Q-chip MEMS magnetic device

• US 20070241201A1
• Filed: 06/30/2006
• Published: 10/18/2007
• Est. Priority Date: 12/17/2003
• Status: Active Grant

• Current Assignee: Fitbit, Inc. (Alphabet Inc.)
• Original Assignee: Qsecure Inc.
• Inventors: Li, Weidong, Brown, Kerry D., Thompson, Joyce, Pariseau, David K., Williams, Edgar M.
• Granted Patent: US 7,641,124 B2
• Time in Patent Office: Days
• US Class Current: 235/493
• CPC Class Codes: G06Q 20/26 Debit schemes, e.g. "pay now"
• CPC Class Codes: G06Q 20/385 using an alias or single-use codes
• CPC Class Codes: G06Q 30/00 Commerce
• CPC Class Codes: G07F 7/08 by coded identity card or credit card or other personal identification means without personal verification means G07F7/02
• CPC Class Codes: G07F 7/1016 Devices or methods for securing the PIN and other transaction-data, e.g. by encryption arrangements for secret communication, see H04L9/00
• CPC Class Codes: G11B 5/00808 magnetic cards

Abstract

A Q-Chip MEMS magnetic device comprises a thin-film electronic circuit for implantation in the Track-2 area of a magnetic stripe on the back of a credit card. The Q-Chip MEMS magnetic device periodically self-generates new sub-sets of magnetic data that are to be read in combination with other magnetic data that is permanently recorded in the surrounding surface of the magnetic stripe. A collocated battery and microcontroller provide operating power and new data for magnetic bit updates. A swipe sensor triggers such updates by sensing electrical contact with a legacy card reader. Several thin-film coils of wire are wound end-to-end around a common, flat, ferrous core. These are driven by the microcontroller. In one instance, such core comprises “hard” magnetic material with a coercivity of 200-300 Oersteds. Magnetic data written from the corresponding adjacent coils will persist for later readings by a legacy card reader. In another instance, the core comprises “soft” magnetic material with a coercivity of about one Oersted. A media stripe of “hard” magnetic film material overlays respective coils to receive magnetic data transfers. Magnetic data written from the corresponding adjacent coils will persist in the overlaying hard media for later readings by a legacy card reader. In a data input mode, the thin-film coils can be used as readers to provide updates and new programming to the microcontroller.

Claims

1. A magnetic device, comprising:

means providing for the reading of programmable and persistent magnetic data by a legacy card reader in combination with permanent magnetic data recordings in a surrounding magnetic stripe.

2. The magnetic device of claim 1, further comprising:

a plurality of writing coils collinearly wound around a common flat longitudinal hard magnetic core and embedded in said surrounding magnetic stripe.

3. The magnetic device of claim 1, further comprising:

a plurality of writing coils collinearly wound around a common flat longitudinal soft magnetic core and embedded in a recess in said surrounding magnetic stripe and beneath a hard magnetic media.

4. The magnetic device of claim 1, further comprising:

a plurality of writing coils collinearly wound around a common flat longitudinal magnetic core and embedded in said surrounding magnetic stripe; and

a microcontroller connected to provide changeable data to the plurality of writing coils.

5. The magnetic device of claim 4, further comprising:

a swipe sensor disposed over the plurality of writing coils and providing for a trigger to the microcontroller to provide a data update.

6. The magnetic device of claim 4, further comprising:

a capacitor to receive a slow charge from a battery and to deliver a fast discharge to each of the plurality of writing coils sufficient to record repeatable magnetic data for a later reading by said legacy card reader.

7. The magnetic device of claim 4, further comprising:

induction means for communicating card personalization data through the plurality of writing coils to the microcontroller.

8. The magnetic device of claim 1, further comprising:

a beading of magnetic material providing for a blending of magnetic properties at a joint with the surrounding magnetic stripe.

9. The magnetic device of claim 1, further comprising:

a silicon substrate on which are disposed a plurality of writing coils, and set flush within a recess in said surrounding magnetic stripe.

10. A thin-film magnetic device, comprising:

a substrate;

a first insulation (ins-1) layer deposited on the substrate;

a first metallization (met-1) layer deposited on the ins-i layer, and comprising copper (Cu), and forming a bottom half of a number of individual coil windings;

a second insulation (ins-2) layer deposited on the met-1 layer, and comprising an insulative material deposited, without a mask;

a hard magnetic core (mag-l) of ferromagnetic alloy deposited about 1-μ

m thick over the ins-2 layer;

a third insulation (ins-3) layer deposited over the mag-1 layer, and comprising an insulative material;

a second metallization (met-2) layer deposited on the ins-3 layer, and comprising copper (Cu), and forming a top half of said number of individual coil windings;

a fourth insulation (ins-4) layer deposited over the mag-1 layer, and comprising an insulative material; and

a passivation overcoat (psvn-1) of relatively hard material deposited over the ins-4 layer;

wherein, the met-1 and met-2 layers form coil windings that encircle a magnetic core formed by the mag-1 layer, and such provide for the writing of magnetic data readable by a legacy card reader shuttled along the surface of the psvn-1 layer.

