering that spacing between parts is extremely important. Proper spacing saves money and limits overheating and signal resistance.

Start With the Components

Starting with your component placement can greatly assist with quality PCB building and design. By placing the components first, you make sure that your PCB can do what you need. Just make sure that you leave space between and around components for traces and overheating prevention.

Focus on Traces

Traces connect all the pieces of a PCB. Without them, signals can’t flow through the board. Try keeping all your traces as short and direct as possible, limiting the wasted space and signal travel time. Also, be aware of signal interference and resistance when spacing your traces.

Don’t Forget Your Overheating Prevention

The last major step in PCB design is overheating worries. A lot of this comes down to material selection and the spacing of your parts. Drill holes and vias can really help with overheating in your board.

PCB Prototyping and Fabrication

Once you’ve the design layout set as you like, it’s time for fabricating your PCB. PCB fabrication services can be very useful if you’re making a full line of PCB, but you can start with some prototypes so you can test your design. Finding an experienced PCB fabrication service can be a godsend as you can lean on their experience to fix any issues that pop up.

These are just a few simple steps to create a custom PCB that may help improve your design process. Following this advice should help you create the designs you need for your projects with as few problems as possible. If you’re ever unsure about your design, try PCB prototyping so you don’t make a full line before you know the design will work.

The post PCB Prototype Process: 5 Steps To Create a Custom PCB appeared first on Blog PCB Unlimited.

Their Services

The first thing you should consider is the breadth of services the PCB prototype fabrication company offers and what they can handle. Some companies don’t offer the kind of prototype creation you need, so look for companies that can make your specific designs on your schedule.

Help in Design

A great PCB fabrication company can aid you in the development of your PCB design, either before or after you use their prototyping service. This means that you can tap into their expertise and gain a new perspective on improvements to your PCB.

Expertise and Experience

Another equally important factor is the company’s experience and expertise in the subject of PCB creation and design. You should look for a company that has individuals that can help you, with years of experience in PCB work. You don’t want to work with people who barely know how to answer the question, “What is a printed circuit board?”

Quality Assurance

One service that you need to look out for is a quality assurance (QA) department or process that’ll check your PCBs before they’re sent back to you. A company without a good QA program is at a much higher risk of giving you bad PCBs.

Communication

Another sign that you found the right PCB company is their willingness to communicate with you during, before, and after the fabrication process. A company that isn’t flexible to changes in what you need isn’t going to get you the perfect PCB, nor do you want to work with a company that won’t respond to your requests.

Following this guide on how to choose a PCB prototype fabrication company will help you find the right company for your project. As one last piece of advice, check on a company’s client reviews to get a better idea about how the company works with their customers.

The post How To Choose a PCB Prototype Fabrication Company appeared first on Blog PCB Unlimited.

Surface-Mount Technology

SMT is not that easy of a concept to understand. However, as the name implies, the technology works by mounting components onto a blank PCB. the SMT printer can usually do this automatically while taking custom design instructions to build complex PCBs. The reason that this technology is so important is the finesse that it provides. Before SMT, the average PCB could only be so small before it was too difficult to handle. Now, PCB can be much smaller because of the SMT process. This is usually automatic, where previous PCBs were mostly handcrafted, which saves everyone time and money.

SMT Process

The process of SMT starts with feeding the printer the necessary designs for whatever PCB you want to make. The SMT then needs the materials to make the PCB—usually it is soldering paste and the prebuilt components for each unique PCB. The printer then starts to apply the soldering paste to a blank PCB to prepare it for the next step. The SMT printer then starts to function as a PCB component placement machine as it places each separate part onto the paste of the blank PCB. Soon after this step, the PCB is complete and ready for use.

Now that you understand the answer to “What does SMT stand for in PCB manufacturing?” you should be able to make informed decisions about if you want to use SMT.

The post What Does SMT Stand for in PCB Manufacturing? appeared first on Blog PCB Unlimited.

