HPA-LU-M | Low Th & U Alumina

Main features

4N - 5N Purity
Ultra low uranium & Thorium
Ideal as an EMC filler

Product Description

HPA-LU-M is characterized by its exceptionally low levels of uranium and thorium, achieving an impressive purity range of 4N to 5N (99.99% to 99.999%). This ultra-pure material is applicable for critical applications where minimal radioactive impurities are essential, making it particularly well-suited for semiconductor epoxy molding compound (EMC) fillers and other advanced technologies.

HPA-LU-M features an irregular particle morphology that enhances surface contact, resulting in increased dispersion and integration in composite materials. Its specific surface area, ranging from 8 to 15 m²/g, ensures controlled reactivity and stability, contributing to consistent performance across various high-tech applications. With a D50 particle size distribution between 1-5 µm, this alumina product guarantees uniform mixing and processing, crucial for industries that demand precision and reliability. Whether used in semiconductor manufacturing, advanced ceramics, specialty coatings, or optoelectronics

Specifications
Additional Information

Technical Specifications

General Properties

Density (g)

0.3 - 0.5 g/cm3

Morphology

Irregular

Particle size (D50)

1 - 5 um

Purity

99.99 - 99.999 %

Surface Area

8 - 15 m2/g

Chemical Properties

Phase

Other Properties

Impurities
Calcium (Ca)	5 ppm
Iron (Fe) Iron (Fe) A chemical element with a melting point of 1,538 C	3 ppm
Silicon (Si)	4 ppm
Sodium (Na)	10 ppm

Additional Information

Purity	Key Element concentration (ppmw)
	Na	Mg	Si	Ca	Ti	Cu	Cr	Fe	K
4N	<30	<5	<10	<10	<5	<5	<5	<20	<10
5N	<4	<1	<3	<3	<0.5	<0.5	<1	<1	<0.5

Applications

Epoxy Molding Compound (EMC) Fillers

Increasing relative dielectric constant of the Al2O3/epoxy composites as a function of the Al₂O₃ content
Reference: https://doi.org/10.1016/j.compscitech.2016.01.010

HPA-LU-M is ideal for use as a filler in epoxy molding compounds due to its ultra-low uranium and thorium content. This ensures that the material does not introduce radioactive contamination, which is crucial for sensitive electronic components and devices. The high purity level also contributes to the overall performance and reliability of the final product. HPA as a filler in epoxy resin system enhances the performance and reliability of EMC, providing superior insulation and reduced impurities for semiconductor devices.

Additionaly, HPA increased the flexural strength of the epoxy molding compound. The table below shows that the flexural strength are remarkably higher on epoxy system with Al₂O₃ as fillers compared to silica and AlN.

Composites	Filler cont. (Vol.%)	Flex. Strength (Mpa)	Therm. Conduct. (W/m-K)
AlN/Epoxy	58	101.3	3.56
Al₂O₃/Epoxy	60	–	4.3
Al₂O₃/Epoxy	58	150.9	7.15
AlN/Epoxy	70	180	4.6
Cryst. SiO₂/Epoxy	70	145	2.0
Diamond/Epoxy	68	–	4.1
Al₂O₃/Epoxy	70	304.9	13.46

How to improve compatibility of HPA fillers to Epoxy Molding Resin (EMR)?

Using High Purity Alumina (HPA) as a filler in epoxy mold resin (EMR) can have implications for thermal degradation and cracking, depending on factors like filler loading, particle size, and resin compatibility. These are very common not just with HPA, but other fillers as well such as silica. Here are the key considerations:

(1) Epoxy resin decomposition typically starts around 250–350°C, depending on the formulation.
(2) HPA has excellent thermal stability, but if the filler-resin interface is weak, thermal cycling can lead to microvoids or interfacial degradation, reducing performance over time.
(3) High HPA loading can increase thermal conductivity, reducing hot spots, but excessive amounts may compromise the resin’s mechanical integrity.
(4) Poor dispersion of HPA can create stress concentration points, acting as crack initiation sites.
(5) Higher HPA loading increases stiffness but reduces fracture toughness, making the composite more prone to cracking under mechanical stress.

Typical strategies on the EMC formulation for fillers compatibility are the following:

(1) Optimize Filler Loading: Maintain a balance between thermal conductivity improvement and mechanical flexibility.
(2) Use silane coupling agents to improve HPA-resin adhesion, reducing interfacial cracking.
(3) Combining HPA with other fillers (e.g., silica, boron nitride) can help mitigate CTE mismatch and improve fracture toughness.

Semiconductor Manufacturing

In semiconductor applications, the ultra-low impurities of HPU-LU-M reduce the risk of contamination, which can cause device failure or decreased performance. The material's high thermal stability and purity ensure that it performs well in the demanding environments of semiconductor fabrication processes.

Advanced Technical Ceramics

The controlled morphology and high purity of HPU-LU-M enhance the mechanical and electrical properties of technical ceramics. These properties are essential for applications requiring high strength, wear resistance, and low dielectric loss, such as substrates, insulators, and advanced structural components.

Additional Information

HPU-LU-M is produced using state-of-the-art manufacturing techniques that ensure the highest standards of quality and purity. Our advanced processing technology guarantees consistent product performance, making it a reliable choice for high-tech applications. Customizable solutions are available to meet specific application needs, supported by our expert technical team and collaborative R&D partnerships.