阅读说明：本技术 一种堆叠封装结构及堆叠封装结构的制造方法 (Stack packaging structure and manufacturing method thereof ) 是由 曹周 于 2020-06-05 设计创作，主要内容包括：本发明公开一种堆叠封装结构及堆叠封装结构的制造方法；该堆叠封装结构,包括堆叠组装的上层封装件和下层封装件,上层封装件包括上层引线框架以及焊接于上层引线框架上的上层芯片,下层封装件包括下层引线框架以及焊接于下层引线框架上的下层芯片；上层引线框架和/或下层引线框架形成有沿堆叠方向延伸的凸柱,凸柱通过框架焊材层与另一引线框架焊接固定；凸柱用于支撑上层引线框架,并用于保持下层芯片与上层引线框架之间的绝缘间距；该制造方法包括：引线框架准备、芯片焊接步骤、堆叠组装步骤和注塑封装步骤。本发明能够保持堆叠封装结构中上层引线框架与下层芯片之间的有效绝缘间距。(The invention discloses a stacked packaging structure and a manufacturing method thereof; the stacked packaging structure comprises an upper packaging piece and a lower packaging piece which are stacked and assembled, wherein the upper packaging piece comprises an upper lead frame and an upper chip welded on the upper lead frame, and the lower packaging piece comprises a lower lead frame and a lower chip welded on the lower lead frame; the upper lead frame and/or the lower lead frame are/is provided with a convex column extending along the stacking direction, and the convex column is fixedly welded with the other lead frame through the frame welding material layer; the convex columns are used for supporting the upper-layer lead frame and keeping the insulation distance between the lower-layer chip and the upper-layer lead frame; the manufacturing method comprises the following steps: the method comprises the steps of lead frame preparation, chip welding, stacking and assembling and injection molding packaging. The invention can keep the effective insulation distance between the upper lead frame and the lower chip in the stacked packaging structure.)

1. A stacked package structure, comprising an upper package (10) and a lower package (20) assembled in a stacked manner, wherein the upper package (10) comprises an upper lead frame (11) and an upper chip (12) soldered on the upper lead frame (11), and the lower package (20) comprises a lower lead frame (21) and a lower chip (22) soldered on the lower lead frame (21);

the upper lead frame (11) and/or the lower lead frame (21) are/is provided with convex columns (30) extending along the stacking direction, and the convex columns (30) are welded and fixed with the other lead frame through a frame welding material layer (41); the convex columns (30) are used for supporting the upper-layer lead frame (11) and maintaining the insulation distance between the lower-layer chip (22) and the upper-layer lead frame (11).

2. The package on package structure according to claim 1, further comprising a package body (60), wherein the package body (60) encapsulates the upper package (10) and the lower package (20); the upper-layer lead frame (11) comprises an upper-layer pin (111), the upper-layer chip (12) is electrically connected with the upper-layer pin (111), and the upper-layer pin (111) extends out of the packaging body (60) from the side wall of the packaging body (60) and is used for being electrically connected with an external circuit carrier.

3. The stacked package structure of claim 2, wherein the lower lead frame (21) includes lower pins (211), the lower chip (22) is electrically connected to the lower pins (211), and the lower pins (211) are exposed from a bottom wall of the package body (60) for electrical connection to an external circuit carrier.

4. The stacked package structure of any one of claims 1-3, wherein the frame solder layer (41) is an insulating solder layer or a conductive solder layer.

5. The stacked package structure of any one of claims 1-3, wherein said frame solder layer (41) is a conductive solder layer; the upper chip (12) and the lower chip (22) are connected with each other through the convex columns (30) and the conductive welding material layers in a circuit mode.

6. The stacked package structure of any one of claims 1-3, wherein said frame solder layer (41) is a conductive solder layer; the lower-layer lead frame (21) comprises a lower-layer pin (211), and the lower-layer chip (22) is electrically connected with the lower-layer pin (211); the lower layer pin (211) is electrically connected with the upper layer pin (111) through the convex column (30), and the lower layer pin (211) is electrically connected with an external circuit carrier through the upper layer pin (111).

