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What are PCB Gerber Files and How They are Used in PCB Manufacturing?

By | Date posted: | Last updated: December 27, 2021
PCB Gerber Files

For your electronics contract manufacturer to create PCBs with meeting your bespoke requirements, what is essential is the manufacturing documentation to be robust. An extremely important document is the PCB Gerber file that is used to create the circuit board.

Let us look at what PCB Gerber files are, in some detail.

What is a PCB Gerber file?

The PCB Gerber files were initially developed by a company called Gerber Scientific, founded by Joseph Gerber, and have become the benchmark for consistent production of printed circuit boards.

A PCB Gerber file is developed to detail the printed circuit board requirements in every stage of the product development. These files are used for both PCB fabrication as well as PCB assembly.

Gerber Files are open ASCII vector format files. What they contain is information on every layer of the PCB. All objects on the circuit board such as vias, solder mask, silkscreen images and more, all find representation by way of vector coordinates. It is these files that are then translated into the PCB.

As for the generation of Gerber files, they are generated as per the RS-274X Gerber format. Gerber files typically come with the following extensions:

  • .gb
  • .gbr

How are PCB Gerber Files Generated?

Once the design is complete, you need to be able to create the PCB Gerber Files for the manufacturer. While earlier this used to be a cumbersome process with many steps involved, today the CAD packages have simplified the process. What you need to do is to produce an individual file for each layer of the board. Additionally, there would be separate files for the solder mask layer, top and bottom silkscreen layers, and top and bottom solder paste layers. Some manufacturers will also require Gerber layers for PCB assembly information, particularly if your design configurations are unique.

The files are typically zipped into a single file. The file names are descriptive enough so that the contract manufacturer can understand which board layer the file has to do with. Supplying a stackup marked as the Gerber files are labeled within the zip file works well to avoid any errors.

An important aspect to remember before you create the PCB Gerber files is to configure the Gerber file generator. This will ensure that the formats and units are consistent. Another file that is created along with the Gerber File is the NC Drill file. This is a documentation that instructs where the holes are to be drilled in the board.

PCB Gerber File Formats

RS274-D

This is the oldest format where the file is represented in numerical control format. This was compatible with the photo plotters used in the 1970s. However, on account of several disadvantages of the format, manual input of d-codes and more, the use of these files is fairly restricted and several other Gerber files have been developed.

RS274X

This format has been in use since 1998. This uses an embedded format, unit, and data information. This allows for standard sizes and custom apertures. The other advantages with this format include:

  • Multiple layer structures for single layers
  • Polygon Fill Commands
  • Polarity Controls
  • Elimination of manual data entry
  • Reduction of photo plotting errors, and more.

ODB++

This is a highly standardized input format and automates the process for stack up, drill placement and labeling. It is now widely used by most CAD programs. The added advantage with this is that there isn’t room for any manual errors as the need for manual naming conventions was taken away.

Gerber X2

This is the latest format used by advanced CAM software applications. Some of the attributes that this allows to be applied within the Gerber file include:

  • Function of file
  • Part represented by the file
  • Function of pad

Documentation After PCB Gerber Files

It is important to ensure that all your files are well documented. What you need is to have the following in place:

  • Fabrication & Assembly drawings
  • Pick & Place data
  • Test Data
  • Schematic Netlist
  • Readme File

Last, but definitely not the least, it is important to work closely with your contract manufacturer to ensure that you provide the necessary details for best results.

Mer-Mar Electronics is an ISO 9001:2015 certified company and ITAR (International Traffic in Arms Regulations) compliant manufacturer that delivers one-stop PCB manufacturing services with specialized support, reliable testing, and multi-functional features. Our consistent quality and quick turnaround time captivate us to our customers, who look on us as a one-stop shop for all their PCB requirements. To know more contact us at sales@mermarinc.com or call us on (760) 244-6149.

What is PCB BOM? Effective Tips for Creating PCB Bill of Materials!

By | Date posted: | Last updated: December 29, 2021
pcb-bill-of-materials

Before we look at how to create an effective Bill of Materials, it is worthwhile to look at what a BOM really is and what purpose it solves in an effective PCB manufacturing process.

