Aluminum PCB Board Manufacturing Service
Aluminum PCB Prototype | MCPCB | Single-sided Aluminum PCB | Double-sided Aluminum PCB | Multilayer Aluminum PCB | LED Aluminum Base PCB | COB Aluminum PCB | High Thermal Conductivity Aluminum PCB | Ultra-long Aluminum Substrate PCB
Metal core PCBs have gotten massive attention due to their heat dissipation features and durability. Aluminum PCB is the most prevalent metal core PCB nowadays. It is used for many applications, but the most common form is in the LED circuit and other high-power circuits. Today, we are going to discuss Aluminum PCBs in detail.
What is Aluminum PCB?
Aluminum Printed Circuit Board, Recognized Best Solutions for High Power and High Thermal Conductivity
Aluminum PCB is just like a common PCB; the only difference is in the base material. The base material in the aluminum PCBs is aluminum, which has more excellent heat dissipation capability, durability, and dimension stability.
Normal PCBs cannot handle high temperatures, and due to high heat-dissipating components, they bend quickly. Therefore, it’s necessary to use aluminum PCB where high temperature or heat dissipation is expected.
Aluminum Based PCBs are a unique metal-based copper clad laminate. These types of Printed Circuit Boards have good thermal conductivity, electrical insulation, and excellent machining performance.
According to the different design structures and application scenarios of aluminum PCB, there are mainly single-sided aluminum PCB, double-sided aluminm PCB, Flexible aluminum PCB, mixed aluminum PCB, multi-layer aluminum PCB, through-hole aluminum PCB, and so on.
As a printed circuit board Manufacturer in China, JingHongYi PCB has rich experience in manufacturing aluminum PCB boards. It provides customers with high-quality aluminum substrate Manufacturing and one-stop aluminum PCB turnkey assembly services, prompt delivery on time, and competitive prices.
Aluminum PCB Design: Stackup, structure and layers
Aluminum PCB consists of three layers: the copper layer, dielectric layer, and aluminum base layer. There can be a fourth layer, which is known as the aluminum base membrane layer. The membrane layer protects the aluminum from scraping, scratches, and unwanted etching.
Aluminum PCB Structure
- Copper Layer: At the top of the aluminum PCB, there is a copper layer, which creates the circuit. The layer is common in all types of PCBs, including FR-4. It offers the electrical connection and conductivity of current among the components.
- Dielectric Layer: Aluminum can also conduct electricity; therefore, a dielectric material is used between the copper layer and the aluminum layer. This layer can be of different materials depending on the temperature range. Although this layer is electrically insulated, it can conduct heat efficiently. It has excellent thermal conductivity to hold the heat from the components to the aluminum layer.
- Aluminum Base Layer: This is the most crucial layer of the PCB. It provides thermal conductivity, durability, and strength to the PCB. The layer is made of aluminum substrate. The substrate can be of different types, such as Aluminum 505, Aluminum 6061, etc. You can choose the perfect aluminum substrate according to your requirements.
- Aluminum Base Membrane Layer: The aluminum base film is selective. It has a protective effect by protecting the aluminum surface from scratches and unnecessary corrosion. It has two types, namely less than 120 degrees or about 250 degrees (high-temperature resistance)
Aluminum PCB Stackup
Schematic diagram of heat dissipation of aluminum Core PCB
Common LED PCBs or Aluminum PCBs have front and back sides. The white side is for soldering the LED pins, and the other side is the color of aluminum. Generally, a thermally conductive paste is applied to contact the thermal conductive part. Aluminum PCB is mainly used in LED lamps and audio equipment, power supply equipment, etc. The main advantages of aluminum PCB are fast heat conduction and good heat dissipation performance.
Advantages of Aluminium PCB
There are various advantages of aluminum PCBs, some of them are,
Aluminum PCBs are much cheaper than other metal core PCBs. They have higher thermal conductivity as compared to commonly used FR-4 PCBs. In contrast, if you use copper or stainless-steel PCBs, then it will be higher in cost. Thus, you can save money by getting the cheapest type of metal core PCBs. The reason behind the low cost is that aluminum is easily available and has a low cost as compared to other metals used for MCPCBs.
Aluminum is used because of its high thermal conductivity. It can easily dissipate the heat generated by the components on board. It can withstand high temperatures. The dielectric conducts the heat from the components and helps in dissipating the heat. Thus, it protects the components working on the board and can increase life. Moreover, there is no need to use heat sinks. If your PCB needs many heat sinks, then a better option could be aluminum PCB. It could save you money.
