CN113725088A

CN113725088A - Manufacturing method of chip packaging structure

Info

Publication number: CN113725088A
Application number: CN202010230888.3A
Authority: CN
Inventors: 周辉星
Original assignee: SIPLP Microelectronics Chongqing Ltd
Current assignee: SIPLP Microelectronics Chongqing Ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2021-11-30
Anticipated expiration: 2040-03-27
Also published as: CN113725088B

Abstract

The invention provides a manufacturing method of a chip packaging structure.A bare chip is provided with an electric connecting piece, the electric connecting piece comprises a first conductive part, a second conductive part and a connecting part for connecting the first conductive part and the second conductive part, the second conductive part comprises a first sub-conductive part and a second sub-conductive part, and the first conductive part is electrically connected to the back surface of the bare chip; the bare chip and the electric connecting piece are plastically packaged by the first plastic packaging layer, and the first conductive part and the second conductive part of the electric connecting piece and the active surface of the bare chip are exposed outside the first plastic packaging layer; a circuit layer is formed on the active surface of the bare chip, the second conductive part of the electric connecting piece and the first plastic packaging layer, the circuit layer comprises a rewiring layer, part of the rewiring layer is electrically connected with the first sub-conductive part and the first inner bonding pad, and part of the rewiring layer is electrically connected with the second sub-conductive part and the back grounding inner bonding pad. The specific electric connection point position of the active surface of the bare chip is back grounded by using the electric connectors. The heat at the heat generating region on the active surface of the die where heat is likely to accumulate can be dissipated.

Description

Manufacturing method of chip packaging structure

Technical Field

The invention relates to the technical field of chip packaging, in particular to a manufacturing method of a chip packaging structure.

Background

In recent years, with the continuous development of circuit integration technology, electronic products are increasingly developed toward miniaturization, intellectualization, high performance, and high reliability. The packaging technique not only affects the performance of the product, but also restricts the miniaturization of the product. In a power chip (power module), it is necessary to back-ground a specific electrical connection point on the active side of a die.

In view of the above, the present invention provides a method for manufacturing a novel chip package structure for packaging a power chip.

Disclosure of Invention

The invention aims to provide a manufacturing method of a chip packaging structure, which is used for packaging a power chip.

In order to achieve the above object, the present invention provides a method for manufacturing a chip package structure, including:

providing a carrier plate and a plurality of dies, wherein each die comprises an active surface and a back surface which are opposite, the active surface is provided with a first inner bonding pad, a second inner bonding pad and a protective layer which covers the first inner bonding pad and the second inner bonding pad; the first inner bonding pad is positioned in the heat generation area of the bare chip, and the second inner bonding pad at least comprises a back grounding inner bonding pad; fixing the active surface of each bare chip to the carrier plate;

providing a plurality of electrical connectors, each electrical connector comprising a first conductive portion, a second conductive portion, and a connecting portion connecting the first conductive portion and the second conductive portion, the second conductive portion comprising a first sub-conductive portion and a second sub-conductive portion; disposing each electrical connector on each die, wherein the first conductive portion is electrically connected to the back surface of the die, and the second conductive portion is disposed on the surface of the carrier;

forming a first plastic packaging layer embedding each bare chip and each electric connecting piece on the surface of the carrier plate; thinning the first plastic packaging layer until the first conductive part of each electric connecting piece is exposed; removing the carrier plate;

forming a circuit layer on the active surface of each die, the second conductive part of each electrical connector and the first plastic package layer to form a package intermediate structure containing a plurality of dies, wherein the circuit layer comprises a rewiring layer, part of the rewiring layer is electrically connected with the first sub-conductive part and the first inner bonding pad, and part of the rewiring layer is electrically connected with the second sub-conductive part and the back grounding inner bonding pad;

and cutting the packaging intermediate structure to form a plurality of chip packaging structures, wherein each chip packaging structure comprises a bare chip.

Optionally, a plurality of electrical connections are provided arranged on a first support plate.

Optionally, the first conductive part, the connecting part and the first sub-conductive part of the electrical connector are H-shaped; and/or the first conductive part, the connecting part and the second sub-conductive part of the electric connecting piece are H-shaped; and/or the electrical connector is formed by at least one of cutting, stamping, etching and stamping; and/or the first sub-conductive portion comprises two or more.

Optionally, the method further comprises: and forming a first oxidation resisting layer on the first conductive part of each electric connector exposed out of the first plastic packaging layer.

Optionally, forming a circuit layer on the active surface of each die, the second conductive portion of each electrical connector, and the first molding layer comprises:

forming the rewiring layer on the first inner bonding pad, the second inner bonding pad, the protective layer, the first plastic packaging layer between the bare chips and the second conductive part of the electric connecting piece;

and forming a conductive convex column on the rewiring layer.

Optionally, the redistribution layer includes two or more layers, and/or the redistribution layer is a fan-out line.

Optionally, the method further comprises: and forming a solder ball on the conductive convex column, wherein the solder ball is an outer pin.

Optionally, the method further comprises: and forming a second anti-oxidation layer on the conductive convex column.

Optionally, forming a conductive post on the redistribution layer includes:

forming a conductive convex column on the metal block of the rewiring layer;

forming a second dielectric layer on the conductive convex columns and between the adjacent conductive convex columns, wherein the second dielectric layer is made of inorganic materials;

and polishing the second dielectric layer until the conductive convex columns are exposed.

