阅读说明：本技术 一种具有电磁干扰防护的fowlp封装结构的制备方法 (Preparation method of FOWLP packaging structure with electromagnetic interference protection function ) 是由 汪民 于 2020-12-11 设计创作，主要内容包括：本发明公开了一种具有电磁干扰防护的FOWLP封装结构的制备方法,属于集成电路封装领域。所述制备方法包括：a)在芯片的芯片焊盘上制备导电凸点,芯片背面与载体粘合,制得芯片封装单元；b)在所得芯片封装单元的边缘粘贴金属部件,所述金属部件与所述载体构成防护底座；c)向所得防护底座内进行塑封后,将塑封后的表面进行研磨,研磨至露出导电凸点后,在露出的导电凸点上进行再布线操作和植球操作,制得具有电磁干扰防护的FOWLP封装结构。本发明所述制备方法通过简单高效的工艺方法,无需依赖额外的喷镀或溅射设备,能够有效控制具有电磁干扰防护的FOWLP封装结构的制备成本投入。(The invention discloses a preparation method of an FOWLP packaging structure with electromagnetic interference protection, and belongs to the field of integrated circuit packaging. The preparation method comprises the following steps: a) preparing conductive salient points on a chip bonding pad of a chip, and bonding the back surface of the chip with a carrier to obtain a chip packaging unit; b) adhering a metal part to the edge of the obtained chip packaging unit, wherein the metal part and the carrier form a protective base; c) and after plastic packaging is carried out in the obtained protective base, grinding the surface after the plastic packaging, and after the conductive salient points are exposed, carrying out rewiring operation and ball planting operation on the exposed conductive salient points to prepare the FOWLP packaging structure with electromagnetic interference protection. The preparation method provided by the invention can effectively control the preparation cost investment of the FOWLP packaging structure with electromagnetic interference protection through a simple and efficient process method without depending on additional spraying or sputtering equipment.)

1. A preparation method of an FOWLP packaging structure with electromagnetic interference protection is characterized by comprising the following steps:

a) preparing conductive bumps (5) on a chip bonding pad of a chip (3), and bonding the back surface of the chip (3) with a carrier to obtain a chip packaging unit;

b) adhering a metal part (4) to the edge of the obtained chip packaging unit, wherein the metal part (4) and the carrier form a protective base;

c) and after plastic packaging is carried out in the obtained protective base, grinding the surface after the plastic packaging until the conductive salient points (5) are exposed, and then carrying out rewiring operation and ball mounting operation on the exposed conductive salient points (5) to prepare the FOWLP packaging structure with electromagnetic interference protection.

2. The method for manufacturing a FOWLP package structure with electromagnetic interference protection as recited in claim 1, wherein in step c), the rerouting operation and the ball-mounting operation specifically include the following operations:

firstly, preparing an electroplated layer (8) of a metal circuit on the plastic package surface of the conductive bump (5) exposed by grinding, etching the electroplated layer (8) to obtain a metal circuit pad (9), wherein the metal circuit pad (9) corresponds to the conductive bump (5), then continuously depositing a surface protection layer (6), and finally implanting a package solder ball (7) on the metal circuit pad (9).

3. The method for manufacturing a FOWLP package structure with emi protection as claimed in claim 2, wherein the package solder balls (7) are solder balls or tin-silver alloy balls.

4. A method for manufacturing a FOWLP package structure with electromagnetic interference protection as claimed in claim 1, wherein in step a), the conductive bump (5) is manufactured by a metal plating method or a wire bonding method.

5. A method for manufacturing a FOWLP package with electromagnetic interference protection as claimed in claim 1, wherein the back surface of the chip (3) is bonded to the carrier through the adhesive film (2).

6. The manufacturing method of the FOWLP package structure with electromagnetic interference protection as recited in claim 5, wherein the back surface of the chip (3) is bonded to the carrier in a Face Up manner.

7. The method as claimed in claim 1, wherein the carrier is a metal carrier (1).

8. A method for manufacturing a FOWLP package structure with emi protection as claimed in claim 1, wherein the metal part (4) is made of copper.

9. A method for manufacturing a FOWLP package structure with electromagnetic interference protection as claimed in claim 1, wherein the conductive bump (5) is a metal bump.

10. The method as claimed in claim 9, wherein the metal bump is made of copper or silver alloy.

Technical Field

The invention belongs to the field of integrated circuit packaging, and relates to a preparation method of an FOWLP packaging structure with electromagnetic interference protection.

