CN206432258U - Encapsulation device for power switch - Google Patents

Abstract

The utility model discloses a power switch's packaging hardware. The packaging device comprises a substrate, a metal sheet, a chip and a packaging body. The metal sheet has a contact portion, a connection portion and a pin portion. The connecting part connects the contact part and the pin part, and the extending direction of the contact part is different from the extending direction of the connecting part. The chip is arranged between the substrate and the metal sheet. The chip is provided with a first electrode and a second electrode, and the first electrode and the second electrode are respectively positioned on a first surface and a second surface of the chip, which are opposite to each other. The packaging body covers a part of the substrate, the chip and at least a part of the metal sheet. The second electrode of the chip is coupled to the substrate, and the first electrode of the chip is coupled to the surface of the contact portion. Therefore, the packaging device provides the power switch device with good heat dissipation and better electrical conductivity.

Description

Encapsulation device for power switch

technical field

The utility model relates to chip packaging, in particular to a packaging device for a power switch that adopts flip-chip (Flip-chip) packaging technology for chip packaging.

Background technique

Please refer to FIG. 1 . FIG. 1 is a schematic diagram of a conventional power switch packaging device. As shown in FIG. 1 , in a conventional power switch packaging device 1 , a chip 12 is arranged on a lead frame 10 , the drain D positioned on the lower surface of the chip 12 directly contacts the lead frame 10 , and the source D positioned on the upper surface of the chip 12 The S and the gate G are respectively connected to the lead frame 10 through the metal sheet 14 or by wire bonding.

However, in practical applications, the heat dissipation effect of this packaging structure is obviously not good, and since the drain D with a larger area is in direct contact with the lead frame 10 , it is difficult to reduce the area of the lead frame 10 . In addition, no matter whether the source S and the gate G are connected to the lead frame 10 through the metal sheet 14 or bonding, there will be additional impedance caused by welding, which will also make the conductivity worse.

Utility model content

In view of this, the utility model provides a packaging device for a power switch to solve the problems mentioned in the prior art.

A preferred embodiment of the utility model is a packaging device for a power switch. In this embodiment, the packaging device of the power switch includes a substrate, a metal sheet, a chip and a packaging body. The metal sheet has a contact portion, a connection portion and a leg portion, the connection portion connects the contact portion and the leg portion, and the extension direction of the contact portion is different from that of the connection portion. The chip has a first electrode and a second electrode, and the chip is arranged between the substrate and the metal sheet, and the first electrode and the second electrode are respectively located on the first surface and the second surface of the chip opposite to each other. The packaging body covers part of the substrate, chip and at least part of the metal sheet. The second electrode of the chip is coupled to the substrate, and the first electrode of the chip is coupled to the surface of the contact portion.

In one embodiment, the pin portion has a first side, and a portion of the first side is exposed to the package body.

In one embodiment, the contact portion has a top surface, and the top surface is at least partially exposed to the package.

In one embodiment, the contact portion, the connection portion and the pin portion of the metal sheet are sequentially connected to present a zigzag shape.

In one embodiment, the contact portion has a plurality of bumps.

In one embodiment, the connecting portion is stepped.

In one embodiment, the second surface further includes a third electrode.

In one embodiment, the metal sheet is electrically isolated from the substrate.

In one embodiment, the substrate includes a plurality of pins, and the metal sheet is in electrical contact with some of the plurality of pins.

In one embodiment, the chip is a single die of a single metal oxide half field effect transistor (MOSFET) device.

In one embodiment, the chip is a single die of multiple common-drain MOSFETs.

In one embodiment, the second surface is further provided with a third electrode, a fourth electrode and a fifth electrode, and the third electrode, the fourth electrode and the fifth electrode are electrically connected to the substrate.

Compared with the prior art, the packaging device of the power switch according to the utility model directly uses the pins of the metal sheet exposed on the surface of the package as the pins of the drain, so it can effectively reduce the number of drain pins in the traditional power switch device. The additional impedance caused by the metal sheet soldered to the lead frame improves its conductivity.

In addition, since the packaging device of the power switch of the present invention uses flip-chip (Flip-chip) packaging technology to package the chip, the drain with a larger area is located on the top surface of the chip and the source with a smaller area is located at the top of the chip. The bottom surface can not only reduce the area of the required lead frame to save costs, but also add a heat sink (Heat sink) to assist the heat dissipation of the drain, and the source can pass through the through hole (Via ) to help dissipate heat.

The advantages and spirit of the present utility model can be further understood through the following detailed description of the utility model and accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram of a conventional power switch packaging device.

2A , 2B , 3A , 3B , 4 , 5A and 5B are schematic diagrams of packaging devices for power switches according to different embodiments of the present invention.