Optionally, forming a conductive post on the redistribution layer includes:

forming a conductive convex column on the metal block of the rewiring layer;

and forming a second dielectric layer between the adjacent conductive convex columns, wherein the upper surface of the second dielectric layer is flush with the upper surfaces of the conductive convex columns, and the second dielectric layer is made of organic materials.

Optionally, forming a conductive post on the redistribution layer includes:

forming a second dielectric layer on the rewiring layer;

forming a plurality of third openings in the second dielectric layer, wherein the third openings expose the metal blocks of the rewiring layer;

forming a layer of conductive material on the second dielectric layer and within the third opening;

and polishing the conductive material layer until the second dielectric layer is exposed, wherein the conductive material layer in the third opening forms a conductive convex column.

Optionally, forming a conductive post on the redistribution layer includes:

forming a conductive convex column on the metal block of the rewiring layer, and forming a second plastic package layer embedding the conductive convex column on the rewiring layer;

and thinning the second plastic packaging layer until the conductive convex columns are exposed.

Optionally, a conductive layer is disposed on the back surface of the die, and/or a conductive adhesive is disposed between the first conductive portion and the back surface of the die.

Optionally, the conductive glue comprises a nano-copper/conductive polymer composite.

Optionally, in the nano copper/conductive polymer composite material, the conductive polymer is: at least one of polypyrrole, polythiophene, polyaniline and polyphenylene sulfide, and/or the particle size of the nano copper is less than 800 nm.

Optionally, the particle size of the nano-copper ranges from 200nm to 500 nm.

Optionally, the material of the protection layer is at least one of an insulating resin material, silicon dioxide, and silicon nitride. The protective layer can play an insulating role, and in the process of forming the first plastic package layer and grinding the first plastic package layer, the hardness can meet the requirement of protecting the first inner bonding pad, the second inner bonding pad and an electric interconnection structure in the bare chip from being damaged, and the specific material of the protective layer is not limited in the invention.

Optionally, in the step of fixing the active surface of each die to the carrier board, the protective layer has a plurality of first openings therein, a partial number of the first openings expose a partial region of the first inner bonding pad, and a partial number of the first openings expose a partial region of the second inner bonding pad; or forming first openings in the protective layer in the step of forming the circuit layer, wherein part of the first openings expose part of the first inner bonding pads, and part of the first openings expose part of the second inner bonding pads.

Compared with the prior art, the invention has the beneficial effects that:

arranging an electric connecting piece on the bare chip, wherein the electric connecting piece comprises a first conductive part, a second conductive part and a connecting part for connecting the first conductive part and the second conductive part, the second conductive part comprises a first sub-conductive part and a second sub-conductive part, the first conductive part is electrically connected to the back surface of the bare chip, and the second conductive part and the active surface of the bare chip are basically in the same plane; the bare chip and the electric connecting piece are plastically packaged by the first plastic packaging layer, and the first conductive part and the second conductive part of the electric connecting piece and the active surface of the bare chip are exposed outside the first plastic packaging layer; a circuit layer is formed on the active surface of the bare chip, the second conductive part of the electric connecting piece and the first plastic packaging layer, the circuit layer comprises a rewiring layer, part of the rewiring layer is electrically connected with the first sub-conductive part and the first inner bonding pad, and part of the rewiring layer is electrically connected with the second sub-conductive part and the back grounding inner bonding pad. The specific electric connection point position of the active surface of the bare chip is back grounded by using the electric connectors. In addition, the first conductive part of the electric connector is exposed outside the chip packaging structure, and heat at the heating area which is easy to accumulate heat on the active surface of the bare chip can be dissipated, so that the heat dissipation performance of the chip is improved, the continuous and efficient operation of the chip can be ensured, and the problem of service life influence caused by overheating of the chip is solved.

Drawings

Fig. 1 is a schematic cross-sectional structure diagram of a chip package structure according to a first embodiment of the invention.

FIG. 2 is a top view of an electrical connector;

FIG. 3 is a flow chart of a method of fabricating the chip package structure of FIG. 1;

FIGS. 4-15 are schematic intermediate structures corresponding to the flow chart of FIG. 3;

fig. 16 is a top view of an electrical connector in a method for manufacturing a chip package structure according to a second embodiment of the present invention.

To facilitate an understanding of the invention, all reference numerals appearing in the invention are listed below:

bare chip 11 electrical connection 12

Die active side 11a and die back side 11b

First inner pad 110a and second inner pad 110b

First opening 111a of protective layer 111

First conductive part 12a of first plastic package layer 10

Second conductive portion 12b and connecting portion 12c

First sub-conductive part 120a and second sub-conductive part 120b

Outer lead 13a of circuit layer 13

Metal block 131a second plastic-sealed layer 133

Conductive pillar 132 second anti-oxidation layer 134

First anti-oxidation layer 121 chip packaging structure 1a

Carrier 2 encapsulation intermediate structure 1

First support plate 3 second support plate 4

First dielectric layer 131b and second dielectric layer 132b

Rewiring layer 131 back ground inner pad 110c

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Referring to fig. 1, a chip package structure 1a includes:

a bare chip 11, the bare chip 11 includes an active surface 11a and a back surface 11b opposite to each other, the active surface 11a has a first inner bonding pad 110a, a second inner bonding pad 110b and a protection layer 111, the first inner bonding pad 110a is located in the heat generating region of the bare chip 11, the second inner bonding pad 110b includes at least one back ground inner bonding pad 110 c; the protective layer 111 has a plurality of first openings 111a, a part of the number of first openings 111a exposing a partial area of the first inner pad 110a, and a part of the number of first openings 111a exposing a partial area of the second inner pad 110 b;

