Semiconductor chip packaging assemblyTechnical Field
The present invention relates to the field of semiconductor chip packaging technology, and in particular, to a semiconductor chip packaging assembly.
Background
As shown in fig. 21 and 22, in the conventional semiconductor chip packaging process, the semiconductor chip is generally fixed above a chip carrying area (commonly called a base island) of a metal lead frame or an organic substrate by conductive adhesive or non-conductive adhesive, then the semiconductor chip and pins of the corresponding metal lead frame or organic substrate are bonded with each other by a wire bonding manner, and then a component capable of protecting the semiconductor chip is formed by a plastic package material plastic package process, and in a plastic package body structure of each object and interface of the semiconductor chip, the metal pins led out by the plastic package body and a PCB (printed circuit board) outside the plastic package body are used for interconnection welding.
In the whole packaging process of the semiconductor chip, wire bonding plays a role in transmitting power and signals between the chip in the plastic package and the power supply and signals outside the plastic package. Whether it is a digital chip, a memory chip, a power management chip, a control driving chip or a power electronic power chip, in the traditional chip packaging technology, the bare chip and the metal pins outside the bare chip are bonded and interconnected through metal wires, the bonding of the metal wires needs to be performed one by one under the conditions of temperature, time and pressure, especially the bonding of hundreds or even hundreds of metal wires is required when the digital chip, so the following common defects occur, and the bonding is a difficult problem that needs to be overcome in the traditional semiconductor chip packaging industry worldwide at present:
1. The number of the metal wires is large, so that the production efficiency is low, and the production cost is increased intangibly.
2. When the wire density is high and the length is long, the signal or the electrical interference of different wires is easily caused by the small distance, and the distance between the wires is determined according to the voltage.
The longer the wires, the weaker the structural support they carry, which can easily lead to poor wire loops, collapse or line-to-line contact and short circuits during plastic packaging.
A flexible, high temperature resistant circuit board (FPC) is a printed wiring made of a flexible, high temperature resistant insulating substrate. The flexible, high temperature resistant circuit board provides excellent electrical capabilities, meets the design requirements of smaller and higher density installations, and also helps to reduce assembly processes and enhance reliability. The flexible high-temperature-resistant circuit board is a better solution for meeting the requirements of thinning and high plasticity of electronic products, can be freely bent, rolled and folded, can bear millions of dynamic bending without damaging wires, can be randomly arranged according to space layout requirements and can be randomly moved and stretched in a three-dimensional space, thereby achieving the integration of component assembly and wire connection, can greatly reduce the volume and weight of the electronic products, is suitable for the requirements of developing the electronic products to the high-density, thinning and high-reliability directions, and has the advantages of good heat dissipation and weldability, easiness in assembly and connection, lower comprehensive cost and the like.
Disclosure of Invention
The invention aims to provide a semiconductor chip packaging assembly, which solves the following technical problems:
1, in the prior art, bonding of a single metal lead wire circuit can be realized each time, and when more leads are connected and bonded with a semiconductor chip and a metal pin, the time consumed by bonding is very long;
2, in the process of bonding metal leads, the metal leads are too close in distance due to the fact that the number of the metal leads is relatively large. When the semiconductor chip is in operation, an arc is generated due to the fact that the metal leads are too close to each other, or the leads are in contact with each other to generate a short circuit, and high-density wire bonding is difficult to achieve.