11. The thin-film magnetic device of claim 10, wherein:

the first insulation (ins-1) layer deposited on the substrate includes bisbenzocyclobutene (BCB) or photoresist about two micrometers (μ

m) thick;

the first metallization (met-1) layer deposited on the ins-1 layer comprises copper (Cu) about 8-μ

m thick;

the second insulation (ins-2) layer deposited on the met-1 layer comprises BCB or photoresist deposited about 5-μ

m thick;

the hard magnetic core (mag-1) is a CoFe alloy deposited about 1-μ

m thick and has a coercivity of about 200-600 Oe;

the third insulation (ins-3) layer deposited over the mag-1 layer comprises BCB deposited about 2-μ

m to 5-μ

m thick;

the second metallization (met-2) layer deposited on the ins-3 layer comprises copper (Cu) about 8-μ

m thick;

the fourth insulation (ins-4) layer deposited over the mag-1 layer comprises BCB or photoresist deposited about 2-μ

m to 5-μ

m thick; and

the passivation overcoat (psvn-1) comprises silicon nitride (SiN), silicon oxide, or diamond-like carbon (DLC) deposited over the ins-4 layer about 0.05-μ

m thick;

12. The thin-film magnetic device of claim 10, further comprising:

a conductive overlay on the passivation overcoat (psvn-1) to complete an electrical circuit to sense when a read head passes over.

13. A thin-film magnetic device, comprising:

a substrate;

a first insulation (ins-1) layer deposited on the substrate;

a first metallization (met-1) layer deposited on the ins-1 layer, and comprising copper (Cu), and forming a bottom half of a number of individual coil windings;

a second insulation (ins-2) layer deposited on the met-1 layer, and comprising an insulative material deposited, without a mask;

a soft magnetic core (mag-1) of deposited over the ins-2 layer, and having a coercivity of about one Oe;

a third insulation (ins-3) layer deposited over the mag-1 layer;

a second metallization (met-2) layer deposited on the ins-3 layer, and comprising copper (Cu), and forming a top half of said number of individual coil windings;

a fourth insulation (ins-4) layer deposited over the mag-1 layer;

a hard magnetic media (mag-2) of a ferromagnetic alloy deposited over the ins-4 layer; and

a passivation overcoat (psvn-1) deposited over the ins-4 layer;

wherein, the met-1 and met-2 layers form coil windings that encircle a magnetic core formed by the mag-1 layer, and such provide for the writing of magnetic data to the mag-2 layer which is readable by a legacy card reader when shuttled along the surface of the psvn-1 layer.

14. The thin-film magnetic device of claim 13, wherein:

the first insulation (ins-1) layer deposited on the substrate comprises bisbenzocyclobutene (BCB) or photoresist about two micrometers (μ

m) thick;

the first metallization (met-1) layer deposited on the ins-1 layer comprises copper (Cu) about 8-μ

m thick;

the second insulation (ins-2) layer deposited on the met-1 layer comprises BCB or photoresist deposited, without a mask, about 5-μ

m thick;

the soft magnetic core (mag-1) of nickel-iron (NiFe) deposited about 6-μ

m thick over the ins-2 layer, and having a coercivity of about one Oe;

the third insulation (ins-3) layer deposited over the mag-1 layer comprises BCB or photoresist deposited about 2-μ

m to 5-μ

m thick;

the second metallization (met-2) layer deposited on the ins-3 layer comprises copper (Cu) about 8-μ

m thick;

the fourth insulation (ins-4) layer deposited over the mag-1 layer comprises BCB or photoresist deposited about 2-μ

m to 5-μ

m thick;

the hard magnetic media (mag-2) is CoFe or CoNi deposited about 1-μ

m thick over the ins-4 layer, and has a coercivity of about 200-600 Oe; and

the passivation overcoat (psvn-1) comprises silicon nitride (SiN), silicon oxide, or diamond-like carbon (DLC) deposited over the ins-4 layer about 0.05-μ

m thick;

wherein, the met-1 and met-2 layers form coil windings that encircle a magnetic core formed by the mag-1 layer, and such provide for the writing of magnetic data to the mag-2 layer which is readable by a legacy card reader when shuttled along the surface of the psvn-1 layer.

15. The thin-film magnetic device of claim 14, lastly further comprising:

a conductive overlay on the passivation overcoat (psvn-1) to complete an electrical circuit to sense when a read head passes over.