Module substrate and method of producing the same

• US 6,534,726 B1
• Filed: 10/25/2000
• Issued: 03/18/2003
• Est. Priority Date: 10/25/1999
• Status: Expired due to Fees

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Koide, Tomoyuki, Nakaji, Hiroyuki, Nakaya, Kazuyoshi, Okada, Masanobu
• Primary Examiner(s): Talbott, David L.
• Assistant Examiner(s): PATEL, ISHWARBHAI B
• Application Number:
  US09/696,097
• Time in Patent Office: 874 Days
• Field of Search: 174/259, 174/263, 174/264, 174/266, 174/260, 174/261, 174/262, 298/52, 298/25
• US Class Current: 174/263
• CPC Class Codes: H01L 23/49805 the leads being also applied on the sidewalls or the bottom of the substrate, e.g. leadless packages for surface mounting
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 2201/09181 Notches in edge pads
• CPC Class Codes: H05K 2201/209 Auto-mechanical connection between a component and a PCB or between two PCBs
• CPC Class Codes: H05K 2203/0415 Small preforms other than balls, e.g. discs, cylinders or pillars
• CPC Class Codes: H05K 3/3442 having edge contacts, e.g. leadless chip capacitors, chip carriers
• CPC Class Codes: H05K 3/368 parallel to each other H05K3/361 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: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base

Abstract

End-face through holes each comprising a concave-curved end-face opening groove and an end-face electrode covering the inner wall of the groove are formed in the end-faces of a substrate. Furthermore, a solder having a semi-circular shape is attached to the end-face electrode. The solder comprises an electrode facing portion facing the end-face electrode in the end-face groove, and a protuberant portion elongated from the electrode facing portion to protrude on the back-surface side of the substrate. Thereby, even if the substrate or the like is warped, a gap between the end-face electrode and the electrode pad of a mother board can be filled with the protuberant portion of the solder to connect the end-face electrode and the electrode pad to each other.

Claims

1. A module substrate comprising a substrate for mounting an electronic component on the front surface side thereof, and end-face electrodes provided in end-faces defining an outer peripheral edge of the substrate and adapted to be connected to the electronic component, said end-face electrodes each being provided with a solder to be connected to a mother board provided on the back surface side of the substrate, said solder being protruded on the back surface side of the substrate past a thickness of a portion of the end-face electrode extending onto the back surface side of the substrate and comprising a columnar shape without a laterally projecting portion on the portion of the end-face electrodes disposed on the back surface side of the substrate.

2. A module substrate according to claim 1, wherein said substrate is provided with end-face opening grooves each opening at the end-faces of the substrate, said end-face electrodes are provided on the inner walls of the end-face opening grooves, respectively, and said solders each including an electrode facing portion facing the end-face electrode and being disposed in the end-face opening groove, and an protuberant portion provided so as to protrude from the electrode facing portion to the back-surface side of the substrate.

3. A module substrate according to claim 2 or 1, wherein said end-face opening grooves are each opened in a substantially semi-circular shape at the front and back surfaces of the substrate.

4. A module substrate according to any one of claims 1, 2, and 3, wherein said solders are each positioned only on the inner side of the substrate with respect to the end-face thereof.

5. A module substrate according to any one claims 1 or 2, wherein said solders are each positioned on the inner side of the substrate with respect to the end face thereof, facing the end-face electrode, and are protruded outward of the substrate with respect to the end-face thereof.

6. A module substrate according to claim 1, wherein the end-face electrodes each comprise a plane electrode provided on the end-face of the substrate, the solders each have a columnar shape elongating in the thickness direction of the substrate, and the solder is fixed to the plane electrode with a part of the solder being protruded on the back-surface side of the substrate.

7. A module substrate according to claim 1 or 6, wherein the solders are each positioned only on the outer side of the substrate with respect to the end-face thereof.

8. A method of producing a module substrate comprising a substrate for mounting an electronic component on the front surface side thereof, and end-face electrodes provided in the end-faces defining the outer peripheral edge of the substrate and adapted to be connected to the electronic component, said end-face electrodes each being provided with a solder to be connected to a mother board, the method comprising the steps of:

forming the solder into a columnar shape longer than the thickness of the substrate and past a thickness of a portion of the end-face electrode extending onto a back surface side of the substrate, and

providing the solder on the end-face electrode with a part of the solder having the columnar shape being protruded on the back-surface side of the substrate such that the solder does not have a portion extending laterally from the columnar shape onto the portion of the end-face electrode extending into the backsurface side of the substrate.