In order to achieve the above object, the present invention provides a semiconductor chip package assembly comprising:
The metal lead frame comprises a base island and metal pins, and the metal pins are positioned on the outer side of the base island;
the semiconductor chip is fixedly connected to the base island, and a plurality of bonding pads for connecting the semiconductor chip with the outside are arranged on the semiconductor chip;
The flexible high-temperature-resistant insulating soft board is internally provided with a plurality of disjoint grooves;
The metal lead wire circuit is made of conductive materials and is arranged in the groove, and two ends of the metal lead wire circuit are respectively provided with a section of connecting part exposed from one side of the flexible high-temperature-resistant insulating soft board, wherein the connecting part comprises a first connecting part and a second connecting part, the first connecting part is used for connecting the semiconductor chip, and the second connecting part is used for connecting the metal pins;
and the plastic package body is used for coating the semiconductor chip, the metal lead frame, the flexible high-temperature-resistant insulating soft board and the metal lead line, and at least one end of the metal pin, which is not connected with the metal lead line, is exposed to the outer side of the plastic package body.
Further, a first bump is arranged on a bonding pad of the semiconductor chip or a first connection part of the metal lead line;
And arranging a second bump on a part of the metal pin, which is required to be bonded, or a second connection part of the metal lead wire circuit.
As a further aspect of the present invention, a first bump is provided at a selected one of a portion of the semiconductor chip to be bonded and a connection portion to which the conductive metal lead line is connected;
and a second bump is arranged at one selected part of the parts of the metal pins which need to be bonded and the connecting parts of the conductive metal lead wires which are used for connecting with the metal pins.
Further, the length of the metal lead wire circuit is equal to that of the flexible high-temperature-resistant insulating soft board, the end faces of the first connecting portion and the second connecting portion are not surrounded and sealed by the flexible high-temperature-resistant insulating soft board, a notch is formed in the same side of the flexible high-temperature-resistant insulating soft board and located under the connecting portion respectively, and the first connecting portion and the second connecting portion are bonded with the semiconductor chip and the metal pins through the notch.
Further, a third bump is respectively arranged on the connecting part at the notch.
Further, the length of the metal lead wire circuit is equal to that of the flexible high-temperature-resistant insulating soft board, the end faces of the first connecting portion and the second connecting portion are surrounded and sealed by the flexible high-temperature-resistant insulating soft board, a window is formed in the same side of the flexible high-temperature-resistant insulating soft board and located under the connecting portion respectively, and the first connecting portion and the second connecting portion are bonded with the semiconductor chip and the metal pins through the windows.
Further, a fourth bump is respectively arranged on the connecting part of the window.
Further, the plurality of flexible high temperature resistant insulating flexible boards are vertically overlapped, and the plurality of first connecting parts and the plurality of second connecting parts are exposed from the side surfaces of the plurality of flexible high temperature resistant insulating flexible boards.
Further, a hollow part is formed in the middle of the flexible high-temperature-resistant insulating soft board, the hollow part is used for placing the semiconductor chip which needs multi-surface bonding, and a plurality of disjoint grooves are formed in the flexible high-temperature-resistant insulating soft board around the hollow part.
Further, a plurality of guide holes are formed in the flexible high-temperature-resistant insulating soft board at positions avoiding the metal lead line, and the plastic package body can enter the lower part covered by the flexible high-temperature-resistant insulating soft board through the guide holes.
The invention has the beneficial effects that:
The flexible high-temperature-resistant insulating flexible printed circuit board is characterized in that a groove is formed in the flexible high-temperature-resistant insulating flexible printed circuit board in advance, a conductive metal lead wire circuit is placed in the groove, the middle part of the conductive metal lead wire circuit is located in the flexible high-temperature-resistant insulating flexible printed circuit board, a small part of each of two ends of the conductive metal lead wire circuit is exposed to be connected with a semiconductor chip and metal pins, the metal lead wire circuit can be formed in the flexible high-temperature-resistant insulating flexible printed circuit board in advance, the number of the metal lead wire circuits can be adjusted according to actual requirements, in the subsequent bonding process, all the metal lead wire circuits can be connected at the same time only by one-time connection, bonding efficiency is improved, and the flexible high-temperature-resistant insulating flexible printed circuit board adopts polyimide or polyester film as a base material, so that good insulating effect can be achieved, and the situation that electric arcs are easily generated due to the fact that the number of the metal lead wire circuits is too close, or short circuit is easily generated due to mutual contact of the metal lead wire circuits can be realized.
