Passivation Glasses

Product Description

Passivation glasses are used for the chemical and mechanical protection of discrete semiconductor and varistor surfaces.

The applied glass layer reliably protects the function of the “passivating” the p-n-junction. At the same time, it may serve as hermetic housing of the discrete device.

Passivation glass powders feature specially developed material compositions. One of the key properties is a particularly high insulation resistance achieved by limiting the alkali content (particularly Na+) to a minimum. This is guaranteed by using only the highest grade raw materials as well as special manufacturing procedures.

To avoid stress in the finished part as well as the formation of cracks, the coefficients of thermal expansion of the passivation glass and the other semiconductor components must be matched as closely as possible. Special semiconductors also require fine tuning with respect to the surface load of the glass. SCHOTT offers different glass compositions to accomplish the best match possible.

Advantages

  • Comprehensive assortment of different glass compositions for various semiconductor and varistor types
  • Lead-free solutions for all common passivation applications
  • Supply of highest material purity with lowest alkaline content by choosing only the highest grade raw materials, tightly controlled melting as well as special grinding processes

Applications

  • Sinter glass diodes and rectifiers
  • Wafer passivation e.g for thyristors and diodes
  • Glazing of high-voltage varistors

Technical Details

Technology

Glass powders are manufactured in two steps:
The raw glass is first melted in specially designed aggregates
The glass ribbons are ground into fine powders of different grain size distribution.
Our customers process our passivation glass powders in different ways. For the manufacturing of sintered glass diodes, a slurry of glass powder and deionized water is applied to the diode body before sintering it in a furnace. For wafer passivation, an organic suspension is applied by spinning, doctor blading, sedimentation, electrophoresis or screen printing.


Features / Specifications

Passivation glasses are offered in various individual specifications due to diversified glass systems, see table below.
All passivation glasses are supplied as glass powder and are available in different grain sizes.


Forms of Supply and Product Packaging

Our standard packaging consists of sealed PE-Bags in cardboard drums. For alternative packaging solutions please contact us.


SCHOTT passivation glasses:

Lead-containing
Typ
Main applications
α(20/300)
10-6/K
Tg
oC
Pb-contents
wt%
Firing temp.
oC
Holding Time
Min.
Tj
oC
Layer thickness
µm
G018-205 Pb-Zn-B sinter glass diodes 4.45 632 1-5 690 10 - -
G017-388 Zn-B-Si composite thyristors, high-blocking rectifiers 3.6 550 1-5 700 5 180 ≥ 30
G017-002 Zn-B-Si composite sintered glass diodes 3.7 545 1-5 700 10 180 -
G017-096R Pb-B-Si sinter glass, planar- and mesa-diodes 4.8 456 10-50 680 5 160 -
G017-004 Pb-B-Si composite mesa diodes 4.1 440 10-50 740 5 160 ≥30
G017-230 Pb-B-Si composite transistors 4.2 440 10-50 700 4 160 ≥25
G017-725 Pb-B-Si sinter glass diodes 4.9 468 10-50 670 10 180 -
G017-997 Pb-B-Si composite wafer passivation 4.4 485 10-50 760 20 180 -
G018-133 Pb-B-Si composite sinter glass diodes 4.8 463 10-50 690 30 - -
                   
Lead-free                  
G018-200 Zn-B-Si sinter glass diodes 4.6 557 - 665 10 - -
G018-197 Zn-B-Si sinter glass diodes 4.4 557 - 675 10 - -
G018-255 Bi-Zn-B varistors 9.4 396 - 520 15 - -

Quality

Please click on our quality assurance processes pages for more information on our various quality assurance programs.
Trade Fairs & Events
30.
May
Trade fair Materials, Veldhoven, Netherlands, 30.05 - 31.05.2018
05.
September
Trade fair CIOE - China International Optoelectronic Expo, Shenzhen, China, 05.09 - 08.09.2018
17.
September
Trade fair Gastech, Barcelona, Spain, 17.09 - 20.09.2018
25.
September
Trade fair European Microwave Week, Madrid, Spain, 25.09 - 27.09.2018
Contact
SCHOTT AG
Christoph-Dorner-Strasse 29
84028 Landshut
Germany
E-Mail to SCHOTT+49 (0)871/826-0
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