By Mer-Mar Electronics | Date posted: | Last updated: July 26, 2022
Prototype testing

A PCB prototype offers a great opportunity to be able to test any teething issues that could turn into costly errors post-deployment. It is however important to have a robust checklist for PCB prototype testing. If you have been looking for one, here is help:

Why is circuit board prototype testing important?

Before we get on to the checklist let us quickly look at the importance of prototype testing in the first place. When tested correctly, you can be sure that there will be minimal issues at the manufacturing stage. In turn this will save a lot of costs as you will not have to go back to the drawing board. Importantly, any errors post manufacturing can also cost you your company reputation.

Before powering up your prototype, however, the following common causes of error need to be taken note of:

1. Short Circuit

Among the commonest causes of damage to PCB prototypes, it is imperative that you pay attention to fine-pitch elements. Also, any tiny solder lead can result in a short circuit, thereby destroying the micro-controller. As a thumb rule, it is important to measure the impedance of each voltage node.

2. Populated Components

Double check to see that you have not missed any parts during assembly, as that could lead to power-up failure. Having a detailed PCB bill of materials ready with you can also go a long way in minimizing errors.

3. Inverted Polarity

In case the integrated circuits are soldered in opposite polarity, it could lead to damaged components. It is therefore important that each element is assembled as per its polarity and the scope for any errors, minimized.

Some of the precautions that you need to follow before powering up your PCB prototype therefore include:

Use LED indicators that stand for different voltages

This will act as an alert to notify you when a particular voltage regulator is active. Importantly, you will also need to ensure that you take voltage measurements for every single voltage regulator.

Watch out for signs of damaged components

If one or more LEDs are off, it could indicate damaged components. It is also possible that there could have been an error and some components may not have been soldered.

Missing Components

Ensure that your BOM is cross-referenced so that any missing part can be easily found. It is also advisable to automate BOM generation so that chances of manual errors are significantly reduced.

A checklist for PCB prototype testing will not be complete without including a robust checklist to choose the right PCB Prototype manufacturer in the first place. It is the choice of a reliable PCB assembly manufacturer that will make or break your project So here goes:

Checklist for choosing a PCB prototype manufacturer

  • Can they offer design and layout support? – Essentially you need to make sure that the manufacturer has expert design engineers who can help implement your plan. If they are equipped with industry best practices they can make sure that you do not face any issues at the manufacturing stage.
  • What kind of turnaround time do they offer? – In today’s world, the quick go-to-market is the biggest source of competitive advantage. It is imperative that the manufacturer can offer quick turnaround times.
  • Are they equipped to offer debugging service? – The engineers need to be experienced enough to be able to wean out any issues in the initial plan so that there are minimal chances of error later.
  • Do they offer optimal cost? – Optimal costs are a big determinant when it comes to the viability of your project.
  • Pro tip – It is important however to be able to do a cost-quality evaluation. Ever so often you could land up making the mistake of going with a manufacturer that offers you the lowest quote without paying sufficient attention to quality. Needless to mention that this can bring in detrimental results that can impact your reputation.

To sum up

Following the above checklist will significantly extend to ensure that your prototypes are robust. Importantly going ahead with the right manufacturer will ensure that you do not have to worry about costly errors as they are equipped with industry best practices and can make all the difference.

Mer-Mar Electronics is one of the leading PCB manufacturing companies, providing services from designing to final prototypes. We follow industry’s best practices, ensure standard quality PCB prototype that our clients do not deal with recall or rework. Ask your queries related to prototype PCB manufacturing services by emailing us at or call us at (760) 244-6149.

By Mer-Mar Electronics | Date posted: | Last updated: May 13, 2022
Rapid PCB Prototyping Process

With a competitive market with large number of players, the key to success is to offer innovative products that meet consumer needs. Speed is clearly of essence. To maintain your competitive advantage, it is therefore important that PCB prototypes are built quickly and that they adhere to the highest quality standards.

Getting a PCB prototype with speed as well as precision is a specialized job. A fine balance needs to be maintained between manufacturability and electrical performance. In order that the board goes through the rapid PCB prototyping process, the following prerequisites need to be maintained.

Aspects that you need to complete before you submit your design for rapid PCB prototyping:

  • Proof of concept: Prior to building your prototype, a design proof of concept needs to be fully developed. Additionally, the circuitry should be verified on the proof of concept. This will ensure that when it comes to the prototype, you do not have to spend a lot of time in testing. What you will also save on is on costs as well as on costly redesigns.

  • Ready for manufacturing: The PCB layout should be such that it is compliant with the Design for Manufacturing requirements. You sure do not want a situation where you need to completely redesign the prototype. This will involve a lot of time that will in turn delay your go-to-market plans and impact competitiveness.

  • Select the components carefully: In the rush towards having your prototype ready, ever so often you could miss proper selection of components. You need to be mindful of the fact that you need to select components that aren’t likely to be discontinued. In such a scenario it will be hard to either find replacements of components or to altogether redesign the board to accept new parts.

