Magnet placement for integrated sensor packages

Patent metadata

Field	Value
Publication number	US-9791470-B2
Application number	US-201314141759-A
Country	US
Kind code	B2
Filing date	Dec 27, 2013
Priority date	Dec 27, 2013
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

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.

First claim

What is claimed is:

1. A method comprising:
forming a metal mechanical sensor structure in a sensor metal layer of a package substrate;
forming a top metal layer of the package substrate over the sensor metal layer, the top layer of the substrate defining pads on opposite sides of the sensor structure;
applying a dielectric layer over the top metal layer, the dielectric layer extending across the sensor structure from one side to an opposite side of the sensor structure and patterned to expose the pads;
applying connection terminals to a magnet;
placing the magnet over the top metal layer of the substrate over the pads and over the sensor structure with solder between the terminals and the pads, the magnet being positioned to produce a magnetic field to influence the sensor structure; and
reflowing the solder to attach the magnet to the substrate.

2. The method of claim 1 , wherein placing comprises placing the magnet using a chip capacitor shooter.

3. The method of claim 1 , wherein the magnet is preformed and wherein applying connection terminals comprises:
applying an electrode paste on an edge of a 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 metal layer is adjacent to the sensor metal layer in which the metal mechanical sensor structure is formed.

6. The method of claim 3 , wherein the edge comprises a perimeter of a planar surface of the magnet.

7. The method of claim 1 , wherein the dielectric layer is applied by applying solder resist over the top metal layer and patterning solder resist openings on the dielectric layer over the pads.

8. The method of claim 7 , further comprising printing solder paste on the solder resist openings before placing the magnet and wherein placing the magnet comprises placing the magnet over the printed solder paste.

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

10. The method of claim 1 , wherein applying connection terminals comprises applying a mend terminal to enclose a surface area of the magnet and wherein reflowing the solder seals the surface area against the substrate and seals the sensor structure under the magnet.

11. The method of claim 10 , Wherein the surface area is a planar face of the magnet and the connection terminals correspond to a perimeter surrounding the planar face and the sensor structure.

12. The method of claim 1 , wherein the sensor structure comprises 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 elongated beams comprise a detector beam of an accelerometer.

14. An apparatus comprising:
a magnet having attachment terminals; and
an integrated sensor package having a metal mechanical sensor structure in a sensor metal layer of a package substrate, a top metal layer over the sensor metal layer defining pads on opposite sides of the sensor structure, a dielectric layer over the top metal layer extending across the sensor structure from one side to an opposite side of the sensor structure and patterned to expose the pads, the magnet being placed over the pads and over the sensor structure of the substrate in a position to produce a magnetic field to influence the sensor structure and having a reflowed solder connection between the magnet attachment terminals and the pads to attach the magnet to the substrate.

15. The apparatus of claim 14 , wherein the attachment terminals comprise a tin coating to connect to the solder.

16. The apparatus of claim 15 , wherein the attachment terminals comprise 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 attachment terminals comprise 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;
an integrated circuit die in the package; and
an integrated sensor package having a metal mechanical sensor structure in a sensor metal layer of a package substrate, a top metal layer over the sensor metal layer defining pads on opposite sides of the sensor structure, a dielectric layer over the top metal layer extending across the sensor structure from one side to an opposite side of the sensor structure and patterned to expose the pads, the magnet being placed over the pads and over the sensor structure of the substrate in a position to produce a magnetic field to influence the sensor structure and having a reflowed solder connection between the magnet attachment terminals and the pads to attach the magnet to the substrate.

19. The computing device of claim 18 , wherein the attachment terminals comprise a sintered copper electrode paste on an edge of the magnet covered with an electroplated tin coating.

20. The computing device of claim 18 , wherein the attachment terminals comprise a metal terminal that encloses a surface area of the magnet and wherein the revved solder connection seals the surface area of the magnet against the substrate.

Assignees

• Intel Corp

Inventors

• Eid Feras
• Oster Sasha N
• Lee Kyu Oh
• Haney Sarah

Classifications

• G01P1/04 Primary

  Special adaptations of driving means · CPC title

• B81C1/00333

  Aspects relating to packaging of MEMS devices, not covered by groups B81C1/00269 - B81C1/00325 · CPC title

• B81B7/007

  Interconnections between the MEMS and external electrical signals · CPC title

• G01P15/097

  by vibratory elements · CPC title

• B81C2203/0792

  Forming interconnections between the electronic processing unit and the micromechanical structure · CPC title