阅读说明：本技术 一种二次塑封封装结构及其制作方法 (Secondary plastic package structure and manufacturing method thereof ) 是由 孙鹏 曹立强 徐成 耿菲 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种二次塑封封装结构,包括：转接板；导电通孔,所述导电硅通孔贯穿所述转接板；第一芯片,所述第一芯片倒装设置在所述转接板的正面,电连接至所述导电通孔；第一塑封层,所述第一塑封层设置在所述转接板的正面,四面环绕包覆所述第一芯片,且所述第一芯片的背面从所述第一塑封层中漏出；第二塑封层,所述第二塑封层设置在所述转接板的正面,四面环绕包覆所述第一塑封层,所述第二塑封层与所述第一塑封层相对于所述转接板具有不同的内应力；金属布线层,所述金属布线层设置在所述转接板的背面,电连接至所述导电通孔；以及外接焊球,所述外接焊球电连接至金属布线层。(The invention discloses a secondary plastic package structure, which comprises: an adapter plate; the conductive through silicon hole penetrates through the adapter plate; the first chip is arranged on the front surface of the adapter plate in a flip-chip mode and is electrically connected to the conductive through hole; the first plastic package layer is arranged on the front surface of the adapter plate, the first chip is wrapped around the four surfaces of the first plastic package layer, and the back surface of the first chip leaks out of the first plastic package layer; the second plastic package layer is arranged on the front surface of the adapter plate, the first plastic package layer is wrapped around the four surfaces of the second plastic package layer, and the second plastic package layer and the first plastic package layer have different internal stresses relative to the adapter plate; the metal wiring layer is arranged on the back surface of the adapter plate and is electrically connected to the conductive through hole; and an external solder ball electrically connected to the metal wiring layer.)

1. A secondary plastic package structure comprises:

an adapter plate;

the conductive through silicon hole penetrates through the adapter plate;

the first chip is arranged on the front surface of the adapter plate in a flip-chip mode and is electrically connected to the conductive through hole;

the first plastic package layer is arranged on the front surface of the adapter plate, the first chip is wrapped around the four surfaces of the first plastic package layer, and the back surface of the first chip leaks out of the first plastic package layer;

the second plastic package layer is arranged on the front surface of the adapter plate, the first plastic package layer is wrapped around the four surfaces of the second plastic package layer, and the second plastic package layer and the first plastic package layer have different internal stresses relative to the adapter plate;

the metal wiring layer is arranged on the back surface of the adapter plate and is electrically connected to the conductive through hole; and

and the external solder balls are electrically connected to the metal wiring layer.

2. The secondary plastic package structure of claim 1, further comprising a second chip flip-chip disposed on the front surface of the interposer and electrically connected to the conductive vias.

3. The secondary plastic package structure of claim 1 or 2, wherein a redistribution layer is further disposed on the front surface of the interposer, the redistribution layer is electrically connected to the conductive through hole, and the first chip and/or the second chip are flip-chip bonded to corresponding chip pads on the redistribution layer.

4. The secondary plastic package structure of claim 1 or 3, wherein the metal wiring layer and/or the redistribution wiring layer has M metal wiring layers, wherein M ≧ 2.

5. The secondary plastic package assembly of claim 1, wherein the first plastic package layer has a tensile stress with respect to the interposer, and the second plastic package layer has a compressive stress with respect to the interposer.

6. The secondary plastic package assembly of claim 1, wherein the first plastic package layer has a compressive stress with respect to the interposer, and the second plastic package layer has a tensile stress with respect to the interposer.

7. A secondary plastic package structure according to claim 1, wherein the external solder balls are copper pillars or lead-free solder balls.

8. A manufacturing method of a secondary plastic package structure comprises the following steps:

providing a wafer with a non-exposed conductive silicon through hole;

the front surface of the wafer is pasted with a first chip and a second chip;

forming a first plastic packaging layer covering the first chip and the second chip on the front surface of the wafer;

thinning the first plastic packaging layer, leaking the back surfaces of the first chip and the second chip, and dividing the thinned first plastic packaging layer to form a plurality of first plastic packaging layer units;

forming a second plastic packaging layer covering the first plastic packaging layer, the back surface of the first chip and the back surface of the second chip on the front surface of the wafer;

thinning the second plastic package layer to leak the first plastic package layer, the back surface of the first chip and the back surface of the second chip;

temporarily bonding a carrier plate on the second plastic packaging layer, the back surface of the first chip and the back surface of the second chip;

thinning the back of the wafer to realize the exposure of the back of the conductive silicon through hole;

forming a metal wiring layer and an external solder ball on the back of the thinned wafer;

removing the temporary bonding carrier plate; and

and (5) cutting to obtain a secondary plastic package structure.

9. The method for manufacturing a secondary plastic package structure according to claim 8, wherein the first plastic package layer and the second plastic package layer have different internal stresses with respect to the wafer, and the second plastic package layer has compressive stress with respect to the interposer.