The problem with the FR-4 board is that they cannot retain their shape at high temperatures. The board starts to bend, and it cannot retain its dimensions. On the other hand, the aluminum board can retain the shape under temperature and pressure stress.
Aluminum is environmentally friendly, and there is no harm in using it. It’s according to international standards. It’s 100% non-toxic. It can also be recycled.
Aluminum PCBs are durable. They can withstand wear and tear and extreme temperatures. Aluminum is much stronger than a common FR-4 substrate, and it has a high capability of preventing accidental damages. It can handle more pressure and stress. There is a very low probability of the breakage of the board.
Aluminum has a very lightweight as compared to copper and stainless steel. So, the final product can have less weight.
Disadvantages of Aluminum PCBs
- Indeed, there are many benefits of Aluminum PCBs, but there are some disadvantages. The disadvantages cannot beat the advantages, but it’s important to discuss them.
- The first disadvantage of the PCB is that its cost is more than FR-4 PCBs. The reason is simple, which is the use of aluminum. If your project can work with normal PCBs, then you should not invest money on aluminum PCBs. It will save you money. But if the project needs a high thermal conductivity, then there is no choice, and aluminum is the next feasible option. The other reason for the high cost is the manufacturing process. The process is a bit more complicated than manufacturing normal PCBs.
- The next disadvantage is the limitation of the layers. You cannot have as many layers as you want for an aluminum PCB. Usually, there is only one layer. But there can be two layers as well. You cannot expect more than two layers in aluminum PCBs.
Aluminum Base PCB Performance
- Better heat dissipation and conductivity: Compared with ordinary FR4 PCB, aluminum PCB has excellent heat dissipation performance. For example, Fr4 PCB with a thickness of 1.5mm will have a thermal resistance of 20-22 degrees per watt, while aluminum PCB with a depth of 1.5mm will have a thermal resistance of 1-2 degrees per watt.
- There is no serious problem of thermal expansion or contraction: each substance has its coefficient of thermal expansion. The CTE of aluminum (22ppm/C) and copper(18ppm/C)is quite close. Since aluminum PCBs work well in terms of Thermal dissipation, they do not have the severe expansion or contraction issues. They work excellently and are durable and reliable.
- Dimensional Stability: aluminum PCBs show dimensional stability and stable size. For example, when they are heated from 30-140 degrees, their size only had a change by 2.5%-3.0%.
- Others: Aluminum PCBs can be used in power device surface mount technology. They are valid for use in circuit design because of their performance in terms of thermal expansion of circuit design. They help to prolong product shelf life and product power density. They are also extremely reliable. They can help to shrink the overall volume of the product and is also a cheaper option. They show electromagnetic shielding and high dielectric strength.
Aluminum PCB Circuit Board Applications
- The most common use of aluminum PCBs is where high heat dissipation is required. Aluminum can dissipate the heat and omit the need for heat sinks. It can be cost-effective and a reliable option to manage the heat of the board. The heat generated by different components can be quickly dissipated with the help of the dielectric material. Thus, the parts never experience high thermal stress; it increases the life of the elements.
- Nowadays, aluminum PCBs are mostly used for LEDs(LED PCB). It’s primarily used in LED lights, lamps, tube lights, car lights, etc. LEDs dissipate a lot of heat, and they cannot work on common PCBs; thus, they need a metal core PCB.
- Other than LEDs, aluminum PCBs are used in the power supply. They are used to make DC/DC and DC/AC converters. The other applications are in automotive, telecommunications, computers, power modules, and many other sectors.
Electronic regulator, ignition, power supply controller, etc.
Switching regulator, DC / AC converter, SW regulator, etc.
Inverter, solid-state relays, rectifier bridges.
CPU board, floppy disk drive, power supply devices, etc.
Motor drive, etc.
Input, output amplifier, balanced amplifier, audio amplifier, pre-amplifier, power amplifier.
High-frequency amplifier, filtering appliances, the transmitter circuit
As the advocated promotion of energy-saving lamps, aluminum PCB used in LED lights also begin large-scale applications.
Types of PCB Aluminum Board
There are several types of aluminum PCBs which are used in many applications based on their construction and design. However, the primary purpose of all the aluminum PCBs is almost the same; providing heat dissipation solutions for the applications involving high temperatures.
The following are the main types of aluminum PCB.
Flexible Aluminum PCB Board
Firstly, Flexible aluminum PCB is a new flexible dielectric developed in the development of aluminum products. It is also a kind of flexible circuit board. Because of the combination of polyimide resin and ceramic filter, it has high flexibility, thermal efficiency, and excellent electrical insulation. When used in aluminum PCB products, the expensive cables and connectors no longer need to be used.