7. The stacked package structure according to any one of claims 1 to 3, wherein the upper lead frame (11) comprises an upper base island and an upper pin (111), the upper chip (12) is soldered to the upper base island by a solder material layer, and the upper chip (12) is electrically connected to the upper pin (111) by a metal wire (50); the lower-layer lead frame (21) comprises a lower-layer base island and a lower-layer pin (211), the lower-layer chip (22) is welded on the lower-layer base island through a welding material layer, and the lower-layer chip (22) is electrically connected with the lower-layer pin (211) through a metal wire (50);

the convex column (30) is formed by bending the upper-layer lead frame (11), and the convex column (30) is welded and fixed on the lower-layer lead frame (21) through a frame welding material layer (41); the upper-layer lead frame (11) is provided with at least two convex columns (30), and the lower-layer chip (22) is located between the convex columns (30) in the horizontal direction of the stacked packaging structure.

8. The stacked package structure of any one of claims 1-3, wherein the upper chip (12) is flip-chip mounted to the upper lead frame (11) and the lower chip (22) is flip-chip mounted to the lower lead frame (21);

the convex column (30) is formed by bending the upper-layer lead frame (11), and the convex column (30) is welded and fixed on the lower-layer lead frame (21) through a frame welding material layer (41); the upper-layer lead frame (11) is provided with at least two convex columns (30), and the lower-layer chip (22) is located between the convex columns (30) in the horizontal direction of the stacked packaging structure.

9. A method for manufacturing a package on package structure includes:

preparing a lead frame: preparing at least two lead frames; bending one or more lead frames, wherein the convex part formed after bending is a convex column (30), and the part which is not bent is a lead frame body; when the lead frame placed on the upper layer is bent, the convex column (30) is processed to be convex downwards; when the lead frame placed on the lower layer is bent, the convex column (30) is processed to be convex upwards;

chip welding: welding and fixing a chip on each frame body, and electrically connecting the chip with pins of the frame body to form a package;

stacking and assembling: stacking a plurality of packages, and welding and fixing the convex columns (30) and the lead frames of the adjacent layers by adopting welding materials;

and (3) injection molding and packaging: packaging and protecting the lead frames and the chips by adopting packaging materials; the encapsulating material is cured to form an encapsulation body (60).

10. The method for manufacturing a package on package structure according to claim 9, wherein in the step of injection molding, the upper pins (111) of the lead frame located at the upper layer extend out of the package body (60) for electrical connection of an external circuit carrier, and the lead frame located at the lower layer is exposed from the bottom of the package body (60);

the manufacturing method further includes a step of bending the upper pins (111) exposed outside the package body (60).

Technical Field

The invention relates to the technical field of semiconductor packaging, in particular to a stacked packaging structure and a manufacturing method thereof.

Background

Along with the development of the technology, the volume of electronic component products is smaller and smaller; the multi-chip packaging technology comes from the birth, the multi-chip packaging structure on the market at present mostly adopts a stacking packaging structure form, and the packaging structure can greatly reduce the size of a product; when two layers of packaging parts are stacked and assembled, the upper layer packaging part is easy to incline too much, the effective insulation interval between chips in the upper layer packaging part and the lower layer packaging part cannot be ensured, and the packaging is poor.

Disclosure of Invention

One object of an embodiment of the present invention is to: provided is a package on package structure capable of supporting an upper lead frame well.

Yet another object of embodiments of the present invention is to: a stack package structure is provided, which can maintain an effective insulation distance between an upper lead frame and a lower chip.

Another object of an embodiment of the present invention is to: a method for manufacturing a stacked package structure is provided, and the stacked package structure manufactured by the method can maintain an effective insulation distance between an upper lead frame and a lower chip.

In order to achieve the purpose, the invention adopts the following technical scheme:

a stacked package structure comprises an upper-layer package piece and a lower-layer package piece which are stacked and assembled, wherein the upper-layer package piece comprises an upper-layer lead frame and an upper-layer chip welded on the upper-layer lead frame, and the lower-layer package piece comprises a lower-layer lead frame and a lower-layer chip welded on the lower-layer lead frame;

the upper lead frame and/or the lower lead frame are/is provided with a convex column extending along the stacking direction, and the convex column is fixedly welded with the other lead frame through a frame welding material layer; the convex columns are used for supporting the upper-layer lead frame and maintaining the insulation distance between the lower-layer chip and the upper-layer lead frame.

