Reflow method and system

Patent metadata

Field	Value
Publication number	US-11610859-B2
Application number	US-202017080842-A
Country	US
Kind code	B2
Filing date	Oct 27, 2020
Priority date	Oct 27, 2020
Publication date	Mar 21, 2023
Grant date	Mar 21, 2023

Abstract

A system for reflowing a semiconductor workpiece including a stage, a first vacuum module and a second vacuum module, and an energy source is provided. The stage includes a base and a protrusion connected to the base, the stage is movable along a height direction of the stage relative to the semiconductor workpiece, the protrusion operably holds and heats the semiconductor workpiece, and the protrusion includes a first portion and a second portion surrounded by and spatially separated from the first portion. The first vacuum module and the second vacuum module respectively coupled to the first portion and the second portion of the protrusion, and the first vacuum module and the second vacuum module are operable to respectively apply a pressure to the first portion and the second portion. The energy source is disposed over the stage to heat the semiconductor workpiece held by the protrusion of the stage.

First claim

What is claimed is:

1. A method of processing a semiconductor workpiece, comprising:
moving a semiconductor workpiece to be positioned between an energy source and a protrusion of a stage, wherein the protrusion comprises a first portion and a second portion encircled by the first portion;
moving the stage to be in contact with a bottom surface of the semiconductor workpiece;
vacuuming the first portion and the second portion of the protrusion in a sequential manner to respectively apply a vacuum pressure to each region of the bottom surface of the semiconductor workpiece corresponding to one of the first portion and the second portion; and
reflowing the semiconductor workpiece during the vacuuming.

2. The method of claim 1 , further comprising:
vacuuming the second portion of the protrusion prior to vacuuming the first portion of the protrusion when the protrusion of the stage is abutted against the semiconductor workpiece.

3. The method of claim 1 , further comprising:
during the vacuuming, lowering the vacuum pressure to a preset pressure in a period of time, wherein the period of time is divided into a plurality of time segments; and
regulating the vacuum pressure in each of the plurality of time segments, wherein a ratio of a change in pressure to a change in time varies in the plurality of time segments.

4. The method of claim 1 , further comprising:
during the vacuuming, changing a warpage profile of the semiconductor workpiece by individually controlling the vacuum pressure applied to each of the first portion and the second portion of the protrusion of the stage.

5. The method of claim 1 , further comprising:
during the vacuuming, detecting an abnormal condition of the first portion and the second portion via separate sensors respectively coupled to the first portion and the second portion.

6. The method of claim 1 , wherein the semiconductor workpiece is placed on and transferred via a conveyor mechanism, and moving the stage comprises:
passing the stage vertically through the conveyor mechanism to connect the bottom surface of the semiconductor workpiece.

7. The method of claim 1 , wherein reflowing the semiconductor workpiece comprises:
radiating an energy to a top of the semiconductor workpiece via the energy source, and heating from the bottom surface of the semiconductor workpiece via the stage.

8. A method of bonding package components, comprising:
positioning a carrier that carries a plurality of semiconductor workpieces over a stage, wherein each of the plurality of semiconductor workpieces comprises a first package component and a second package component placed on the first package component;
abutting a plurality of protrusions of a stage against the plurality of semiconductor workpieces with a one-to-one correspondence, wherein the plurality of protrusions pass through the carrier to be in contact with bottom surfaces of the first package components of the plurality of semiconductor workpieces;
vacuuming the plurality of protrusions of the stage to change warpage profiles of the plurality of semiconductor workpieces; and
rising a temperature of each of the plurality of semiconductor workpieces to form conductive joints bonding the second package component to the first package component.

9. The method of claim 8 , wherein each of the plurality of protrusions of the stage comprises a first portion and a second portion surrounded by the first portion, and vacuuming the plurality of protrusions comprises:
vacuuming the second portions of the plurality of protrusions; and
vacuuming the first portion of the plurality of protrusions after a predetermined time delay.

10. The method of claim 9 , for each of the plurality of semiconductor workpieces, wherein:
changing a warpage profile of the second package component and a warpage profile of a portion of the first package component underlying the second package component during vacuuming the second portions of the plurality of protrusions; and
curving a rest portion of the first package component downwardly during vacuuming the first portion of the plurality of protrusions.

11. The method of claim 8 , wherein abutting the stage against the plurality of semiconductor workpieces comprises:
moving the stage upwardly, wherein the stage is heated before abutting against the plurality of semiconductor workpieces.

12. The method of claim 8 , wherein vacuuming the plurality of protrusions of the stage comprises:
regulating a vacuum pressure applied to each of the plurality of protrusions until a preset pressure is reached, wherein a ratio of a change in pressure to a change in time varies during a time period of lowering to the preset pressure.

13. The method of claim 8 , further comprising:
detecting an abnormal condition via a plurality of sensors coupled to the plurality protrusions of the stage during rising the temperature of each of the plurality of semiconductor workpieces, wherein the plurality of sensors are linked in parallel.

14. A method of processing a semiconductor workpiece, comprising:
transferring the semiconductor workpiece toward a stage, so that a bottom surface of the semiconductor workpiece faces carrying surfaces of a first protrusion portion and a second protrusion portion of the stage, wherein the second protrusion portion surrounds the first protrusion portion;
moving the stage to bring the carrying surfaces of the first protrusion portion and the second protrusion portion in contact with the bottom surface of the semiconductor workpiece;
vacuuming the first protrusion portion and the second protrusion portion with a first pressure and a second pressure, respectively; and
rising a temperature of the semiconductor workpiece during the vacuuming.

15. The method of claim 14 , wherein the first pressure and the second pressure are respectively regulated by a first pressure vacuum regulator operably coupled to the first protrusion portion and a second pressure vacuum regulator operably coupled to the second protrusion portion.

16. The method of claim 14 , further comprising:
during the vacuuming, detecting an abnormal condition of the first protrusion portion and the second protrusion portion via separate sensors respectively coupled to the first protrusion portion and the second protrusion portion.

17. The method of claim 14 , wherein the semiconductor workpiece is transferred via a conveyor mechanism, and moving the stage comprises:
passing the stage vertically through the conveyor mechanism to connect the bottom surface of the semiconductor workpiece.

18. The method of claim 14 , wherein rising the temperature of the semiconductor workpiece comprises:
radiating an energy to a top of the semiconductor workpiece via an energy source, and heating from the bottom surface of the semiconductor workpiece via the stage.

19. The method of claim 14 , wherein vacuuming the first protrusion portion and the second protrusion portion comprises:
vacuuming the first protrusion portion; and
vacuuming the second protrusion portion after a predetermined time delay.

20. The method of claim 14 , further comprising:
during the vacuuming, changing a warpage profile of the semiconductor workpiece by individually controlling the first pressure and the second pressure.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Wong Cheng-Shiuan
• Hsieh Ching-Hua
• Lin Hsiu-Jen
• Pei Hao-Jan
• Kuo Hsuan-Ting
• Chen Wei-Yu
• Cheng Chia-Shen
• Chung Philip Yu-Shuan

Classifications

• H10W70/09

  extending onto an encapsulation that laterally surrounds the chip or wafer, e.g. fan-out wafer level package [FOWLP] RDLs · CPC title

• H10W70/60

  Insulating or insulated package substrates; Interposers; Redistribution layers (leadframes H10W70/40) · CPC title

• H10W72/07141

  Means for applying energy, e.g. ovens or lasers · CPC title

• H10W72/07236

  Soldering or alloying · CPC title

• H10W72/072

  of bump connectors · CPC title