What is PCB BOM (Bill of Materials)?

A Bill of Materials is a list of raw materials, assemblies and sub assemblies, components as well as other crucial items for product manufacturing. It is imperative that the BOM be highly accurate and detailed so that the boards are built to the customer’s satisfaction.

What are the details that a PCB BOM should include to make it effective?

Here is a list of components that an effective PCB BOM must have:

Part Number

In order to make sure that you have the exact parts, it is important to list the manufacturer’s part number. That way there is no chance of any confusion as each part number is unique.

Name of the PCB manufacturer

Similar to the part number, it is also important to list the PCB manufacturer name. It will also be prudent to see that the parts are available with the manufacturer as also to check the cost and delivery time. That way, you will not have to wait precious time looking for part replacements.

Part Specification

The description of each part such as its dimensions, color, voltage and more will also ensure that you do not land up ordering the wrong part.

Quantity

It is also important to take stock of the quantity required for each part. This information has a cost benefit, as you are able to avail of bulk discounts.

Type of procurement

Is the procurement happening off-the-shelf or is it custom made, is yet another information that needs to find place on the PCB BOM sheet.

Flexibility

It is helpful to categorize the parts and state how flexible you could be with that particular item. There could be some critical parts which you wouldn’t want the assembler to substitute, whereas the flexible parts are the ones that can be substituted, if necessary. It is therefore fine to label generic parts as being non-critical. For parts that you are flexible towards, it is also prudent to list some potential alternate parts. Although it will be good to indicate whether the alternate parts are the only acceptable substitutions or mere examples.

BOM Level

It is advisable to have the PCB BOM at multiple levels to represent the main and sub assembly. This can go a long way to help users understand the PCB assembly.

Supporting Files

It is important to have the supporting files in lace. These include but aren’t limited to:

  • CAD Files
  • Data Sheets
  • Diagrams, and more

Reference Designator

A unique reference designator is needed so that it is clear where each piece fits on the board. By ensuring that this designator is the same as the label used on the design documents, cross-reference is made easy.

Placement Method

The placement method that the project will use also needs to be documented. The method, whether through-hole or surface mount, will describe how each part attaches to the board.

Board Layer

This will indicate the layer on the board on which the component will be placed.

Points

It is important to notate the number of connection points that the component has on the board. It is also advisable to include the footprint of each part.

Comments

This is the section where you can leave any important comments and notes that will come in handy to the assembler.

Other than the above components, here are some handy tips to create an effective PCB Bill of Materials:

  • Remember to customize the BOM to the unique needs of your project.
  • Use a template from the company with which you are working so that there are no accessibility issues or any issues to do with incompatible files.
  • Ensure you include the right number of details so that the PCB BOM is clear and does not have any ambiguity.
  • Double-checking the information before the BOM is sent is another effective practice as you should not have to pay for small mistakes.
  • You also must ensure that you keep track of changes, if any, to the BOM. It is best to label each version correctly and to ensure that the latest version is in use. Ensuring that the BOM does not have editing rights can also ensure that there aren’t any accidental changes.
  • Last, but definitely not the least, as much automation as you can include in your BOM management, can help you easily identify discrepancies. It will also make import and export that much easier.

Mer-Mar Electronics is an ISO 9001:2015 certified company and ITAR (International Traffic in Arms Regulations) compliant manufacturer that delivers one-stop printed circuit board manufacturing services with specialized support, reliable testing, and multi-functional features. Our consistent quality and quick turnaround time endear itself to our customers, who look on us as a one-stop-shop for all their PCB requirements. To know more contact us at sales@mermarinc.com or call us at (760) 244-6149.

Will eco-friendly printed circuit boards be the next horizon for the DFM best practices?

By | Date posted: | Last updated: November 1, 2021
Eco-Friendly Printed Circuit Boards

Industries per se have a strong role to play in impacting the environment. Unfortunately, like other industries, the electronics industry also contributes to the imbalance. Traditional PCB manufacturing, in fact, has a number of high-emission processes adding to the global electronic waste. This has its implications on the environment besides impacting human health.

