Method for producing multilayer substrate and electronic part, and multilayer electronic part

• US 6,808,642 B2
• Filed: 09/11/2002
• Issued: 10/26/2004
• Est. Priority Date: 12/28/2000
• Status: Expired due to Fees

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Endo, Toshikazu, Sasaki, Masami, Takaya, Minoru
• Primary Examiner(s): Mills, Gregory
• Assistant Examiner(s): Culbert, Roberts
• Application Number:
  US10/238,677
• Publication Number:
  US 20030029830A1
• Time in Patent Office: 776 Days
• Field of Search: 156/233, 216/13, 216/20, 216/33, 174/250, 174/255, 174/256, 298/30, 428/646, 438/617, 438/106, 438/123
• US Class Current: 216/13
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 17/0013 with stacked layers
• CPC Class Codes: H01F 41/041 Printed circuit coils apparatus or processes for manufacturing printed circuits in general H05K3/00
• CPC Class Codes: H01G 4/308 made by transfer techniques
• CPC Class Codes: H05K 1/0373 containing additives, e.g. fillers H05K1/036 takes precedence
• CPC Class Codes: H05K 1/16 incorporating printed electric components, e.g. printed resistor, capacitor, inductor
• CPC Class Codes: H05K 1/162 incorporating printed capacitors
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/0209 Inorganic, non-metallic particles
• CPC Class Codes: H05K 2201/086 for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: H05K 3/0052 Depaneling, i.e. dividing a panel into circuit boards; Working of the edges of circuit boards
• CPC Class Codes: H05K 3/06 the conductive material being removed chemically or electrolytically, e.g. by photo-etch process semi-additive methods H05K3/108
• CPC Class Codes: H05K 3/20 by affixing prefabricated conductor pattern H05K1/187, H05K3/046, H05K3/4658, H05K3/4682 takes precedence
• CPC Class Codes: H05K 3/403 Edge contacts; Windows or holes in the substrate having plural connections on the walls thereof H05K3/4092 takes precedence
• CPC Class Codes: H05K 3/429 Plated through-holes specially for multilayer circuits, e.g. having connections to inner circuit layers
• CPC Class Codes: H05K 3/4652 Adding a circuit layer by laminating a metal foil or a preformed metal foil pattern H05K3/4647 takes precedence
• CPC Class Codes: Y10T 29/49124 On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

This invention has an object of providing a method for producing a multilayer substrate or an electronic part wherein decrease in the thickness has been enabled without causing the problem of insufficient strength or the like in the handling, as well as the electronic part. Such object has been attained by a method for producing a multilayer substrate or an electronic part comprising the steps of adhering a conductor layer to a transfer film, patterning the conductor layer to form a predetermined pattern, placing the transfer film overlaid with the patterned conductor layer on a prepreg so that the side of the conductor layer faces the prepreg, and then adhering the transfer film to the prepreg by applying heat and pressure and peeling the transfer film to produce the prepreg having the conductor layer formed thereon; and the multilayer electronic part produced by such method.

Claims

1. A method for producing a multi-layer substrate, comprising the steps of:

adhering a transfer film comprised of a resin film support layer having an adhesive layer comprised of a base polymer and a foaming agent thereon, the transfer film having an adhesive force ranging from 3.7 to 7.0 N/20 mm to an electrically conductive layer;

patterning the conductor layer by etching to form a predetermined pattern;

placing the transfer film overlaid with the patterned conductor layer on a prepreg such that the patterned conductor layer is in surface contact with a surface of the prepreg; and

then compressing the combined layers and transfer film under a pressure of 4.9 to 39 Mpa while heating at 1300-1700 C; and

peeling the transfer film from the conductor layer;

thereby leaving the prepreg in contact with the conductor layer.

2. The method for producing a multi-layer substrate according to claim 1, wherein said adhesion by heat and pressure application is conducted under the conditions of a temperature of 140°

-160°

C. and a processing time of 120 to 180 minutes.

3. The method for producing a multi-layer substrate according to claim 1, further comprising the step of heat treating said transfer film at a temperature of 100°

-130°

C. for 5 to 20 minutes before placing the transfer film on the prepreg.

4. The method for producing a multi-layer substrate according to claim 1, wherein the prepreg produced comprises a resin, and at least one of a dielectric powder and a magnetic powder dispersed in the resin, and has a thickness of 2 to 40 μ

m.