Things to look for in a PCB manufacturer

There are many manufacturers of printed circuit boards — so many that when you need to find one fast, it can be very easy to feel overwhelmed. How do you choose the right one for your project?

Believe it or not, not all PCB manufacturers are created equal. Before you place your printed circuit board order with a PCB manufacturer, make sure they have the following things going for them. This will help ensure you have a good experience and a successful project.

Several Years in Business

Experience counts for the most when it comes to manufacturing printed circuit boards. This isn’t to say newbies can’t do it well, but when you’re facing a critical project deadline or working on something important, you don’t want to take chances. Several years in business indicates that a manufacturer is competent and that they can consistently innovate and adapt over time. Try to find a manufacturer to partner with who’s been active in the industry for at least a few years.

The Appropriate Certifications

There are two different processes used in PCB construction: through the hole and surface mount. You should learn about a specific manufacturer’s processes and quality standards before doing business with them. Make sure they have the right credentials and certifications to demonstrate high-quality processes and materials. Tread carefully when investigating this aspect of a printed circuit board manufacturer. Some of them say that they’re compliant with industry quality standards, but they’re really just going through the motions. They don’t actually have the right procedures in place to become properly certified.

Know Where Customer Service is Located

Some PCB manufacturers don’t actually have a customer service team. Instead, they hand off customer service calls to their sales representatives (see PCB brokers below). This doesn’t have to be a bad thing if their sales reps are skilled at providing the information existing customers need, and most of them probably are. But it’s a good idea to find out where the customer service team is located. If they’re in a time zone on the other side of the world, it could be difficult for you to get the support you need. If there are language barriers because none of the support reps speak English as their first language, it may be hard for you to get the service you need. This probably wouldn’t be a dealbreaker in any case, but you should know what you’re getting yourself into.

Competitive Pricing

If you have the chance to speak with a representative of the printed circuit board manufacturer, you should ask if their pricing can compete with that of offshore manufacturers. If the company is based and operated in the United States, the answer will probably be no, but it doesn’t hurt to ask. More importantly, the manufacturer’s processes and materials should be of a quality that justifies the price they’re charging. Cheaper doesn’t always mean better. As long as it’s within your budget and they have the qualifications and services you require, you shouldn’t see their pricing as an issue.

Proof of the Above

As sad as it is, not all business representatives are honest when they provide information about the company they work for. If you’ve been on the phone asking a manufacturer’s rep about the things discussed so far, you should take it a step further and make sure it all checks out on their website. Look for seals from official organizations verifying their credentials and quality standards. Check their ratings with the Better Business Bureau. You should also look for reviews left by other customers who’ve used them in the past.

If everything checks out, you’ll have found a PCB manufacturer you can be comfortable doing business with, for both your current project and all of your projects to come.

PCB Brokers

The vast majority of the Chinese and Taiwanese PCB manufacturers do not have a customer service or sales team in North America. They rely completely on PCB brokers. PCB broker typically works with several offshore PCB manufacturers and some domestic ones as well. A good PCB broker will take the time to understand your project requirements and find the best PCB manufacturer for you project in terms of technology, lead time and pricing.

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1. Solder Paste

Solder paste has to be added in requisite areas before any component is added to the board. Some of these areas include component pads, where solder addition is done using a solder screen. Solder paste is in form of minute solder grains laced with flux. This mixture is added to the appropriate place in a manner that mirrors typical printing processes.

By moving a runner across the screen, solder paste permeates through the screen holes and gets deposited on the PCB board. Note that the solder deposits are only found in the solder pads. This is because the printed circuit board files are used to generate the solder screen. Therefore, the solder screen holes are always in line with the solder pads. For the best PCB fabrication result, the solder amount needs to be monitored so that the correct volume goes into the resulting joints.

2. Pick and Place

In this part of the PCB fabrication and assembly process, the board undergoes a process known as pick and place. A pick and place machine takes the components from the dispenser and puts them in the needed location on the board. Tension from the solder paste helps in keeping all the components in their rightful place on condition that the PCB doesn’t shake. In order to keep components secured on the board, some pick and place machines add glue drops during the PCB fabrication process. To avoid repair complications, degradable glue is the best to use during the soldering process.

