Tag Archives: printed circuit assembly companies

Printed Circuit Board

Printed Circuit Board Heat Sink Features/Functions

Heat management is essential for living on this earth as weather and devices affect buildings, vehicles, and equipment. Thermal management is also necessary for printed circuit boards, as they will get damaged if they can’t dissipate the heat their components generate. Besides, the board also gets hot due to soldering during manufacturing. Hence, heat dissipation methods become mandatory to increase the PCB speed.

Though FR4 is good at heat management, sometimes it is not enough when there is a high-speed circuit board. Likewise, the power supplies also generate heat and you have to install heat sinks and insulators. You must have experienced mechanical engineers to assess the heat flow to create a suitable heat dissipation system.

Printed circuit boards provide current to help devices function, but electronic devices get hot and heat sinks dissipate unnecessary heat. A PCB Manufacturer will use different heat sinks to prevent the overheating of PCB components and their damage, increasing the performance of the board.

Fourier’s law is an important law of heat that determines the heat sink function. When an element gets hot, heat travels from high-temperature areas to a low- temperature surface. The heat transfer occurs in three ways, such as:

  • Conduction
  • Radiation
  • Convention

When two components having different temperatures connect, it results in thermal conduction. In other words, fast molecules collide with slow molecules, resulting in heat transfer from hot components to cool components. PCB has high-temperature components like transistors, so you need to dissipate heat to cooling mediums, like water, air, or it can be oil, or some other element. This heat transfer occurs through conduction and convention.

Types of Heat Sinks

Heat sinks come up in different types as below:

Active Heat Sinks: There is a fan in an active heat sink to provide cooling. Such a heat sink provides great cooling, however, it needs regular maintenance as it is mostly running which affects its condition.

Passive Heat Sink: Passive heat sink is without a fan, so it remains still and needs less maintenance. You can consider it reliable and more effective than an active heat sink.

The shape and design also determine the type of heat sink, including swaged, stamped heat sinks, machining, folded and bonded fin, single fin sink, and forged heat sink.

Factors Affecting a Heat Sink

The main purpose of the heat sink is to exchange heat, so a large part of its surface area should be in contact with the cooling component like air. The quality of the heat sink depends on different factors, including its material, finishing, and certain physical features, like:

  • Air velocity
  • Attachment technique
  • Protrusion type

    Materials That Enhance Heat Sink Function

Manufacturers use specific materials to enhance the function of the heat sink in terms of heat transfer. These materials include:

  • Compounds
  • Conductive tape
  • Thermal paste

These materials are inserted between the surface of the heat sink and the surface of the component that generates heat. Metals having high thermal conductivity are ideal for heat sinks, including aluminum, copper, etc. But, aluminum is common as it is cheaper than others.

What To Consider Regarding Heat Sinks

Many factors affecting heat sink function include length, fin spacing and density, width, airflow, heat resistance, etc.

Which Devices Need Heat Sinks?

Electronic devices with components having poor heat dissipation ability need heat sinks. The devices in this case include multiple integrated circuits, diodes, transistors, switching devices, CPU and graphic processors, and LEDs.

Key Factors of Heat Sink Design

Heat sinks dissipate heat with the help of natural and forced convection, liquid, or radiation. The requirements of thermal management vary, depending upon the applications. Apart from a heat sink design, you have to consider several other factors while designing a thermal management system for a specific device. For like, you have to consider the standards of the component level, heat sink level standards, chassis levels, and requirements for a system level.

Let’s discuss essential factors that you have to consider during heat sink PCB design.

Heat Resistance: Thermal or heat resistance is the sum of multiple resistances occurring to heat flow between a cooling liquid and the die, thermal interference resistance, as well as the resistance between a moving fluid and a heat sink. Thermal resistance is bad for thermally unstable modeling systems.

The Value of Thermal Resistance: It is not precise, instead, it is approximate. It helps evaluate the thermal conductivity of the heat sinks and semiconductors. Heat dissipation depends on heat sink parameters that need proper analysis while designing the heat sink device. Heat sinks can be meshed through a 3D thermal resistance to have a complex system of thermal factors. Different platforms help design heat sink meshes.

Heat Sink Materials:  Generally, copper and aluminum are ideal heat sink materials as described above. These materials are good at conducting heat, especially copper as it also helps absorb heat, resists rust, and resist biofouling, moreover, it is also antimicrobial resistant. Though copper is better than aluminum, it is thick and costly compared to aluminum.

Another material is diamond and its thermal conductivity is also high due to the lattice vibrations it has. Some other materials for thermal applications include copper-tungsten pseudo-alloy, and AlSiCDymalloy.

Size and Shape of Heat Sink:  The shape and the size of the fins also help enhance heat dissipation. You can evaluate various fin shapes through modeling.

Fin Placement or Location: The arrangement of fins in a heat sink affects its cooling quality. Its configuration should be optimized to minimize the resistance of fluid movement, providing maximum air in the heat sink.