Flexible circuit boards have unparalleled flexibility, so flexible aluminum PCB can be arbitrarily folded, twisted, or formed in any other desired form.
However, it should be noted that once a specific shape is created, it can no longer be changed like other conventional flexible circuit boards or deform.
Classification of Aluminum PCB
Aluminum PCBs are mainly divided into three categories.
- Universal Aluminum PCB: the dielectric layer used here is made up of epoxy glass fiber pre-preg.
- High Thermal-Conductive Aluminum PCB: the dielectric layer is made up of epoxy resin. The resin used must have high thermal conductivity.
- High-frequency Aluminum PCB: the dielectric layer is composed of polyolefin or polyimide resin glass fiber pre-preg.
Hybrid Aluminum PCB Board
In hybrid aluminum construction, nonthermal material is processed and refined separately before it is applied to the thermal materials with aluminum base.
The most common practice is developing a two-layer or four-layer structure which comprises of FR4 material.
A nonthermal material that is bonded with thermal material and the aluminum base provides rigidity and helps in the dissipation of heat.
This nonthermal bonding is preferred over using all thermal materials because it features less cost and encompasses efficient thermal conductance over regular FR4 products.
No heat sinks or assembly steps are required for the development of this product.
Through-hole components can be easily adjusted using component windows on the aluminum base.
This helps in passing the cables and connectors through the substrate. Also, the seal created by solder fillet eliminates the need for costly adapters
Multilayer Aluminum PCB Board
Multilayer Aluminum PCBs are ubiquitous in power supply products and come with multiple layers of thermally conductive dielectrics.
These materials are beneficial when they are combined with one or more layers of circuitry in which thermally conductive dielectric is buried between the sheets with the help of blind vias, which also act as a signal or thermal vias.
Single-layer construction of these designs is not very active; however, when they come with more elaborate designs, they provide an ideal solution for many applications involving heat dissipation.
Through-Hole Aluminum PCB
When it comes to most complex constructions, a single layer of aluminum is back-filled and pre-drilled with before applying lamination, forming a Core of a multilayer construction.
Thermal bonding materials are then used for laminating the thermal materials on both sides of the aluminum.
Once lamination is done, drilling is applied to the assembly.
To maintain proper electrical insulation, the plated through holes created as the result of drilling must pass through aluminum clearances.
Aluminum PCB Manufacturing
The following table presents some of our Aluminum Core materials:
|Items||Performance Index (Measured value)|
|Peeling strength (n/mm)||1.8|
|Insulation resistance (ω)||>1*10 g|
|Breakdown voltage (VDC)||>2 k|
|Soakable soldering (°C/m)||280°C / 260°C, 1 min, no bubble & delamination|
|Thermal conductivity (ω/m-k)||>0.8|
|Thermal resistance (°C/ω)||< 1.2|
|Dielectric constant (1mhz)||4|
|Dielectric loss angle (tangent)||0.03|
Can the aluminum in the aluminum substrate be replaced with other materials? Such as copper, stainless steel, iron, or silicon steel plates? What kind of metal is used as the PCB substrate, in addition to its heat dissipation performance, the thermal expansion coefficient, thermal conductivity, strength, hardness, weight, surface condition, and cost of the metal substrate must also be considered.
Under normal circumstances, considering conditions such as cost and technical performance, aluminum is the best choice. Available aluminum models are 6061/5052/1060 and so on. If there are higher thermal conductivity, mechanical properties, electrical properties, and other special performance requirements, copper, stainless steel, iron, or silicon steel can also be used as the substrate of the circuit board.
Check our Aluminum core PCB manufacturing capabilities:
|Quality Grade||Standard IPC 2|
|Number of Layers||1- 24 layers|
|Order Quantity||1pc – 10000+pcs|
|Build Time||2days – 5weeks|
|Material||Aluminum core (Domestic 1060), Copper core, FR4 covering|
|Board Size||Min 6*6mm | Max 610*610mm|
|Board Thickness||0.8mm – 5.0mm|
|Copper Weight (Finished)||0.5oz – 10.0oz|
|Solder Mask Sides||As per the file|
|Solder Mask Color||Green, White, Blue, Black, Red, Yellow|
|Silkscreen Sides||As per the file|
|Silkscreen Color||White, Black, Yellow|
|Surface Finish||HASL – Hot Air Solder Leveling|
|Lead Free HASL – RoHS|
|ENIG – Electroless Nickle/Immersion Gold – RoHS|
|Min Annular Ring||4mil|
|Min Drilling Hole Diameter||6mil|
|Other Techniques||Countersink holes|
Aluminum PCB Vs. Fr4 PCB, How to Choose?