an electrical connector 12, the electrical connector 12 including a first conductive portion 12a, a second conductive portion 12b, and a connecting portion 12c connecting the first conductive portion 12a and the second conductive portion 12b, the second conductive portion 12b including a first sub-conductive portion 120a and a second sub-conductive portion 120 b; the first conductive part 12a is electrically connected to the back surface 11b of the die 11;

a first plastic package layer 10 covering the bare chip 11 and the electrical connector 12, wherein the first conductive part 12a and the second conductive part 12b of the electrical connector 12 and the active surface 11a of the bare chip 11 are exposed outside the first plastic package layer 10;

a circuit layer 13, wherein the circuit layer 13 is positioned on the active surface 11a of the bare chip 11, the second conductive part 12b of the electric connector 12 and the first plastic package layer 10; the circuit layer 13 includes a redistribution layer 131, a portion of the redistribution layer 131 electrically connects the first sub-conductive portion 120a and the first inner pad 110a, and a portion of the redistribution layer 131 electrically connects the second sub-conductive portion 120b and the back ground inner pad 110 c.

The die 11 may include a variety of devices formed on a semiconductor substrate, as well as electrical interconnect structures electrically connecting the various devices. The second inner bonding pads 110b of the die active side 11a are connected to electrical interconnect structures for inputting/outputting electrical signals of the respective devices. The back ground inner pad 110c is used to electrically connect with the back surface 11b of the die 11. The die 11 may be a power chip. The first inner pad 110a may be located near a channel region of the power chip.

The protection layer 111 is made of an insulating material, and may be at least one of an insulating resin material, silicon dioxide, and silicon nitride. Examples of the insulating resin material include polyimide, epoxy resin, abf (ajinomoto build file), pbo (polybenzoxazole), and the like.

FIG. 2 is a top view of an electrical connector. Referring to fig. 2, the electrical connector 12 includes a first conductive portion 12a and four second conductive portions 12 b. Of the four second conductive portions 12b, three are the first sub-conductive portions 120a, and one is the second sub-conductive portion 120 b. The first conductive part 12a, the connecting part 12c, and the first sub-conductive part 120a of the electrical connector 12 are rectangular in plan view. The first conductive part 12a, the connection part 12c, and the second sub-conductive part 120b of the electrical connector 12 are also rectangular in plan view. In other embodiments, second conductive portion 12b may include at least a first sub-conductive portion 120a and a second sub-conductive portion 120 b.

Referring to fig. 1, the electrical connector 12 is convex in vertical cross-section for receiving the die 11. The material of the electrical connector 12 may be a metal with good electrical conductivity and certain hardness, such as copper. A first oxidation resistant layer 121 may be disposed on the first conductive portion 12a exposed outside the first molding layer 10.

In the embodiment shown in fig. 1, the angles between the first conductive portion 12a and the second conductive portion 12b and the connecting portion 12c are right angles. In some embodiments, the angles between the first conductive portion 12a, the second conductive portion 12b, and the connection portion 12c may be obtuse angles.

In some embodiments, a conductive adhesive may be disposed between the first conductive portion 12a and the back surface 11b of the die 11 to electrically connect the two. The conductive paste may include a nano-copper/conductive polymer composite.

In the nano copper/conductive polymer composite material, the conductive polymer can be: at least one of polypyrrole, polythiophene, polyaniline and polyphenylene sulfide. The conductive polymer is formed by chemically or electrochemically doping high molecules with conjugated pi-bonds to convert the high molecules from insulators to conductors, and the conductive polymer has good conductive characteristics and is further enhanced in conductivity after nano copper is added.

The copper material is one of the metal materials with the most excellent electrical conductivity, and when the size of copper is reduced to the nanometer level, the copper material has more excellent electrical and thermal conductivity due to large specific surface area and high surface activity. Preferably, the nano copper is spherical, and the particle size is less than 800 nm; more preferably, the particle size of the nano-copper is in the range of 200nm to 500 nm. This is because: the specific surface area of the nano copper material is increased along with the reduction of the particle size of the material, and the electric and heat conduction properties of the material are enhanced; when the particle size is reduced to be below 800nm, the material has excellent electric and heat conduction characteristics; however, when the particle size is further reduced to below 200nm, the cost of the nano material is significantly increased, which affects the economic benefit of the package, and when the particle size of the nano copper is reduced to below 200nm, the surface energy of the nano copper particles is increased, and the particles are easy to agglomerate to form larger particles, which may impair the conductive and heat conductive properties of the composite material.

Preferably, the nano copper is added in an amount of more than 5 wt% in the nano copper/conductive polymer composite material.

In some embodiments, the first conductive portion 12a and the back surface 11b of the die 11 may be in direct contact to electrically connect the two.

In some embodiments, the back side 11b of the die 11 may also be provided with a conductive layer. The conductive layer may be copper. A titanium layer may also be provided between the copper layer and the back surface 11b of the die 11 to improve adhesion between the die back surface 11b and the copper layer.

In the embodiment shown in fig. 1, there is no gap between the connection portion 12c of the electrical connection member 12 and the die 11, and in other embodiments, there may also be a gap therebetween to allow the first molding compound layer 10 to enter, so as to improve the connection strength between the electrical connection member 12 and the die 11.

The material of the first molding compound layer 10 may be epoxy resin, polyimide resin, benzocyclobutene resin, polybenzoxazole resin, polybutylene terephthalate, polycarbonate, polyethylene terephthalate, polyethylene, polypropylene, polyolefin, polyurethane, polyolefin, polyethersulfone, polyamide, polyurethane, ethylene-vinyl acetate copolymer, polyvinyl alcohol, or the like.

