The rise in heat generation has triggered the need to control heat diffusion in electronic devices, and it has become the duty of PCB manufacturers, to implement design ideas to control heat generation in electronic devices. One such PCB type is insulated metal substrate, which is on the rise in the global chipset market.
In this article, you’ll get a deeper insight into insulated metal substrate, it’s pros, uses, and some technical details related to it.
What’s IMS?
IMS, short for insulated metal substrate is a type of PCB, which is used to control overheating issues in the PCBA. It has a metal base or metal core, which acts as a heatsink and offers incredible rigidness, hardness, and strength to the overall PCB.
The primary idea behind insulated metal substrate is that the manufacturer will use a metallic chip sort of thing and will attach it to the base of the PCB or will embed it in between the PCB layers. Any simple single layer or multi-layer PCB can be transformed into IMS simply by equipping it with a proper metal core or metal base.
What materials are used in insulated metal substrate?
1.Aluminum
Among various PCB materials, aluminum is a fantastic choice when installing a metal core or metal base for IMS. The reason behind aluminum’s popularity is even distribution of heat. Moreover, aluminum is way cheaper than other alternatives and hence, a client with a tight budget can still purchase insulated metal substrate.
2.Copper
Copper is preferred over aluminum when the heat dissipation has no scope for compromises. Copper is similar to aluminum in heat dissipation i.e., it conducts heat evenly. But, copper is a far better candidate of heat conductors. It’s molecules are tightly compressed than aluminum and it can be complimented with metal-based thermal pastes. The increased cost is the only issue with copper IMS, though.
What are the advantages of insulated metal substrate?
1.IMS offers better support to the overall PCB. In case if it’s a single layer PCB, it’ll be very thin and adding a layer of metal will give incredible strength to it.
2.Insulated metal substrate helps in making a good quality electronics product. If you’re an electronic gadgets company, you would want your products to be of good quality. In order to achieve high quality in your products for improved customer satisfaction, you’ll need a good quality PCB, such as insulated metal substrate due to its impressive conductive and thermal properties.
3.Using an insulated metal substrate would help reduce the heatsink size and thickness, because there’s already a good conductor of heat in the PCB. As a result, the cost of heatsink can be reduced, and the overall size of the heatsink and PCBA will reduce to a large extent.
Where can insulated metal substrate be used?
- Consumer Electronics
General consumer electronics such as washing machines, refrigerators, etc., nowadays have insulated metal substrate since they need small heatsinks. That helps them keep their consumer electronics sleek and attractive. Some more common examples of consumer electronics with insulated metal substrate include amplifiers, equalizers, electronics with motor-based functions, etc. - LEDs
Your common household LED can have an insulated metal substrate PCB but not necessarily. Some brands that thrive for quality LEDs have started using IMS, while the cheap products may still have a regular single layer PCB. - Solid State Relays
An advanced version of mechanical relays is solid state relays, that have high heat generation. In order to tackle that, an IMS PCB installation seems like a good option. The IMS will be responsible for transferring heat away from the electronic components to its housing or enclosure.
FR-4 PCB Vs. Insulated metal substrate PCB- Thermal comparison
Comparison Criteria | FR-4 | IMS |
Heat sink | 31.8 | 31.8 |
PCB’s thermal vias | 3.76 | 0.83 |
Junction to ambient thermal resistance | 61.56 | 39.1 |
The table below lists some thermal conduction criteria that were taken into consideration in researches. A research stated, that the thermal resistance of FR-4 and IMS from their junction to the ambience was 61.56 and 39.1 w/mk respectively. In brief, the table above proves that IMS has an excellent thermal conductivity as compared to FR-4 PCB.
Why insulated metal substrate is preferred for LEDs?
LEDs have an array or a matrix of small diodes, that make up a high-lumen LED. LEDs are often used continuously for long hours, which is why they start to generate a lot of heat. You might notice a metallic circular disc sort of thing in every LED, which is meant for conduction.
The increased amount of heat build-up in the LEDs can cause the outer cover to blast. To avoid such accidents, IMS is highly recommended.
How to manufacture the insulated metal substrate?
1.Designing
The designing phase include identifying the number of layers you need for your PCB. This depends on the application. For heavy applications, multi-layer PCB is preferred.
2.Metal Selection
The metal such as copper or aluminum is selected. The metal selection depends on your product application and the amount of heat it’ll generate. If you need a good conductor, then copper is preferred or else aluminum. If you’re low on budget, aluminum is used instead of copper.
3.Layers Processing
All the layers are printed and they’re stacked on top of each other as per the design. Then the metal layer may be put in the middle (to act as a core) or simply at the base. The layers are then attached to each other using adhesive and then baked to make the joints super strong.
4.Post Processing
The PCB is now ready. It shall be sent to the client or to the PCB assembly phase, as per the client’s contract.
Thermal conductivity Vs. Thermal diffusivity in insulated metal substrate
Thermal conductivity is how much heat can a metal or a component absorb. Thermal diffusion is the amount of heat that a substance can get off to another substance or in air. Heatsinks are used to promote thermal diffusion, and the metal core or base in the IMS is also meant for thermal diffusion and thermal conductivity.
Comparison Criteria | Criteria Value | IMS PCB Conductivity/Diffusivity Values |
PCB thickness | 0.84 mm | 3w/m-k |
Thermal vias size | 0.1 mm | 1.6w/m-k |
How to select insulated metal substrate manufacturers?
Selecting the right insulated metal substrate manufacturer is easy. You just have to take care of the following qualities in them:
1.Ask the manufacturer about their work experience. How many years have they been in the industry, how many clients they’ve dealt with, success rate of their products, etc.
2.Ask their annual turnover to identify how established that manufacturer is.
3.Ask about the technologies they’re using, and ask if they’ll be able to fulfil your requirements or not.
Conclusion
Now that you’ve got an idea of insulated metal substrate, the next thing to do is to find a good supplier. If that sounds like too much work, then you can cut the line and jump to IBE Electronics without hesitation. IBE Electronics uses updated technologies to fulfil the latest requirements of clients trending in the market. You’ll be guided properly for your project and you’ll be told what type of PCB you’ll exactly need according to your project plans.
Insulated metal substrate is combined the materials of aluminum, copper and thermal conductive dielectric with high mechanical stability and good thermal conductivity.
- IMS PCBs have higher thermal conductivity performance.
- During manufacturing, IMS PCBs adopt saw blades to cope with the substrate materials, while FR4 PCBs can use regular machining tools to cope with.
- Consumer Electronics
- LEDs
- Solid State Relays