Compared with the traditional FR-4, the aluminum base PCB can minimize thermal resistance. Therefore, the aluminum-based PCB has excellent thermal conductivity; compared with the ceramic-based PCB, the mechanical properties of the aluminum substrate PCB are incredibly excellent.
Advantages of aluminum base PCB compared with FR4 PCB
In addition to good heat dissipation performance, aluminum PCB also has the following advantages:
- Comply with RoHS environmental protection requirements
- More suitable for SMT process
- Higher current carrying capacity
- Highly effective treatment of thermal diffusion in the circuit design scheme, thereby reducing the operating temperature of the module, prolonging the service life, and improving the power density and reliability;
Reduce the assembly of heat sinks and other hardware (including thermal interface materials), reduce product volume, and reduce hardware and assembly costs; optimize the combination of power circuits and control circuits;
Replace fragile ceramic base PCB to obtain better mechanical durability.
Compared with the ordinary FR-4 sheet, the aluminum substrate PCB has the most significant advantage in carrying a higher current. Like FR-4, the circuit layer uses copper foil as the wire for connection. Compared with the traditional FR-4, the aluminum substrate PCB can carry a higher current with the same thickness and line width.
The core technology of the aluminum PCB is the insulating material in the middle, which mainly functions as adhesion, insulation, and heat conduction. The insulating layer of the aluminum PCB is the most significant thermal barrier in the power module structure. The better the thermal conductivity of the insulating layer, the more conducive to the diffusion of heat generated during the operation of the device, and the more conducive to reducing the operating temperature of the device, to achieve the purpose of increasing the power load of the module, reducing the volume, extending the life, and improving the power output. While satisfying good thermal conductivity, it must also have high-voltage insulation capability.
The difference between aluminum substrate and FR-4 sheet
The most significant difference between aluminum-based copper-clad laminates and conventional FR-4 copper-clad laminates lies in heat dissipation. Compared with aluminum-based copper-clad laminates with a thickness of 1.5mm, the former has a thermal resistance of 20~22 ℃, and the latter has a thermal resistance of 1.0~2.0. ℃, the latter is much smaller.
Because the general FR-4 has the problem of thermal expansion, that is, high temperature will cause the thickness and flatness of the plate to change, especially the thermal expansion in the thickness direction of the plate, which affects the quality of the metalized holes and circuits. The main reason for this is that the thermal expansion coefficient of the raw material of the board is different: the thermal expansion coefficient of copper is 17×106cm/cm℃, and the base material of the FR-4 board is 110×106cm/cm℃. The thermal expansion coefficient of the aluminum substrate is 50×106cm/cm°C, which is smaller than the general FR-4 board and closer to the thermal expansion coefficient of copper foil. This helps to ensure the quality and reliability of the printed circuit board.
FR-4 PCB board is suitable for general circuit design and general electronic products. The aluminum core PCB is ideal for circuits with special requirements. Such as thick-film hybrid integrated circuits, heat dissipation of power circuits, heat dissipation and cooling of components in circuits, large-scale substrates that ceramic substrates are difficult to handle, and courses that cannot solve reliability with ordinary heat sinks.
Aluminum clad PCB has high mechanical strength and toughness, which is better than FR-4 board. For this reason, large-area printed circuit boards can be manufactured on aluminum substrates, and heavy components can be installed on such substrates.
From comparing the aluminum core PCB and the FR-4 PCB board, the wire fusing current is significantly improved due to the high heat dissipation of the metal substrate, showing the aluminum Clad PCB’s high heat dissipation characteristics from another angle. The heat dissipation of its aluminum substrate is related to its insulating layer thickness and thermal conductivity. The thinner the insulating layer, the higher the thermal conductivity of the aluminum-backed PCB (but the lower the voltage resistance). To ensure the performance of electronic circuits, some components in electronic products need to prevent electromagnetic wave radiation and interference. The aluminum base PCB can act as a shielding plate to shield electromagnetic waves.
Under general conditions, the withstand voltage value of the aluminum substrate CB is determined by the thickness of the insulating layer. The fight voltage value of the aluminum substrate PCB is generally about 500v. If you need to test the withstand voltage value of the LED fluorescent lamp’s aluminum base PCB, it is only sufficient to perform a high-voltage test on the input port shell. UL and CE certification value should be 2500V, 3C certification should be 3750V.
JHYPCB: A Excellent Aluminum PCB Manufacturer
Most frequent questions and answers
Aluminum-clad PCBs are generally stored in a dark, dry environment. Most aluminum core PCBs are prone to dampness, yellowing, and blackening. Commonly, Aluminum PCB should be used within 48 hours after opening the vacuum package.
