MULTI-CHIP MODULE FOR BATTERY POWER CONTROL

Abstract

A multi-chip module suitable for use in a battery protection circuit. The multi-chip module includes an integrated circuit chip, a first power transistor, a second power transistor, a first connection structure electrically coupling the integrated circuit chip to the first power transistor, a second connection structure electrically coupling the integrated circuit chip to the second power transistor, and a leadframe structure comprising a first lead, a second lead, a third lead and a fourth lead, wherein the integrated circuit chip, the first power transistor, and the second power transistor are mounted on the leadframe structure. A molding material covers at least part of the integrated circuit chip, the first power transistor, the second power transistor, the first connection structure, and the second connection structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a conventional battery protection circuit diagram.

FIG. 2 shows a perspective view of a multi-chip module according to an embodiment of the invention. Inner components in the multi-chip module are also shown.

FIG. 3 shows a side view of the module shown in FIG. 2.

FIGS. 4( a)-4(e) show perspective views of components in the multi-chip module. FIGS. 4(a)-4(e) illustrate a process flow for making the multi-chip module shown in FIG. 2.

FIG. 5 shows a battery protection circuit diagram incorporating the multi-chip module shown in FIG. 2.

FIG. 6 shows a circuit diagram for the multi-chip module shown in FIG. 2.

FIG. 7 shows a bottom view of a multi-chip module.

FIG. 8 shows an electrical assembly including a circuit substrate and the multi-chip module shown in FIG. 2 mounted on the circuit substrate.

FIG. 9 shows a system including a lithium ion battery coupled to the electrical assembly shown in FIG. 8.

FIG. 10( a) shows a bottom plan view of another module embodiment.

FIG. 10( b) shows a top bottom perspective view of the leadframe structure and the die used in the module in FIG. 10(a).

FIG. 10( c) shows a top perspective view of the leadframe structure shown in FIG. 10(b).

Claims

1. A multi-chip module comprising: at least one integrated circuit (IC) chip;at least one power device chip;a metal leadframe structure including leads, at least two independent die mounting pads electrically isolated from one another, the at least two independent die mounting pads including a first pad for mounting at least one IC chip and a second pad for mounting at least one power device chip; andbonding wires having more than one diameter connecting the at least one IC chip and the at least one power device chip to the leads.

2. The module of claim 1 including a wire bond connection from one chip to another chip.

3. The module of claim 1 wherein said mounting pads are exposed on the back side of the module and wherein the module includes an epoxy molding material.

4. The module of claim 1 wherein the leadframe structure includes a dedicated test lead.

5. The module of claim 1 wherein at least one of the die mounting pads has no external leads, mounting pads, or other die mounting pads along both of two opposite sides of the pad.

6. A battery protection multi-chip module comprising: an integrated circuit chip;a power device chip housed in a single housing for regulating the charging and discharging of a battery external to the multi-chip module, the integrated circuit chip and the at least one power device chip forming at least part of a circuit; andwherein required external connections to the circuit are limited to four leads.

7. A multi-chip module comprising: an integrated circuit chip;a first power transistor;a second power transistor;a first connection structure electrically coupling the integrated circuit chip to the first power transistor;a second connection structure electrically coupling the integrated circuit chip to the second power transistor;a leadframe structure comprising a first lead, a second lead, a third lead and a fourth lead, wherein the integrated circuit chip, the first power transistor, and the second power transistor are mounted on the leadframe structure; anda molding material covering at least part of the integrated circuit chip, the first power transistor, the second power transistor, the first connection structure, and the second connection structure,wherein the first lead provides an electrical connection to the first power transistor and the second lead provides an electrical connection to the second power transistor, andwherein the first and second leads are at a first end of the multi-chip module, and the third and fourth leads are at a second end of the multi-chip module.

8. The multi-chip module of claim 7 wherein the leadframe further comprises a test lead and a bonding structure electrically coupling the test lead and the integrated circuit chip, and wherein the leads in the leadframe structure include only the test lead and the first, second, third, and fourth leads.

9. The multi-chip module of claim 7 wherein the multi-chip module has an elongated shape and an aspect ratio greater than 1.

10. The multi-chip module of claim 7 wherein the first power transistor and the second power transistor are in a single power chip and the first power transistor and the second power transistor are vertical power MOSFETs.

11. The multi-chip module of claim 7 wherein the first and second bonding structures are wires, and wherein the leadframe structure comprises a first die mounting pad and a second die mounting pad, the integrated circuit chip being mounted on the first die mounting pad and the first and second power transistors being present in one or more chips, the one or more chips being mounted on the second die mounting pad.

12. The multi-chip module of claim 11 wherein the leadframe structure further comprises a test lead electrically coupled to the integrated circuit chip.

13. The multi-chip module of claim 11 wherein an exterior surface of leadframe structure is exposed through the molding material.

14. An electrical assembly comprising: a circuit board; andthe multi-chip module of claim 7 mounted on the circuit board.

15. A system comprising: the electrical assembly of claim 14;and a rechargeable battery electrically coupled to the electrical assembly.

16. A method comprising: obtaining a leadframe structure comprising a first lead, a second lead, a third lead and a fourth lead;mounting an integrated circuit chip to the leadframe structure;mounting at least one semiconductor chip comprising a first power transistor and a second power transistor on the leadframe structure;attaching a first connection structure to the integrated circuit chip and to the first power transistor;attaching a second connection structure to the integrated circuit chip and to the second power transistor; andmolding a material around at least part of the integrated circuit chip, the first power transistor, the second power transistor, the first connection structure, and the second connection structure, thereby forming a multichip module,wherein the first lead provides an electrical connection to the first power transistor and the second lead provides an electrical connection to the second power transistor, andwherein the first and second leads are at a first end of the multi-chip module, and the third and fourth leads are at a second end of the multi-chip module.

17. The method of claim 16 wherein the leadframe structure further comprises a test lead, and wherein the method further comprising: attaching a third connection structure to the integrated circuit chip and to the test lead.

18. The method of claim 16 further comprising: mounting the multi-chip module to a circuit board.

19. A method comprising: obtaining a metal leadframe structure including leads, at least two independent die mounting pads electrically isolated from one another, the at least two independent die mounting pads including a first pad for mounting at least one IC chip and a second pad for mounting at least one power device chip;mounting the at least one IC chip to the first pad;mounting the at least one power device chip to the second pad; andattaching bonding wires having more than one diameter to the at least one IC chip and the at least one power device chip to the leads.

20. The method of claim 19 further comprising molding a molding material around at least a portion of the metal leadframe structure, the at least one IC chip, the at least one power chip, and the bonding wires.