Preferably, the package further comprises a packaging body, and the packaging body wraps and packages the upper layer packaging piece and the lower layer packaging piece; the upper-layer lead frame comprises an upper-layer pin, the upper-layer chip is electrically connected with the upper-layer pin, and the upper-layer pin extends out of the packaging body from the side wall of the packaging body and is used for being electrically connected with an external circuit carrier.

Preferably, the lower lead frame includes a lower pin, the lower chip is electrically connected to the lower pin, and the lower pin is exposed from the bottom wall of the package body for electrical connection with an external circuit carrier.

Preferably, the frame welding material layer is an insulating welding material layer or a conductive welding material layer.

Preferably, the frame welding material layer is a conductive welding material layer; the upper layer chip and the lower layer chip are connected with each other through the convex column and the conductive welding material layer in a circuit mode.

Preferably, the frame welding material layer is a conductive welding material layer; the lower lead frame comprises a lower pin, and the lower chip is electrically connected with the lower pin; the lower layer pin is electrically connected with the upper layer pin through the convex column, and the lower layer pin is electrically connected with an external circuit carrier through the upper layer pin.

Preferably, the upper-layer lead frame comprises an upper-layer base island and an upper-layer pin, the upper-layer chip is welded on the upper-layer base island through a welding material layer, and the upper-layer chip is electrically connected with the upper-layer pin through a metal wire; the lower-layer lead frame comprises a lower-layer base island and a lower-layer pin, the lower-layer chip is welded on the lower-layer base island through a welding material layer, and the lower-layer chip is electrically connected with the lower-layer pin through a metal wire;

the convex column is formed by bending the upper-layer lead frame, and is fixed on the lower-layer lead frame through a frame welding material layer in a welding manner; the upper-layer lead frame is provided with at least two convex columns, and the lower-layer chip is positioned among the convex columns in the horizontal direction of the stacked packaging structure.

Preferably, the upper chip is inversely installed on the upper lead frame, and the lower chip is inversely installed on the lower lead frame;

the convex column is formed by bending the upper-layer lead frame, and is fixed on the lower-layer lead frame through a frame welding material layer in a welding manner; the upper-layer lead frame is provided with at least two convex columns, and the lower-layer chip is positioned among the convex columns in the horizontal direction of the stacked packaging structure.

A method of manufacturing a package on package structure, comprising:

preparing a lead frame: preparing at least two lead frames; bending one or more lead frames, wherein the convex part formed after bending is a convex column, and the part which is not bent is a lead frame body; when the lead frame placed on the upper layer is bent, the convex column is processed to be convex downwards; when the lead frame placed on the lower layer is bent, the convex column is processed to be convex upwards;

chip welding: welding and fixing a chip on each frame body, and electrically connecting the chip with pins of the frame body to form a package;

stacking and assembling: stacking a plurality of packaging pieces, and welding and fixing the convex columns and the lead frames of the adjacent layers by adopting welding materials;

and (3) injection molding and packaging: packaging and protecting the lead frames and the chips by adopting packaging materials; and curing the packaging material to form a packaging body.

Preferably, in the injection molding packaging step, the upper layer pins of the lead frame on the upper layer extend out of the packaging body for the external circuit carrier to be electrically connected, and the lead frame on the lower layer is exposed from the bottom of the packaging body;

the manufacturing method further includes a step of forming a bent leg, in which the upper layer pin exposed outside the package body is bent.

The invention has the beneficial effects that: the stacked packaging structure can well support the upper-layer lead frame through the convex columns, so that the effective insulation distance between the upper-layer lead frame and the lower-layer chip can be kept; according to the stacked packaging structure manufactured by the manufacturing method of the stacked packaging structure, an effective insulation distance can be kept between the upper layer lead frame and the lower layer chip.

