Thick Film Processing & LTCC

Thick Film Processing & LTCC 참고문헌 MURATA http://www.hibridas.co.uk http://81.161.252.57/ipci/courses/thickfilm/index_25.htm http://www.piezocrystal.com/technology http://www.globalspec.com/learnmore/passive_discrete_devices/capacitors/chip_capacitors Metal Paste for Solar Cell Technology and Market Forecast 2nd Edition (2010~2015)

Thick Film Paste http://www.hibridas.co.uk http://www.gwent.org/gem_thick_film.html /

Applications and paste types Applications Conductor materials Resistor materials Dielectric materials Hybrid IC Alumina substrates Aluminum nitride substrates, et c LED, etc. Ag-Pd paste Ag-Pt paste Ag paste Cu paste Au paste RuO 2 resistor paste Ag-Pd resistor paste Glass paste for: Cross-over Multilayer printing N 2 firing Overcoat Resistor Ag paste Ag-Pd paste RuO 2 resistor paste Ag-Pd resistor paste Glass paste for overc oat Sensor Pt paste Au paste Pt-Pd alloy paste RuO 2 resistor paste Glass paste for overc oat Laminated ceramic Device LTCC Ag paste Ag-Pt paste Ag-Pd paste Au paste RuO 2 resistor paste Ag-Pd resistor paste Glass paste for overc oat Tantalum capacitor Ag paste for coating C paste Ag adhesive - - Thermal printer head Panel display Au paste MOD/Au paste Ag paste Ag paste Au paste MOD/Au paste RuO 2 resistor paste - - Heater Ag-Pd paste Ag-Pd resistor paste Glass paste for overc oat Glass paste for overc oat

Screen printing & Firing Screen printing & Firing Firing conductors, resistors and dielectrics on substrates 8 50 um Simple processing equipment Simple manufacturing process Multilayer hybrids are constructed by alternating printing and firing

Applications Thick film elements Manufacturing of many resistive components Sensors; electrodes, encapsulants and sensing materials Heaters Solar cell PDP

Screen printing process Selected deposition of thin film onto a substrate Forcing ink through a patterned screen, stencil or metal mask mounted under tension on a metal frame Nylon, PE and Stainless Steel Screen Stainless Steel Screen Mesh 120 400, 325-mesh is common

Screen printing process http://81.161.252.57/ipci/courses/thickfilm/index_25.htm Thick film circuit fabricated by. screen printing and firing process The pressure applied to the squeegee The angle of inclination of the squeegee blade The speed of traverse The viscosity and amount of pastes on the screen

The viscosity of pseudoplastic materials decrease with increased shear rate. The viscosity of a thixotropic materials increases with time after the shear stress has been removed Most screen printed materials are designded to have both properties Such materials decrease in the viscosity upon shearing and recover to high viscosity upon removal of the shear stress after short period.

The ideal paste Relatively low viscosity( ~ 10 Pa-s) at high shear strain rate produced when the squeegee traverses the pattern, so the paste transfer to the substrate is easily effected. The shear strain rate: 200 1000 s-1 Polymer, solvent, inorganics, surfactants, thixotropers.

Tape casting 에쓰이는각종첨가제의대표적예

대표적슬러리조합

Doctor Blade http://www.piezocrystal.com/technology

Drying and Firing Polymerization 70 80 C Drying 100-150 C 10 15 min, to remove solvents Firing 200-500 C burn off In air -firing In nitrogen firing

MLCC process http://www.globalspec.com/learnmore/passive_discrete_devices/capacitors/chip_capacitors

Substrates Fused Silica Alumina Glass AlN SiC

Substrates CTE Thermal conductivity Dielectric properties Dielectric break down strength Volume resistivity Flexural Strength

Thermal endurance Tensile strength Thermal conductivity TEC Young s modulus Density Specific heat

Conductors Resistivity Solderbility Adhesion migration Line resolution cost

Conductors Ag Ag-Pd Au Au-Pd Cu Al

Adhesion 1-5% of a reative oxide CuAlO 2, Spinel Bi 2 O 3 -Al 2 O 3 2-10% of glass powder modifed borosilicates

Resistors The resistance directly proportional to resistors length and inversely proportional to its cross section area TCR Ag-Pd PdO NTC RuO 2

Trimming Cutting away part of resistors using a laser to the resistance value. Nd-YAG laser

Multifunctional smart LTCC MOEMS http://www.infotech.oulu.fi/annual/2002/empart.html http://mwrf.com/components/what-ltcc

Process (Murata)

http://www.murata.com/products/catalog/pdf/n20e.pdf

http://www.murata.com/products/ceramic/basic/ltcc/outline.html

LTCC 1. In LTCC fabrication, holes are first punched to create vias through layers (Step 1). 2. Then, each via hole is filled with conductive material and layers are printed with appropriate pattern (Step 2 & Step 3) separately. 3. After that, all layers are stacked, laminated and co-fired (Step 4 Step6) at temperature between 800 C and 900 C into a highly compact ceramic structure

Thermal via http://www.murata.com/products/catalog/pdf/n20e.pdf In order to disperse heat generated by the components, thermal vias are provided, enabling the heat from the modules to escape from the aluminum heat dissipation plate on the underside of the board. The inside of the via holes of Murata's thermal vias use the same "silver as that used for the circuit conductors, enabling the heat dissipation performance of the board to be increased

Ceramic Products http://www.murata.com/products/ceramic/basic/ltcc/application.html Control module boards for ABS (Anti-Lock Brake Systems) and ESC (Electronic Stability Control) EPS (Electric Power Steering) systems which are becoming increasingly small and lightweight. Excellent heat resistance and reliability for electro-mechanical integrated type control module TCU (Transmission Control Units) for these transmission applications. Communication modules

Ink jet printing

Sheet 의수축에맞출수있는 via 용 paste LTCC 용 Ag paste 의수축특성

Ag paste market Metal Paste for Solar Cell Technology and Market Forecast 2nd Edition (2010~2015)