Sunday, November 8, 2015

Flexible PCBs Supporting the New Wave of Electronic Products

The electronics industry is witnessing a new wave of change. A number of miniaturized products are now available. Many commercial products are being designed to be worn by the user. At the same time, there is a demand for better speeds, and small packaging densities. All these aspects have to be taken into consideration by flex PCB manufacturers during PCB assembly. 

A Brief Look at one Application Industry
Let us take the example of the medical device market. This is one of the fast growing markets in the world. In this industry, you have equipment such as wireless healthcare units, and remote patient monitoring systems. Many of the devices used by doctors or patients are now wearable. These devices require miniature components, thinner materials, and custom circuit geometries.
For such requirements, the standard 1 ounce copper will not be equitable. With the reduction in densities, PCBs will need to be constructed with materials between 9 and 12 microns. 

The Solution for the Issue
Flexible printed circuit boards are the answer to this new requirement. Flex circuits can be designed in small sizes, thus assisting in the product miniaturization process. They can be designed in almost any thickness level, depending on the manufacturing materials. They are not limited by the standard PCB thickness ranging from .031 to .062ʺ. 

They can create strong interconnections, while supporting assembly and packaging processes. Overall, they provide a dynamic electro-mechanical solution. Flex PCBs are particularly useful for PCB assembly processes. They can be configured with repeatable conductors that ensure no errors in the assembly process.

These various points are the reasons behind the continual popularity of Flex PCBs. The points justify manufacturers choosing flex circuits rather than rigid PCB designs. With more custom flex designs being created by manufacturers, the new wave of electronics components will be extremely successful.
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Tuesday, September 22, 2015

4 Mechanical Components That Help Create Reliable PCBs

When designing a PCB, it is important to pay attention to the components and other supportive structures. Every product has some limitations. This takes place due to the raw materials used, technological drawbacks, or human errors. Either way, there are some factors beyond the control of current technologies. Hence, it is imperative that we identify these limitations and include design components that resolve them.

Modifications to Improve on Current PCB Designs
The following components can be included in a Printed Circuit Board Manufacturing to counteract its limitations:

1. Stiffeners
The weak points of any PCB are the soldered joints. Solder is inflexible and it can break when the application is in operation. Hence, stiffeners are used to support soldered components and joints.

2. PSAs
PSAs act as double sided tape helping affix the board within an enclosure. PSAs can be made available to dissipate heat, be electrically conductive, or shield from interferences.

3. RF & EMI Shielding
Some applications are EMI or RF sensitive. Hence, the PCB needs to feature protective layers to shield it from these radiations and interferences. Special films or silver ink layers can be used to shield the PCB effectively. The material can be chosen depending on the magnitude and intensity of these interferences.

4. Epoxy Strain Relief
If a bend is situated too close to the rigid board or a stiffener, there is a high chance that the circuit could break. A drop of epoxy on this interface can help in reducing the strain to a large extent, keeping the circuit intact.

These components not only counterbalance the limitations of materials, components, and technologies but also increase the efficiency and reliability of PCBs. You can incorporate these components to give your PCB a practical edge.
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Tuesday, April 21, 2015

5 Precautions to Take When Fabricating PCBs

Certain precautions need to be taken when working with Printed Circuit Boards (PCBs). These precautions need to be taken at all stages of PCB fabrication.

Precautions to Take When Fabricating PCBs

When working around PCBs, certain precautions needs to be followed for your own safety.

  1. The different steps involved in PCB fabrication are complex. Hence, it is important for the fabricator to work in a well-lit place. A visually enhanced workplace will ensure that the technician/ engineer work with maximum efficiency. 
  2. Since the PCB comprises many small components. It is imperative to work with forks and pins of the appropriate sizes. This will ensure accurate installation and keep you from causing any damage to the components. 
  3. Wearing the right safety gear will ensure that you are protected at all times. Wearing goggles is important to protect your eyes from any undesirable fumes emitted by the acids used, as well as from any parts that may fly off if not handled properly. Hand gloves are also essential during the entire fabrication process. Protective gloves will keep you safe from any harmful effects of chemicals used during the fabrication process. Most gloves will also provide you with better grip. 
  4. When checking the connection of the PCB, ensure that the power source is functioning well and is compatible with the voltage required by the PCB. Using the wrong voltage can lead to electric shocks, short circuits, and other such problems. 
  5.  As the final step, it is important to check all the connections and installation of the components. Loose connections are the primary source for short circuits. The components need to be firmly installed onto the PCB.

