Granulated Glass for Metal Packages

Granulated glass with excellent flowability and fillability, ideal for tablet forming process

Glass for matching seals is used with Kovar stems and leads, while those for compression seals are used with iron or stainless steel stems and leads of iron-nickel, iron-chrome alloys or Kovar. Glass for part support is used for stand-off.

Properties
Application examples

Properties

Usage			Seal							Part support
Usage			Compression seal			Matching seal				Standoff
Glass code			ST-W/K	ST-4W/K	FN-13W/K	BH-W/K	BH-7W/K	BH-8W/K	BH-14W/K	ST-4F/K	BH-FW/K
Particle size	D₅₀	μm	135	130	110	135	135	135	135	120	125
Particle size	D₉₉	μm	265	250	215	265	265	265	265	235	245
Firing temperature: T1		℃	650～660		680～690		700～710	670～680	730～750	650～660	750～800
Sealing temperature: T2		℃	960			980		930	980	960	1050
Coefficient of thermal expansion	30～380℃	×10^-7/K	95	95	75.5	45.5	49.5	62.5	31.5	94	57
Density		×10³kg/m³	2.60	2.60	2.51	2.28	2.32	2.41	2.13	2.65	2.83
Transformation point		℃	450	460	510	470	505	510	-	460	515
Deformation point			510	520	570	550	565	570	-	520	635
Strain point			420	427	480	435	472	475	-	-	-
Annealing point			460	472	517	480	513	520	-	-	-
Softening point			663	672	687	698	715	685	782	-	-
Working point			980	1030	990	1050	1130	990	1090	-	-
Dielectric constant	1MHz 25℃		6.4	6.5	6.3	5.0	5.5	5.8	4.0	6.7	6.4
tan δ	1MHz 25℃	×10^-4	22	21	32	30	39	37	3	24	31
Volume resistivity Log ρ	150℃	Ω･cm	11.4	11.2	11.2	11.5	10.8	11.1	15.5	11.4	-
	250℃		8.8	8.7	8.7	8.8	8.2	8.5	12.3	8.8	-
	350℃		6.9	7.0	7.0	7.0	6.4	6.8	10.2	7.0	-
Young’s modulus		GPa	68	68	-	57	57	-	-	-	-
Poisson’s ratio			0.21	0.21	-	0.22	0.22	-	-	-	-
Glass type			Na₂O･BaO･SiO₂		Na₂O･Al₂O₃･B₂O₃･SiO₂					Na₂O･BaO･SiO₂	Na₂O･Al₂O₃･B₂O₃･SiO₂
Application			Fe, Fe-Ni, Fe-Cr, Fe-Ni-Cr		Fe Kovar	Kovar Mo				Fe	Kovar

ST-4F/K and BH-FW/K are composite glass (glass-ceramic).
Please contact us about color variations.

Application examples

Pressing
The appropriate molding pressure is 8 to 10 MPa. Tablets molded at this pressure offer sufficient green strength, with a porosity of 0.35 to 0.37, and allow for easy thermal decomposition of the binder during the pre-firing process.
Pre-firing
Pre-firing is carried out in an oxidizing atmosphere such as oxygen or air. Refer to T₁ in the property table above for the pre-firing temperature. Binder decomposition begins at 150°C and completes around 530°C, so the temperature increase rate in this range should be less than 15°C/min. Following the pre-firing schedule in Figure 1, the shrinkage of a tablet molded at 8 to 10 MPa pressure will be between 13.5% and 14.5%.