3. Soldering

Now that the necessary components are already on the PCB, it is now time to pass the board through a soldering machine. Though not as common nowadays, some PCB fabrication processes involve passing the board through wave soldering machines. Solder paste addition to the board isn’t necessary with wave soldering because the machine has its own solder. In place of wave soldering, most PCB manufacturers prefer using a reflow oven.

4. Inspection

Once the soldering stage is complete, printed circuit boards need to be inspected. When it comes to surface mounts, manual inspection is impossible considering that the board has many components. It would also need a lot of employees to perform manual inspections and this would not make economic sense. Automatic optical inspection, on the other hand, is a much better way of going about this. These machines have what it takes to detect misplaced components, poor joints, and even wrong components.

5. Testing

Electronic products need to be tested before leaving the factory, and PCBs are no exception. Testing helps in knowing whether the printed circuit board is functioning properly. Some of the methods used to test boards after PCB fabrication are:

• A quick visual inspection to ensure all electrical components are in place.
• Analog signature analysis: This involves the use of AC current across two areas of the circuit and electrical components.
• Functional testing: This helps in verifying whether the printed circuit board does what it is intended to do.
• In-circuit testing: This involves checking numerous parameters like frequency and voltage.

6. Feedback

Monitoring the outputs helps in knowing whether the PCB fabrication process is going on well. A good way of achieving this is by investigating all detected failures. The optical inspection stage is the best time to do so because it usually takes place after soldering. Therefore, any defects are quickly identified and corrected before the mass production of boards with the same problem.

Conclusion

There are many uses of a printed circuit board today. From televisions to microwaves and anything in between, PCBs are almost everywhere in the electronic world. With the above information, you now know what PCB fabrication and assembly is all about.

The post PCB Assembly Process: 6 Things You Need To Know appeared first on Blog PCB Unlimited.

Here’s how prototype PCBs are made with such accuracy.

Front-End Engineering Checks

Before a PCB prototype is built, there are countless aspects that go into planning the final result. First, the PCB manufacturer will look over the board design (Gerber files), and begin preparing the circuit board with a list of step-by-step instructions that are laid out for fabrication. After review, an engineer will then convert these plans into a data format that will help to engineer the PCB. This engineer also will check for any issues with format or clean up.

This data is used to create the final board, which is also given a unique tool number. This number keeps track of the printed circuit boards that go through the building process. Even the smallest of changes to a circuit board revision will result in a new tool number, which helps to ensure there is no confusion during the PCB manufacturing and fabrication processes of multiple orders.

Plotting

After the correct files are inspected, and a panel array is chosen for the best fit, photo plotting begins. This is the start of the production process. The photoplotter utilizes a laser to plot the patterns, silk screens, and other primary images that are required on the PCB.

Lamination and Drilling

One of the three primary types of printed circuit boards, multi-layered PCBs, require lamination to fuse the multiple layers together. This is typically done using heat and pressure.

Once the product is laminated, expert drilling systems are programmed to drill holes precisely and accurately into the boards. The drilling program ensures that there is no human error during the PCB manufacturing process.

Copper Deposition and Plating

The conductive copper layer, which is deposited through electrolysis, is essential to the functionality of all prototype printed circuit boards. PCBs officially become conductive surfaces after electroplating, which is where the copper is plated via a plating bath. These copper tracks are a type of conductive path that connect two points within the PCB.

After the prototype printed circuit boards are tested for quality assurance, they are then fabricated into cross sections and lastly, inspected for cleanliness.

For more information on PCB manufacturing, contact PCB Unlimited today!

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Printed Circuit Boards typically include mechanical layers, solder mask layers, silkscreen layers, solder paste layers and one or more copper layers depending on the complexity of the boards.

The outer layer contain the boundaries (shape and physical dimensions) of the PCB. Additional mechanical layers may contain tooling specification and other mechanical information.

