Multi-stacked electronic device with defect-free solder connection

Patent metadata

Field	Value
Publication number	US-9936576-B2
Application number	US-201615174208-A
Country	US
Kind code	B2
Filing date	Jun 6, 2016
Priority date	Jul 16, 2014
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

A method includes forming a multi-stacked electronic device having two or more electronic components, each of the electronic components includes a leadframe, the leadframes of each electronic component are physically joined together using a non-solder metal joining process to form a joint, and the joint is located outside a solder connection region.

First claim

What is claim is:

1. A method comprising:
forming a stacked electronic device having first, second and third electronic components, the first electronic component is positioned above the second and third electronic components in said stack, said second electronic component is positioned beneath the first and third electronic components in said stack, and the third electronic component is positioned between the first and second components in said stack, and the first electronic component including a lateral, outside downwardly extending first leadframe, the second electronic component including a lateral, upwardly extending second leadframe, the second leadframe extending upwardly, laterally inside of, and vertically overlapping with, the first leadframe, wherein the first and second leadframes include respective vertically overlapping portions, and the first leadframe including a lower portion spaced from said overlapping portions and defining a solder connection region for soldering the stacked electronic device to a soldering surface,
the forming a stacked electronic device including using a first joining process to form a joint directly between and physically joining together the overlapping portions of the first and second leadframes, with the third electronic component positioned between the first and second electronic components, and wherein the joint is located outside the solder connection region.

2. The method according to claim 1 , wherein the forming a stacked electronic device further includes using a second joining process to join the third electronic component to one of the first and second electronic components.

3. The method according to claim 2 , wherein the using a second joining process to join the third electronic component to one of the first and second electronic components includes using the second joining process to join the third electronic component to the first electronic component.

4. The method according to claim 2 , wherein the third electronic component includes a lateral third leadframe, and the using a second joining process to join the third electronic component to one of the first and second electronic components includes using the second joining process to join the third leadframe to one of the first and second electronic components.

5. The method according to claim 4 , wherein the using the second joining process to join the third leadframe to one of the first and second electronic components includes using the second joining process to join the third leadframe to the first electronic component.

6. The method according to claim 5 , wherein the third leadframe extends upwards, laterally inside of the first leadframe.

7. The method according to claim 6 , wherein the first and third leadframes include respective vertically overlapping portions.

8. The method according to claim 7 , wherein the using the second joining process to join the third leadframe to the first electronic component includes using the second joining process to form another joint directly between and physically joining together the overlapping portions of the first and third leadframes.

9. The method according to claim 1 , wherein the non-solder metal joining process comprises brazing or welding the first and second leadframes together.

10. The method of claim 1 , wherein:
the solder connection region comprises a predefined solderable area; and
the soldering surface comprises a circuit board, a PCB, laminate substrate, or other electronic device.

11. A method comprising:
providing a first electronic component, the first electronic component comprising a lateral, outside, downwardly extending, first leadframe;
providing a second electronic component, the second electronic component comprising a lateral, upwardly extending second leadframe;
providing a third electronic component;
placing the third electronic component above and in close proximity with the second electronic component, and placing the first electronic component above and in close proximity with the third electronic component to form a stacked electronic device, wherein the second leadframe extends upwardly, laterally inside of, and vertically overlapping with, the first leadframe, wherein the first and second leadframes include vertically overlapping portions in a contact region, and the first leadframe includes a lower portion spaced from said overlapping portions and defining a solder connection region for soldering the stacked electronic device to a soldering surface;
joining the first leadframe of the first electronic component to the second leadframe of the second electronic component using a non-solder metal joining process to form a joint in the contact region directly between and physically joining together the overlapping portions of the first and second leadframes, with the third electronic component between the first and second electronic components, and wherein the joint is located outside the solder connection region; and
forming a solder connection in the solder connection region, wherein the solder connection attaches the multi-stacked electronic device to the soldering surface.

12. The method according to claim 11 , further comprising joining the third electronic component to one of the first and second electronic components using another non-solder metal joining process to form a further joint joining together the third electronic component and said one of the first and second electronic components.

13. The method according to claim 12 , wherein the using another non-solder metal joining process to form a further joint joining together the third electronic component and said one of the first and second electronic components includes using the another non-solder metal joining process to join the third electronic component to the first electronic component.

14. The method according to claim 12 , wherein the third electronic component includes a lateral third leadframe, and the using another non-solder metal joining process to join the third electronic component to one of the first and second electronic components includes using the another non-solder metal joining process to join the third leadframe to one of the first and second electronic components.

15. The method according to claim 14 , wherein the using another non-solder metal joining process to join the third leadframe to one of the first and second electronic components includes using the another non-solder metal joining process to join the third leadframe to the first electronic component.

Assignees

• IBM

Inventors

• Ang Ai Kiar
• Lauri Michael

Classifications

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W70/40

  Leadframes · CPC title

• H10W90/811

  Multiple chips on leadframes · CPC title

• H10W90/00

  Package configurations · CPC title

• H10W70/442

  of multiple leadframes in a single chip · CPC title