The redistribution layer 131 is a fan-out line (fan-out).

In the embodiment shown in fig. 1, the redistribution layer 131 includes metal blocks 131a and a second molding layer 133 between adjacent metal blocks 131a, having one layer. In other embodiments, the redistribution layer 131 may include two or more layers. In addition to electrically connecting the second sub-conductive portion 120b and the back-grounded inner pad 110c, and electrically connecting the first sub-conductive portion 120a and the first inner pad 110a, some number of metal blocks 131a are electrically connected to one or more second inner pads 110b for implementing other functions, and/or some number of metal blocks 131a are electrically connected to one or more first inner pads 110 a.

In the embodiment shown in fig. 1, the conductive pillar 132 is an outer lead 13 a. The conductive pillars 132 may be made of copper or the like, and may have a second anti-oxidation layer 134 thereon. In other embodiments, solder balls may be disposed on the conductive studs 132, and the solder balls are the outer leads 13 a.

Referring to fig. 1, chip package 1a utilizes electrical connector 12 to achieve a specific electrical connection point location (back-ground inner pad 110c) of die active surface 11a for back-side 11b grounding. In addition, the first conductive part 12a of the electrical connector 12 is exposed outside the chip packaging structure 1a, and heat at the heating area, where heat is easily accumulated, on the active surface 11a of the bare chip can be dissipated, so that the heat dissipation performance of the chip can be improved, the continuous and efficient operation of the chip can be ensured, and the problem of the influence on the service life caused by overheating of the chip can be solved.

An embodiment of the invention provides a method for manufacturing the chip package structure 1a in fig. 1. Fig. 3 is a flow chart of a method of fabrication. Fig. 4 to 15 are intermediate schematic diagrams corresponding to the flow chart in fig. 3.

First, referring to step S1 in fig. 3, fig. 4 and fig. 5, a carrier board 2 and a plurality of dies 11 are provided, each die 11 includes an active surface 11a and a back surface 11b, the active surface 11a has a first inner pad 110a, a second inner pad 110b and a protection layer 111 covering the first inner pad 110a and the second inner pad 110b, the first inner pad 110a is located in a heat generating region of the die 11, and the second inner pad 110b includes at least one back-ground inner pad 110 c; the active surface 11a of each die 11 is fixed to the carrier board 2. Wherein fig. 4 is a top view of a carrier board and a plurality of dies; fig. 5 is a sectional view taken along line AA in fig. 4.

The die 11 is formed as a singulated wafer that includes a wafer active side having inner pads 110 and an insulating layer (not shown) that protects the inner pads 110 and a wafer backside. After the wafer dicing, a die 11 is formed, and accordingly, the die 11 includes a die active surface 11a and a die back surface 11b, and the die active surface 11a has an inner pad 110 and an insulating layer for protecting the inner pad 110. Applying a protective layer 111 on the active side 11a of the die, the protective layer 111 may be applied by: before the wafer is cut into the dies 11, the protective layer 111 is applied on the active surface of the wafer, and the wafer with the protective layer 111 is cut to form the dies 11 with the protective layer 111, which may be: after the wafer is diced into dies 11, a protective layer 111 is applied on the dies 11.

The respective dies 11 may have the same structure and function, or may have different structures and functions.

The protection layer 111 is made of an insulating material, and may be at least one of an insulating resin material, silicon dioxide, and silicon nitride.

The insulating resin material, such as polyimide, epoxy, abf (ajinomoto build file), pbo (polybenzoxazole), and the like, may be a) laminated on the first and second

inner pads

110a and 110b and the insulating layer between the first and second

inner pads

110a and 110b through a lamination process, or b) coated on the first and second

inner pads

110a and 110b and the insulating layer between the first and second

inner pads

110a and 110b first and then cured, or c) cured on the first and second

inner pads

110a and 110b and the insulating layer between the first and second

inner pads

110a and 110b through an injection molding process.

When the material of the protection layer 111 is silicon dioxide or silicon nitride, the protection layer may be formed on the first inner pad 110a, the second inner pad 110b, and the insulation layer between the first inner pad 110a and the second inner pad 110b by a deposition process.

Referring to fig. 5, the protective layer 111 has a plurality of first openings 111a therein, a part of the number of first openings 111a exposes a partial region of the first inner pad 110a, and a part of the number of first openings 111a exposes a partial region of the second inner pad 110 b. In some embodiments, the first inner bonding pad 110a and the second inner bonding pad 110b on the die 11 may be embedded in the protection layer 111, and the first opening 111a is formed in the process of forming the circuit layer 13 (see fig. 12).

In the embodiment shown in fig. 5, one first opening 111a exposes a partial region of one first inner pad 110a (or second inner pad 110 b). In other embodiments, one first opening 111a may also expose partial areas of two or more first inner pads 110a (or second inner pads 110 b).

The number of the die 11 may be two, three, all the die after one wafer dicing, or even all the die after a plurality of wafer dicing, and the invention is not limited to the number of the die 11.

The wafer may be thinned from the back side prior to dicing to reduce the thickness of the die 11.

The carrier plate 2 is a rigid plate and may comprise a plastic plate, a glass plate, a ceramic plate, a metal plate, or the like.

An adhesive layer may be disposed between the carrier 2 and the die 11 to fix the two. Specifically, a whole surface of the carrier 2 may be coated with an adhesive layer, and the plurality of dies 11 are disposed on the adhesive layer. The adhesive layer may be a peelable material to peel the carrier 2 and the die 11 apart, for example, a thermal release material that can be tack-free by heating or a UV release material that can be tack-free by UV irradiation.

