LASER SUBASSEMBLY METALLIZATION FOR HEAT ASSISTED MAGNETIC RECORDING

• US 20130279311A1
• Filed: 03/12/2013
• Published: 10/24/2013
• Est. Priority Date: 04/24/2012
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Bell, Bernard W. Jr., Axdal, Steven Harlow Anderson, Hurley, Jon Paul
• Granted Patent: US 9,227,257 B2
• Time in Patent Office: Days
• US Class Current: 369/13.02
• CPC Class Codes: B23K 1/0008 specially adapted for particular articles or work
• CPC Class Codes: B23K 35/24 Selection of soldering or welding materials proper B23K35/34 takes precedence
• CPC Class Codes: B23K 35/262 Sn as the principal constituent
• CPC Class Codes: B23K 35/3013 Au as the principal constituent
• CPC Class Codes: C22C 13/00 Alloys based on tin
• CPC Class Codes: C22C 5/02 Alloys based on gold
• CPC Class Codes: G11B 13/04 magnetically or by magnetisation and optically or by radiation, for changing or sensing optical properties
• CPC Class Codes: G11B 2005/0021 Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/105 Mounting of head within housing or assembling of head and housing G11B5/3103 takes precedence
• CPC Class Codes: G11B 5/6005 Specially adapted for spacing from a rotating disc using a fluid cushion
• CPC Class Codes: G11B 5/6088 Optical waveguide in or on flying head
• CPC Class Codes: G11B 7/127 Lasers; Multiple laser arrays lasers per se H01S
• CPC Class Codes: H01L 2021/60022 using bump connectors, e.g. for flip chip mounting
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2225/06517 Bump or bump-like direct electrical connections from device to substrate
• CPC Class Codes: H01L 23/488 consisting of soldered or bonded constructions bump connectors H01L24/01
• CPC Class Codes: H01L 24/15 Structure, shape, material or disposition of the bump connectors after the connecting process
• CPC Class Codes: H01S 5/0216 using an intermediate compound, e.g. a glue or solder
• CPC Class Codes: H05K 2201/10674 Flip chip

Abstract

A heat assisted magnetic recording (HAMR) assembly includes a slider, a laser diode and solder connections between the laser diode and the slider. The solder connections mechanically and electrically attach the laser diode to the slider. Each solder connection has a total volume per unit area (i.e., height) of less than or equal to about 15 μm. The solder connections have a first intermetallic zone adjacent to the laser diode, a second intermetallic zone adjacent to the slider, and a eutectic zone of eutectic material between the first and second intermetallic zones. The eutectic zone occupies greater than or equal to about 35% of the total volume per unit area of the solder connection.

Claims

1. A heat assisted magnetic recording (HAMR) assembly, comprising;

a slider comprising read and write transducers;

a laser diode;

solder connections between the laser diode and the slider that mechanically and electrically attach the laser diode to the slider, each solder connection having a total volume per unit area of less than or equal to about 15 μ

m and having a first intermetallic zone adjacent to the laser diode, a second intermetallic zone adjacent to the slider, and a eutectic zone of eutectic material between the first and second intermetallic zones, the eutectic zone occupying greater than or equal to about 35% of the total volume per unit area of the solder connection.

2. The assembly of claim 1, wherein the eutectic material is an Sn-containing eutectic material.

3. The assembly of claim 2, wherein the eutectic material is Sn—

Ag or Au—

Sn.

4. The assembly of claim 1, wherein the eutectic material is about 96.5 wt. % Sn and about 3.5 wt. % Ag.

5. The assembly of claim 1, wherein the eutectic material is about 90 wt. % Au and about 10% Sn.

6. The assembly of claim 1, wherein the volume per unit area is less than or equal to about 8 μ

m.

8. The assembly of claim 1, wherein the eutectic material is an Sn-containing eutectic material.

9. The assembly of claim 1, wherein the volume per unit area is less than or equal to about 8 μ

m.

10. The assembly of claim 1, wherein the volume per unit area is less than or equal to about 4 μ

m.

7. An assembly, comprising:

a substrate;

an electronic component;

solder connections between the electronic component and the substrate that mechanically and electrically attaches the electrical component to the substrate, at least one of the solder connections having total volume per unit area of less than or equal to about 15 μ

m and having a first intermetallic zone adjacent to the electronic component, a second intermetallic zone adjacent to the substrate, and a eutectic zone of eutectic material between the first and second intermetallic zones, the eutectic zone occupying greater than or equal to about 35% of the total volume per unit area of the solder connection.

11. A laser subassembly comprising:

a laser diode;

a metallization stack on the laser diode, the metallization stack comprising;

a metallization wetting layer having a thickness less than about 1000 Å

; and

a Pt layer having a thickness from about 300 Å

to about 3000 Å

.

12. The subassembly of claim 11, wherein the metallization stack is configured to provide a solder connection having total volume per unit area of less than or equal to about 15 μ

m and having a first intermetallic zone adjacent to the electronic component, a second intermetallic zone adjacent to the substrate, and a eutectic zone of eutectic material between the first and second intermetallic zones, the eutectic zone occupying greater than or equal to about 35% of the total volume per unit area of the solder connection.

13. The subassembly of claim 11, wherein the metallization stack further comprises an Ni layer having a thickness from about 300 Å

to about 3000 Å

.

14. The subassembly of claim 11, wherein the metallization stack further comprises a Cu layer having a thickness less than about 1000 Å

.

15. The subassembly of claim 11, wherein the metallization stack further comprises an Ti layer between the metallization stack and at least one of an N and P-metal stack of the laser diode.

16. The subassembly of claim 15, wherein the Ti layer has a thickness from about 100 Å

to about 500 Å

.

18. The subassembly of claim 11, wherein the metallization stack is configured to provide a solder connection having total volume per unit area of less than or equal to about 15 μ

m and having a first intermetallic zone adjacent to the electronic component, a second intermetallic zone adjacent to the substrate, and a eutectic zone of eutectic material between the first and second intermetallic zones, the eutectic zone occupying greater than or equal to about 35% of the total volume per unit area of the solder connection.

17. A subassembly comprising:

an electronic component;

a metallization stack on the electronic component, the metallization stack comprising;

a metallization wetting layer having a thickness less than about 1000 Å

; and

a Pt layer having a thickness from about 300 Å

to about 3000 Å

.

19. A method comprising:

aligning contacts of an electronic component with contacts of a substrate, at least one of the electronic component contacts and the substrate contacts comprising a metallization stack comprising;

an Au layer having a thickness less than about 1,000 Å

; and

a Pt layer having a thickness from about 300 Å

to about 3000 Å

; and

reflowing soldering the component contacts and the substrate contacts to form solder connections between the electronic component and the substrate, the solder connections having total volume per unit area of less than about 15 μ

m and having a first intermetallic zone adjacent to the electronic component, a second intermetallic zone adjacent to the substrate, and a eutectic zone of a eutectic material between the first and second intermetallic zones and occupying greater than or equal to about 35% of the total volume per unit area of the solder connection.

20. The method of claim 19, wherein the metallization stack further comprises a layer of Ti having a thickness of between about 100 Å

and 500 Å

.