Solutions for Electronic Cooling

By controlling key characteristics like particle size and distribution, density, particle shape and purity, Saint-Gobain is able to maximize the inherent material properties of boron nitride that make it valuable to the TIM market. Saint-Gobain Boron Nitride Powder Solutions offers a variety of grades with high thermal conductivity and excellent dielectric properties. 

 Size and Size Distribution: 

Different agglomerate sizes and size distributions, from 35 to 300 microns, offer customers the ability to optimize the packing of BN in the matrix. Larger agglomerates provide improved flowability and typically improve thermal conductivity by providing larger contact area for heat flow.

Key process parameters that can help determine the optimal size and particle morphology are (1) bond line thickness, extrusion size or coating thickness and (2) intensity of mixing forces. Due to the nature of particle-to-particle bonding, BN agglomerates best retain their morphology in low-medium shear forces.

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 Density: 

Density is an important factor when working with BN agglomerates. Higher density improves the thermal performance by increasing the number of contact points within the agglomerate, providing an efficient heat transfer path. Higher density also yields stronger agglomerates, improving the energy tolerance of BN agglomerates in maintaining their morphology. 

Saint-Gobain Boron Nitride Powder Solutions offers 3 grades of high density agglomerates (HD grades), ranging from 75 µm to 200 µm in median size.

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 Shape: 

Saint-Gobain offers a selection of shapes utilizing its expertise in manufacturing BN. High density agglomerates have a more irregular and random shape, whereas spherical agglomerates offer uniquely tight particle size distributions, and therefore better packing density and particle to particle interactions to achieve optimum thermal conductivity.



Our current product range includes spherical agglomerates from 35 to 300 microns.

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 Purity: 

Saint-Gobain can tune the purity and composition of BN agglomerated products to meet customer demands. Our standard suite of agglomerated powders offers over 99.5% purity which allows for the highest dielectric properties for increased breakdown voltage and signal strength in the final products.

In certain applications, we can offer composite powder, our Flowable Platelet grade FP30, to meet application demands and balance both performance and cost to bring value.

By utilizing our unique synthesis processes and expertise, we can offer precise value without over engineering the solution.

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Dispensable gap filler has been growing in popularity due to the push for more and more automation in the manufacturing industry.  Application of a thermal interface material (TIM) to an electronic package has been done historically through pads, films and greases.  These systems can be effective, but a dispensable system offers the most benefit in an automated process. 

Boron nitride (BN) offers a unique solution for this system with its combination of high thermal conductivity, dielectric properties and low coefficient of friction. 

• The low coefficient of friction and low wear property of BN lends itself to the dispensable gap filler market because of the need for high precision on the nozzle tip to precisely control the amount and placement of the gap filler in the electronic.  This, along with the other characteristics of BN, makes it an effective choice for this application.
• To further enhance the performance of BN in this application, Saint-Gobain offers a series of spherical agglomerates to maximize the thermal conductivity of the filler and improve the processability by providing a flowable powder to incorporate into the gap filler matrix.
• For information, see the Saint-Gobain Boron Nitride Powder Solutions range of Spherical Agglomerates (SA grades). 

Glass fiber/epoxy laminates have been the foundational structural substrate in printed circuit boards for decades. A PCB substrate can be made from paper, glass fiber in woven or nonwoven form, or a composite of paper and glass fiber. These materials can be impregnated with a variety of resins, but epoxy is the most common.  This mix is called a prepreg and is where thermally conductive fillers can also be added to the composition.  The need for enhanced thermal performance of the prepreg material which is laminated with copper foil has increased as the industry has progressed from single sided PCBs to multilayer PCBs where several layers of prepreg are laminated with copper foil to become a laminate.  It is common for 8 to 16 layer boards to be manufactured.

Due to the concentration of energy in these multilayer boards and ever increasing power requirements in electronic components, thermal demands have increased and boron nitride is an excellent option for heat management within the PCB.

• A key for laminate production is the bonding strength between the copper foil and the laminate which is typically measured via a peel strength test.  Standard boron nitride platelets are a very inert and generally have difficulty maintaining good peel strength in the different prepreg compositions.
• Saint-Gobain boron nitride has shown the ability to optimize this situation in different resin systems with tight control of the platelet size, morphology, chemistry and surface properties.
• Utilization of an agglomerated boron nitride material can also improve peel strength while having the added benefit of improved thermal performance.  Saint-Gobain offers fine agglomerates, both 75 µm and our new 35 µm spherical agglomerates, that provide improved performance characteristics while still allowing for the targeted thickness of each layer.
• An added benefit to boron nitride in the PCB vs other thermal materials such as alumina is that in multilayer PCBs there are holes drilled to connect the layers electrically.  This is a very critical and precise operation where having a BN filler improves tool life and ease of drilling accurate and repeatable holes in the PCB.