  • Robust BOM: Your PCB design has to be very well documented including having a robust Bill of Materials. The documentation will go a long way in helping the contract manufacturer adhere to your requirements and create a product without any manufacturing mistakes.

Other than the above aspects, one crucial prerequisite to consider is to spend time and energy looking for the right contract manufacturing partner.

Here are some things that you should look for in making the choice of partner for rapid PCB prototyping:

  • Prototyping capabilities – It will be worth your while to do enough research to choose a vendor who is known for his prototyping capabilities. Someone who has high mix low volume capabilities works exceptionally well when it comes to prototype development. Make sure that the CM has the right certifications that will assure you of receiving high quality product. In addition, if the CM also has the requisite experience in your industry, it will be an added advantage. In this case they will have access to industry best practices that will ensure that you do not have to re invent the wheel. Speaking to clients, checking out the testimonials can all be good ways to figure out the CM’s reputation when it comes to prototypes.

  • Robust network of partners – Do ensure that the CM has a robust network of partners including raw board fabricators, component manufacturers and distributors. With a wide vendor network, you can be sure that the CM will deliver a quality product in the agreed timelines.

  • Engineering capabilities – A strong engineering team is a major prerequisite since they can resolve any issues that may be related to mechanical or electrical issues. In house competence will ensure that such issues are speedily resolved.

  • Production capabilities – Additionally once the prototype is done, the contract manufacturer must have the ability to mass produce the boards. You need to with a CM who is equipped with the latest technology and has experienced and skilled staff.

To Sum Up

To ensure that the PCB prototyping process is carried out with speed and accuracy there need to be enough checks and balances at your end. Right from choosing the right contract manufacturer to having the proof of concept in place and having robust documentation, can go a long way in rapid prototyping and offering a unique competitive advantage.

As a leading PCB manufacturer, at Mer-Mar Electronics, we offer rapid PCB prototyping services with superior facility, adherence to strict industry standards, best practices and faster lead times. If you have any queries regarding to our PCB prototyping services or need an urgent assistance, then please don’t hesitate to contact our team of skilled personnel’s. Send us an email with your queries at or call us at (760) 244-6149.

By Mer-Mar Electronics | Date posted: | Last updated: December 24, 2021

Flex PCBs are ubiquitous in their use these days. From finding a place in smart watches, mobile phones to industrial application, its usage will only increase, as miniaturization becomes a norm.

The big advantage of flex PCBs is that it can be fitted into space-constrained environments. In addition, they are suited for use in products where there is vibration, constant movement as also mechanical stress.

Additionally, Flex PCBs offer great electric performance. They have a low dielectric constant that allows electrical signal transmission. Their excellent thermal properties make the cooling of components easier, and a higher glass transition temperature ensures that components can operate in elevated temperature conditions.

Despite its advantages, however, designing of Flex PCBs comes with some constraints. For one, the set-up cost of manufacturing flex PCBs is higher. Let us look at some design tips for flex PCB prototypes.

Design tips for Flex PCB Prototypes

  • Due importance needs to be given to component placement. You need to be particularly careful of the spacing when the circuit is being bent. The use of 3D flex PCB design tools can go a long way in ensuring this.
  • In order to prevent vias from cracking, it is important that the vias be tear-dropped. Also, wherever anchors or tabs are added the annular rings need to be large.
  • Due to the flexible nature of the circuit, the pads are susceptible to lifting off the substrate. It, therefore, needs to be anchored. This is done by extending ties from the pad that are encapsulated by the coverlay. Also, large pad sizes work well as they help with stress relief. In fact, pads need to be larger than the drilled hole as the prototype could be subject to bending at different angles.
  • Traces need to be routed perpendicular to the bend line.
  • Mechanical stress needs to be spread evenly on all traces.
  • A large bend radius works much better than sharp angles. Curved traces cause lower stress than angled ones. Also, traces should be kept perpendicular to the overall bend.
  • A hatched polygon for the ground plane works much better than a solid-filled polygon plane. With a hatched polygon, the risk of copper cracking is significantly reduced.
  • The flex layers should be placed in the center of the stack-up. By doing so you tend to offer protection from exposure to outer-layer plating. It also eases manufacturing and improves impedance.
  • The thickness of the material needs to be determined taking into account factors such as size of the bend radius. As a thumb rule, the bend radius of a flex PCB shouldn’t be more than 10 times its thickness.
  • Impedance control is a challenge when it comes to flex circuits. Single-layer flex circuits can use a co-planar stripline construction. Two-layer flex stack-ups will benefit from a microstrip structure that works well for 50-ohm circuits. With higher layer counts you can create a stripline construction.

Some of the pitfalls to avoid at the design stage, when it comes to Flex PCBs include:

  • Considering flex at the end of the assembly as opposed to the beginning results in many issues including creating a more expensive flex.
  • Not taking into account Design for Manufacturability practices into account results in costly errors. Factors such as minimum line width/spacing, annular ring etc. must all have manufacturing allowances built into the CAD design.
  • Not taking into account the different tolerance capacities can have its implications. Very often, designs don’t take into account the realities of the material. Hole pattern locations, for example, can inhibit flexing.
  • Not having the documentation in order also leads to a number of issues. Whether it is not creating a comprehensive drawing package or improper revision control can all have their implications.
  • There are also electrical and mechanical design issues to be considered. Some of these include considering the number of flexes, balancing the electrical and mechanical requirements. For example, high-speed signals require thick substrates. Similarly, high current layers require thicker foil and adhesives.
  • It is also important to take into account the cost drivers such as the number of layers into account. Also, slight adjustments in shape can lead to cost differences, especially for larger circuits.