Drawings
FIG. 1 is a schematic top view of a metal wire line bonding structure according to the present invention;
FIG. 2 is a schematic front view of a bonding structure of a metal wire line according to the present invention;
FIG. 3 is a schematic top view of the structure of the metal lead wire of the present invention with an extension portion;
FIG. 4 is a schematic top view of a bump-on-metal wire bond structure of a semiconductor chip and a metal lead according to the present invention;
FIG. 5 is a schematic top view of a bump-formed metal wire bond structure on a metal wire trace connection in accordance with the present invention;
fig. 6 is a schematic front view of a metal wire bonding structure with bumps formed on a semiconductor chip and a second connection portion according to the present invention;
FIG. 7 is a schematic front view of a bump-forming metal wire bonding structure on a metal lead and a first connection portion according to the present invention;
FIG. 8 is a schematic cross-sectional view of a single-layer flexible high-temperature-resistant insulating flexible board with notches;
FIG. 9 is a schematic cross-sectional front view of a bump structure formed at a notch in accordance with the present invention;
FIG. 10 is a schematic cross-sectional view of a single-layer flexible high-temperature-resistant insulating flexible board forming a fenestration structure according to the present invention;
FIG. 11 is a schematic cross-sectional front view of a bump structure formed at a window according to the present invention;
FIG. 12 is a schematic perspective view of a structure of a multi-layer flexible high temperature resistant insulating flexible board of the present invention stacked up and down;
FIG. 13 is a schematic top view of a cross-line bonding structure according to the present invention;
FIG. 14 is a schematic front view of a structure with height differences at the connection points of metal lead wires according to the present invention;
FIG. 15 is a schematic top view of a peripheral enclosable structure of the present invention;
FIG. 16 is a schematic top view of a dual-sided encapsulatable structure of the void of the present invention;
FIG. 17 is a schematic top view of a three-sided encapsulatable structure with a void according to the present invention;
FIG. 18 is a schematic front cross-sectional view of a stacked semiconductor chip configuration of the present invention;
FIG. 19 is a schematic front view in cross section of a heat dissipating plate structure provided on a flexible high temperature resistant insulating flexible board according to the present invention;
FIG. 20 is a schematic top view of a flexible high temperature resistant insulation flexible board with a guide hole;
FIG. 21 is a schematic diagram illustrating a front view of a prior art mosfet package structure;
fig. 22 is a schematic top-view cross-section of a prior art mosfet package structure.
The semiconductor chip comprises a semiconductor chip, a metal lead frame, a base island, a metal pin, a metal lead line, a metal lead wire, a first connecting part, a second connecting part, a first extending part, a flexible high-temperature-resistant insulation soft board, a plastic package body, a first bump, a second bump, a first opening, a notch, a third bump, a second bump, a third bump, a window, a fourth bump, a third bump, a fourth bump, a gap, a material guide hole, a heat dissipation plate and a heat dissipation plate.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
As shown in fig. 1 to 20, the invention discloses a semiconductor chip package assembly, which comprises a semiconductor chip 1, a metal lead frame 2, a flexible high temperature resistant insulating soft board 4, a metal lead line 3 and a plastic package body 5;
The semiconductor chip 1 is provided with a plurality of bonding pads (not shown in the drawing) for connecting the semiconductor chip 1 with the outside, the bonding pads are at least positioned on one side of the surface of the semiconductor chip 1, the metal lead frame 2 comprises a base island 21 and metal pins 22, the base island 21 is used for fixing the semiconductor chip 1, the metal pins 22 are used for connecting the semiconductor chip 1 fixed on the base island 21 with the outside circuit, the metal pins 22 are positioned on the periphery of the base island 21, and the metal lead frame 2 serves as a carrier of the semiconductor chip 1 and plays a role of a bridge for connecting the semiconductor chip 1 with the outside circuit; the flexible high temperature resistant insulation flexible board 4 is internally provided