Next, referring to step S2 in fig. 3, fig. 2 and fig. 6, a plurality of electrical connection members 12 are provided, each electrical connection member 12 including a first conductive part 12a, a second conductive part 12b, and a connection part 12c connecting the first conductive part 12a and the second conductive part 12b, the second conductive part 12b including a first sub-conductive part 120a and a second sub-conductive part 120 b; referring to fig. 7, each electrical connector 12 is disposed on each die 11, the first conductive portion 12a is electrically connected to the back surface 11b of the die 11, and the second conductive portion 12b is disposed on the surface of the carrier 2.

The material of the electrical connector 12 may be a metal with good electrical conductivity and certain hardness, such as copper.

Referring to fig. 2, the electrical connection member 12 may include one first conductive portion 12a and four second conductive portions 12 b. Of the four second conductive portions 12b, three are the first sub-conductive portions 120a, and one is the second sub-conductive portion 120 b. The first conductive part 12a, the connecting part 12c, and the first sub-conductive part 120a of the electrical connector 12 are rectangular in plan view. The first conductive part 12a, the connection part 12c, and the second sub-conductive part 120b of the electrical connector 12 are also rectangular in plan view. In other embodiments, the second conductive portion 12b includes at least a first sub-conductive portion 120a and a second sub-conductive portion 120 b.

Referring to fig. 6, a plurality of electrical connectors 12 may be arranged on a first support plate 3. The vertical cross-section of the electrical connector 12 may be convex to accommodate the die 11. The convex shape can be formed by at least one of cutting, stamping, etching and stamping, and can be produced in large batch to reduce cost.

In the embodiment shown in fig. 6, the angles between the first conductive portion 12a and the second conductive portion 12b and the connecting portion 12c are right angles. In some embodiments, the angles between the first conductive portion 12a, the second conductive portion 12b and the connecting portion 12c are obtuse angles.

The first support plate 3 is a hard plate member and may include a glass plate, a ceramic plate, a metal plate, and the like.

An adhesive layer may be provided between the first conductive part 12a of the electrical connector 12 and the first support plate 3 to secure the two. Specifically, a full-surface adhesive layer may be coated on the surface of the first support plate 3, and the first conductive parts 12a of the plurality of electrical connectors 12 may be placed on the adhesive layer. The adhesive layer may be made of a material that is easily peelable to peel off the electrical connector 12 from the first support plate 3, and for example, a thermal release material that can be made tack-free by heating or a UV release material that can be made tack-free by ultraviolet irradiation may be used.

Referring to fig. 7, the first support plate 3 is aligned with the carrier plate 2, each electrical connector 12 is disposed on each die 11, the first conductive part 12a is disposed on the back surface 11b of the die 11, and the second conductive part 12b is disposed on the surface of the carrier plate 2.

In some embodiments, a conductive adhesive may be disposed between the first conductive portion 12a and the back surface 11b of the die 11 to electrically connect the two. The conductive paste may include a nano-copper/conductive polymer composite. The nano-copper/conductive polymer composite material is a composite material formed by adding nano-copper particles into a conductive polymer and uniformly dispersing nano-copper in the conductive polymer. The composite material is a solid flat sheet-like structure, and the shape and size are preferably the same as those of the surface of the die back surface 11 b.

Specifically, the nano-copper/conductive polymer composite material is first placed on the die back surface 11b, and then the electrical connection members 12 arranged on the first support plate 3 are transferred to predetermined positions on the carrier plate 2, and the first conductive parts 12a of the electrical connection members 12 cover the composite material on the die back surface 11 b. Then heating the bare chip 11, the nano copper/conductive polymer composite material and the electric connector 12 on the carrier plate 2 to a temperature higher than the glass transition temperature of the conductive polymer material; at this time, the conductive polymer material changes from a solid to a semi-liquid having a certain viscosity, bonding the die back surface 11b and the first conductive portion 12a together.

In some embodiments, the back side 11b of the die 11 may also be provided with a conductive layer. The conductive layer may be formed before the die 11 is cut.

In the embodiment shown in fig. 7, there is no gap between the connecting portion 12c of the electrical connector 12 and the die 11, and in other embodiments, there may be a gap between the connecting portion and the die to allow the molding compound to enter.

After that, the first support plate 3 is removed. The first support plate 3 may be removed by conventional methods such as laser lift-off and UV irradiation.

Then, referring to step S3, fig. 8 and fig. 9 in fig. 3, forming a first molding compound layer 10 on the surface of the carrier 2 to embed each die 11 and each electrical connector 12; referring to fig. 10, the first molding compound 10 is thinned until the first conductive portion 12a of each electrical connector 12 is exposed; referring to fig. 11, the carrier plate 2 is removed. Fig. 8 is a top view of the first plastic package layer, and the first plastic package layer shows a perspective effect; fig. 9 is a cross-sectional view taken along line BB in fig. 8.

The material of the first molding compound layer 10 may be epoxy resin, polyimide resin, benzocyclobutene resin, polybenzoxazole resin, polybutylene terephthalate, polycarbonate, polyethylene terephthalate, polyethylene, polypropylene, polyolefin, polyurethane, polyolefin, polyethersulfone, polyamide, polyurethane, ethylene-vinyl acetate copolymer, polyvinyl alcohol, or the like. Correspondingly, the encapsulation may be performed by filling a liquid molding compound between each bare chip 11 and each electrical connector 12, and then curing the liquid molding compound at a high temperature through a molding die.