If you are unsure about any procedure, you should consult a manual, professional, or your vendor. Following these steps should help increase your efficiency when designing and fabricating PCBs. Safe and secure handling of the PCB is essential for your own safety as well as to create a well-functioning PCB.
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Tuesday, January 13, 2015

The Importance of Best Practices in Printed Circuit Board Manufacturing

The immensely growing competition in the printed circuit board manufacturing industry is creating a situation of ‘survival of the fittest’. Quality is still the name of the game, and companies are doing their best to ensure that they stay ahead.

While new technologies and custom designs will provide support, the inherent factor is the manufacturing process that is followed by companies. To ensure that the process always stays at a high level of excellence, best practices need to be followed.

Back to Basics

This is something you may have heard before. However, it doesn’t stop it from being true. Consistent use of practical techniques can provide superior results in printed circuit board manufacturing. Best practices can also be used in process analysis to identify any areas that need improvement.

  • Annular Rings: These can be used to help reduce costs when it comes to board thickness and drilled holes. Smaller holes mean that annular rings can be used to maintain performance and durability. The small size can lead to lesser costs for the customers. Generally, the annular ring widths are of 0.005″.
  • Greater Spaces and Traces: The smaller the size of the spaces and traces, the higher your costs will be. It is important that the spaces and traces be at 0.007″/0.007″ or higher. There should be space between traces and the ground plane, and the plane should be at least 0.020″ from the circuit board edge.
  • Changes in Documentation: Undocumented changes are one of the biggest causes for errors. This can lead to complete cancellation of the orders. When changes occur, your documentation should contain a revision number as a notation of the change. The change should be maintained throughout the manufacturing process.
  • Routing Patterns: The general gap between boards is measured at 0.100″. During routing, the hole, position, and patterns for the breakout tabs can be edited to help improve the product’s manufacturability.
  • Unplated Slots: Plated slots tend to increase the manufacturing costs, especially when they are specified in unnecessary places. Using unplated slots is better as there are no extra charges for them.
By carefully following these steps at the right time in design and production, one can easily improve the entire printed circuit board manufacturing process.
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Thursday, January 8, 2015

Why Design for Manufacturability is Important for PCB Design

If you own a company that provides PCB layout and PCB design services, then you probably use the term ‘Design for Manufacturability’ (DFM) quite a bit. Everyone in the PCB designing industry knows that DFM is a method used to create PCB products that can be easily manufactured. It includes a list of practices that are designed to benefit both the manufacturer and the end customer.

DFM has now become more important than ever. It is been a crucial aspect for creating good turnaround time on PCB designs. However, there is still a disparity between the PCB layout created by the designers, and what the fabricator needs to make a functional and durable product.

IPC has tried to solve this problem by creating DFX – Design for ‘X’. In DFX, the designers are trained to understand all the manufacturing aspects such as materials, processes, steps, etc. so that they create a PCB design that can be easily manufactured.

Why DFX is Vital for PCB Designers ?

While this can be quite a time consuming process, it is extremely important for designers to be aware of the fabrication process and the limitations within the same. This is particularly true when the board may be a flex or a rigid-flex type that is small in size. An example can provide more clarity on this subject.

If a PCB has narrow flex sections, the polyimide coverlay film would have to extend over the entire lamination of the board. This would lead to adhesive layers being used to adhere to the polyimide coverlay. If the PCB has three or more rigid layers, this would amount to an immensely populated PCB. Also, the adhesive layers would expand during the soldering process, thus, effectively covering the vias.