with a plurality of disjoint grooves, a single-layer flexible high temperature resistant insulation flexible board 4 with the thickness of 10-40 mu m is made of polyimide, polyester film and other materials with flexibility and good insulation performance, the grooves are formed through the existing technology and are not repeated, the metal lead wires 3 are made of copper, palladium copper, silver, gold and other materials with good conductivity, the metal lead wires 3 are pre-arranged in the grooves of the flexible high temperature resistant insulation flexible board 4 through the existing technology, the flexible high temperature resistant insulation flexible board 4 adopts polyimide or polyester film as a base material, the good insulation effect is achieved, the problems that the electric arcs are easily generated due to the fact that the metal lead wires 3 are too close in distance or short circuits are generated due to the fact that the metal lead wires 3 are in contact with each other are effectively avoided, the bonding of the high density metal lead wires 3 can be realized, two ends of the metal lead wires 3 are respectively provided with a connecting part exposed from one side of the flexible high temperature resistant insulation flexible board 4, the connecting part comprises a first connecting part 31 and a second connecting part 32, the flexible high temperature resistant insulation flexible board 4 with the metal lead wires 3 inside is placed between the semiconductor chip 1 and the metal pins 22, the first connecting part 31 is connected with the bonding pads on the semiconductor chip 1, the second connecting part 32 is connected with the metal pins 22, through the method, the simultaneous connection of all the metal lead wires 3 can be realized by only one connection, and the bonding efficiency is improved, when the connecting part of the metal lead wires 3 is directly connected with the semiconductor chip 1 and the metal pins 22, as shown in fig. 3, the expansion part 33 can be formed in advance at the connecting part of the metal lead wires 3, so that the connection stability of the connecting part with the semiconductor chip 1 and the metal pins 22 is improved.
Since each area of the semiconductor chip 1 to be bonded has a specific function, if the conventional semiconductor chip 1 is adopted to flip, the semiconductor chip needs to be flipped 180 degrees, the electrical property is completely changed, and most of the conventional semiconductor chips 1 are positively mounted, i.e. the invention is applicable to the use of more types of semiconductor chips 1.
After bonding, the semiconductor chip 1, the metal lead frame 2, the flexible high temperature resistant insulating soft board 4 and the metal lead line 3 are covered by the plastic package body 5, and at least one end of the metal pin 22, which is not connected with the second connecting part 32, is exposed to the outer side of the plastic package body 5, so that the connection with an external circuit is facilitated.
As shown in fig. 4 to 7, as an embodiment of the present invention, the first bump 6 is disposed on the pad of the semiconductor chip 1 or the first connection portion 31 of the metal lead line 3, and the second bump 7 is disposed on the portion where the metal lead 22 needs to be bonded or the second connection portion 32 of the metal lead line 3, so that the metal lead line 3 can be more conveniently connected to the semiconductor chip 1 and the metal lead line 22, which is specifically provided in the following form:
form 1, forming a plurality of first bumps 6 on a bonding pad of a semiconductor chip 1, and forming a plurality of second bumps 7 on a part of a metal pin 22 to be bonded;
form 2, a plurality of first bumps 6 are formed on the first connection portion 31 of the metal lead wire circuit 3, and a plurality of second bumps 7 are formed on the second connection portion 32 of the metal lead wire circuit 3;
Form 3. First bumps 6 are formed on pads of the semiconductor chip 1, second connection portions 32 of the metal lead lines 3 are formed with second bumps 7,
Form 4, forming a plurality of first bumps 6 on the first connection part 31 of the metal lead wire circuit 3, and forming a plurality of second bumps 7 on the part of the metal pin 22 to be bonded;
Taking form 1 as an example, the bump formation method is described:
The bump is made of tin, copper, palladium copper, silver, gold and other conductive materials, and can be formed by 3D printing, ball implantation, etching and other modes, and the height of the bump is selected according to actual requirements.