The first molding compound layer 10 can be thinned by mechanical grinding, such as grinding with a grinding wheel.

The protective layer 111 may prevent the first inner pad 110a, the second inner pad 110b, and the electrical interconnection structure in the die 11 from being damaged during the process of forming the first molding compound 10 and grinding the first molding compound 10.

Referring to fig. 11, after the carrier board 2 is removed, the second conductive part 12b of the electrical connector 12 is substantially in the same plane as the active surface 11a of the die 11. Furthermore, a second support plate 4 may be disposed on the first molding layer 10 and the first conductive portion 12a of each electrical connector 12. The second support plate 4 can support the die 11 embedded in the first molding compound layer 10 in a subsequent process.

The second support plate 4 is a hard plate member and may include a glass plate, a ceramic plate, a metal plate, and the like.

Next, referring to step S4 in fig. 3 and fig. 12, a circuit layer 13 is formed on the active surface 11a of each die 11, the second conductive portion 12b of each electrical connector 12, and the first molding compound layer 10 to form the package intermediate structure 1 including a plurality of dies 11, the circuit layer 13 includes a redistribution layer 131, a portion of the redistribution layer 131 electrically connects the first sub-conductive portion 120a and the first inner pad 110a, and a portion of the redistribution layer 131 electrically connects the second sub-conductive portion 120b and the back ground inner pad 110 c.

In this embodiment, the forming of the circuit layer 13 includes the following steps S41 to S42.

Step S41: a redistribution layer 131 is formed on the active surface 11a of each die 11, the second conductive part 12b of each electrical connector 12, and the first molding compound layer 10, a part of the redistribution layer 131 electrically connects the first sub-conductive part 120a and the first inner pad 110a, and a part of the redistribution layer 131 electrically connects the second sub-conductive part 120b and the back ground inner pad 110 c.

The redistribution layer 131 is a fan-out line (fan-out).

Step S42: conductive posts 132 are formed on the redistribution layer 131. The conductive posts 132 are outer leads 13 a.

In one alternative, step S41 of forming the re-wiring layer 131 includes steps S410-S413.

Step S410: a photoresist layer is formed on the active surface 11a of each die 11, the second conductive portion 12b of each electrical connector 12, and the first molding layer 10.

In this step S410, in an alternative embodiment, the photoresist layer may be a photosensitive film. The photosensitive film may be peeled off from the adhesive tape and applied on the active surface 11a of each die 11, the second conductive portion 12b of each electrical connector 12, and the first molding layer 10. In other alternatives, the photoresist layer may be formed by first applying a liquid photoresist and then curing the liquid photoresist by heating.

Step S411: the photoresist layer is exposed and developed, leaving the photoresist layer in a first predetermined area, which is complementary to the area where the metal block 131a of the rewiring layer 131 to be formed is located.

Of the metal blocks 131a, a partial number of the metal blocks 131a are positioned to electrically connect the first sub-conductive portion 120a and the first inner pad 110a, and a partial number of the metal blocks 131a are positioned to electrically connect the second sub-conductive portion 120b and the back ground inner pad 110 c. In addition, there are a partial number of metal blocks 131a positioned so as to electrically connect one or more second inner pads 110b for performing other functions.

This step S411 patterns the photoresist layer. In other alternatives, other sacrificial materials that are easily removable may be used in place of the photoresist layer.

Step S412: the complementary region of the first predetermined region is filled with a metal layer to form a metal block 131a of the re-wiring layer 131.

The step S412 may be performed by an electroplating process. The process of electroplating copper or aluminum is mature.

Specifically, before forming the photoresist Layer in step S410, a Seed Layer (Seed Layer) may be formed on the active surface 11a of each die 11, the second conductive portion 12b of each electrical connector 12, and the first molding compound Layer 10 by a physical vapor deposition method or a chemical vapor deposition method. The seed layer may serve as a power supply layer for electroplating copper or aluminum.

Step S413: and ashing to remove the residual photoresist layer in the first preset area.

And after ashing, removing the seed crystal layer in the first preset area by dry etching or wet etching.

The metal blocks 131a of the rewiring layer 131 may be planarized on the upper surface thereof by a polishing process, such as chemical mechanical polishing.

In step S41, the metal blocks 131a of the redistribution layer 131 are arranged according to design requirements, and the distribution of the redistribution layer 131 on each die 11 may be the same or different.

This step S42 may include steps S420-S425.

Step S420: a photoresist layer is formed on the metal block 131a, the protective layer 111, the second conductive part 12b of each electrical connector 12, and the first molding layer 10.

In this step S420, in an alternative embodiment, the photoresist layer may be a photosensitive film. The photosensitive film may be peeled off from the adhesive tape and applied on the metal block 131a, the protective layer 111, the second conductive portion 12b of each electrical connector 12, and the first molding layer 10. In other alternatives, the photoresist layer may be formed by first applying a liquid photoresist and then curing the liquid photoresist by heating.

Step S421: and exposing and developing the photoresist layer to retain the photoresist in the second predetermined area. The second predetermined area is complementary to the area where the conductive stud 132 is to be formed.

In this embodiment, the second predetermined region is located such that the at least one conductive stud 132 can lead out the metal block 131a electrically connecting the second sub-conductive portion 120b and the inner back-ground pad 110 c. In some embodiments, the metal block 131a electrically connecting the second sub-conductive portion 120b and the inner back-ground pad 110c may not be led out through the conductive pillar 132.