The only way to address this impact is to follow environmentally friendly practices. A number of sustainable manufacturing and DFM (design for manufacturing) methods are therefore on the rise. Some of these include:

Lean Manufacturing

This involves using of concepts and processes that can remove wastes from production.

Green Manufacturing

This reduces environmental impact by the following methods:

  • Reducing waste
  • Recycling
  • Minimizing usage of natural resources and more.

Additive Manufacturing

Essentially it involves creating 3-D objects. This method is cost effective and allows for the making of complex products efficiently.

Additive PCB printing processes involve:

  • 3D Printed Electronics
  • Conformal Electronics
  • Aerosol, Inkjet and LaserJet Printing

As opposed to subtractive processes that lead to waste material, additive processes apply only the material needed. In case of an additive process, the design team can use the PCB design software and then simply export the finished design to the printer. They do not require etchants or photomasks.

The use of 100% conductive inks and toners do not have volatile organic compounds or etch resists. With precise printing there is little material wastage. 3D printing allows the manufacturer to 3D print the entire electronic circuit including the board, traces, and components. With PCBs having different shapes and designs, this method is extremely helpful. In fact, it allows for custom printing as per the bespoke needs of the project. Additive manufacturing can either work as:

  • Single-build Process
  • Post-Production Process

In the case of a single-build process both the internal circuitry as well as the external case is produced as a single assembly. In case of the post-production process, the electronic circuit needs to be integrated into the product.

Paper PCBs

Researchers have been able to produce the prototype of paper based PCBs. Along with the use of additive processes this comes with sizeable environmental benefits. Paper PCBs involve testing the mechanical properties of paper as also its capabilities to form inter-layer connections. Fortunately, tests went on to show that the flexibility of paper PCBs did not come in the way of the desired conductivity. The fact that paper PCBs have much lower costs add to the efficacy.

Besides paper, some of the other researches have shown the use of PCBs made from natural cellulose fibers, effective. The advantages of bio-composite boards stem from the fact that:

  • They do not contain chemicals
  • They work well even when exposed to elevated temperature or humidity

There have also been successful attempts to construct PCBs from unzippable polymeric layers such as polylactide, polycaprolactone and polyglycolide. These work for all kinds of PCBs namely rigid, flex and rigid-flex boards. Prototype testing revealed that the boards can withstand thermal cycling. Once the boards reach the end of their lifecycle, they can simply be immersed in hot water where the polymers, ink and adhesive separate. Reuse is, therefore, easy.

Biodegradability

Research into biodegradable PCB Materials has shown promising results. There is hope that traditional metal conductors can be replaced with water soluble metallic pastes. If this indeed can be implemented on a large scale, the impact on the planet can be significantly reduced.

How to Design for Sustainable Manufacturing of PCBs?

In order to design for sustainable manufacturing of PCBs, the following elements need to be kept in mind:

  • It is important that eco-friendly components be selected.
  • Wherever possible eco-friendly board materials need to be used.
  • Small board sizes work well as they mean less material. They also consume less energy.
  • Effective use of Design for Manufacturing can go a long way in efficient manufacturing as also in minimizing delays and in cost optimization.
  • An important aspect of sustainable manufacturing is also prioritizing safety. This involves robust testing for manufacturing.

To Sum Up

From finding new materials that aren’t toxic while PCB assembly processes that are lead free, there is a wide range of best practices that go a long way in minimizing the harm done to the ecosystem at large.

Mer-Mar Electronics is a premier printed circuit board assembly provider. You can rely on us for end-to-end PCB assembly process and be assured of high-quality and high-performance. We are an ISO-certified company and ITAR (International Traffic in Arms Regulations) registered manufacturer who have been striving to deliver the best RoHS (Restrictions of Hazardous Substance) compliant PCB Assembly services for over 4 decades. We can be your reliable partner for the PCB assembly right from the material selection till the finish line of final PCB assembly prototypes.

If you have any requirements regarding our PCB assembly services or need urgent assistance, Request a quick PCB assembly quote.