Drawings

The invention is explained in more detail below with reference to the figures and examples.

Fig. 1 is a schematic structural diagram of the package on package structure according to an embodiment of the invention;

FIG. 2 is a schematic structural diagram of the package on package structure according to another embodiment of the present invention;

FIG. 3 is one illustration of a lead frame preparation performed during manufacture of the stacked package structure of FIG. 1;

FIG. 4 is a second schematic diagram of the stacked package structure of FIG. 1 illustrating lead frame preparation during fabrication;

FIG. 5 is a schematic diagram of the stacked package structure of FIG. 1 during fabrication with die bonding;

FIG. 6 is a second schematic diagram illustrating die bonding during manufacturing of the stacked package structure of FIG. 1;

FIG. 7 is a schematic diagram of the stacked package structure of FIG. 1 during fabrication for stack assembly;

FIG. 8 is a schematic diagram of the package on package structure of FIG. 1 during fabrication for injection molding;

FIG. 9 is one of the schematic diagrams of the stacked package structure of FIG. 2 illustrating lead frame preparation during fabrication;

FIG. 10 is a second schematic diagram of the stacked package structure of FIG. 2 illustrating lead frame preparation during fabrication;

FIG. 11 is a schematic diagram of the stacked package structure of FIG. 2 during fabrication with die bonding;

FIG. 12 is a second schematic diagram illustrating die bonding during manufacturing of the stacked package structure of FIG. 2;

FIG. 13 is a schematic diagram of the stacked package structure of FIG. 2 during fabrication thereof;

FIG. 14 is a schematic view of the package on package structure of FIG. 2 being injection molded during manufacture;

FIG. 15 is a diagram illustrating steps in a method for fabricating a package on package structure according to an embodiment of the present invention;

in the figure: 10. an upper package; 11. an upper layer lead frame; 111. an upper layer pin; 12. an upper chip; 20. a lower package; 21. a lower lead frame; 211. a lower layer pin; 22. a lower chip; 30. a convex column; 41. a frame solder layer; 42. a first solder layer; 43. a second solder layer; 50. a metal wire; 60. a package body; 70. and a copper pillar.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, unless otherwise explicitly specified or limited, the terms "connected" and "fixed" are to be understood broadly, e.g., as being fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly specified or limited, "upper" or "lower" an upper feature than a lower feature may include the upper and lower features being in direct contact, and may also include the upper and lower features not being in direct contact but being in contact with each other through another feature therebetween. Also, an upper feature "on," "over," and "above" an underlying feature includes an upper feature directly above and obliquely above an underlying feature, or simply means that the upper feature is higher in level than the underlying feature. An upper feature "under", "below" and "beneath" an underlying feature includes an upper feature directly under and obliquely below the underlying feature, or simply means that the upper feature is less level than the underlying feature.

The invention provides a stacked packaging structure, which adopts a lead frame with convex columns 30 as a chip carrier, and when two layers of packaging parts are stacked, namely when the two layers of lead frames are stacked, the convex columns 30 can well support an upper layer of lead frame 11, so that the effective insulation distance between the upper layer of lead frame 11 and a sunken chip can be kept.

As shown in fig. 1 to 14, in an embodiment of the package on package structure of the present invention, the package on package structure includes an upper package 10 and a lower package 20 assembled in a stacked manner, the upper package 10 includes an upper lead frame 11 and an upper chip 12 soldered on the upper lead frame 11, and the lower package 20 includes a lower lead frame 21 and a lower chip 22 soldered on the lower lead frame 21;

the upper lead frame 11 and/or the lower lead frame 21 are/is formed with a convex column 30 extending along the stacking direction, and the convex column 30 is welded and fixed with the other lead frame through a frame welding material layer 41; the protruding columns 30 are used for supporting the upper lead frame 11 and maintaining an insulation distance between the lower chip 22 and the upper lead frame 11.

Specifically, the upper chip 12 is soldered to the upper lead frame 11 by a first solder layer 42, and the lower chip 22 is soldered to the lower lead frame 21 by a second solder layer 43.

Further, the convex column 30 can adopt at least any one of the following embodiments: