Glass Frit for Laser-Sealing of Ceramic Package

We have developed the world’s first glass frit for laser-sealing with a lower coefficient of thermal expansion (CTE) than conventional products and improved ceramic wettability.

Semi-conductor ceramic packages in image sensors, LEDs, MEMS mirror and other products requiring good light transmission use a transparent glass lid and ceramic cavity. The sealing between these components has been used a resin with low temperature sealing capability. However, sealing with a resin creates issues of durability, so for applications where high reliability is required use expensive gold-tin soldering as sealing material. Conversely, the biggest advantage of a glass frit is the pinpoint laser irradiation to a local sealing area, thereby avoid damage to the inside devices. However, the difference in CTE between the glass frit and the ceramic material and poor wettability required higher laser power, which resulted in thermal shock which causes cracking.

With this in mind, we have developed a glass frit for laser-sealing optimized for the sealing the glass lid and a ceramic cavity.

<Characteristics and Effectiveness of the Product>

 Similar CTE to ceramic material (6.5 - 7.2 ppm/C)
While cooling after the sealing, there is less difference in the contraction amounts for each component and thus, less damage to the components.

 Excellent wettability with ceramics
As laser power can be reduced by 10% (according to an our study comparing to conventional product), it is possible to achieve sealing with low temperature which restrains cracking in the glass lid due to thermal shock.

Applications of glass frit for laser-sealing

Glass for supporting semiconductor wafers with various CTE

We have developed glass for supporting semiconductor wafer with various CTE※ and excellent flatness. Samples of the new glass are now available for shipment.
*CTE: Coefficient of thermal expansion
In processes in which semiconductors are combined with materials with different CTE such as redistribution layers and resin on the same substrate to manufacture, for example, a fan out wafer level package (FOWLP*1), anticipated as a next-generation semiconductor technology, a substrate having a CTE compatible with the specific combination is needed to prevent warping as a result of the difference in CTE.

As a substrate to respond to such a need, the newly developed glasses for supporting semiconductor wafer varies allows the most suitable glass to be selected in accordance with the design materials for a semiconductor package.

*1 FOWLP : A package that forms redistribution layers over a wide domain exceeding the area of a chip

●Product dimensions : 300 mm diameter × 0.55 - 1.00 mm thickness
●Surface flatness : Total thickness variation (TTV) within 2 μm
●Other characteristics : Optically transparent. The product is correspond to the use of UV-hardening resin.

Glass for supporting semiconductor wafers

Dinorex® with AG/AR/AF Coating

Dinorex® is glass for chemical strengthening developed for use as cover glass for mobile handsets such as smartphone and tablets and other new applications. Dinorex® protects such devices from impact shocks and scratches.
Dinorex® was named by integrating the words “Dinosaur” and “Rex” meaning ‘King’ in Latin.

Coating with various functions can be added to Dinorex®. Dinorex® with AG/AR/AF coating is suitable for the cover glass for vehicle displays.
This coated glass has various features, such as excellent optical properties, good uniformity, high durability and curved-surface capability.

Anti-Glare(AG) reduces the glare of reflected light.
Anti-Reflection(AR) reduces the reflectance of light from outside and increase the transparency of light from inside.
Anti-Fingerprint(AF) prevents fingerprints, dirt, stains and scratches.

Dinorex® with AG/AR/AF Coating