Semiconductor chip with coil antenna and communication system

• US 7,355,270 B2
• Filed: 01/07/2005
• Issued: 04/08/2008
• Est. Priority Date: 02/10/2004
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yazawa, Yoshiaki, Goto, Yasushi, Torigoe, Makoto, Uesaka, Kouichi, Hasebe, Takehiko
• Primary Examiner(s): Menz; Douglas M.
• Application Number:
  US11/030,058
• Publication Number:
  US 20050173532A1
• Time in Patent Office: 1,187 Days
• Field of Search: 257/679, 257/684, 257/728
• US Class Current: 257/679
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/07756 the connection being non-galvanic, e.g. capacitive
• CPC Class Codes: G06K 19/07775 the antenna being on-chip
• CPC Class Codes: G06K 19/07779 the inductive antenna being a coil
• CPC Class Codes: G06K 19/07783 the coil being planar
• CPC Class Codes: G06K 19/07784 the inductive antenna consisting of a plurality of coils stacked on top of one another
• CPC Class Codes: G06K 7/10178 including auxiliary means for focusing, repeating or boosting the electromagnetic interrogation field comparable booster antennas integrated on the record carrier itself G06K19/07794
• CPC Class Codes: H01L 2223/6677 for antenna, e.g. antenna included within housing of semiconductor device antennas per se H01Q
• CPC Class Codes: H01L 2224/04105 Bonding areas formed on an encapsulation of the semiconductor or solid-state body, e.g. bonding areas on chip-scale packages
• CPC Class Codes: H01L 23/48 Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• 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: H01L 2924/3011 Impedance
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

The present invention intends to prevent the communication distance from becoming shorter with a reduction in size of a coil antenna to the chip size and with a consequent decrease of an induced voltage. According to the present invention there is provided a semiconductor chip having a coil antenna and a circuit surface and adapted to transmit and receive signals by radio to and from an external device. The semiconductor chip has a configuration for increasing an electromagnetic coupling coefficient between the coil antenna and the external device. According to a concrete example thereof, a magnetic material is disposed, the coil antenna is formed by a stacked structure comprising plural conductor layers and insulating layers superimposed one on another, or the coil antenna is disposed outside an external form of a circuit of the semiconductor chip.

Claims

1. A semiconductor chip comprising:

a coil antenna;

a circuit for transmission and reception of signals to and from an external device with use of said coil antenna;

a mechanism for increasing a coupling coefficient in an electromagnetic coupling between said coil antenna and said external device; and

wherein in connection with said mechanism, a circuit surface of said semiconductor chip and said coil antenna are arranged in such a manner that magnetic field lines passing through the coil antenna are strengthened by a mirror effect of the coil antenna induced by the circuit surface of said semiconductor chip, in which an external form of the circuit surface of said semiconductor chip is formed inside an external form of said coil antenna and said coil antenna is formed outside, or in an area mainly outside, an external form of the circuit surface of said semiconductor chip, in a plan view of the circuit surface of the chip.

2. A semiconductor chip according to claim 1, wherein said mechanism comprises plural layers of said coil antenna.

3. A semiconductor chip according to claim 2, wherein said plural layers of said coil antenna are arranged in such a manner that parallel components in an odd-numbered layer of coil wiring and in an even-numbered layer of coil wiring in said coil antenna overlap each other as viewed from an upper surface side of said coil antenna.

4. A semiconductor chip according to claim 2, wherein coil wiring widths of most adjacent layers in said coil antenna having the plural layers are different from each other.

5. A semiconductor chip according to claim 1, wherein a width of the circuit surface of said semiconductor chip is larger than an innermost periphery diameter of said coil antenna.

6. A communication system comprising:

the semiconductor chip recited in claim 1; and

an external device adapted to transmit and receive signals by radio to and from the semiconductor chip.