1 . introduction to glass

• 1 . Introduction to Glass

• 2 . Glass Frit

Glass Frit

Ⅰ. Glass

1 . Introduction

to Glass

American Society for Testing Materials (ASTM) defined glass as

" inorganic matter’s melt not crystallized, but a super cooled liquid”.

1. Definition

liquid

Super cooled

liquid

State of glass

Tm

crystallization

crystal

Tg

Vo

lum

e/m

ol

Transition temperature melting temperature

temperature

Ⅰ.Glass 1 . Introduction to Glass

Network structure formed of disordered unit structure

Short-range order, long-range disorder

2. Structure of glass

melting cooling

Silica structure in the state of crystal

Silica structure in the state of non-crystalline

(not enough reordering, similar to liquid)

Silica structure in melting (very disordered)

[unit structure melting and crystallization of Silica]


Network former

Glass oxide which can form glass independently

SiO2, , B2O3 , P2O 5 , V2O3, GeO2 …

Network modifiers

Modifier oxide which cut off and diminish the network

Na2O, K2O, CaO, Li2O…

If network modifiers, then

melting temperature coefficient of thermal expansion chemical durability

Intermediate

Play a role of both network former and network modifier

Al2O3, PbO, ZnO, BeO…

3. Classification of glass component elements Ⅰ.Glass

1 . Introduction to Glass

[structure and ion arrangement of soda glass]

Si

O

O

O O Si

O

O

O + Na2O Si

O

O

O O Si

O

O

O Na+

O - -

Na+

-. Introduction of Na2O(network modifier) Bridged Oxygen into 2 Non-Bridged Oxygen

4. Relationship between Network former and Network modifier Ⅰ.Glass

1 . Introduction to Glass

5. Relation of viscosity and temperature

Strain annealing softening working melting

point point point point point

viscosity

temperature

(pa·s)

102 Poise

104 Poise

107.6 Poise

1013 Poise

1014.5 Poise


Ⅰ. Glass

2 . Glass Frit

Traditional meaning

Glass powder named as china’s solder(sealing) glass,

used for surface protection, gloss, sealing and etc.

Modern meaning

Glass powder used in industry of display, ceramics, electronic parts

and etc.

1. Definition of Glass Frit Ⅰ.Glass

2 . Glass Frit

1st step : frit, softened and flow

2nd Step: chemical reaction (ionic bonding) occurred on the interface

firing

Base

Frit

Ionic bonding

Covalent bonding

2. Glass Frit Sealing Mechanism

Heating up

Ⅰ.Glass 2 . Glass Frit

Glass transition point (Tg)

Definition : temperature when physical properties (volume, density, calory) sharply change while

super cooled liquid be cooled continuously.

the viscosity then is 1013 poise → endothermic reaction temperature

Measuring instrument

- DSC(Differential Scanning Calorimetry)

- DTA(Differential Thermal Analysis)

3. Property of Glass Frit

exothermic

endothermic

Transition temperature

Crystallization temperature

Melting temperature

temperature DTA

DSC • S: Sample

• R: Referance


Example : DSC measurement


Tg : Glass Transition Point


Coefficient of thermal expansion (CTE)

Definition : the fractional change in the length or volume of a body per degree of temperature change.

usually ×10-7/℃ in glass.

Measuring instrument: Dilatometer, TMA(Thermo mechanical Analyzer)


Temperature check of the sample

LVDT (Linear Variable Differential Transformer)

→ length check according to electric signal change


Softening point

Tdsp (Dilatometric Softening point) Ts (Softening Point)

Definition Temperature at 1011~12 poise Temperature at 107.6 poise

Measuring

instrument

Dilatometer, TMA(Thermo mechanical

Analyzer) Softening point measuring instrument

3. Property of Glass Frit Ⅰ.Glass

2 . Glass Frit

Dtg : Dilatometric Transition Point

Tdsp : Dilatometric Softening Point

Example of TMA measurement : CTE, Dtg, Tdsp

3. Property of Glass Frit Ⅰ.Glass

2 . Glass Frit

Composition Design consideration of usage, temperature, CTE, electrical properties,

chemical durability

Raw Materials oxide

Weighing Balance

Mixing Henschel Mixer, V-mixer, Ribbon Mixer…..

Melting Pt-Crucible & Melter

Ribbon Cullet Forming Ribbon Roller

First Milling Alumina Pot Mill, Ball Mill(Dry), Disk Mill

Second Milling Ball Mill(Wet) , Jet Mill, Fine Mill

Glass Frit Preparation &

Powder Characterization

Particle Size Distribution Analysis : CILAS 1064L , Malvern 2000

Tg : DSC/DTA

CTE & Ts : TMA/Dilatometer

4. Manufacturing Process of Glass frit Ⅰ.Glass

2 . Glass Frit

1. Raw material mix 2. Melting /shaping 3. Preliminary grinding

4. Fine grinding (Dry) 5. Filler mix 6. Package

4. Manufacturing Process of Glass frit Ⅰ.Glass

2 . Glass Frit

5. Analysis instruments of glass properties

Softening pointer Strain viewer Impedance Analyzer

PSA

SEM

Microscope

DSC

TMA


Frit Seals

Glass-Glass

Glass- Ceramic

Glass-Metal

Metal-Metal

Ceramic-Ceramic

Coating

Ceramics

Metals

6. Applications for Glass Frit Ⅰ.Glass

2 . Glass Frit

Automobile

• Black Enamel for windshields

Dental Ceramic Package

[Panel parts of PDP]

Solar Cell [VFD]

[Mobile Projection]

Display

[OLED]

6. Applications for Glass Frit Ⅰ.Glass

2 . Glass Frit

Bass Co., Ltd.

103-9 Sinhang-ri Dunpo-myeon

Asan-si Chungnam, South Korea

Tel. 82-41-533-3537

Fax. 82-41-533-3503

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1 . introduction to glass

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