When you get a PCB manufactured, it becomes important to laminate it with a layer of strong laminate. Doing so will keep your PCB safe from spillage, wear and tear, and many other types of damages. This article will walk you through an engineering study on PCB laminate in a user-friendly manner.
Table of Contents
- What’s a PCB stackup?
- What’s a PCB laminate?
- What are the types of PCB laminate?
- What are the properties of PCB laminate?
- PCB Laminate VS PCB Prepreg
- What is the Importance of PCB Laminate?
- What is PCB lamination process?
- How to choose a PCB lamination material?
- Laminate production and application
- Conclusion
What’s a PCB stackup?
When a manufacturer manufactures PCB, they create several thin layers and stack them on top of each other according to the design. The concept of stacking all the layers of a PCB to make one final PCB product is called PCB stackup. The stacked layers are stuck together using an adhesive and baked at a high temperature so that the adhesive becomes a permanent bond.
What’s a PCB laminate?
Once the manufacturer stacks up and bakes all the layers using adhesive, they apply a layer of lamination. The lamination material can be of different types. Just like we laminate important documents to protect it from weather, moisture, water, etc., the PCB manufacturers laminate a PCB to keep it protected from outside interference.
What are the types of PCB laminate?
1.Polyimide
Many makers use polyamide for its strong thermal stability and its ability to resist high temperatures. If high-quality laminate is your preference, then you can go with polyamide lamination on your PCB. PCBs used in aerospace, automotives, etc., often use polyamide lamination.
Also read: What is polyimide PCB? – a comprehensive guideline – material, types, advantages
2.Ceramic
As the name suggests, a ceramic laminate has a ceramic base that can include but is not limited to alumina, etc. PCB makers use this type of laminate when they need resistance to high temperature, thermal conductivity, and strong dimensional stability.
Also read: Ceramic PCB – what is it, why we should use and how to manufacture
3.FR-4 (Flame Retardant 4)
If you want a highly economic laminate, then FR-4 is the way to go. It’s the most common type of PCB laminate that’s used and trusted by millions of PCB makers globally. This type of laminate is easily available in the market and has strong resistance to fire and high temperature. On top of that, it has incredible electrical insulation and other features.
Also read: FR4 PCB – The design and how it can be used for multiple applications
What are the properties of PCB laminate?
1.Thermal Properties
Thermal property of a PCB is responsible for throwing away all the heat that is generated in a PCB because of all the components on it. Components can get overheated and it’s the responsibility of a PCB laminate to get rid of all the excess heat and aid heatsink attached to the PCB (if any). High-Tg, FR-4, ceramic, etc., are some laminates with fantastic thermal properties.
2.Electrical Properties
Electrical property of a PCB laminate helps it keep the PCB safe from electrical interference and give a good electrical insulation. This helps in avoiding any short circuit occurring due to moisture or water spillage on the PCB. It’s just like a plastic coating on a wire that creates insulation.
3.Chemical Properties
Once the PCB is manufactured and the lamination is done, it’s time for PCB assembly. That’s a stage where a lot of chemicals will be poured on the PCB and the PCB will go through a lot of chemical reactions. Therefore, it’s important for a PCB laminate to have high chemical properties that can protect it from chemicals like solder mask, flux, solvents, etc.
4.Mechanical Properties
It’s very important for a PCB laminate to have high strength. It’s not at all feasible for a PCB laminate to be weak that can easily break, tear down, or chip off the PCB. during PCBA and fabrication, the PCB laminate shouldn’t wear off. That’s called the mechanical property of a PCB laminate.
PCB Laminate VS PCB Prepreg
| Comparison Basis | PC Laminate | PCB Prepreg |
| Definition | Strong, rigid, and cured material | Pre-impregnated, partially cured, and acts as a middle layer in the PCB |
| Function | To offer rigidness and structural integrity to the PCB | To act as an adhesive bond in the PCB stackup |
| Properties | Electrical insulation, mechanical strength, chemical resistance, temperature resistance, etc. | Flexibility, electrical strength, and mechanical toughness. |
| Thickness | At least 0.1mm and can be up to several mm | Less than 1mm to several mm |
| Applications | Most probably applied on both the sides of the PCB | Applied between the layers of a PCB, preferably between core laminates and copper foils |
What is the Importance of PCB Laminate?
PCB laminate is crucial in the design and manufacturing of printed circuit boards (PCBs) for several reasons:
1、Structural Support: The laminate provides the essential structural foundation for the PCB. It supports and holds the copper traces, components, and other elements in place, ensuring the board remains stable and intact throughout its lifecycle.
2、Electrical Insulation: PCB laminates are made from materials that offer excellent electrical insulation. This prevents unintended electrical interactions between the copper traces and other components, helping to avoid short circuits and ensure reliable circuit performance.
3、Thermal Management: Laminates help with managing heat dissipation in the PCB. Certain types of laminates are designed to conduct heat away from sensitive components, helping to prevent overheating and maintain optimal operating conditions.