Aluminum-based PCB is a metal-based copper clad laminate with a good heat dissipation function. According to different applications, aluminum-based PCB can be divided into single-sided aluminum-based PCB, 2 layer aluminum PCB, and multilayer aluminum PCB. The thermal conductivity of aluminum-based PCB is between 1.0 and 2.0, and the thermal conductivity of aluminum-based PCB is related to its insulating layer.
The most significant difference between ceramic-based PCB and aluminum-based PCB is the difference in material and structure. Ceramic PCB uses ceramic as the base material. In terms of design, ceramic PCB does not require an insulating layer because of the excellent insulation performance of the ceramic itself.
At present, ceramic PCBs on the market are mainly divided into aluminum nitride ceramic PCBs and alumina ceramic PCBs. The thermal conductivity of alumina ceramic PCBs is 15-31, and aluminum nitride PCBs are between 135-175.
In short, the thermal conductivity of ceramic PCB is better than aluminum-based PCB, and the core technology of aluminum-based PCB is the insulation layer. The better the thermal conductivity of the insulation layer of aluminum-based PCB, the more conducive to the heat dissipation generated when the components are running.
With the same specifications, the price of ceramic circuit boards will be at least 5 times higher than that of aluminum PCBs.
Aluminum-based PCB welding skills
Because the LED aluminum-based PCB has good heat dissipation capacity, manual soldering is relatively tricky. Therefore, some soldering skills are critical in the soldering process. The following talks explicitly about the main items and abilities in the aluminum substrate soldering process.
1. The temperature of the welding zone should be controlled at 255℃±5℃. The welding time should be between 10S~15S because the heat sink is a copper foil of thermal conductivity material. The thermal expansion parameters of the metal layer composed of aluminum, copper, or iron The thermal expansion parameters of the high thermal conductivity materials of the layers are very different. When the temperature is too high or the time is too long, the brutal force will occur due to the other thermal expansion parameters of the three, which will cause the heat sink to bubble or delamination.
2. When using a manual soldering iron to solder aluminum PCB, you must pay attention to the temperature control during the soldering process. Generally, the temperature should be controlled at 260℃±5℃, the time should be held at about 3 seconds, and the constant temperature must be used when soldering. For soldering iron soldering, you must strictly abide by the relevant specifications and systems of the soldering operation when soldering. Do not solder during the soldering process when the soldering iron temperature is not enough, and do not loosen the soldering iron tip too quickly during soldering. Do not solder multiple times; otherwise, the pad may fall off. When soldering aluminum PCBs with a large area, it is recommended to use additional processing tools to heat them before soldering.
3. When starting to solder all the pins, add solder to the tip of the soldering iron, and apply flux to all the pins to keep the pins moist. Touch the end of each pin of the chip with the tip of a soldering iron until you see the solder flowing into the pin. When soldering, keep the tip of the soldering iron parallel to the soldered pin to prevent overlap due to excessive soldering.
4. After soldering all the component pins, soak all the nails with flux to clean the solder. Suck off the excess solder was needed to eliminate any short circuits and overlaps. Finally, use tweezers to check whether there is false soldering. After the inspection is completed, remove the solder from the circuit board, soak the harrowing brush with alcohol and wipe it carefully along the pin direction until the solder disappears.
Yes, sure. The most significant advantage and function of aluminum-based PCB is heat dissipation. The heat generated by the power amplifier circuit board will be very much, so using aluminum as the substrate of the printed circuit board is the right choice.
PCB design software has nothing to do with what kind of material is used for PCB production. Therefore, we can use Protel99, DXP, CAD, AltiumDesigner 10, etc. It should be noted that when designing aluminum PCB, the line width is generally not less than 0.2mm, and the spacing is not less than 0.5mm.
For more PCB design software, here is a detailed introduction, and download link is provided.
The insulation layer is the core technology of aluminum PCB, which mainly plays the functions of bonding, insulation, and heat conduction. The aluminum PCB insulation layer is the most significant thermal barrier in the power module structure. The better the heat conduction performance of the insulating layer, the more conducive it is to the diffusion of heat generated during the operation of components. The more conducive it is to reduce the operating temperature of elements to improve the power load of the module, reduce the volume, prolong the service life and enhance the power output.
Aluminum PCB uses aluminum as the substrate material instead of the standard FR-4 fiberglass board as the substrate for PCB manufacturing. We know that the movement of charged particles will generate a lot of heat, and aluminum has excellent thermal conductivity. Therefore, when the heat is transferred to the aluminum PCB, it can effectively dissipate it. This layer is also called the dielectric layer.