Cooling Quality: The cooling quality of the heat sinks has to be high. The aspect ratio of fins should be less to perform well. If the distance of the fin from the heat sink base is more, it will reduce the heat transfer to a cooling medium.

The function of the fins in a heat sink is to absorb heat from the electrical components of a device and sends it to the cooling medium. Besides, you should choose a cooling medium matching a PCB design and device requirements.

Heat Dissipation: Certain factors reduce the heat sink performance like a rough surface and gaps. They cause high resistance to thermal contact, thus affecting heat dissipation. You can reduce such thermal resistance by using thermal interface materials because most resistance-reduction techniques have limitations. You should consider specific things while selecting a thermal interface material, such as contact pressure, the material’s resistivity to current, and the dimensions of the surface gaps.

Attachment Methods: The attachment of the heat sink with PC Board components affects its thermal efficiency. So, you should choose the attachment technique carefully, considering the requirements of a thermal management system in terms of mechanical and thermal properties. Some popular attachment techniques include,

  • Thermal tape
  • Standoff spacers
  • Flat spring clamps

However, these attachment methods don’t end here as there are many others. You would also see m rein the future as engineers continuously update these methods according to new technologies.

By considering the above factors, engineers can design an effective heat dissipation system, including a heat sink.

Frequently Asked Questions

What Is Heat Sink?

The heat sink is a device and a way to manage heat in electronic products. Electronic components like transistors release heat, and you need heat sinks to dissipate heat to cooling mediums, like water, air, or it can be oil and other elements.

Do All Electronic Devices Need Heat Sinks?

Most devices need heat sinks to dissipate heat to cooling components. However, some electronic components have a built-in ability to dissipate heat. Generally, lasers or power transistors can’t transfer heat and need a solution to manage heat. MOSFETs and IGBTs are good examples in this case. So, here you need a heat sink device. 

Can PCB Survive Without Heat Sinks?

PCB components release heat which can damage them, making the electronic device slow. However, it also depends on the PCB materials as some have their heat dissipation property. Mostly you need a cooling system to enhance PCB performance. 

What Are The Types Of Heat Sinks?

The basic types in this case include the active heat sink system and the passive heat sink system. Some other types are also popular, like swaged heat sinks, stamped heat sinks, machining, folded and bonded fin, single-fin sinks, and forged heat sinks. 

Which Factors Influence The Heat Sink Design?

Many factors affect heat sink design, including its material, fin shape, and performance, fin size and location fin configuration, attachment technique of heat sink, and finally the thermal interface.

Final Thoughts

Devices having PCB also have heat sinks because they get hot due to high temperatures caused by different components. Heat sinks are either active or passive. You have to consider a few factors while designing the heat sinks, like its material, fin shape, and performance, fin size and location fin configuration, attachment technique of the heat sink, and finally the thermal interface. Various models help determine the heat sink parameters and geometry to provide a high-level heat transfer.

Would like to know more about the Heat Sink Features and Functions or pcb assembly services? Just Email us at sales@pnconline.com


Total Concept Company

PNC’s expertise in design, manufacturing printed circuit boards, PCB assembly, and Box builds in one 70,000 sq./ft. facility makes us the ultimate total concept company. PNC’s unique manufacturing facility is just that, a PCB assembly usa manufacturer located in Nutley, New Jersey. PNC has been a vital supplier of electronics in the PCB industry for over 50 years and serves the military/defense, medical, aerospace, automotive, RF/Microwave, industrial and consumer sectors. Having these capabilities all in-house stream lines the turnkey process under one PO which is invaluable to our customers.


Being able to design in-house has its importance when designing for PCB manufacturing as well as prototype pcb assembly and production PCB assembly. Our designers have an edge in designing for PCB manufacturing since they are knowledgeable of the PCB manufacturing process. Designing for manufacturability eliminates defects, delays and process issues. Our design tools used are Cadence Allegro, OrCAD Capture, OrCAD PCB Designer and PADS. Our deliverables are Gerber, drill files, PCB File, schematics, Assembly and fabrication files and Formal drawings on customer format.

Having the capability to manufacture printed circuit boards, pcb contract manufacturing, in the same facility also has its benefits for prototype pcb assembly and production PCB assembly. While the printed circuit boards are in process of being fabricated, our pcb assembly division can work in parallel creating pick & place data, SMT Stencils, work instructions, AOI programing, selective soldering programming, and pre-pare testing procedures to expedite the PCB’s once the hit the SMT assembly floor. The work in parallel process makes for an efficient seamless transition from PCB manufacturing to Assembly.