This step S421 patterns the photoresist layer. In other alternatives, other sacrificial materials that are easily removable may be used in place of the photoresist layer.

Step S422: the complementary region of the second predetermined region is filled with a metal layer to form the conductive stud 132.

This step S422 may be accomplished by an electroplating process. The process of electroplating copper or aluminum is mature. Before electroplating copper or aluminum, a Seed Layer (Seed Layer) can be physically or chemically vapor deposited as a power supply Layer.

Step S423: and ashing to remove the residual photoresist layer in the second preset area.

The conductive posts 132 may be planarized by a polishing process, such as chemical mechanical polishing.

Step S424: referring to fig. 12, a second molding layer 133 embedding the conductive stud 132 is formed on the conductive stud 132, the metal block 131a, the protective layer 111, the second conductive part 12b of each electrical connector 12, and the first molding layer 10.

In an alternative, step S424 includes: firstly, sticking a semi-solid plastic package film on the conductive convex column 132, the metal block 131a, the protective layer 111, the second conductive part 12b of each electric connector 12 and the first plastic package layer 10; then, placing the structure to be plastic-packaged with the semi-solid plastic-packaging film on the lower mold body, and closing the high-temperature upper mold body; when the upper mold body is subjected to hot compression molding, the semi-solid plastic package film is changed into a liquid plastic package material, and after the semi-solid plastic package film flows, the plastic package material is continuously heated to be changed into a solid second plastic package layer 133 from the liquid state; and removing the mold.

In another alternative, the second molding layer 133 formed in step S424 is formed by an injection molding process. Specifically, a structure to be plastically packaged is placed on a lower die body, and a high-temperature upper die body is closed; injecting a normal-temperature liquid plastic package material into the high-temperature mold cavity; the normal temperature liquid molding compound flows while changing from a liquid state to a solid second molding layer 133 due to heat.

The second molding layer 133 can improve the electrical insulation between the adjacent conductive studs 132 and the metal blocks 131 a.

Step S425: still referring to fig. 12, the second molding layer 133 is thinned until the conductive posts 132 are exposed.

The second molding layer 133 can be thinned by mechanical grinding, such as grinding with a grinding wheel.

In some embodiments, step S41 may include S410 '-S413'.

Step S410': referring to fig. 13, a first dielectric layer 131b is formed on the active surface 11a of each die 11, the second conductive portion 12b of each electrical connector 12, and the first molding layer 10. The first dielectric layer 131b may be made of silicon dioxide or silicon nitride, and is formed by a physical vapor deposition method or a chemical vapor deposition method.

In step S411', a number of second openings are formed in the first dielectric layer 131b, a part of the number of second openings exposing the first inner pads 110a, and a part of the number of second openings exposing the second inner pads 110 b. The second opening is a region where the metal block 131a is to be formed. The second opening may be formed by dry etching using the patterned photoresist as a mask.

In step S412', a conductive material layer is formed on the first dielectric layer 131b and in the second opening. The conductive material layer may be made of copper or aluminum, and is formed by physical vapor deposition or chemical vapor deposition.

In step S413', the conductive material layer is polished until the first dielectric layer 131b is exposed, and the conductive material layer in the second opening forms the metal block 131 a.

In still other embodiments, two or more redistribution layers 131 may be formed.

In some embodiments, step S42 may include S420 '-S422'.

Step S420': referring to fig. 13, conductive posts 132 are formed on the metal blocks 131a and the first dielectric layer 131b (or the protective layer 111, the second conductive parts 12b of the electrical connectors 12, and the first molding layer 10).

Step S421': a second dielectric layer 132b is formed on the conductive posts 132 and between adjacent conductive posts 132. The second dielectric layer 132b may be made of silicon dioxide or silicon nitride, and is formed by a physical vapor deposition method or a chemical vapor deposition method.

Step S422', polish the second dielectric layer 132b until the conductive pillars 132 are exposed.

In other embodiments, a second dielectric layer 132b is formed between adjacent conductive pillars 132, the upper surface of the second dielectric layer 132b is flush with the upper surface of the conductive pillars 132, and the second dielectric layer 132b is an organic material. The organic material may be polyimide with good fluidity, and is cured after heating.

In still other embodiments, a second molding layer 133 is formed on the conductive posts 132 and between adjacent conductive posts 132, and the second molding layer 133 is thinned until the conductive posts 132 are exposed.

In still other embodiments, a second dielectric layer 132b is formed on the metal block 131a, the second conductive part 12b of each electrical connector 12 and the first molding layer 10, a third opening exposing the metal block 131a is formed in the second dielectric layer 132b, the third opening is filled with a conductive material, and the conductive material is polished until the second dielectric layer 132b is exposed. The conductive material filled in the third opening forms the conductive pillar 132.

a) In an alternative, referring to fig. 12 and 13, the conductive stud 132 is an outer pin 13 a.

b) Alternatively, referring to fig. 14, after exposing the conductive pillar 132, a second anti-oxidation layer 134 is further formed on the conductive pillar 132.

The second anti-oxidation layer 134 may include: b1) tin layer, or b2) nickel layer and gold layer stacked from bottom to top, or b3) nickel layer, palladium layer and gold layer stacked from bottom to top. The second anti-oxidation layer 134 may be formed using an electroplating process. The conductive posts 132 may be made of copper, and the second anti-oxidation layer 134 may prevent oxidation of copper, thereby preventing deterioration of electrical connection performance due to oxidation of copper.

c) Alternatively, after exposing the conductive stud 132, a solder ball is further formed on the conductive stud 132 for flip-chip mounting of the chip package structure 1a (see fig. 1).

