PATTERN FORMING METHOD AND CIRCUIT BOARD

• US 20080122898A1
• Filed: 10/31/2007
• Published: 05/29/2008
• Est. Priority Date: 11/29/2006
• Status: Abandoned Application

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: TOYODA, Naoyuki
• Application Number:
  US11/930,918
• Publication Number:
  US 20080122898A1
• Time in Patent Office: Days
• US Class Current: 347/56
• CPC Class Codes: B41J 3/28 for printing downwardly on flat surfaces, e.g. of books, drawings, boxes , envelopes, e.g. flat-bed ink-jet printers
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 2203/013 Inkjet printing, e.g. for printing insulating material or resist
• CPC Class Codes: H05K 2203/1105 Heating or thermal processing not related to soldering, firing, curing or laminating, e.g. for shaping the substrate or during finish plating
• CPC Class Codes: H05K 3/125 by ink-jet printing

Abstract

A pattern forming method successively discharges droplets of a functional fluid including a functional material towards a base substrate and forms a pattern on a surface of the base substrate. The pattern forming method comprises heating a surface of the base substrate to a surface temperature equal to or more than a temperature of the functional fluid during discharging and less than a boiling point of a liquid composition included in the functional fluid and, when the base substrate is heated to the surface temperature, discharging the droplets of the functional fluid onto the base substrate and forming a pattern.

Claims

1. A pattern forming method that successively discharges droplets of a functional fluid including a functional material towards a base substrate and forms a pattern on a surface of the base substrate, the pattern forming method comprising:

heating a surface of the base substrate to a surface temperature equal to or more than a temperature of the functional fluid during discharging and less than a boiling point of a liquid composition included in the functional fluid; and

discharging the droplets of the functional fluid onto the base substrate and forming a pattern under the condition when the base substrate is heated to the surface temperature.

2. The pattern forming method according to claim 1, wherein,

when heating the surface of the base substrate, the base substrate is heated to a surface temperature at which a concentration of solid matter (particles) in an outer periphery of the droplet that has struck the base substrate reaches a saturated concentration more quickly, compared to a center of the droplet.

3. The pattern forming method according to claim 1, wherein,

the pattern formed is formed by droplets being discharged such that adjacent droplets that have struck the base substrate at least partially overlap with each other.

4. The pattern forming method according to claim 1, wherein,

when a droplet is discharged such as to partially overlap with a droplet that has struck the base substrate first, the droplet is discharged after an outer diameter of the droplet that has struck the base substrate first stops changing.

5. The pattern forming method according to claim 1, wherein,

when discharging the droplets of the functional fluid onto the base substrate and forming the pattern, a time required until the outer diameter of the droplet that has struck stops changing, for the surface temperature, is determined in advance, the determined time serves as a discharging interval time of the droplets, and the droplets are successively discharged at an interval greater than the discharging interval time.

6. The pattern forming method according to claim 1, wherein:

the base substrate is a low-temperature firing sheet composed of ceramic particles and resin; and

the functional fluid is a liquid in which metal particles are dispersed as functional material.

7. The pattern forming method according to claim 1, wherein,

the boiling point of the liquid composition included in the functional fluid is a boiling point of a liquid composition with a lowest boiling point among the liquid compositions.

8. The pattern forming method according to claim 1, wherein,

the boiling point of the liquid composition included in the functional fluid is a boiling point of a liquid composition with a lowest boiling point among liquid compositions having a concentration that affects pattern formation when bumping occurs.

9. A circuit board on which a circuit element is mounted and wiring electrically connected to the mounted circuit element is formed, wherein,

the wiring is formed using the pattern forming method according to claim 1.