Importance of PCB insulation in PCB manufacturing!

By | Date posted: | Last updated: September 8, 2022
PCB insulation

While the use of PCBs is ever increasing, what is also increasing is the heat that is generated by them. In fact, a large percentage of printed circuit boards are known to fail on account of the heat. The need to insulate PCBs is therefore paramount. Insulation helps provide protection against changes in temperature.

PCB Insulation is the process of using a dielectric material to offer the much-needed coverage that does not allow for contact with electrical conductors and helps separate & isolate conducting elements & layers. When the PCB is rightly insulated it also protects the non-conductive metals from corrosion.

Major objectives served by insulation of PCBs

The major objectives served by insulation of PCBs include:

  • It ensures there is no signal interference between adjoining layers.
  • It supports voltage integrity.
  • It ensures suitable thermal delivery & aids in PCB operation.
  • It helps maintain adhesion during the cycling of assembly temperature.

Categories of insulation coating materials

Some of the insulation coating materials commonly used include:

Epoxy Resin Coating

This is known for its strength as also its resistance to corrosion, moisture & temperature. However, it is important to remember that this isn’t too suitable when it comes to cold conditions, as it is known to shrink. Additionally, any alterations are difficult as it needs to physically stripped and can cause damage.

Polyurethane Coating

This coating is known for its durability & resistance to acids. However, the flipside with this is that rectifying any PCB defects with a polyurethane coating is tough.

Organic Silicon Coating

This is highly suited for high-circuit PCBs. The fact that it is pliable & is resistant to moisture & heat adds to its advantages. On the other hand, however, it is not known for its mechanical stability as well as its inability to resist corrosion.

Parylene Coating

This works very well for high frequency PCBs especially as it provides total cover. The only thing that stands in the way of its wide application is its cost.

Acrylic Acid Resin coating

This coating lends itself easily to any modifications & is also known for its affordability. The additional advantage that it offers is that it is moisture resistant & also dries quickly.

PCB Insulation Materials

Let us also take a look at the commonly used PCB insulation materials:

FR-4

Fabricated from entwine fiberglass, it is known for its flame-retardant coverage. The fact that it is also cost effective explains its widespread use.

FR-2

A blended material fabricated from paper & plastic carbolic acid; it is known to be long lasting and works well for single sided PCBs. It is also extremely cost effective.

Radio Frequency Coating

As their name suggests they are well suited for PCBs that enable high radio to frequency & find wide use in in-flight & other such electronics.

Flex

For flexible circuit boards, Flexible and thin plastic is typically used as substrate. Flex circuits are often protected by PCB insulation coating spray.

Metal

Metals are conductive in nature hence this may seem like a strange insulation option. However, metal substrate works well for insulation of PCBs. Being good conductors of heat & electricity, they ensure the current is handled without burning or breaking it.

Factors to be considered for material selection, Insulation thickness and layer signals

If thin insulation is used, it helps to have the ground layer adjacent to the signal layer to reduce EMI. In case of a thicker dielectric however, two signal layers can be routed on adjacent layers, provided traces on one layer is routed perpendicularly.

Type of board

For most board types, FR4 works well. However, especially for high-speed boards, controlled impedance can be a factor. In such cases the height of the PCB insulation is important.

Overall board height

The number of layers, insulation type & board height all go a long way in being able to make the right choice.

Thermal Cycling

Yet another factor is the number of times the board is exposed to high temperatures cycling.

To sum up

PCB insulation goes a long way when it comes to ensuring the durability as well as the integrity of PCBs. With PCB insulation ensuring that heat is channelized away from sensitive components, optimal operation of the PCB & hence of the electronic device is a reality.

Technotronix provides a one-stop solution for PCB manufacturing services with specialized support, reliable testing, and multi-functional features. In case if you have any questions, please feel free to contact us via email at [email protected] or call us at 714/630-9200.

What makes flexible PCB board the best choice for satellite applications?

By | Date posted: | Last updated: November 11, 2022
Flexible PCB Board

When it comes to satellite applications, the use of flexible PCB boards is only growing! Not without reason! There are a large number of benefits that are pushing industry players towards the adoption of flexible PCBs. From reduced weight to increased reliability, there are a whole lot of advantages that flex PCB offer. Before we look at some of these advantages in detail, let us first understand how a satellite operates:

How does a satellite operate & what is its use case?

The satellite system has 3 main circuitries, namely:

  • Satellite
  • Receiver
  • Transmitter

While the communication between a satellite & transmitter is referred to as uplink, the one between the satellite & receiver is referred to as downlink.

The use cases of satellites include:

  • Disaster risk management
  • Weather Forecast
  • Remote Sensing
  • Geo-Positioning
  • Navigation
  • Telecommunication
  • Emergency Response Monitoring

Satellites, in turn, can be of 3 types, Fixed, Mobile & Broadcast, depending on the services they offer. A Fixed Satellite Service uses fixed receiving stations. These are primarily used in cable TV and internet stations. Mobile satellite services also deal with mobile systems for communication with fleet vehicles. Broadcast Satellite Service broadcasts TV & radio signals.