Background

WLP (wafer level package) has the advantage of small size, but as the functional requirements of chips increase, the pin output will be more, and FOWLP (Fan Out wafer level) can ensure more pin outputs of chips to a certain extent. In addition, with the development of 5G, the shielding protection requirement for the electromagnetic interference of the chip package is higher and higher.

The method comprises the steps of firstly, packaging a wafer by using a wafer surface Down (Chip front Face Down), then, carrying out plastic packaging, removing the adhesive film and the carrier from leaking out of the front Face of the wafer after the plastic packaging is finished, and then, completing the FOWLP packaging structure by using a RDL rewiring process.

The TSMC FOWLP packaging structure is realized by the steps that salient points are obtained on a Chip through an electroplating method, then the front side of the Chip is upwards attached to a carrier, plastic package is carried out, the salient points are leaked out through polishing after the plastic package is finished, pad layout is finished through a subsequent RDL process, balls are planted to obtain the FOWLP packaging structure, if the electromagnetic interference shielding function is to be realized, a metal sputtering or an electromagnetic interference protective layer is required to be coated on the surface of a packaging body, and the specific process operation is complex.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a preparation method of an FOWLP package structure with electromagnetic interference protection. The preparation method provided by the invention is used for preparing the FOWLP packaging structure with electromagnetic interference protection through a simple and efficient process method.

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

the invention discloses a preparation method of an FOWLP packaging structure with electromagnetic interference protection, which comprises the following steps:

a) preparing conductive salient points on a chip bonding pad of a chip, and bonding the back surface of the chip with a carrier to obtain a chip packaging unit;

b) adhering a metal part to the edge of the obtained chip packaging unit, wherein the metal part and the carrier form a protective base;

c) and after plastic packaging is carried out in the obtained protective base, grinding the surface after the plastic packaging, and after the conductive salient points are exposed, carrying out rewiring operation and ball planting operation on the exposed conductive salient points to prepare the FOWLP packaging structure with electromagnetic interference protection.

Preferably, in step c), the rewiring operation and the ball mounting operation specifically include the following operations:

firstly, preparing an electroplated layer of a metal circuit on the plastic package surface with the conductive salient points exposed by grinding, etching the electroplated layer to obtain a metal circuit pad, wherein the metal circuit pad corresponds to the conductive salient points, then continuously depositing a surface protection layer, and finally implanting a package body solder ball on the metal circuit pad.

Further preferably, the package solder is a solder ball or a tin-silver alloy ball.

Preferably, in step a), the conductive bump is prepared by an electro-metal plating method or a wire bonding method.

Preferably, the back surface of the chip is bonded to the carrier by an adhesive film.

Further preferably, the back surface of the chip is bonded with the carrier by adopting a Face Up mode.

Preferably, the carrier is a metal carrier.

Preferably, the metal member is made of copper.

Preferably, the conductive bump is a metal bump.

Further preferably, the material of the metal bump is copper or silver alloy.

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

the invention discloses a preparation method of an FOWLP packaging structure with electromagnetic interference protection, which comprises the steps of preparing conductive salient points on a chip in advance, exposing the conductive salient points through plastic package and grinding, and leading out IO bonding pads on the chip by adopting a conductive salient point leading-out process to realize chip circuit epitaxy; then carrying out surface packaging operation to obtain a packaging structure; in addition, in the preparation method, the metal part is adhered to the edge of the chip packaging unit, so that the metal part and the carrier form a protection base with an electromagnetic interference protection function. Therefore, the preparation method integrates the electromagnetic interference protection metal shell for synchronously preparing the packaging structure in the packaging process, has simple operation process, does not need to depend on additional spraying or sputtering equipment, and can effectively control the preparation cost input of the FOWLP packaging structure with electromagnetic interference protection.

Furthermore, the preparation method adopts a rewiring process to carry out surface packaging operation, and can complete reasonable distribution of the chip output pins.

Furthermore, the conductive bumps are prepared on the chip bonding pads by adopting a metal electroplating method or a Wire Bond method, so that the preparation of the bumps on the surface of the chip can be quickly realized, and particularly, the Wire Bond method has a simple and quick process.

Furthermore, the back of the chip is bonded with the carrier through the adhesive film, so that the process difficulty is reduced, and the production efficiency is improved.

In summary, compared with the existing FOWLP packaging scheme, the preparation method provided by the present invention adopts a simple scheme to prepare the conductive bumps on the chip, for example, the conductive bumps can be prepared by adopting a traditional wire bonding method, and rewiring is realized by combining the plastic packaging and grinding processes in the present invention; meanwhile, the scheme of the invention also integrates the preparation of the peripheral metal protection base of the packaging body, and the FOWLP packaging structure with electromagnetic interference protection is obtained by adopting a synchronous preparation process.

