Micromirror device package fabrication method

• US 6,624,921 B1
• Filed: 03/12/2001
• Issued: 09/23/2003
• Est. Priority Date: 03/12/2001
• Status: Expired due to Term

• Current Assignee: Amkor Technology Singapore Holding Pte., Ltd. (Amkor Technology Incorporated)
• Original Assignee: Amkor Technology Incorporated
• Inventors: Webster, Steven, Glenn, Thomas P., Hollaway, Roy Dale
• Primary Examiner(s): Ben, Loha
• Application Number:
  US09/804,805
• Time in Patent Office: 925 Days
• Field of Search: 359/290, 359/291, 359/292, 359/298, 359/877, 257/704, 257/710, 257/416, 257/417, 257/659, 257/680, 257/686, 257/687, 257/738, 438/53, 438/54, 438/106, 438/108, 438/743, 438/764, 438/755, 361/707, 353/122
• US Class Current: 359/291
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 7/0067 for controlling the passage of optical signals through the package
• CPC Class Codes: B81C 1/00865 Multistep processes for the separation of wafers into individual elements
• CPC Class Codes: B81C 1/00904 Multistep processes for the separation of wafers into individual elements not provided for in groups B81C1/00873 - B81C1/00896
• CPC Class Codes: H01L 2224/05571 the external layer being disposed in a recess of the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/16235 Connecting to a semiconductor or solid-state bodies, i.e. cap-to-chip

Abstract

A window is mounted directly to an upper surface of a micromirror device chip. More particularly, the window is mounted above a micromirror device area on the upper surface of the micromirror device chip by a bead. The window in combination with the bead form a hermetic enclosure about the micromirror device area thus protecting the micromirror device area from moisture and contamination.

Claims

1. A method comprising:

coupling a window to a first surface of a micromirror device chip with a bead, said window being coupled above a micromirror device area on said first surface of said micromirror device chip.

2. The method of claim 1 wherein said micromirror device area comprises miniature moveable micromirrors.

3. The method of claim 1 further comprising directing radiation at said micromirror device area.

4. The method of claim 3 wherein said radiation passes through said window and strikes said micromirror device area.

5. The method of claim 4 further comprising selectively reflecting said radiation with said micromirror device area.

6. The method of claim 5 wherein said radiation is selectively reflected with said micromirror device area back through said window.

7. The method of claim 1 further comprising protecting said micromirror device area with said window and said bead.

8. The method of claim 7 wherein said window and said bead form a hermetic enclosure around said micromirror device area.

9. The method of claim 1 wherein said coupling comprises melting said bead.

10. A method of forming a micromirror device assembly comprising:

aligning a window above a micromirror device chip; and

coupling said window to a first surface of said micromirror device chip to form an enclosure above a micromirror device area on said first surface of said micromirror device chip.

11. The method of claim 10 wherein said window is coupled to said first surface with a bead.

12. The method of claim 11 further wherein said coupling comprises:

coupling said bead to said window;

melting said bead;

placing said window over said micromirror device area such that said bead contacts said first surface of said micromirror device chip; and

cooling said bead.

13. The method of claim 11 further wherein said coupling comprises:

coupling said bead to said first surface of said micromirror device chip;

melting said bead;

placing said window over said micromirror device area such that said bead contacts said window; and

cooling said bead.

14. The method of claim 11 wherein said window comprises borosilicate glass and wherein said bead comprises solder glass.

15. The method of claim 14 further comprising hermetically sealing said micromirror device area with said window and said bead.

16. A method comprising:

positioning a window sheet comprising windows above a micromirror device substrate comprising micromirror device chips; and

mounting said window sheet to said micromirror device substrate by beads.

17. The method of claim 16 wherein said mounting comprises melting said beads.

18. The method of claim 17 wherein said beads are applied to said window sheet, said melting comprising heating said window sheet.

19. The method of claim 17 wherein said beads are applied to said micromirror device substrate, said melting comprising heating said micromirror device substrate.

20. The method of claim 16 further comprising forming cuts in said window sheet to delineate said windows.

21. The method of claim 20 wherein singulation streets delineate said micromirror device chips.

22. The method of claim 21 wherein said cuts are aligned with said singulation streets, said method further comprising singulating said window sheet by sawing through said window sheet to said cuts.

23. The method of claim 22 wherein said cuts have a first width, said sawing being performed with a sawblade having said first width.

24. The method of claim 22 wherein said cuts have a first width, said sawing being performed with a sawblade having said second width greater than said first width.

25. The method of claim 24 wherein said windows comprise locking features.

26. A method comprising:

directing radiation at a micromirror device assembly, said radiation passing through a window coupled to a first surface of a micromirror device chip of said micromirror device assembly, said radiation striking a micromirror device area on said first surface of said micromirror device chip; and

selectively reflecting said radiation back through said window with said micromirror device area.