If a fabricator finds this, he would realize that the PCB would work ineffectively due to these problems. This would also lead to overtime as the designer would have to make changes first in his layout and then the PCB would be fabricated.

All of these problems can be reduced when the best practices of Design for Manufacturability are used throughout the PCB layout and PCB design processes.

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Monday, January 5, 2015

Specifications to Create Reliable Military Printed Circuit Boards

Printed Circuit Boards (PCBs) used in the military are designed in a manner to withstand extreme conditions. Military PCBs are designed in a manner so that they can perform in these conditions, work for extensive periods, and still last a long time.

Steps Taken To Enhance PCB Performance in Military Applications

Some very important specifications need to be kept in mind when fabricating heavy duty PCBs for military operations.
  1. Use of Thermal Compound: A thermal compound acts as an insulator by reducing the heat transfer. Application of which, also reduces the vibrations, reducing the formation of cracks on the soldering. Thus, it reinforces the structure by preventing the solder from cracking.
  2. Soldering Flange Mounts: Generally, flange mounts are hand pressed onto PCBs. Flanges in military specific PCBs are press-fit and then hand soldered to reduce vibrations and increase reliability.
  3. Pre-tinning of Wires:Pre-tinning is conducted to improve the reliability of wires. Stranded wires are dipped in hot melted solder to form a single consistent piece of wire. This makes the wire resistant to electromagnetic interference and increases its life.
  4. Resolving Heat Dissipation Issues: If some components dissipate more than one watt of heat, a spacer can be installed or the component can be mounted 20.00 mils away from the board.
  5. Application of Conformal Coating: An acrylic based conformal coating keeps dust, water, moisture and other contaminants away from the surface of the board.
  6. Increasing Volume of Solder Paste: The solder paste applied to the military PCBs must be 25% higher than the amount applied on commercial PCBs. This increases the reliability of the PCB as well.
Other than the above-mentioned steps, rigorous military level quality checks must be conducted. All divisions of the military use these PCBs. The applications range from land operations to aviation and marine activities. Some specific examples of such applications include temperature sensors, cyber counterintelligence systems, and radio communication systems. The boards designed for the military need to be reliable and have the ability to sustain rigorous applications and environments.
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Monday, December 15, 2014

Role of PLCC Plugs in PCB Interconnections

Numerous components are utilized in the design and production of mainstream and industrial electronic appliances. Printed Circuit Boards or PCBs are one of the vital components. Similarly, some components are used to support the PCB’s performance. Plastic Lead Chip Carrier or PLCC plugs are one such device.

Functions of a PLCC Plug

The PLCC plug is a high density plug, which serves the function of providing multiple electronic and mechanical connections. These connections allow the device and circuit board to communicate, thus providing seamless performance.

Generally, a PLCC plug is constructed from FR4 and plated brass materials. This construction designed to provide superior performance as well as cost-effectiveness. By rule, all PLCC plugs irrespective of size and shape are four-sided so as to allow maximum number of connections.
Micro-Level Functions of A PLCC Plug

One might wonder why a PLCC plug is so important. Well, this plug serves several functions on a micro-level. Some of these are listed below:
  • It allows a connection to be made between the printed circuit board and PLCC production socket.
  • The PLCC plug connects one circuit board to another.
  • It is used for testing, when trying to gain access to signals.
  • It decreases stress on target sockets.
PLCC plugs are cost-effective and more efficient in performance when compared to other chip-carrier packages. A PLCC plug is used to connect a PCB and a PLCC socket (where a PLCC circuit is installed). This process is completed using specialized hand soldering solutions like through-hole solder and surface mount solder.

Attention to detail is paid when manufacturing this component so as to enable flawless integration with the PLCC socket or circuit board. The PLCC plug can provide numerous electric connections at a time, owing to its high density.

Here, at A-Flex, we provide high quality, low cost PLCC plugs that ensure reliable interconnections. Along with supplying standard PLCC plugs, we also undertake custom orders of the same.
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