4、Mechanical Properties: The laminate affects the mechanical properties of the PCB, such as its rigidity and flexibility. This impacts how well the board can withstand mechanical stresses during handling, assembly, and operation.
5、Signal Integrity: High-quality laminates contribute to better signal integrity by minimizing interference and maintaining consistent electrical characteristics. This is essential for high-speed and high-frequency applications where signal quality is critical.
6、Durability and Longevity: The laminate material also plays a role in the overall durability and longevity of the PCB. It protects the circuitry from environmental factors such as moisture and chemicals, which helps extend the life of the board.
PCB laminate is vital because it provides structural support, electrical insulation, thermal management, mechanical stability, signal integrity, and durability. Choosing the right laminate material is key to ensuring that a PCB performs reliably and meets the specific needs of its application.
What is PCB lamination process?
1.Material selection: The most relevant PCB laminate material is chosen based on the application and requirement of the PCB.
2.Prepreg manufacturing: Resin binder and fiberglass cloth are processed to make prepreg.
3.Core laminate manufacturing: Once the resin binder and fiberglass cloth are pre-impregnated, they’re applied between the layers of the PCB during PCB stackup. The number of layers are subject to the overall design of the PCB. Once the layers are stacked up and the prepreg is between the layers, a high pressure and heat is applied to the stackup, so that the adhesive cures.
4.Drilling: Vias and holes are drilled as per the PCB design and requirements. Drilling ain’t directly related to lamination, but is important during the lamination process.
Also read: PCB Drilling – What is it and how to minimize its cost during assembling
5.Lamination: The PCB makers might use additional prepreg to bond the laminate layer with the PCB layers. Once again, heat and pressure is used to bond the prepreg, so that the lamination layer and PCB layers get stuck well.
6.Surface treatment: The outermost surface may be roughened a little bit, and/or a layer of copper or aluminum may be embedded on the PCB, completing the lamination process.
Also read: What’s the type of PCB surface treatment?
How to choose a PCB lamination material?
1.Look for electrical requirements in your PCB and choose a material that can offer required electrical insulation.
2.Thermal conduction is also important to look for. If you need high resistance to temperatures, go for FR-4 or FR-4 Tg versions. Or go for Roger, etc., if you have low thermal conduction requirements.
Also read: How does Rogers PCB outperform FR4 PCB?
3.Frequency and signal integrity of a laminate is vital if you need low dielectric loss, low insertion loss, etc.
Laminate production and application
Laminate production and application are essential aspects of creating and using printed circuit boards (PCBs) in various electronic devices.
Laminate Production
1、Material Selection: The production of laminates begins with selecting appropriate materials. Typically, laminates are made from layers of fiberglass or paper impregnated with resin. The choice of material depends on the desired properties, such as electrical insulation, heat resistance, and mechanical strength.
2、Layer Formation: The selected material is then processed into thin sheets or layers. For instance, fiberglass is woven into fabric and coated with a resin that is cured to create a rigid, insulating board. These layers are stacked together to form the core structure of the laminate.
3、Pressing and Curing: The layers are assembled into a stack and subjected to high pressure and temperature in a process known as lamination. This presses the layers together and cures the resin, creating a solid, uniform laminate with the desired properties.
4、Finishing: After curing, the laminate is cut to size and sometimes treated or coated to enhance its performance. This might involve adding protective coatings or other treatments to improve its durability or electrical characteristics.
Laminate Application
1、PCB Fabrication: Once the laminate is ready, it is used as the base material for PCB fabrication. The laminate provides the structural support and electrical insulation needed for the PCB’s circuitry. The copper traces and other components are added to this base material through various processes, including etching and plating.
2、Assembly: In the assembly stage, electronic components are soldered onto the PCB. The laminate’s properties ensure that the board can handle the heat from soldering and provide a stable platform for the components.
3、Performance and Reliability: The quality of the laminate directly affects the PCB’s performance and reliability. A good laminate ensures effective electrical insulation, efficient heat dissipation, and mechanical stability, contributing to the overall functionality of the electronic device.
4、End Use: Laminates are used in a wide range of electronic devices, from consumer electronics like smartphones and computers to industrial equipment and automotive systems. The choice of laminate material can vary based on the specific requirements of each application, such as temperature tolerance or signal integrity.
Laminate production involves creating a robust and reliable base material for PCBs through a detailed process of material selection, layer formation, pressing, and curing. Its application in PCBs ensures that electronic devices have the necessary structural support, electrical insulation, and performance characteristics needed for their intended functions.
Conclusion
Now that you’ve got a great idea on PCB laminates, here’s what you can do- go with IBE Electronics, who’ll take care of using the right PCB laminate according to your project. You don’t have to mention the laminate type explicitly, as IBE Electronics’ experts will figure out the most suitable PCB laminate and will take care of the entire lamination process smoothly for you.
