Process for producing a circuit module

• US 8,240,037 B2
• Filed: 11/13/2009
• Issued: 08/14/2012
• Est. Priority Date: 06/28/2007
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Kitamura, Yoichi, Hashimoto, Minoru, Kaneko, Tatsuya
• Primary Examiner(s): Banks, Derris
• Assistant Examiner(s): Nguyen, Tai
• Application Number:
  US12/591,240
• Publication Number:
  US 20100126008A1
• Time in Patent Office: 1,005 Days
• Field of Search: 297/46, 298/52, 298/32, 298/47, 298/48, 298/55, 361/816, 361/777, 361/766, 361/763, 361/772, 361/767, 174/261, 174/250, 174/72.R, 174/72.B, 174/72.C, 257/703, 257/704, 257/734
• US Class Current: 29/846
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• 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 23/04 characterised by the shape of the container or parts, e.g. caps, walls
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• 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: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01327 Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/15153 the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/15165 Monolayer substrate
• CPC Class Codes: H01L 2924/16153 Cap enclosing a plurality of side-by-side cavities [e.g. E-shaped cap]
• CPC Class Codes: H01L 2924/16315 Shape
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H05K 2201/10371 Shields or metal cases
• CPC Class Codes: H05K 2203/043 : Reflowing of solder coated conductors, not during connection of components, e.g. reflowing solder paste
• CPC Class Codes: H05K 2203/0465 : Shape of solder, e.g. differing from spherical shape, different shapes due to different solder pads
• CPC Class Codes: H05K 3/341 : Surface mounted components
• CPC Class Codes: H05K 9/0056 : specially adapted for microwave applications
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49156 : with selective destruction of conductive paths
• CPC Class Codes: Y10T 29/49158 : with molding of insulated base
• CPC Class Codes: Y10T 29/49165 : by forming conductive walled aperture in base
• CPC Class Codes: Y10T 29/49171 : with encapsulating

Abstract

A process for producing a circuit module including, carried out in this order, preparing a ceramic carrier substrate having ceramic substrate pads for mounting electronic parts, forming solder paste layers on the ceramic substrate pads, forming precoated solder layers by heating the ceramic carrier substrate having the solder paste layers on the ceramic substrate pads to melt the solder paste layers, and then cooling for solidifying the solder, preliminarily fixing stepped lid having protrusions adjacent to a cavity and dents adjacent to the cavity with the protrusions intervening therebetween to the precoated solder layers of the ceramic carrier substrate and joining the stepped lid to the ceramic carrier substrate with solder by placing the ceramic carrier substrate having the stepped lid preliminarily fixed to the precoated solder layers in a reflow furnace.

Claims

1. A process for producing a circuit module comprising, in this order:

preparing a ceramic carrier substrate having ceramic substrate pads and for mounting electronic parts;

forming solder paste layers on the ceramic substrate pads;

forming precoated solder layers by heating the ceramic carrier substrate having the solder paste layers on the ceramic substrate pads to melt the solder paste layers, and then cooling for solidifying the solder;

preliminarily fixing a stepped lid having protrusions adjacent to a cavity and dents adjacent to the cavity with the protrusions intervening therebetween to the precoated solder layers of the ceramic carrier substrate; and

joining the stepped lid to the ceramic carrier substrate with solder by placing the ceramic carrier substrate having the stepped lid preliminarily fixed to the precoated solder layers in a reflow furnace.

2. The process for producing a circuit module as claimed in claim 1, wherein the process further comprising, immediately before the step of preliminarily fixing the stepped lid to the precoated solder layers of the ceramic carrier substrate, a step of preliminarily joining the stepped lid to the precoated solder layers by heating the ceramic carrier substrate having the stepped lid in contact with the precoated solder layer to a temperature, at which the solder is softened by applying a load, that is lower than a melting point of the solder.