The copper layers contain the routing layers as well as the ground and power planes.

The solder mask is a solder resist coat that is usually applied to the outer layers of the PCB for protection against oxidation and to prevent solder bridges from forming between closely spaced solder pads. Solder mask is usually green but is also available in many colors.

The silkscreen layers contains the reference designators, among other things, for the electronic components located on the top and bottom sides of the board. The text is usually printed with a permanent non-conductive ink. Silkscreen is usually white but is also available in other colors.

The solder paste layers contain the location, the size and the shape of the SMD pads on the board. This information is then used to make the apertures in the SMT stencil.

Reasons For Using Multiple Layers In Printed Circuit Boards.

Miniaturization
Multilayer PCBs enable designers to reduce the board size by adding layers. This is very important as miniaturization of electronic products continue to drive the industry.

Reduced complexity
Multiple layers make PCB routing easy because copper traces in one layer can connect to traces in other layers to complete the path.

Supply and ground isolation
Multi-layer PCBs (4 or more layers) have their own supply and ground layers. This provides isolation between supply and ground pins preventing short circuit.

Simplify Construction & Reduce Weight
Eliminate or reduce the need of connectors for multiple separate PCBs.

Higher density of assembly

Single Layer Versus Multiple Layer Printed Circuit Boards.

Single Layer PCBs have the electronic components on one side of the board and the conductor pattern on the other side. Multilayer PCBs can have the electronic components on the top side, the bottom side or both sides of boards and have one or more conductor patterns.

Single-layer or single-sided PCBs are typically used in simple electronics. They are cheap to manufacture and are often used in applications that demand high volumes such as calculators, radios, and printers.

Double-layer boards are necessary for moderately advanced technology including HVAC systems, power supplies, LED lighting, and automotive dashboard lighting.

Multi-layered boards delve into the territory of complex data storage, GPS technology, medical equipment, and satellites.

The post Why Are Printed Circuit Boards Made In Layers? appeared first on Blog PCB Unlimited.

Similarities between the two

Though these PCB options have major differences, they still utilize many of the same components. Both single and double-sided prototype PCBs serve as electrical catalysts in order to transmit power and make connections between different components.

They are also made of the same FR4 material, a type of fiberglass that is mixed with epoxy and formed into multiple layers. For example, a four-layer board has internal layers that improve the distribution of power on your PCB layout. It does this by decreasing the loop area and improving EMI performance.

Single-Sided PCBs

Single-sided PCBs have one layer of conductive material and are best suited for low density designs. A series of leads pass among the through-holes of the component-side before they are soldered to the copper tracks.

Single-sided PCB assembly was the original way to fabricate prototype circuit boards. As technology advanced and more power was needed for surface mount components, double-sided PCBs were manufactured.

• Ideal for simple low-density designs
• Lower cost than double sided PCBs, especially for large orders
• Easier to manufacture

Double-Sided PCBs

Double-sided PCBs became a convenient way to double the conducting power of the substrate core without sacrificing surface area, the key problem with single-sided PCBs. In a double-sided PCB, through-holes components are mounted on the top and surface mounts are present on the bottom. They are connected through “vias,” or holes that connect the two sides.

• Reduce board size by increasing circuit
• Provide greater flexibility for designers
• Reduce cost of for high density circuits

The main differences

Simply put, double-sided PCBs have more power. As the world’s need for technology advances, double-sided PCBs have become the most popular option for prototype printed circuit boards on the market today. Regardless, this is still the more expensive option for your printed circuit board prototype. Many small electronics are still able to benefit from single-sided uses and the cost is much cheaper. If you’re stuck trying to choose between the two options, the intended use for your prototype PCBs will be the determining factor.

When you want to get involved in printed circuit board manufacturing, each option has pros and cons when building prototype PCBs. To find out which option is best for you, don’t hesitate to contact PCB Unlimited, the best PCB assembly, design and layout, and fabrication company around. Visit our website at pcbunlimited.com for more information today.

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