Description of main component symbols:

1, 2A, 2B, 3A, 3B, 4, 5A: Packaging devices for power switches

10: lead frame

20: Substrate

12, 22: chip

14, 24: metal sheet

16, 26: Encapsulation

240: contact part

242, 242': connecting part

244: Connecting feet

20a, 20b: pins

22a: first surface

22b: second surface

D: the first electrode (drain)

S, S1: second electrode (source)

G, G1: The third electrode (gate)

G2: The fourth electrode (gate)

S2: fifth electrode (source)

PCB: circuit board

W: bump

detailed description

Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Elements/members with the same or similar numbers used in the drawings and embodiments are used to represent the same or similar parts.

A preferred embodiment of the present invention is a packaging device for a power switch. In this embodiment, the packaging device of the power switch adopts flip-chip (Flip-chip) packaging technology for chip packaging. Please refer to FIG. 2A . FIG. 2A is a schematic diagram of the packaging device of the power switch in this embodiment.

As shown in FIG. 2A , a power switch packaging device 2A formed on a circuit board PCB includes a substrate 20 , a chip 22 , a metal sheet 24 and a packaging body 26 . The substrate 20 is arranged on the circuit board PCB; the chip 22 has a first electrode D, a second electrode S and a third electrode G, and the chip 22 is arranged between the substrate 20 and the metal sheet 24; the metal sheet 24 has a contact portion 240, a connection part 242 and pin part 244. The connection portion 242 connects the contact portion 240 and the pin portion 244 , and the extension direction of the contact portion 240 is different from the extension direction of the connection portion 242 . The first electrode D is located on the first surface 22 a of the chip 22 and the second electrode S and the third electrode G are located on the second surface 22 b of the chip 22 . The first surface 22a and the second surface 22b of the chip 22 are opposite to each other. The package body 26 covers part of the circuit board PCB, part of the substrate 20 , the chip 22 and at least part of the metal sheet 24 .

In this embodiment, the substrate 20 can be a lead frame; the first electrode D, the second electrode S, and the third electrode G of the chip 22 can be respectively a drain electrode (Drain electrode), a source electrode (Source electrode) And the gate (Gateelectrode), and the area of the first electrode D is greater than the area of the second electrode S and the third electrode G; the first surface 22a and the second surface 22b of the chip 22 are respectively the top surface and the bottom surface of the chip 22; circuit The board PCB can be a printed circuit board; the metal sheet 24 can be made of a metal material with good conductivity; the contact portion 240, the connecting portion 242 and the pin portion 244 of the metal sheet 24 are connected in sequence to present a zigzag; the package body 26 can be formed by Insulating materials such as packaging glue, but not limited thereto.

The second electrode S and the third electrode G located on the second surface (bottom surface) 22 b of the chip 22 are coupled to the substrate 20 , and the substrate 20 is used as pins of the second electrode S and the third electrode G. In practical applications, the second electrode S and the third electrode G can pass through the through holes (Via) of the substrate 20 and the circuit board PCB to assist heat dissipation (not shown).

The first electrode D located on the first surface (top surface) 22 a of the chip 22 is coupled to the surface of the contact portion 240 of the metal sheet 24 . Two ends of the connection portion 242 of the metal sheet 24 are respectively connected to the contact portion 240 and the leg portion 244 . The connection portion 242 of the metal sheet 24 is located on one side of the chip 22 and the substrate 20 , and the connection portion 242 , the chip 22 and the substrate 20 are spaced apart from each other and not connected. That is to say, the metal sheet 24 is electrically isolated from the substrate 20 and will not be welded together.

The extending direction of the connection portion 242 of the metal sheet 24 is different from the extending direction of the contact portion 240 of the metal sheet 24 . In this embodiment, the contact portion 240 of the metal sheet 24 extends along the horizontal direction, while the connecting portion 242 of the metal sheet 24 extends along the vertical direction. However, the angle between the contact portion 240 and the connection portion 242 of the metal sheet 24 can be adjusted according to actual requirements, and the shape of the connection portion 242 can also be a straight line, a curve or a step shape, and is not limited thereto.

The package body 26 is used to cover the metal sheet 24 and fill the space between the metal sheet 24 , the circuit board PCB and the chip 22 , so that the metal sheet 24 and the circuit board PCB are electrically isolated from each other. It should be noted that, for the pin portion 244 of the metal sheet 24 , although the package body 26 covers the pin portion 244 of the metal sheet 24 , the bottom and sides of the pin portion 244 are exposed to the package body 26 . Since the contact portion 240 of the metal sheet 24 is coupled to the first electrode D, the pin portion 244 of the metal sheet 24 exposed to the package body 26 can serve as a pin of the first electrode D. Referring to FIG.

Because this embodiment uses the metal sheet 24 coupled with the first electrode D as the pin of the first electrode D directly, it is not necessary to weld the metal sheet 24 on the substrate 20, so the additional impedance caused by welding can be reduced. to enhance its conductivity.

