Apparatus for degolding or tinning conductive portions of a microelectronic device

• US 5,372,293 A
• Filed: 11/23/1993
• Issued: 12/13/1994
• Est. Priority Date: 11/23/1992
• Status: Expired due to Fees

• Current Assignee: Carrar Co.
• Original Assignee: Carrar Co.
• Inventors: Germain, Jean-Claude, Chevalier, Claude, Corlay, Christian
• Primary Examiner(s): Bradley, P. Austin
• Assistant Examiner(s): Elpel, Jeanne M.
• Application Number:
  US08/155,762
• Time in Patent Office: 385 Days
• Field of Search: 228/36, 228/40, 228/56.1, 228/180.1, 228/56.2, 228/38, 228/102, 427/430.1, 427/431, 118/421, 118/422, 118/423, 118/429
• US Class Current: 228/56.1
• CPC Class Codes: B23K 1/20 Preliminary treatment of work or areas to be soldered, e.g. in respect of a galvanic coating preparation of surfaces in particular ways, see the relevant classes for the treatments or the materials treated, e.g. C04B, C23C
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 24/11 Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01023 Vanadium [V]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01074 Tungsten [W]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/014 Solder alloys

Abstract

The apparatus is used for processing a microelectronic device having a face with electrically conductive elements arranged thereon. The apparatus comprises a vessel for containing a solder melt, a bowl for drawing molten solder from the vessel, a device holder for holding the microelectronic device with said face directed downwardly, and drive means for moving the bowl and the device holder vertically with respect to each other, thereby allowing said conductive elements to be immersed in molten solder drawn by the bowl. The bowl has an upper rim with an upwardly directed acute angled edge extending therealong.

Claims

1. An apparatus for processing a microelectronic device having a face with electrically conductive elements arranged thereon, comprising a vessel for containing a solder melt, a bowl for drawing molten solder from the vessel, a device holder for holding the microelectronic device with said face directed downwardly, and drive means for moving the bowl and the device holder vertically with respect to each other, thereby allowing said conductive elements to be immersed in molten solder drawn by the bowl, wherein the bowl has an upper rim which extends in a horizontal plane, said upper rim being formed by an upwardly directed edge extending therealong, said upwardly directed edge forming an acute angle of from 15°

to 60°

.

2. The apparatus of claim 1, further comprising a blade scraper capable of sliding along the surface of the solder melt contained in the vessel for moving a top layer of said molten solder away from a surface region located above the bowl when the bowl is completely immersed in the solder melt contained in the vessel.

3. The apparatus of claim 1, further comprising means for causing the device holder to spin about a substantially vertical axis with a first phase of submitting the device holder to a selected angular acceleration, a second phase, having a selected duration, of spinning the device holder at a selected maximum rotational velocity, and a third phase of submitting the device holder to a selected angular deceleration.

4. The apparatus of claim 3, wherein said maximum rotational velocity is from 1 000 to 16 000 rpm.

5. The apparatus of claim 3, wherein said angular acceleration and deceleration are from 1 to 300 rounds per square second.

6. Apparatus according to claim 1 wherein said upwardly directed edge comprises a surface tapering downwardly from said edge to a surface of said bowl.

7. Apparatus according to claim 6 wherein said surface of said bowl is the outer surface of said bowl.

8. Apparatus according to claim 7 wherein said edge is formed at the intersection of the inner surface of said bowl and said downwardly tapering surface.

9. An apparatus for processing a microelectronic device having a face with electrically conductive elements arranged thereon, comprising a vessel for containing a solder melt, a bowl for drawing molten solder from the vessel, a device holder for holding the microelectronic device with said face directed downwardly, and drive means for moving the bowl and the device holder vertically with respect to each other, thereby allowing said conductive elements to be immersed in molten solder drawn by the bowl, wherein the bowl has an upper rim which extends in a horizontal plane, said upper rim being formed by an upwardly directed edge extending therealong, said upwardly directed edge comprising a surface tapering downwardly from said edge to a surface of said bowl.

10. Apparatus according to claim 9 wherein said surface of said bowl is the outer surface of said bowl.

11. Apparatus according to claim 10 wherein said edge is formed by at the intersection of the inner surface of said bowl and said downwardly tapering surface.

12. The apparatus of claim 9, further comprising a blade scraper capable of sliding along the surface of the solder melt contained in the vessel for moving a top layer of said molten solder away from a surface region located above the bowl when the bowl is completely immersed in the solder melt contained in the vessel.

13. The apparatus of claim 9, further comprising means for causing the device holder to spin about a substantially vertical axis with a first phase of submitting the device holder to a selected angular acceleration, a second phase, having a selected duration, of spinning the device holder at a selected maximum rotational velocity, and a third phase of submitting the device holder to a selected angular deceleration.

14. The apparatus of claim 13, wherein said maximum rotational velocity is from 1,000 to 16,000 rpm.

15. The apparatus of claim 13, wherein said angular acceleration and deceleration are from 1 to 300 revolutions per square second.

16. An apparatus for processing a microelectronic device having a face with electrically conductive elements arranged thereon, comprising a vessel for containing a solder melt, a bowl for drawing molten solder from the vessel, a device holder for holding the microelectronic device with said face directed downwardly, drive means for moving the bowl and the device holder vertically with respect to each other, thereby allowing said conductive elements to be immersed in molten solder drawn by the bowl, and means for causing the device holder to spin about a substantially vertical axis with a first phase of submitting the device holder to a selected angular acceleration, a second phase, having a selected duration, of spinning the device holder at a selected maximum rotational velocity, and a third phase of submitting the device holder to a selected angular deceleration, wherein the bowl has an upper rim which extends in a horizontal plane, said upper rim being formed by an upwardly directed edge extending therealong.

17. The apparatus of claim 16, further comprising a blade scraper capable of sliding along the surface of the solder melt contained in the vessel for moving a top layer of said molten solder away from a surface region located above the bowl when the bowl is completely immersed in the solder melt contained in the vessel.

18. The apparatus of claim 16, wherein said maximum rotational velocity is from 1,000 to 16,000 rpm.

19. The apparatus of claim 16, wherein said angular acceleration and deceleration are from 1 to 300 revolutions per square second.