WIRING BOARD

• US 20090085164A1
• Filed: 09/30/2008
• Published: 04/02/2009
• Est. Priority Date: 10/01/2007
• Status: Active Grant

• Current Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited)
• Original Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited), TOKO Incorporated (Murata Manufacturing Co Limited)
• Inventors: Nakajima, Shinji, Murayama, Kei
• Granted Patent: US 8,026,576 B2
• Time in Patent Office: Days
• US Class Current: 257/603
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2225/06527 Special adaptation of electrical connections, e.g. rewiring, engineering changes, pressure contacts, layout
• CPC Class Codes: H01L 23/481 Internal lead connections, e.g. via connections, feedthrough structures
• CPC Class Codes: H01L 23/585 comprising conductive layers or plates or strips or rods or rings H01L23/60, H01L23/62, H01L23/64, H01L23/66 take precedence
• CPC Class Codes: H01L 23/60 Protection against electrostatic charges or discharges, e.g. Faraday shields
• CPC Class Codes: H01L 23/62 Protection against overvoltage, e.g. fuses, shunts
• CPC Class Codes: H01L 25/16 the devices being of types provided for in two or more different main groups of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. forming hybrid circuits

Abstract

There is provided a wiring board. The wiring board includes: a semiconductor substrate having a through hole and covered with an insulating film; a through electrode formed in the through hole; a first wiring connected to one end of the through electrode; and a second wiring connected to the other end of the through electrode. The semiconductor substrate includes: a semiconductor element and a first guard ring formed to surround the through hole. The semiconductor element includes a first conductivity-type impurity diffusion layer having a different conductivity-type from that of the semiconductor substrate and is electrically connected to the first wiring and the second wiring.

Claims

1. A wiring board comprising:

a semiconductor substrate having a through hole and covered with an insulating film;

a through electrode formed in the through hole;

a first wiring connected to one end of the through electrode; and

a second wiring connected to the other end of the through electrode,

wherein

the semiconductor substrate comprises;

a semiconductor element including a first conductivity-type impurity diffusion layer having a different conductivity-type from that of the semiconductor substrate and electrically connected to the first wiring and the second wiring; and

a first guard ring formed to surround the through hole.

2. The wiring board according to claim 1, wherein the semiconductor element is a Zener diode and includes:

the first conductivity-type impurity diffusion layer;

a first impurity diffusion layer formed to surround an outer periphery of the first conductivity-type impurity diffusion layer, wherein the first impurity diffusion layer has the same conductivity type as that of the first conductivity-type impurity diffusion layer and is lower than the first conductivity-type impurity diffusion layer in terms of an impurity concentration; and

a portion of the semiconductor substrate positioned under the first conductivity-type impurity diffusion layer

3. The wiring board according to claim 2, wherein the semiconductor substrate is a silicon substrate having a low impurity concentration in which an inversion layer is formed by a potential difference between the through electrode and the semiconductor substrate when applying power, and

wherein the first guard ring is formed from a second impurity diffusion layer having the same conductivity type as that of the semiconductor substrate and being higher than the semiconductor substrate in terms of an impurity concentration.

4. The wiring board according to claim 2, wherein the semiconductor substrate is a silicon substrate having a high impurity concentration in which an inversion layer is unlikely to be formed by a potential difference between the through electrode and the semiconductor substrate when applying power, and

the first guard ring is formed from a second impurity diffusion layer having a different conductivity type from that of the semiconductor substrate.

5. The wiring board according to claim 4, wherein the second impurity diffusion layer has the same conductivity type as that of the first conductivity-type impurity diffusion layer and has almost the same impurity concentration as that of the first conductivity-type impurity diffusion layer.

6. The wiring board according to claim 1, wherein the semiconductor substrate further comprises:

a second guard ring shaped like a frame in a plan view and being formed to surround the first conductivity-type impurity diffusion layer, the semiconductor element, the through electrode and the first guard ring.

7. The wiring board according to claim 6, wherein the second guard ring is formed along side surfaces of the semiconductor substrate.

8. The wiring board according to claim 6, wherein the second guard ring is formed from a third impurity diffusion layer having the same conductivity type as that of the second impurity diffusion layer and having almost the same impurity concentration as that of the second impurity diffusion layer.

9. A semiconductor device comprising:

a wiring board; and

an electronic component mounted on the wiring board,

wherein

the wiring board comprises;

a semiconductor substrate having a through hole and covered with an insulating film;

a through electrode formed in the through hole;

a first wiring connected to one end of the through electrode; and

a second wiring connected to the other end of the through electrode,

wherein

the semiconductor substrate comprises;

a semiconductor element including a first conductivity-type impurity diffusion layer having a different conductivity-type from that of the semiconductor substrate and electrically connected to the first wiring and the second wiring; and

a first guard ring formed to surround the through hole.

10. A method of manufacturing a wiring board, the method comprising:

(a) providing a semiconductor substrate;

(b) forming a first impurity diffusion layer having a different conductivity type from that of the semiconductor substrate, in the semiconductor substrate;

(c) forming a first conductivity-type impurity diffusion layer in the semiconductor substrate such that the first impurity diffusion layer surrounds an outer periphery of the first conductivity-type impurity diffusion layer, while forming a first guard ring in the semiconductor substrate;

(d) forming a through hole in the semiconductor substrate such that the through hole is surrounded by the first guard ring;

(e) forming an insulating film to cover the whole surface of the semiconductor substrate;

(f) forming a through electrode in the through hole;

(g) forming openings in the insulating film to expose the first conductivity-type impurity diffusion layer and a portion of the semiconductor substrate opposite to the first conductivity-type impurity diffusion layer;

(h) forming a first wiring connected to one end of the through electrode, on the semiconductor substrate; and

(i) forming a second wiring connected to the other end of the through electrode, on the semiconductor substrate.