In addition, in the packaging device 2A of the power switch, since the first electrode (drain) D with a larger area is located on the top surface of the chip 22 and the second electrode (source) S and third electrode (gate) with smaller areas ) G is located on the bottom surface of the chip 22, not only can reduce the area of the required substrate 20 to save cost, but also add a radiator to assist the heat dissipation of the first electrode (drain) D with a larger area, while the smaller area The second electrode (source) S and the third electrode (gate) G can assist heat dissipation through the through holes of the substrate 20 and the circuit board PCB located below them.

Please refer to FIG. 2B , in another embodiment of the power switch packaging device 2B, the top surface of the contact portion 240 of the metal sheet 24 is at least partially exposed to the package body 26, so that the contact portion 240 can be externally connected to a heat sink to help reduce the area. Heat dissipation of the large first electrode (drain) D.

Please refer to FIG. 3A , in another embodiment of a power switch packaging device 3A, a plurality of protrusions may be formed in the area where the lower surface of the contact portion 240 of the metal sheet 24 is in contact with the first electrode (drain) D of the chip 22 . Point W to increase the connection strength between each other.

Please refer to FIG. 3B , in another embodiment of a power switch packaging device 3B, the connecting portion 242' of the metal sheet 24 is stepped, but not limited thereto.

It should be noted that the chip 22 in the foregoing embodiments is a single crystal grain of a single metal oxide half field effect transistor (MOSFET), but actually the chip 22 can also be a single crystal grain comprising a plurality of metal oxide half field effect transistor elements. grain. For example, as shown in FIG. 4, in the packaging device 4 of the power switch, the first electrode D located on the first surface (top surface) 22a of the chip 22 is a first metal oxide half field effect transistor element and a second gold electrode. The drain (Common drain) shared by the oxygen half field effect transistor element, as for the second electrode (source) S1 and the third electrode (gate) G1 of the first metal oxide half field effect transistor element and the second metal oxide half field effect transistor element The fourth electrode (gate) G2 and the fifth electrode (source) S2 of the effective transistor element are respectively located on the second surface (bottom surface) 22b of the chip 22 .

In another embodiment, as shown in FIG. 5A , the pin portion 244 of the metal sheet 24 may also be located in the package body 26 and be in electrical contact with the substrate 20 located thereunder. In addition, as shown in FIG. 5B , the substrate 20 may include a plurality of pins 20 a - 20 b , and the metal sheet 24 may be in electrical contact with part of the plurality of pins 20 a - 20 b.

Through the detailed description of the preferred specific embodiments above, it is hoped that the features and spirit of the present utility model can be described more clearly, and the scope of the present utility model is not limited by the preferred specific embodiments disclosed above. On the contrary, the purpose is to cover various changes and arrangements with equivalents within the scope of the patent scope of the utility model.

Claims (12)

1. A packaging device for a power switch, characterized in that the packaging device for the above-mentioned power switch comprises: a substrate; A metal sheet having a contact portion, a connection portion, and a leg portion, wherein the connection portion connects the contact portion and the leg portion, and the extension direction of the contact portion is different from the extension direction of the connection portion; A chip has a first electrode and a second electrode, and the chip is arranged between the substrate and the metal sheet, wherein the first electrode and the second electrode are respectively located on a first surface of the chip opposite to each other and a second surface; and A package, covering part of the above-mentioned substrate, the above-mentioned chip and at least part of the above-mentioned metal sheet; Wherein, the second electrode of the chip is coupled to the substrate, and the first electrode of the chip is coupled to the surface of the contact portion. 2 . The packaging device of a power switch according to claim 1 , wherein the pin portion has a first side, and a portion of the first side is exposed to the package. 3 . 3 . The packaging device of a power switch according to claim 1 , wherein the contact portion has a top surface, and the top surface is at least partially exposed to the package body. 4 . 4 . The packaging device for a power switch as claimed in claim 1 , wherein the contact portion, the connection portion and the pin portion of the metal sheet are sequentially connected to present a Z-shape. 5 . 5 . The packaging device for a power switch according to claim 1 , wherein the contact portion has a plurality of bumps. 6 . The packaging device of a power switch according to claim 1 , wherein the connecting portion is in a stepped shape. 7. The packaging device of a power switch according to claim 1, wherein the second surface further comprises a third electrode. 8 . The packaging device of a power switch according to claim 1 , wherein the metal sheet is electrically isolated from the substrate. 9 . The packaging device of a power switch according to claim 1 , wherein the substrate includes a plurality of pins, and the metal sheet is in electrical contact with some of the plurality of pins. 10 . The packaging device of a power switch according to claim 1 , wherein the chip is a single crystal grain of a single metal oxide semiconductor field effect transistor element. 11 . 11 . The packaging device of a power switch according to claim 1 , wherein the chip is a single crystal grain of a plurality of common-drain metal-oxide-semiconductor field-effect transistor elements. 12. The packaging device of a power switch according to claim 11, wherein the second surface is further provided with a third electrode, a fourth electrode and a fifth electrode, and the third electrode, the fourth electrode and the above-mentioned The fifth electrode is electrically connected to the above-mentioned substrate.