Screen Printing
                                                      The flow behavior of thick film ink
                ...
Screen Printer




                  http://www.ahnsclub.com/jejojangbi/jangbi/M-printer3.jpg
Advanced Electronic Ceramics...
Screen Printing: Schematic




                  From P.J.Holmes and R.G.Loasby, “Handbook of thick film technology,”
Adva...
Screen Mesh Dimension and Wet Print Thickness
      Mesh Type             Mesh Count Filament                 Open        ...
Terminology




       Plain weave                            Twill weave

       - most widely used
       - can accommod...
Squeegee
      Materials
      ♦ Polyurethane excellent print quality, highly durable
      ♦ Metal         large pressure...
Electroluminescent Lamp

                                                   ITO sputtered polyester
                      ...
Applications




                                                       Fig.: Selective printing of EL lamp areas
        ...
Upcoming SlideShare
Loading in …5
×

Aem Lect17

939 views

Published on

Published in: Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
939
On SlideShare
0
From Embeds
0
Number of Embeds
34
Actions
Shares
0
Downloads
20
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Aem Lect17

  1. 1. Screen Printing The flow behavior of thick film ink depends on (1) the viscosity and (2) surface tension τ (shear stress) P/A η= = S(shear rate) V/t From P.J.Holmes and R.G.Loasby, “Handbook of thick film technology,” Advanced Electronic Ceramics I (2004) Screen Printer Semi-automatic Manual http://www.bando.net/ Advanced Electronic Ceramics I (2004)
  2. 2. Screen Printer http://www.ahnsclub.com/jejojangbi/jangbi/M-printer3.jpg Advanced Electronic Ceramics I (2004) Screen Printing: Principle Utilize shear thinning at the high stress during the screen printing process - the shear rate(viscosity) decreases after stress screen printing Pseudoplastic Shear rate From P.J.Holmes and R.G.Loasby, “Handbook of thick film technology,” Advanced Electronic Ceramics I (2004)
  3. 3. Screen Printing: Schematic From P.J.Holmes and R.G.Loasby, “Handbook of thick film technology,” Advanced Electronic Ceramics I (2004) Screen Printing: Variables 1. Screen variable 2. Machine variable a. Mesh material a. Squeegee attack angle b. Mesh count b. Squeegee hardness c. Mesh filament diameter c. Squeegee edge shape d. Mesh weave d. Squeegee down pressure e. Mesh tension e. Squeegee traverse speed f. Mesh filament direction f. snap-off setting g. Emulsion type g. Flood blade setting h. Emulsion thickness h. Parallelism of squeegee/screen I. Pattern direction /substrate assembly I. Volume of the ink on the screen From P.J.Holmes and R.G.Loasby, “Handbook of thick film technology,” Advanced Electronic Ceramics I (2004)
  4. 4. Screen Mesh Dimension and Wet Print Thickness Mesh Type Mesh Count Filament Open Typical Wet (per inch) Diameter Area(%) Print Thickness (µm) (µm) Stainless Steel 150 50 45 57-117 Stainless Steel 165 50 41 50-116 Stainless Steel 200 50 36 45-115 Stainless Steel 200 40 46 45-92 Stainless Steel 325 27.5 41 27-62 Nylon 150 47.5 52 50-87 Nylon 230 35 47 32-75 Nylon 280 30 46 27-55 Nylon 330 30 37 25-50 Typical wet print thickness(t) : 1~2 times of filament diameter. t decrease as increasing Mesh count & open area(%). From P.J.Holmes and R.G.Loasby, “Handbook of thick film technology,” Advanced Electronic Ceramics I (2004) Typical Specification for Screen Mesh 1. Thickness of mesh: 2-~2.5 times of the filament diameter 2. Open area : 35 ~47% http://www.wovenwire.com/finemesh-print.htm Advanced Electronic Ceramics I (2004)
  5. 5. Terminology Plain weave Twill weave - most widely used - can accommodate high flow rates with a relatively low pressure drop Advanced Electronic Ceramics I (2004) Composition of Ink vehicle 1. Binder : viscosity control 2. Surface active agent : dispersion of the solid particles and adequate wetting of the substrate 3. Flow control agent : restrict ink flow during drying (ex.) Butyl carbitol acetate (Solvent) 69.12% Ethyl cellulose (Resin) 14.4% 2-Furoic acid (Flow control agent) 6.4% Nonyl phenoxypolyoxyethylene ethanol (Surfactant) 10% Advanced Electronic Ceramics I (2004)
  6. 6. Squeegee Materials ♦ Polyurethane excellent print quality, highly durable ♦ Metal large pressure window than the polyurethane ♦ Composite Hardness - Soft squeegee low mesh, low viscosity - Medium squeegee wide range of mesh - Hard squeegee high squeegee pressure, high viscosity Configuration Advanced Electronic Ceramics I (2004) Metal pastes for the electronic industry Application Conductive Resistive Application Conductive Resistive materials materials materials materials Hybrid IC Ag/Pd RuO2 Tantalum Ag Ag/Pt Ag/Pd resistive Capacitor Ag/Cu Network Ag Au Thick Film Au resistor Cu High TCR resistive Thermal MOD/Au RuO2 resistive Au Printer Ag/Pd Chip resistor Ag RuO2 Head Ag/Pt Ag/Pd Ag/Pd resistive Ag Sensors Pt Panel Display Ag RuO2 resistive Au Au MLCC Ag MOD/Au Pd Piezoelectric Ag Ag/Pd Ceramic Ni Thermistor Ag/Pd Cu Varistor Ag/Pt Heater Ag/Pd Ag/Pd resistive From http://www.tkg-products.com/ Advanced Electronic Ceramics I (2004)
  7. 7. Electroluminescent Lamp ITO sputtered polyester (ITO: lamp’s outer electrode) Bus Bar (Ag, to achieve maximum current to the coating Phosphor (light emitting layer) Barium titanate (dielectric insulator) Rear electrode (Ag or conductive carbon ink) Advanced Electronic Ceramics I (2004) Characteristics of EL Principle: the rapid charge and discharge of phosphor by applying AC current result in the emission of light DCD - Flexible and thin C - minimal heat(cold light source) - small power consumption (including the inverter efficiency) (AC 100 ~ 220 V usually used) (In the case of DC battery system, the inverter is required) - easy to replace - easy to fabricate the large-area display - weak to moisture (applications) - back-lightning LCD displays - control panel - advertising display Advanced Electronic Ceramics I (2004)
  8. 8. Applications Fig.: Selective printing of EL lamp areas Printing all components of EL lamps is especially Fig. The phosphors used in EL lamps will emit useful when the switch design calls for small-area either green, blue, or yellow light. White light lighting of individual keys. By printing a separate can also be generated by mixing phosphors or lamp area for each key, you'll minimize ink adding dyes consumption and keep the lamp from drawing excessive power. Lighting watch faces Flexible lamp http://www.screenweb.com/industrial/cont/el_lamps990128.html Advanced Electronic Ceramics I (2004)

×