Taking the above aspects into account can go a long way in ensuring the efficacy of flex circuits.

Mer-Mar Electronics is one of the leading PCB manufacturing companies, providing services from designing to final prototypes. We follow industry’s best practices, ensure standard quality PCB assembly prototype that our clients do not deal with recall or rework. Ask your queries related to flexible PCB prototyping and flexible PCB fabrication services by emailing us at or call us at (760) 244-6149.

By Mer-Mar Electronics | Date posted: | Last updated: December 27, 2021
Prototype Circuit Board Assembly

With the use of PCBs becoming ubiquitous, what is important is the choice of the right material as that is what determines the functionality as well as durability of the PCB.

Let us first look at what are the elements involved in circuit board material.

Circuit Board Material

The circuit board foundation comprises the substrate and the laminate. The substrate is a non-conductive dielectric material. Laminates when used in conjunction with substrates provide the copper foil or surface material.

It is the substrate and laminate that together define the following:

  • Electrical properties
  • Mechanical Properties
  • Thermal properties of the circuit board

Needless to say, that a choice also has to be made of the most accurate board type to meet the bespoke requirements of the project.

Let us look at the various board types in some detail:


Especially when it comes to circuit board assembly prototypes, FR-4 is the most widely used material. In fact, FR-4 is a grade of material as opposed to a single material. Made of woven fiberglass cloth with a flame resistant epoxy resin binder, it is highly popular and versatile. It is known for its mechanical strength and its near zero water absorption. With its insulating qualities, it is widely used in a variety of applications and can work in different environmental conditions. Importantly, FR-4 also works well when it comes to affordability, durability, and performance.


Rogers as a company is known to manufacture laminate materials for circuit boards. Their laminates are known for cores that have high frequency properties. They are known for their performance as well as electrical properties. Besides, they offer several advantages such as:

  • Low electrical Signal Loss
  • Low Dielectric Loss
  • Better Thermal Management
  • Improved Impedance Control

Little surprise then that Rogers material is used for high-speed designs, RF, Microwave as well as Mobile and high-power situations.

Metal Core

As opposed to the widely used FR-4, metal core PCBs contain a base metal material. The major advantage offered by these PCBs is that the core can redirect heat away from the components. Heat Dissipation is therefore well managed.

Did you know; the metal core PCB is also referred as a thermal PCB, metal backed PCB or MCPCB.

The metal core of the PCB can be:

  • Aluminum Core
  • Copper Core
  • Mixture of Alloys

In case of requirements of high thermal performance, dielectrics are often being used. Metal Core printed circuit boards are also a great solution where cooling of LEDs is a priority. They are therefore increasingly finding application in lighting applications.


HDI boards have a high line distribution density. They are extremely helpful as they not only help reduce the weight and size of equipment, they also improve performance. With blind and buried vias and microvias, HDI PCBs is one of the fastest growing technologies. It lends itself to miniaturization of products and in improving their functionality.

High Tg material

Simply put, Tg or Glass Transition Temperature is the maximum temperature at which the substrate remains rigid. High FR4-Tg material therefore has better resistance to heat and moisture. With a greater adoption of RoHS (Restrictions of Hazardous Substance) PCBs, the importance of High Tg material is going up, as the lead-free solder needs higher temperatures. The High Tg PCBs offer improved stability of the device including the heat and moisture resistance.

How to choose the right PCB material for prototype circuit board assemblies?

As there are a wide variety of choices that are available, it is imperative to analyze the exact needs of your project to be able to use the right material.

The standard FR-4, for example, works effectively in most applications and is also affordable. For prototypes, specifically, this is the material of choice.

However, if you are looking for dielectric properties, Rogers Material will prove to be an excellent choice. High Speed Designs, RF, microwave, or mobile applications particularly benefit from Roger’s material.

An electronics project where heat dissipation is of prime importance will benefit from metal core PCBs.

Similarly, high-tech applications, dense packages, smaller and lighter products benefit from HDI material.

Last, but definitely not the least, high power density and heat generation will benefit from High Tg PCBs. These can also operate in relatively elevated temperatures.

The choice of the right material, of course, is the first and the most crucial step in prototype assembly. In that way, the prototype circuit board assembly will particularly go through close monitoring during the assembly process, so as to watch for any errors as also make any course corrections along the way.

We have over 40 years of experience in complete electronics manufacturing services from designing to final prototypes. We help our clients to select the best suitable material. We follow industry best practices, ensure standard quality PCB assembly prototype that our clients do not deal with recall or rework. In case if you have any requirements, get a quick PCB assembly quote, or get in touch with us at or call us at (760) 244-6149.

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