MAGNET PLACEMENT FOR INTEGRATED SENSOR PACKAGES

• US 20150185247A1
• Filed: 12/27/2013
• Published: 07/02/2015
• Est. Priority Date: 12/27/2013
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Kyu O.H. Lee, Sarah Haney
• Inventors: Eid, Feras, OSTER, Sasha N., HANEY, Sarah, LEE, Kyu Oh
• Granted Patent: US 9,791,470 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/025 Inertial sensors not provided for in B81B2201/0235 - B81B2201/0242
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2203/0127 Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function
• CPC Class Codes: B81B 2207/094 Feed-through, via
• CPC Class Codes: B81B 3/0027 Structures for transforming mechanical energy, e.g. potential energy of a spring into translation, sound into translation
• CPC Class Codes: B81B 7/007 Interconnections between the MEMS and external electrical signals
• CPC Class Codes: B81B 7/008 MEMS characterised by an electronic circuit specially adapted for controlling or driving the same B81B7/0087 takes precedence; arrangements for starting, regulating, braking, or otherwise controlling an actuator H02N; control arrangements or circuits for visual indicators G09G3/00
• CPC Class Codes: B81C 1/00238 Joining a substrate with an electronic processing unit and a substrate with a micromechanical structure
• CPC Class Codes: B81C 1/00246 Monolithic integration, i.e. micromechanical structure and electronic processing unit are integrated on the same substrate
• CPC Class Codes: B81C 1/00333 Aspects relating to packaging of MEMS devices, not covered by groups B81C1/00269 - B81C1/00325
• CPC Class Codes: B81C 1/00547 Etching processes not provided for in groups B81C1/00531 - B81C1/00539
• CPC Class Codes: B81C 2201/056 Releasing structures at the end of the manufacturing process
• CPC Class Codes: B81C 2203/0172 Seals
• CPC Class Codes: B81C 2203/0714 Forming the micromechanical structure with a CMOS process
• CPC Class Codes: B81C 2203/0792 Forming interconnections between the electronic processing unit and the micromechanical structure
• CPC Class Codes: G01P 1/04 Special adaptations of driving means
• CPC Class Codes: G01P 15/097 by vibratory elements
• CPC Class Codes: H10B 61/00 Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
• CPC Class Codes: H10N 59/00 Integrated devices, or assemblies of multiple devices, comprising at least one galvanomagnetic or Hall-effect element covered by groups H10N50/00 - H10N52/00 MRAM devices H10B61/00
• CPC Class Codes: Y10T 29/49075 including permanent magnet or core

Abstract

Magnet placement is described for integrated circuit packages. In one example, a terminal is applied to a magnet. The magnet is then placed on a top layer of a substrate with solder between the terminal and the top layer, and the solder is reflowed to attach the magnet to the substrate.

Claims

1. A method comprising:

applying a terminal to a magnet;

placing the magnet on a top layer of a substrate with solder between the terminal and the top layer; and

reflowing the solder to attach the magnet to the substrate.

2. The method of claim 1, wherein applying a terminal comprises applying tin to a location on the magnet.

3. The method of claim 1, wherein applying a terminal comprises:

applying an electrode paste on an edge of a preformed magnet by dipping; and

sintering the edge of the preformed magnet.

4. The method of claim 3, further comprising electroplating tin over the sintered electrode paste.

5. The method of claim 1, wherein the top layer is a metal layer.

6. The method of claim 5, wherein the edge comprises a perimeter of a planar surface of the magnet.

7. The method of claim 1, further comprising patterning a solder resist opening on the top layer, and wherein placing the magnet comprises placing the terminal on the solder resist opening.

8. The method of claim 7, further comprising printing solder paste on the solder resist before placing the magnet.

9. The method of claim 1, wherein applying a terminal comprises applying a metal terminal on each of two opposite sides of the magnet.

10. The method of claim 1, wherein applying a terminal comprises applying a metal terminal to enclose a surface area of the magnet and wherein reflowing the solder seals the surface area against the substrate.

11. The method of claim 10, wherein the surface area is a planar face of the magnet and the terminal corresponds to a perimeter surrounding the planar face.

12. The method of claim 1, wherein the substrate comprises a sensor, the sensor having elongated beams, and wherein the magnet is placed to extend across the entire length of the elongated beams.

13. The method of claim 12, wherein the sensor beam is a detector beam of an accelerometer.

14. An apparatus comprising:

a magnet having an attachment terminal; and

an integrated sensor package having a top layer substrate, the magnet being placed over the substrate and having a reflowed solder connection between the magnet and the substrate to attach the magnet to the substrate.

15. The apparatus of claim 14, wherein the terminal comprises a tin coating to connect to the solder.

16. The apparatus of claim 15, wherein the terminal comprises a sintered electrode paste on an edge of the magnet, the tin being electroplated over the sintered electrode paste.

17. The apparatus of claim 14, wherein the terminal comprises a coated edge on each of two opposite sides of the magnet.

18. A computing device having an integrated sensor package, the package comprising:

a magnet having an attachment terminal; and

an integrated sensor die having a top layer substrate, the magnet being placed over the substrate and having a reflowed solder connection between the magnet and the substrate to attach the magnet to the substrate.

19. The apparatus of claim 18, wherein the terminal comprises a sintered copper electrode paste on an edge of the magnet covered with an electroplated tin coating.

20. The apparatus of claim 18, wherein the terminal comprises a metal terminal that encloses a surface area of the magnet and wherein the reflowed solder connection seals the surface area of the magnet against the substrate.