Mounting semiconductor chips

• US 20060008943A1
• Filed: 06/30/2005
• Published: 01/12/2006
• Est. Priority Date: 06/30/2004
• Status: Active Application

• Current Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Hahn, Berthold
• Application Number:
  US11/174,007
• Publication Number:
  US 20060008943A1
• Time in Patent Office: Days
• US Class Current: 438/107
• CPC Class Codes: H01L 2224/0554 External layer
• CPC Class Codes: H01L 2224/0555 Shape
• CPC Class Codes: H01L 2224/0556 Disposition
• CPC Class Codes: H01L 2224/0557 the external layer being disposed on a via connection of the semiconductor or solid-state body
• 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 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/838 Bonding techniques
• CPC Class Codes: H01L 2224/95101 in a liquid medium
• CPC Class Codes: H01L 2224/95102 being a colloidal droplet
• CPC Class Codes: H01L 24/31 Structure, shape, material or disposition of the layer connectors after the connecting process
• CPC Class Codes: H01L 24/83 using a layer connector
• CPC Class Codes: H01L 24/95 at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips
• CPC Class Codes: H01L 25/50 Multistep manufacturing processes of assemblies consisting of devices, each device being of a type provided for in group H01L27/00 or H01L29/00 H01L21/50 takes precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01007 : Nitrogen [N]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/0103 : Zinc [Zn]
• CPC Class Codes: H01L 2924/01031 : Gallium [Ga]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01068 : Erbium [Er]
• CPC Class Codes: H01L 2924/01072 : Hafnium [Hf]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/0132 : Binary Alloys
• CPC Class Codes: H01L 2924/0781 : being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/12036 : PN diode
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 33/0095 : Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

To mount semiconductor chips (3), the chips are placed in a liquid (5), and drops (51) of the liquid containing no more than one semiconductor chip are positioned on a substrate (2). On the substrate are molecules of a first type (1), on the semiconductor chips (3) are molecules of a second type (4) which can bond with the molecules of the first type (1). After the liquid (5) dries, the semiconductor chip (3) can be electrically contacted on the substrate (2) by conductive structures (21).

Claims

1. A method for applying semiconductor chips (3) to a substrate (2), comprising:

applying molecules of a first type (1) to a substrate (2) surface on which semiconductor chips (3) are to be applied;

applying molecules of a second type (4) to a surface of a semiconductor chip (3), wherein the molecules of the second type are configured to bond to the molecules of the first type (1);

introducing the semiconductor chip (3) into a liquid (5);

positioning a drop (51) of the liquid (5) with not more than one semiconductor chip (3) on the substrate (2); and

evaporating the drop (51) of liquid (5) from the substrate (2), leaving the semiconductor chip on the substrate (2).

2. The method of claim 1, wherein positioning a drop (51) of the liquid (5) includes positioning a plurality of drops, and wherein each drop has no more than one semiconductor chip (3).

3. The method of claim 1, further comprising electrically contacting the semiconductor chip (3) with an electrically conductive structure (21) on the substrate (2).

4. The method of claim 1, wherein the semiconductor chip (3) is applied to a soluble auxiliary substrate (6) and introduced into the liquid (5) by dissolving the auxiliary substrate (6).

5. The method of claim 4, wherein the liquid (5) contains the molecules of the second type (4) and the molecules of the second type (4) adsorb onto the semiconductor chip (3) after the semiconductor chip (3) is introduced into the liquid (5).

6. The method of claim 1, wherein the molecules of the second type (4) are applied to the semiconductor chip (3) by stamping, printing or photolithography.

7. The method of claim 1, wherein the molecules of the first type (1) are adsorbed on the substrate (2) from a solution.

8. The method of claim 1, wherein the molecules of the first type (1) are applied to the substrate by one of stamping, printing or photolithography.

9. The method of claim 1, wherein the drop (51) is deposited on the substrate (2) by an inkjet system.

10. The method of claim 1, wherein a cell sorting system ensures that not more than one semiconductor chip (3) is in a drop (51).

11. The method of claim 1, wherein metal-containing particles (7) are added to the liquid (5) with the semiconductor chip (3) and the particles electrically connect the semiconductor chips (3) with electrically conductive structures (21) of the substrate (2) after the liquid (5) dries.

12. The method of claim 1, further comprising modifying a part of the surface of the substrate (2) of such that the part is wetted more effectively by the liquid (5) in which the semiconductor chip (3) is introduced than the rest of the surface of the substrate (2).

13. The method of claim 1, further comprising modifying a part of the surface of the semiconductor chip (3) such that the part of the surface is wetted more effectively by the liquid (5) than the remaining surface of the respective semiconductor chip (3).

14. The method of claim 1, wherein the semiconductor chip (3) is a thin-film LED chip (30).

15. The method of claim 14, further comprising forming the thin-film LED chip (30), including the steps of:

forming an active layer sequence (8) suitable to generate electromagnetic radiation on a chip substrate (9);

forming a structured, electrically-conductive reflective contact layer (10) on the active layer sequence (8);

structuring the active layer sequence (8) into separate, active stacks of layers (81) on the chip substrate (9), thereby forming gaps;

applying an electrically-conductive reinforcing layer (11) on the reflective contact layer (10);

forming a passivation layer (12) on the side surfaces of the active stack of layers (81) and reflective contact layer (10) and at least parts of the electrically-conductive reinforcing layer (11);

filling the gaps with a filler (13);

applying an auxiliary substrate layer (61) on the reinforcing layer (11);

removing of the chip substrate (9) and the filler (13); and

applying an electrically-conductive layer (34) on one side of the active stack of layers (81), the reflective contact layer 10 and the electrically-conductive reinforcing layer ( 11) and on a portion of an exposed surface of the active layer stack.

16. The method of claim 15, wherein metal-containing particles (7) are added to the liquid (5) with the semiconductor chip (3) and the particles electrically connect the semiconductor chips (3) with electrically conductive structures (21) of the substrate (2) after the liquid (5) dries.

17. The method of claim 16, wherein the substrate (2) includes a printed circuit board.