5. The method for producing a multi-layer substrate according to claim 1, further comprising the step of placing another prepreg on the patterned surface of said prepreg, and adhering the placed prepreg by applying heat and pressure to produce a multi-layer substrate having an inner conductor pattern.

6. The method for producing a multi-layer substrate according to claim 1, wherein said conductor layer has a surface roughness Rz of 1 to 6 μ

m.

7. The method for producing a multi-layer substrate according to claim 1, wherein said conductor layer comprises at least one element selected from Cu, Al, Ag and Au.

8. The method for producing a multi-layer substrate according to claim 1, wherein said conductor layer is formed by electrolysis or rolling.

9. The method for producing a multi-layer substrate according to claim 1, wherein said conductor layer has a thickness of 3 to 32 μ

m.

10. The method for producing a multi-layer substrate according to claim 4, wherein said dielectric powder comprises at least one member selected from the group consisting of titanium-barium-neodymium based ceramics, titanium-barium-tin based ceramics, lead-calcium based ceramics, titanium dioxide based ceramics, barium titanate based ceramics, lead titanate based ceramics, strontium titanate based ceramics, calcium titanate based ceramics, bismuth titanate based ceramics, magnesium titanate based ceramics, CaWO₄ based ceramics, Ba(Mg,Nb)O₃ based ceramics, Ba(Mg,Ta)O₃ based ceramics, Ba(Co,Mg,Nb)O₃ based ceramics and Ba(Co,Mg,Ta)O₃ based ceramics.

11. The method for producing a multi-layer substrate according to claim 4, wherein said dielectric powder comprises at least one member selected from the group consisting of silica, alumina, zirconia, potassium titanate whiskers, calcium titanate whiskers, barium titanate whiskers, zinc oxide whiskers, chopped glass, glass beads, carbon fibers and magnesium oxide.

12. The method for producing a multi-layer substrate according to claim 4, wherein said dielectric powder is present in an amount the range of 10% by volume to less than 65% by volume based on the sum of the resin and the dielectric powder as 100% by volume.

13. The method for producing a multi-layer substrate according to claim 4, wherein said magnetic powder comprises at least one member selected from the group consisting of ferrites of Mn—

Mg—

Zn, Ni—

Zn and Mn—

Zn based systems.

14. The method for producing a multi-layer substrate according to claim 4, wherein said magnetic powder comprises at least one member selected from the group consisting of iron carbonyl, iron-silicon based alloys, iron-aluminum-silicon based alloys, iron-nickel based alloys;

and amorphous based ferromagnetic metals.

15. The method for producing a multi-layer substrate according to claim 4, wherein said dielectric powder or said magnetic powder has a spherical shape with a projected image of a circle and a sphericity of 0.9 to 1.0, and a mean particle size of 0.1 to 40 μ

m.

16. A method for producing an electronic part, comprising the steps of:

forming an electronic device by patterning at least the conductor layer of the multi-layer substrate of claim 4;

forming throughholes which function as terminals for at least one electronic part device; and

cutting the substrate at the positions of said throughholes into each electronic part device to thereby produce the electronic part.

17. The method for producing a multi-layer substrate according to claim 1, wherein the supporting resin film is a member selected from the group consisting of fluororesin films, polyethylene films, polypropylene films, polystyrene films, polyvinyl chloride films, polycarbonate films, polyimide films, polysulfone films, polyether sulfone films, polyamide films, polyamideimide films, polyetherketone films and polyphenylene sulfide films.

18. The method for producing a multi-layer substrate according to claim 1, wherein the supporting resin film has a thickness of about 10 μ

m to 200 μ

m.

19. The method for producing a multi-layer substrate according to claim 1, wherein the base polymer has a dynamic modulus at room temperature to 150°

C., ranging from 500,000 to 10,000,000 μ

N/cm².

20. The method for producing a multi-layer substrate according to claim 19, wherein the base polymer has a dynamic modulus at room temperature to 150°

C. ranging from 500,000 to 8,000,000 μ

N/cm².