Given the functions that satellites perform, let us now look at the need for flex PCBs in satellite applications.

Advantages of using flexible PCB board in satellite applications

Reliability

Satellites represent mission critical operations and failure can come at an extremely high cost. It is imperative therefore that the PCB being used is extremely reliable. With flexible PCBs being able to withstand higher stress than rigid ones, they are suited for use in satellites that are subject to harsh environmental conditions. Additionally, Flex PCBs take away the use of connectors, which often cause interconnection failures. You are therefore assured of reliability when it comes to the use of flex PCBs in satellites.

Adaptability

The big advantage that flex PCBs offer is they are extremely adaptable, and land lends itself to shapes that ’t regular. Flex PCBs can fit into different surfaces that they are mounted on. However, this is not possible with rigid PCBs that cannot be used in complex shapes.

Their flexibility also comes in handy when you need extensible parts. With flexible circuits you can make use of expendable equipment without any fear of wear & tear.

Lightweight

With thinner copper layers as well as insulating layers, flex circuits are lightweight and can also adapt to tighter spaces with low bend radius.

While flexible circuits are made out of many materials, Kapton is particularly widely used because of its light weight. In addition, it is also known for its mechanical properties as well as vibration resistance.

While Flex PCBs are therefore well suited for use in satellites, it is imperative that PCB designers take the following conditions into account while designing PCBs for satellites:

Operating Temperature

It is important that the material chosen for PCBs to be deployed in satellites is suited for the harsh operating conditions. In fact, the material chosen should be able to survive in elevated temperatures of 120 degrees Celsius, or more.

Outgassing

When a PCB operates in a high-pressure environment, the gases trapped in the PCB are released. The gas released can condense on other sections and cause operational issues. It is therefore important to choose a material with good thermal resistance so that outgassing is controlled.

Orbital Collisions

With satellites, orbital collisions can be a reality. The PCBs should therefore be able to withstand such collisions. To ensure that, the flexing capacity of the PCBs should be high.

PCB standards for use in satellites

Because of these unique issues, there are specific standards when it comes to space applications. The common standards include:

AS9100

Created by the International Aerospace Quality Group, this standard is useful for creating products for the aerospace industry. AS9100D is the latest standard that the aerospace industry needs to adhere to.

The other standards that Aerospace as well as military-grade PCB assemblies need to adhere to include:

  • MIL-PRF-50884
  • MIL-PRF-31032
  • MIL-PRF-55110

To sum up

Rigid flex & fully flex PCBs offer several advantages over traditional PCBs. Their innovative design, reduced weight and more make them an ideal choice. It not only helps to minimize the size of the spacecraft but also improves reliability.

We have over 40 years of fabricating and assembling a wide variety of flexible aerospace PCB assemblies. With state-of-the-art equipment, we deliver the highest quality boards that you can rely on. Armed with an experienced flexible PCB board manufacturer team that can advise you on industry best practices, what you get when you join hands with us, isn’t just a vendor but a partner who is invested in your success. In case you have any questions, please feel free to contact us via email at [email protected].

Top signs that indicate that it is the time for a circuit board test!

By | Date posted: | Last updated: August 26, 2022
Circuit Board Test

The flawless working of a PCB is the key to the reliable working of any electronic equipment. It is therefore imperative that you be watchful of signs that indicate that your circuit board is faulty & that indicate that it is time for a circuit board test. Here are the aspects to look out for:

Common signs and causes of PCB failure:

Burnt Components

When the PCB needs to work under extreme temperature conditions, burnt components can be a reality. There are several factors that can result in burning of components, important among them being:

  • Area surrounding the component
  • Shape & size of the component

Overheating of components is a sign that all is not well with the PCB. Not paid due attention to, it can lead to operational issues.

Issues during manufacturing of PCB components

Issues in either the manufacturing of components or their improper placing can result in a number of issues. Some of the common issues faced include:

  • Improper soldering
  • Chemical leaks
  • Poor connectivity between layers
  • Loose components
  • Other human errors

An easy way to check for any issues with SMT components is to conduct a dye- and- pry test. It will go a long way in telling you about the issue & how the device is being impacted because of it.

Environmental Factors

In assembling electronic components, it is extremely important that environmental conditions are controlled. For example, humidity in the room can lead to a wide variety of issues. Similarly dust & heat can impact the PCB, as can issues such as an accidental fall. Some of the other causes that can lead to malfunctioning of PCBs include accidental submersion in water or exposure to lightening, for example.

Also, overtime dirt can accumulate in the PCB & cause it to malfunction as also reduce its lifespan.

Age of components

As components age, circuit boards can eventually fail. In fact as components reach end of life, malfunctioning can increase many fold. Component replacement at this stage may therefore become a reality.

Armed with this information about potential causes of PCB failure, the importance of printed circuit board testing cannot be overstated. Testing can reveal issues that can be addressed through rework & repair.

If you already suspect that your circuit board may be faulty on account of the above reasons, what then are some of the recourses available to you?