After the outer leads are formed, the second support plate 4 is removed as shown in fig. 15.

The second support plate 4 may be removed by conventional methods such as laser lift-off and UV irradiation.

After removing the second support plate 4, a first oxidation resistant layer 121 may be further formed on the exposed first conductive part 12 a. The material and formation method of the first oxidation resistant layer 121 refer to those of the second oxidation resistant layer 134.

Thereafter, referring to step S5 in fig. 3, fig. 15 and fig. 1, the package intermediate structure 1 is cut to form a plurality of chip package structures 1a, and each chip package structure 1a includes one die 11.

Fig. 16 is a top view of an electrical connector in a method for manufacturing a chip package structure according to a second embodiment of the present invention. Referring to fig. 16, the chip package structure in this embodiment is substantially the same as the chip package structure 1a in fig. 1, except that: the connecting portion 12c of the electrical connector 12 is partially removed, the first conductive portion 12a, the connecting portion 12c, and the first sub-conductive portion 120a of the electrical connector 12 are H-shaped in plan view, and the first conductive portion 12a, the connecting portion 12c, and the second sub-conductive portion 120b of the electrical connector 12 are also H-shaped in plan view.

The area where the connecting portion 12c is removed can provide a deformation accommodating space during the expansion and contraction process of the electrical connector 12 and the first plastic package layer 10. Preferably, the size of the first conductive portion 12a is larger than the size of the second conductive portion 12 b.

Accordingly, the manufacturing method of the chip package structure in this embodiment is substantially the same as the manufacturing method of the chip package structure in fig. 1 to 15, and the differences are only that: in step S2, the connecting portion 12c of the provided electrical connector 12 is partially removed, the first conductive portion 12a, the connecting portion 12c, and the first sub-conductive portion 120a of the electrical connector 12 are H-shaped in plan view, and the first conductive portion 12a, the connecting portion 12c, and the second sub-conductive portion 120b of the electrical connector 12 are H-shaped in plan view. The removed portion of material may be formed by at least one of cutting, stamping, etching, embossing.

In some embodiments, in the electrical connector 12, a part of the number of the first conductive portions 12a, the connection portions 12c, and the first sub-conductive portions 120a may be H-shaped in plan view, a part of the number of the first conductive portions 12a, the connection portions 12c, and the first sub-conductive portions 120a may be rectangular in plan view, a part of the number of the first conductive portions 12a, the connection portions 12c, and the second sub-conductive portions 120b may be H-shaped in plan view, and a part of the number of the first conductive portions 12a, the connection portions 12c, and the second sub-conductive portions 120b may be rectangular in plan view.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method for manufacturing a chip packaging structure is characterized by comprising the following steps:

2. The method of claim 1, wherein the plurality of electrical connections are provided on a first support plate.

3. The method of claim 1, wherein the first conductive portion, the connecting portion, and the first sub-conductive portion of the electrical connector are H-shaped; and/or the first conductive part, the connecting part and the second sub-conductive part of the electric connecting piece are H-shaped; and/or the electrical connector is formed by at least one of cutting, stamping, etching and stamping; and/or the first sub-conductive portion comprises two or more.

4. The method for manufacturing a chip package structure according to claim 1, further comprising: and forming a first oxidation resisting layer on the first conductive part of each electric connector exposed out of the first plastic packaging layer.

5. The method of manufacturing a chip package structure according to claim 1, wherein forming a wiring layer on the active surface of each die, the second conductive portion of each electrical connector, and the first molding compound layer comprises:

and forming a conductive convex column on the rewiring layer.

6. The method of claim 5, wherein the redistribution layer comprises two or more layers.

7. The method for manufacturing the chip packaging structure according to claim 5, further comprising: and forming a solder ball on the conductive convex column, wherein the solder ball is an outer pin.

8. The method for manufacturing the chip packaging structure according to claim 5, further comprising: and forming a second anti-oxidation layer on the conductive convex column.

9. The method of claim 5, wherein forming the conductive post on the redistribution layer comprises:

forming a conductive convex column on the metal block of the rewiring layer;

polishing the second dielectric layer until the conductive posts are exposed;

or comprises the following steps:

forming a conductive convex column on the metal block of the rewiring layer;

forming a second dielectric layer between the adjacent conductive convex columns, wherein the upper surfaces of the second dielectric layers are flush with the upper surfaces of the conductive convex columns, and the second dielectric layer is made of an organic material;

or comprises the following steps:

forming a second dielectric layer on the rewiring layer;

polishing the conductive material layer until the second dielectric layer is exposed, wherein the conductive material layer in the third opening forms a conductive convex column;

or comprises the following steps:

10. The method for manufacturing the chip packaging structure according to claim 1, wherein a conductive layer is disposed on the back surface of the die, and/or a conductive adhesive is disposed between the first conductive portion and the back surface of the die.

11. The method for manufacturing a chip package structure according to claim 10, wherein the conductive adhesive comprises a nano-copper/conductive polymer composite.

12. The method of manufacturing a chip package structure according to claim 1, wherein in the step of fixing the active surface of each of the dies to the carrier board, the protective layer has a plurality of first openings therein, a partial number of the first openings expose a partial area of the first inner bonding pads, and a partial number of the first openings expose a partial area of the second inner bonding pads; or forming first openings in the protective layer in the step of forming the circuit layer, wherein part of the first openings expose part of the first inner bonding pads, and part of the first openings expose part of the second inner bonding pads.