# US 11,115,020 B2 · Signal transmission circuit device, semiconductor device, method and apparatus for inspecting semiconductor device, signal transmission device, and motor drive apparatus using signal transmission device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,115,020 B2 - Document ID: US11115020B2 - Status: Granted - Kind: B2 - Application number: 16/508,682 - Filed: 2019-07-11 - Published: 2019-10-31 - Granted: 2021-09-07 - Earliest claimed: 2009-11-05 - Assignees: Rohm Co., Ltd. - Applicants: Rohm Co., Ltd. - Inventors: Daiki Yanagishima; Toshiyuki Ishikawa; Hirotaka Takihara - Web page: https://patentgrep.com/patent/US11115020B2 ## CPC - H03K 17/691: using transformer coupling - G01R 31/27: Testing of devices without physical removal from the circuit of which they form part, e.g. compensating for effects surrounding elements {(testing printed circuit boards G01R31/2801)} - G01R 31/2884: {using dedicated test connectors, test elements or test circuits on the IC under test (G01R31/2855 takes precedence)} - H02P 31/00: Arrangements for regulating or controlling electric motors not provided for in groups H02P1/00 - H02P5/00, H02P7/00 or H02P21/00 - H02P29/00 - H03K 17/61: using transformer coupling - H04L 25/028: {Arrangements specific to the transmitter end} - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A signal transmission device includes a first lead frame supporting a signal transmission chip that includes first and second inductor spiral rings, a first bonding pad electrically coupled between the first and second inductor spiral rings, and a guard ring provided to roundly cover the first and second inductor spiral rings in a plan view. Bonding pads are provided outside of the guard ring. A direction of rotation between the first and second inductor spiral rings are different from each other so that the first and second inductor spiral rings are disposed substantially symmetrically about the first bonding pad. A second lead frame supports a semiconductor chip, with the signal transmission chip and the semiconductor chip facing each other. ## Claims ### Claim 1 A signal transmission device comprising: a signal transmission chip; and a first lead frame supporting the signal transmission chip, wherein the signal transmission chip comprises: a first inductor spiral ring; a second inductor spiral ring; a first bonding pad electrically coupled between the first inductor spiral ring and the second inductor spiral ring; a guard ring provided to roundly cover the first inductor spiral ring and the second inductor spiral ring in a plan view; and a plurality of bonding pads provided outside of the guard ring; wherein a direction of rotation between the first inductor spiral ring and the second inductor spiral ring are different from each other so that the first and second inductor spiral rings are disposed substantially symmetrically about the first bonding pad, and no bonding pad is provided at a first side of the signal transmission chip, wherein the signal transmission device further comprises a semiconductor chip and a second lead frame supporting the semiconductor chip, wherein the signal transmission chip and the semiconductor chip are placed to face each other. ### Claim 2 (depends on 1) The signal transmission device according to claim 1, wherein a second bonding pad is provided at a center of the first inductor spiral ring, and a third bonding pad is provided at a center of the second inductor spiral ring. ### Claim 3 (depends on 2) The signal transmission device according to claim 2, further comprising a third inductor spiral ring, a fourth inductor spiral ring, and a fourth bonding pad electrically coupled between the third and fourth inductor spiral rings, wherein a direction of rotation between the third and fourth inductor spiral rings are different from each other so that both of the third and fourth inductor spiral rings are disposed substantially symmetrically about the fourth bonding pad. ### Claim 4 (depends on 3) The signal transmission device according to claim 3, wherein a signal transmission direction is same between the first inductor spiral ring and the second inductor spiral ring. ### Claim 5 (depends on 4) The signal transmission device according to claim 4, wherein a signal transmission direction is same between the third inductor spiral ring and the fourth inductor spiral ring. ### Claim 6 (depends on 5) The signal transmission device according to claim 5, wherein a signal transmission direction is different from each other between the first inductor spiral ring and the third inductor spiral ring. ### Claim 7 (depends on 6) The signal transmission device according to claim 6, wherein a layer of material directly under the first bonding pad is composed of a same material as the first inductor spiral ring and is disposed in a same plane as the first inductor spiral ring. ### Claim 8 (depends on 7) The signal transmission device according to claim 7, wherein the guard ring roundly covers the first inductor spiral ring and the second inductor spiral ring in a plan view continuously without any disconnection. ### Claim 9 (depends on 8) The signal transmission device according to claim 8, wherein the plurality of bonding pads are placed as a straight line along a second side of the signal transmission chip. ### Claim 10 (depends on 9) The signal transmission device according to claim 9, wherein the guard ring is connected to a ground potential. ### Claim 11 (depends on 1) A signal transmission device according to claim 1, further comprising a molding resin covering the signal transmission chip, the semiconductor chip, the first lead frame, and the second lead frame. ### Claim 12 (depends on 11) The signal transmission device according to claim 11, wherein lead terminal are protruded from a first side of the signal transmission device and a second side of the signal transmission device, and no lead terminal is protruding from a third side of the signal transmission device and a fourth side of the signal transmission device.