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Aluminas, Spherical & Thermally Conductive Fillers

Manufactured in Japan by DENKA (DENKI KAGAKU KOGYO K.K.)

1. Introduction

So far, a crystal silica, AIN and Si3N4 filler, has been supplied against inquiry of the high thermal conductance filler filled in resin and rubber. However, the performance for the chemical stability, flowability and mold abrasion were not enough. A new spherical alumina filler was developed that has high thermal conductance and basic required characteristics as silica filler by utilizing various technological knowledge that improved the silica filler over a long period.

S.E.M. Photo
2. Basic characteristics of high thermal conductive filler

2 - 1. DAM Series
This grade is high level spherical alumina filler which is produced by high temperature fusing technology. Products that have several particle size distribution (herein after: P.S.D.) (representative value) are prepared.

2 - 2. DAW Series
This product has drastically reduced alumina peculiar ionic impurity content represented by Na ion through the special processing. Products that have several P.S.D. (representative value) are prepared.

2 - 3. DAB Series
This grade can fill up high filler content into a resin by adding developed super fine powder and making suitable P.S.D. with optimum combination of DAW series based on our spherical silica filler technology. Products that have several P.S.D. (representative value) are prepared.

Typical Properties of DAM/DAW Series
		DAM Series			DAW Series
		DAM-45	DAM-10	DAM-05	DAW-45	DAW-10	DAW-05
Al2O3 Content (wt.%)		>99.9	>99.9	>99.9	>99.9	>99.9	>99.9
SSA (m2/g)		0.2	0.4	0.5	0.2	0.4	0.5
Diameter Median (µm)		45	10	5	45	10	5
EC (µS/cm)		50	120	160	2.3	120	160
Wet Sieve %	45 ~ 75 µm	51.2	0.15	0.10	54.0	0.14	0.10
Wet Sieve %	75 ~ 150 µm	0.07	0.004	0.004	0.05	0.004	0.004
Ionic Impurity* (ppm)	Fe: Atomic Absorption	20.0	10.0	10.0	8.0	2.5	2.5
	Na: Atomic Absorption	40.0	155.0	180.0	5.5	4.4	5.0
	Cl: Ion Chromatography	0.5	1.0	1.0	0.2	0.3	0.5

* Extracted Water: Fe = aqua regia, Na/Cl = deionized water

Typical Properties of DAB Series
		DAB Series
		DAB-10SI	DAB-20SA
Content (wt.%)	Al2O3	90	95
Content (wt.%)	SiO2	10	5
SSA (m2/g)		2.3	2.2
Diameter Median (µm)		12.5	7.6
EC (µS/cm)		4.6	3.2
PH		6.5	6.8
Wet Sieve %	45 ~ 75 µm	11.7	10.8
Wet Sieve %	75 ~ 150 µm	0.01	0.01
Ionic Impurity* (ppm)	Fe: Atomic Absorption	7.5	7.0
	Na: Atomic Absorption	4.1	4.1
	Cl: Ion Chromatography	0.4	0.5
Water Content (%)		0.18	0.16
Uranium Content (ppb)		6	6

* Extracted Water: Fe = aqua regia, Na/Cl = deionized water

*Test Method of Mold Abrasion
Weight loss of Al-Disk with hole after EMC pass through the hole.

		EMC Quantity: 150cm³
		Temperature: 175°C
		Hole size of Al-Disk: 3mm
		EMC with no Hardener

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