In the process of selecting 3D printing, selecting micron-sized 3D printing equipment, selecting copper or palladium copper as a printing material, carrying out ball mounting by using a wire bonding machine equipment when a ball mounting process is selected, selecting silver or gold as a material by pre-adjusting parameters, coating a connecting material (solder paste or conductive adhesive) on bump positions and/or surrounding positions after bump formation, taking the bump positions and/or surrounding positions as a connecting medium layer, and carrying out reflow soldering and curing in a reflow oven in a manner of pressing down after a metal lead line 3 is contacted with a first bump 6 and a second bump 7, wherein when solder paste is adopted as the medium layer, carrying out reflow soldering and curing in a reflow oven in a manner of drying when conductive adhesive is adopted as the medium layer;
The bump forming method on the metal lead line 3 is similar to the 3D printing and ball mounting method, and the bump forming height is slightly larger than, equal to or slightly smaller than the thickness of the single-layer flexible high-temperature-resistant insulating soft board 4.
It should be emphasized that when the bump is formed by using tin, lead and tin, the melting temperature is lower than the melting temperature of the single-layer flexible high-temperature-resistant insulating soft board 4, and the tin bump can be melted by direct heating after the bump is connected with the metal lead line 3, so as to realize connection, in this case, the height of the bump should be slightly greater than or equal to that of the single-layer flexible high-temperature-resistant insulating soft board 4.
As shown in fig. 8 and 9, as an embodiment of the present invention, the lengths of the metal lead wire 3 and the flexible high temperature resistant insulation flexible board 4 are equal, the end surfaces of the first connection portion 31 and the second connection portion 32 are not enclosed and sealed by the flexible high temperature resistant insulation flexible board 4, a notch 8 is respectively formed on the same side of the flexible high temperature resistant insulation flexible board 4 and under the connection portion, the first connection portion 31 and the second connection portion 32 are bonded with the semiconductor chip 1 and the metal pins 22 through the notch 8, as shown in fig. 9, a third bump 9 can be further arranged on the connection portion at the notch 8, and the third bump 9 is more convenient for bonding the connection portion with the semiconductor chip 1 and the metal pins 22, so that the application range and the practicability of the present invention are improved.
As shown in fig. 10 and 11, as an embodiment of the present invention, the lengths of the metal lead wires 3 and the flexible high temperature resistant insulation flexible board 4 are equal, the end surfaces of the first connection portion 31 and the second connection portion 32 are enclosed and sealed by the flexible high temperature resistant insulation flexible board 4, a window 10 is respectively opened on the same side of the flexible high temperature resistant insulation flexible board 4 and under the connection portion, the first connection portion 31 and the second connection portion 32 are bonded with the semiconductor chip 1 and the metal pins 22 through the window 10, and as shown in fig. 11, a fourth bump 11 is respectively arranged on the connection portion at the window 10, so as to improve the application range and the practicality of the present invention.
As shown in fig. 12 to 14, as an embodiment of the present invention, a plurality of flexible high temperature resistant insulation flexible boards 4 are stacked up and down, a plurality of first connection portions 31 and second connection portions 32 are exposed from the sides of the plurality of flexible high temperature resistant insulation flexible boards 4, and for a part of semiconductor chips 1, a case of a flying lead and/or a height difference occurs during packaging, when the case of a flying lead and/or a height difference is encountered, the flexible high temperature resistant insulation flexible boards 4 can be provided with a plurality of layers, and metal lead lines 3 are provided between different layers, and the metal lead lines 3 are separated from each other, so that bonding of the flying lead and/or the height difference can be simultaneously realized.