After the PCB’s clear final inspection, they are transferred to the PCB assembly department. For a pcb assembly manufacturer in a total concept configuration, logistically you gain 1-2 days shipping time, since you do not have to outsource the PCB’s as well as a time savings of not have to perform an incoming inspection. PNC’s Assembly division is comprised of multiple high speed SMT lines with 13 zone re-flow ovens, 3d AOI, 3D X-ray, thru-hole stations, selective soldering, and rework stations. If required, PNC can perform Flying probe, ICT and functional testing to ensure a robust and error free PCBA.

Another SMT assembly service with-in our total concept company is box building. The PCB assembly never leaves the facility eliminating any ESD issues from incoming inspection handling. Our expertise in box building varies from small plastic snap together housing, medium sized metal enclosures to rack builds. If provided with a system test procedure, PNC testing engineers and technicians can perform the functional and burn in testing. When looking for total concept printed circuit assembly companies, we are here to help.

Power Electronics: The Hidden Technology

In the last decade of 21st century, power electronics has seen a tremendous amount of growth due to smaller and accurate designs working at the heart of each and every electronic device, machine, appliance or system. The current arena of power electronics is dominated by providing the low noise accurate supply voltage rails and huge power handling capacity at higher efficiency in small factor.
Power electronics in layman terms is defined as the high power circuit design converting one level into different level of electrical energy. Power systems in current decade vary from range of mW (cellular mobile phones) to hundreds of MW. In the last few decades conversion of electrical energy has been done with the dissipative method where most of the energy is dissipated in the form of heat. These types of techniques use normally bulky passive components and huge heat sinks. The usage of huge heat sinks is due to huge amount of power loss and very low efficiency of previous design.


According to the latest surveys/research, currently 40% of the world power/energy are met with the usage of electrical systems, with more advancements in the field of renewable resources, the percentage will be going to shoot up to nearly 70-80% in the coming decade by 2025.The efficiency of power equipment varies from 90% (small design) to 95-98% (big complicated design models). Due to rapid advancements in the field of technology, the cost of the circuit and size is reducing at a faster rate and providing more efficiency as compared to the previous possible designs.

Challenges in Designing Power Electronics

The major challenges in the field of power electronics are cost, reliability, parasitic losses and electromagnetic interference. Areas like aerospace industries, automation and robotics industries has posted the biggest problems in front of power engineers because in order to fulfill the safety requirements. The safety requirement is the most difficult and unsolvable challenge in many fields involving power electronics devices.

The old technology of linear dissipative regulator is reliable as compared to newer regulators since new regulators used the bulky capacitors and lesser amount of shielding in the circuit. If due to some fault, larger supply is fed to the circuit then it will suddenly increase the current in the design which will lead to damaging and even burning of the complete circuit.


Even the latest MOSFETS or transistors, available in the market comes with very low power wattage i.e. 0.5 W or 1W (at max) in order to provide the cost effectiveness but this make the circuit more prone to damage since even small deviation from the expected behavior can lead to damaging the complete circuit. Ex- observed in the latest gadgets like LED TV’s, Mobile phone (since in order to provide cheaper designs, they are using the devices at the bottle neck of their limits).


Electromagnetic Interference in layman terms is defined as the amount of noise/disturbance produced by a power circuit due to change in one of electromagnetic radiation or induction. EMI must be kept in safe level to ensure the reliable operation for the given design.

Issue: Power supplies generate lot of noise in the circuit due to switching current at high operating frequency and most dependent customer being MOSFET for the same. Due to MOSFET, the switching speed is very high varying from 200 KHz to 100 MHz range. The generated EMI due to noise can be characterized as Differential and Common Mode Input

  • Differential Mode Input–It basically consists of in and out of flowing current through the power supply by the path going from power lead to the source. It is the dominated in lower frequency range i.e. less than 5 MHz
  • Common Mode Input – – It basically consists of in and out of flowing current through the power supply by the path going from power lead to the source through the lowest impedance path i.e. ground. It is the dominated in higher frequency range i.e. greater than 5 MHz


Minimizing EMI


  • Bypassing – Bypassing is one of the most effective and cheapest method to tackle this problem. Used for reducing high switching current in the case of MOSFET with the help of large and bulky capacitor.
  • Decoupling –Decoupling refers to isolation of two circuits with the help of a common line. It is implemented using low pass filters.
  • Layout –Increase the distance between VDD and ground plane at the time of chip layout in order to reduce the EMI, reducing the inductor can also provide minimizing the EMI.
  • Shields –Reducing the energy requirement from DC-DC supply by putting a metallic shield outside the power supply.

The single biggest failure for any network/system is power supply which major comprises of the below listed factors

  • Internal supply failure- The Internal Supply failure issue arises in the case of ill-handling the devices but mostly to prevent this problem, there is an automatic shut off system inbuilt in our Laptops and other electronic devices.
  • Voltage Irregularities– Most commonly consists of high voltage spikes, surges and delay in either input paths which switches the logic value.
  • Outraged Power –Mostly external power failures due to change in supply voltage from the plugs can cause outraged power. This will happen for short span of time varying for some seconds to minutes.