Single Sided Vs Double-Sided PCBs – What is the difference?

By | Date posted: | Last updated: December 29, 2021
Single Sided vs Double Sided PCBs

There is no doubt about the fact that PCB is a highly valuable technology that finds extensive use in a wide range of applications. Depending on the appliance involved, the use of the type of PCB differs. While single-sided circuit boards are widely used in simpler appliances, in slightly higher technology electronics, double-sided circuit boards find use.

While single sided and double-sided PCBs are similar in some respects, both of them offer their own distinct advantages. Let us look at both of them in some detail:

What are Single sided PCBs?

Single sided printed circuit board is a kind of PCB that has conductive copper and components that are mounted on one side of the board and the conductive wiring connected on the other side. These are simple, basic and find extensive application in devices such as:

  • Camera systems
  • Printers
  • Calculators
  • Radio Equipment and more

Basically, the working principle behind single sided PCB is that it specifically isolates the copper foil’s conductive layer. The isolation happens on the surface of the base insulating material. This ensures current can flow in the components and several tasks such as attenuation, demodulation, amplification, and encoding are effectively performed.

What are Double Sided PCBs?

Double sided PCBs are similar to single sided ones, however the key difference as the name suggests, lie in the fact that they have two sided traces. In these boards, components can be mounted on both sides. The advantage that it offers is that there is a high density of circuits without any need of point-to-point soldering. While these may be more difficult to produce as compared to single sided PCBs, its advantages far outweigh the complexity of production. Some of the applications where double-sided PCBs find application include:

  • Lighting Systems
  • Amplifiers
  • Vending Machines, and more

Advantages of Single Sided PCBs

The major advantages of single sided PCBs include:

  • They are extremely cost-effective. This is made possible on account of their simple design and the fact that they are low density.
  • They are relatively easy to manufacture, as there have been very few issues during the manufacturing stage due to their simple design.
  • They work well for high volume orders on account of their cost-effectiveness.
  • Repairs are relatively easy for this set of PCBs.
  • They are also made of several different materials, thereby suiting multiple requirements.

Advantages of Double-Sided PCBs

Used in complex circuits, double-sided PCBs offer the following benefits:

  • The big advantage of double-sided boards is that there is an added layer where components can be added. This increases the density of the circuit. Typically, as appliances become smaller, the extra layer goes a long way in terms of increasing the flexibility of design.
  • They tend to offer complex circuitry are as well suited for advanced electronics.
  • Since you can effectively use both sides, the size of the board can be reduced. Hence, they are highly effective for miniaturized appliances.

Difference between single sided and double-sided PCBs

The primary differences between single sided and double-sided PCBs include:

  • Single sided PCBs have a single substrate layer while double sided PCBs have more than one layer, although they have fewer layers as compared to multi-layer PCBs.
  • In terms of cost, single sided PCBs are cost-effective.
  • When it comes to size, double-sided PCBs come with reduced circuit board size as components can be added to a relatively small space.
  • The use of single sided PCBs is restricted to simpler electronic items while double sided PCBs find use in more complex appliances.

Clearly then the choice of single sided versus double sided PCBs is determined by factors such as the kind of electronic appliance and the cost you are willing to pay.

Of course, for highly complex appliances, especially ones where size is of major constraint, multi-layer PCB assemblies are printed circuit boards of choice, as they come with the following advantages:

  • They are inherently smaller than other PCBs
  • They are known for their light weight
  • They offer increased durability
  • They offer enhanced flexibility
  • They offer greater capacity and speed

It is imperative, therefore, that all of these factors are weighed in in making the choice of the right PCB.

Mer-Mar Electronics is an ISO 9001:2015 certified company and ITAR (International Traffic in Arms Regulations) compliant manufacturer that delivers multilayer printed circuit boards with specialized support, reliable testing, and multi-functional features. Our consistent quality and quick turnaround time endear itself to our customers, who look at us as a one-stop shop for all their PCB requirements. Get in touch with us, if you are looking for custom PCB assembly for your next project.

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