As shown in fig. 15-19, as an embodiment of the present invention, the hollow portion 12 is formed in the middle of the flexible high temperature-resistant insulating soft board 4, and the hollow portion 12 is used for placing the semiconductor chip 1 that is not less than two sides to be bonded, for example, the analog semiconductor chip 1 or the digital semiconductor chip 1, which generally needs to bond multiple parts of the semiconductor chip 1 to different metal pins 22, many semiconductor chips 1 also need to bond metal lead wires 3 on the peripheral part of the semiconductor chip 1, and the situation that the periphery, three sides or two sides of the semiconductor chip 1 need to be connected to the metal pins 22 can be adapted by arranging the metal lead wires 3 in the flexible high temperature-resistant insulating soft board 4 around the hollow portion 12 in advance, as shown in fig. 18, when the package body is formed, the upper part of the flexible high temperature-resistant insulating soft board 4 can be exposed, and when the other semiconductor chip 1 is connected, a stacked structure can be formed, and the flexible high temperature-resistant insulating soft board 4 can satisfy good flexibility, and the heat dissipation performance can be enhanced when the semiconductor chip 1 is stacked, and the whole package is shown in fig. 14, and the heat dissipation performance can be enhanced when the package is also shown in fig. 14.
As shown in fig. 20, in order to make the plastic package body 5 better enter the lower part covered by the flexible high temperature resistant insulation soft board 4, a plurality of material guiding holes 13 are formed at the position where the flexible high temperature resistant insulation soft board 4 avoids the metal lead wire circuit 3, the material guiding holes 13 are preferably formed at the raised position of the raised bonding flexible high temperature resistant insulation soft board 4, and the material guiding holes 13 can be formed by etching after integral molding in the connection mode formed by the double-layer or multi-layer flexible high temperature resistant insulation soft board 4, or the material guiding holes 13 can be formed on the single-layer flexible high temperature resistant insulation soft board 4 in advance.
In all embodiments, the shape of the flexible high temperature resistant insulation flexible board 4 can be designed according to the requirement, and each hole, groove, notch, salient point and the like can be set into the required shape according to the actual requirement.
The working principle of the invention is as follows:
Referring to the drawings, a groove is formed in the flexible high temperature-resistant insulating flexible printed circuit board 4 in advance, the metal lead wire 3 is placed in the groove, the middle part of the metal lead wire 3 is positioned in the flexible high temperature-resistant insulating flexible printed circuit board 4, two ends of the metal lead wire 3 are respectively provided with a section of connecting part exposed from one side of the flexible high temperature-resistant insulating flexible printed circuit board 4, the connecting part comprises a first connecting part 31 and a second connecting part 32, the semiconductor chip 1 is fixedly connected to the island 21 of the metal lead frame 2, the prefabricated flexible high temperature-resistant insulating flexible printed circuit board 4 is placed between the semiconductor chip 1 and the metal pins 22, the first connecting part 31 is connected with a bonding pad on the semiconductor chip 1, the second connecting part 32 is connected with the metal pins 22, by the method, the simultaneous connection of all the metal lead wire 3 can be realized only by one time, the bonding efficiency is improved, the flexible high temperature-resistant insulating flexible printed circuit board 4 adopts polyimide or polyester film as a base material, the situation that the metal lead wire 3 is easily generated too much in a distance, or the metal lead wire 3 is easily contacted with each other, and the high-density bonding of the metal lead wire 3 can be realized.
In the description of the present invention, it should be understood that the terms "upper," "lower," "left," "right," and the like indicate an orientation or a positional relationship based on that shown in the drawings, and are merely for convenience of description and to simplify the description, but do not indicate or imply that the apparatus or elements referred to must have a specific orientation, as well as a specific orientation configuration and operation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.
It should be noted that the foregoing description is only a preferred embodiment of the present invention, and although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood that modifications, equivalents, improvements and modifications to the technical solution described in the foregoing embodiments may occur to those skilled in the art, and all modifications, equivalents, and improvements are intended to be included within the spirit and principle of the present invention.