What to do in case of a suspected faulty circuit board?

1. If the board’s electronic components are in place, the first thing to do is to test the board with its power on.

2. In case electrical components have not been installed, the power needs to be shut and the connection wires cut, before the board is inspected.

3. It is important to check the circuit board for any visible signs of damage. Signs can include components that are crushed, wires that are cracked, any burn marks or scratches and more. Scratches can damage connections while misplaced solders can disrupt connections or even cause a short circuit. In case such signs are visible there is no need to continue the testing. Instead the damaged parts need to be immediately replaced.

4. Switching the circuit board on & checking for the voltage of all connections with an oscilloscope is an important step. Voltage probes need to be applied to the end of each connection so as to be able to identify the issue.

5. In case connections aren’t conducting the specified voltage, what is indicated is a bad connection.

To sum up

Over a period of time, PCBs can undergo damages that can impact their functionality and therefore the functionality of your electronic device. Timely testing can ensure that the board is repaired or reworked. Of course, understanding the exact issue is the vital first step to be able to make the necessary repair. Knowing the signs of PCB failure can therefore go a long way in ensuring that you take timely action & that the functioning of your equipment isn’t compromised. Needless to mention, that in mission critical operations timely testing & necessary action can be life saving.

TechnoTronix is an ISO 9001:2015 certified company who delivers one-stop PCB manufacturing services with specialized support, reliable testing, and multi-functional features. Our main strength lies in the extensive experience and skilled team of experts to provide error less and lead-free PCB 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 are the design considerations and guidelines of round circuit boards?

By | Date posted: | Last updated: November 11, 2022
Round Circuit Boards

Today, PCBs are available in a wide range of shapes, even though square and rectangular PCBs remain the most common. With the ever-developing electronics industry, the one shape that is gaining prominence is round PCBs.

As the name implies, a round circuit boards is a PCB that comes in a circular shape. It is often used in consumer electronics, wearable devices and more.

The advantage with round PCBs is that it offers increased board space. Fabrication of round PCBs however requires a lot of care since it is a complex process. In fact, the routing process of a round PCB requires a lot of time. All of this also has a repercussion in terms of the overall costs of round PCBs.

Types of Round PCB

Round PCBs, in turn, are of different types. These include:

  • Single-sided PCBs
  • Double-sided PCBs
  • Multilayer PCBs

A single sided round PCB comes with one conductive copper layer. This type of PCB is extensively used in low-density designs. Such a PCB has components on one side of the board while there is a conductor pattern on the other side. Such PCBs use either through-hole or surface mount technology.

Double-sided round PCBs have conductive layers on two sides of the board. They are extensively used when it comes to applications such as wearable devices, lighting systems & more.

A multilayered round PCB has more than two conductive layers. Even though they are the hardest to fabricate, they offer multiple advantages including:

  • They lend themselves to higher density.
  • They offer increased board space.

Round PCB Design

It is a given that round circuit boards are more complex when it comes to the design bit. Thankfully though there are few tools available that aid the design of a round PCB. There are several design rules, however, that need to be followed when it comes to round circuit boards. For example, the perimeter of such boards can only be shaped with a straight-line segment. Also, in arranging the lines of the perimeter, a circle needs to be placed on the silkscreen layer. Let us look at some more PCB layout and design rules in detail:

Round Circuit Board Design Rules

  • First & foremost, when using the CAD tool, it is important to draw the shape in the CAD tool.
  • Of course, if the round circuit board is being designed for a high-speed appliance, your choice by default will have to be a multilayered printed circuit board.
  • The power and ground planes need to be defined in separate layers. A polygon editor can go a long way to define the shape of ground or power planes.
  • Some software also offers the option of customizing the power & ground planes.
  • What also needs to be kept in mind is that round circuit boards need panelization schemes for their design.
  • To panelize a round PCB, break routing is widely used. It is imperative that a 10 mm (about 0.39 in) clearance is kept between the round circuit boards. With a larger routing tool, however, the clearance can be increased.
  • As far as the mounting technology goes, both SMT (Surface Mount Technology) as well as THT (Through Hole Technology) can be used to place components, although SMT is better suited.

To sum up

Overall with Round PCBs, designers have a lot of flexibility. The added advantage also is that there is the possibility to incorporate more features as you go along. Also, with the help of CAD tools the designer can add pad shapes in the circuit board.

While such boards are complex to design, the use of the right software can aid the designing process. Following design rules & best practices can also go a long way in making eth process seamless. It is also imperative that you deal with a professional electronics contract manufacturer who is involved in the PCB design phase itself. That way, the manufacturer can assist you with the best practices & point out any design flaws early, so that you do not have to contend with any costly issues at the fabrication stage. Needless to mention that design issues once the board is manufactured can sometimes even lead to irreparable damage to a company’s reputation.

At Technotronix, we are fully equipped to handle your PCB manufacturing requirements. With over four decades of experience in delivering high-quality, on-time, competitive price products, you can rely on us for your PCB requirements. In case you have any questions, please feel free to contact us via email at [email protected] or call us at 714/630-9200