Drawings

FIG. 1 is a schematic diagram of a FOWLP package structure with EMI protection according to the present invention;

FIG. 2 is a schematic diagram of the connection of the conductive bumps on the chip according to the present invention;

FIG. 3 is a schematic view of the protective base according to the present invention;

FIG. 4 is a schematic view of plastic-encapsulated grinding in the present invention;

FIG. 5 is a schematic view of the rewiring operation and ball mounting operation of the present invention; the method comprises the following steps of (a) electroplating process of a metal circuit layer, (b) etching process of the metal circuit, (c) deposition process of a surface protection layer of the metal circuit, and (d) ball planting process.

Wherein: 1-a metal carrier; 2-sticking a film; 3-chip; 4-a metal part; 5, conducting salient points; 6-surface protection layer; 7-package solder balls; 8-electroplating layer; 9-metal wiring pad.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The invention is described in further detail below with reference to the accompanying drawings:

the invention relates to a preparation method of an FOWLP packaging structure with electromagnetic interference protection, which proposes that a conductive bump 5 is prepared on a chip 3 in advance, wherein the preparation method of the conductive bump 5 can be electroplating metal (such as a metal bump formed by metals such as Cu, copper-silver alloy and the like), and can also be prepared by adopting a wafer chip bonding pad Wire Bond (lead bonding) with higher simplicity and higher efficiency, and the material of the conductive bump 5 can be a metal bump formed by metals such as Cu, Ag alloy and the like; through electrically conductive bump 5 on the chip 3, can be fast with simple and easy 3 circuit epitaxy of realization chip, rethread electrically conductive bump 5 realizes carrying out RDL rewiring on the basis of epitaxial circuit, realizes the FOWLP packaging body. As shown in fig. 1; meanwhile, fig. 1 further includes a carrier and a metal part 4, specifically, the carrier is a metal carrier 1, and the metal carrier 1 and the metal part 4 are attached to the surface of the package body to form a protection base, which can serve as an EMI (electromagnetic interference) protection effect of the package body; thus, a FOWLP package structure with electromagnetic interference protection is prepared, as shown in fig. 1.

Specifically, the metal member 4 is made of Cu.

The preparation method of the FOWLP packaging structure with electromagnetic interference protection specifically comprises the following steps:

step 1: as shown in fig. 2, conductive bumps 5 are formed on the chip pads of the chip 3, preferably by plating metal or by Wire Bond; the lead bonding method can lead out the circuit efficiently and quickly;

step 2: sticking the chip 3 with the prepared conductive salient points 5 to a carrier by adopting a Face Up mode through an adhesive film 2 to prepare a chip packaging unit; the carrier can be made of metal, and is preferably a metal carrier 1; meanwhile, a metal part 4 is pasted on the edge of the obtained chip packaging unit, as shown in fig. 3;

and step 3: carrying out plastic packaging by adopting a pressing and injection molding mode, as shown in fig. 4, and carrying out surface grinding on the surface after the plastic packaging to enable the conductive salient points 5 to be exposed out of the surface after the plastic packaging;

and 4, step 4: and (3) performing metal circuit preparation operation on the exposed conductive bumps (5) by adopting an RDL rewiring process, and then performing ball mounting operation to obtain the FOWLP packaging structure with electromagnetic interference protection. The RDL rewiring process is adopted to prepare a rewiring layer 6, conductive bumps 5 prepared on the surface of a chip 3 are distributed on the whole surface of a package body, and the whole process is shown in figure 5, wherein (a) shows that a metal circuit layer is electroplated on the surface of the package body to form an electroplated layer 8, (b) shows that a metal circuit on the surface of the package body is obtained by adopting an etching process to form a metal circuit pad 9, (c) shows that a metal circuit surface protective layer is obtained on the surface of the repackage body by adopting a deposition process, (d) shows that balls are planted on the part of the surface of the package body corresponding to pin output to form a package body solder ball 7, and the material of the package body solder ball 7 can be a tin-silver alloy ball or a;

in which, corresponding to (c) and (d) in fig. 5, ball-mounting cutting is performed, so as to prepare the FOWLP package structure with electromagnetic interference protection. Specifically, in the FOWLP package structure with electromagnetic interference protection shown in fig. 5(d), the metal component 4 in the plastic package body is separated and bonded to the side surface of the package body; the metal carrier 1 on the back side is also cut and adhered to the back side of the chip 3, so as to obtain the FOWLP package structure with electromagnetic interference protection shown in fig. 1.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.