10. The method for manufacturing a secondary plastic package structure according to claim 9, wherein the first plastic package layer has a tensile stress with respect to the wafer, and the second plastic package layer has a compressive stress with respect to the wafer; or the first plastic packaging layer has compressive stress relative to the wafer, and the second plastic packaging layer has tensile stress relative to the wafer.

Technical Field

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

Background

With the demand for light weight and miniaturization of electronic products, IC chip packages tend to be thin and miniaturized. The three-dimensional system integrated package utilizing the adapter plate can better meet the requirement.

However, when the conventional wafer-level interposer is stacked and packaged three-dimensionally, the interposer with the conductive through-silicon-vias is subjected to integral plastic packaging after chips are mounted thereon. At this time, local thermal stress is more easily generated due to mismatch of Coefficient of Thermal Expansion (CTE) among the conventional plastic package IC chip, the interposer and the plastic package material, so that surface warpage of the package is generated. The excessive warping not only increases the difficulty of subsequent processes (such as rib cutting, forming and the like) after plastic packaging, but also obviously increases the process reject ratio when the finished product of the plastic packaged IC chip is assembled by SMT, and is easy to generate serious device failure problems such as chip and packaging cracks and the like.

Aiming at the problem of wafer warping in the existing three-dimensional stacking packaging based on the wafer-level adapter plate, the invention provides a secondary plastic packaging structure and a manufacturing method thereof, which can obviously improve the problems in the prior art.

Disclosure of Invention

Aiming at the problem of wafer warpage in the existing three-dimensional stack packaging based on a wafer-level adapter plate, according to one embodiment of the invention, a secondary plastic package structure is provided, which comprises:

an adapter plate;

the conductive through silicon hole penetrates through the adapter plate;

the first chip is arranged on the front surface of the adapter plate in a flip-chip mode and is electrically connected to the conductive through hole;

the first plastic package layer is arranged on the front surface of the adapter plate, the first chip is wrapped around the four surfaces of the first plastic package layer, and the back surface of the first chip leaks out of the first plastic package layer;

the second plastic package layer is arranged on the front surface of the adapter plate, the first plastic package layer is wrapped around the four surfaces of the second plastic package layer, and the second plastic package layer and the first plastic package layer have different internal stresses relative to the adapter plate;

the metal wiring layer is arranged on the back surface of the adapter plate and is electrically connected to the conductive through hole; and

and the external solder balls are electrically connected to the metal wiring layer.

In an embodiment of the invention, the secondary plastic package structure further includes a second chip, and the second chip is flip-chip mounted on the front surface of the interposer and electrically connected to the conductive through hole.

In an embodiment of the invention, the interposer front surface is further provided with a re-layout wiring layer, the re-layout wiring layer is electrically connected to the conductive via, and the first chip and/or the second chip are flip-chip bonded to corresponding chip pads on the re-layout wiring layer.

In one embodiment of the invention, the metal wiring layer and/or the re-layout wiring layer has M metal wiring layers, wherein M ≧ 2.

In one embodiment of the present invention, the first molding compound layer has a tensile stress relative to the interposer, and the second molding compound layer has a compressive stress relative to the interposer.

In one embodiment of the present invention, the first molding compound layer has a compressive stress relative to the interposer, and the second molding compound layer has a tensile stress relative to the interposer.

In one embodiment of the present invention, the external solder balls are copper pillars or lead-free solder balls.

According to another embodiment of the present invention, a method for manufacturing a secondary plastic package structure is provided, including:

providing a wafer with a non-exposed conductive silicon through hole;

the front surface of the wafer is pasted with a first chip and a second chip;

forming a first plastic packaging layer covering the first chip and the second chip on the front surface of the wafer;

thinning the first plastic packaging layer, leaking the back surfaces of the first chip and the second chip, and dividing the thinned first plastic packaging layer to form a plurality of first plastic packaging layer units;

forming a second plastic packaging layer covering the first plastic packaging layer, the back surface of the first chip and the back surface of the second chip on the front surface of the wafer;

thinning the second plastic package layer to leak the first plastic package layer, the back surface of the first chip and the back surface of the second chip;

temporarily bonding a carrier plate on the second plastic packaging layer, the back surface of the first chip and the back surface of the second chip;

thinning the back of the wafer to realize the exposure of the back of the conductive silicon through hole;

forming a metal wiring layer and an external solder ball on the back of the thinned wafer;

removing the temporary bonding carrier plate; and

and (5) cutting to obtain a secondary plastic package structure.

In another embodiment of the present invention, the first molding compound and the second molding compound have different internal stresses relative to the wafer, and the second molding compound has compressive stress relative to the interposer.

In another embodiment of the present invention, the first molding compound layer has a tensile stress relative to the wafer, and the second molding compound layer has a compressive stress relative to the wafer; or the first plastic packaging layer has compressive stress relative to the wafer, and the second plastic packaging layer has tensile stress relative to the wafer.

The invention provides a secondary plastic package packaging structure and a manufacturing method thereof, wherein first plastic package is carried out after chip surface mounting is finished on a wafer-level adapter plate, a plastic package layer is thinned and a plastic package area is cut after plastic package, the whole plastic package layer is divided into plastic package units, and the wafer warpage after the first plastic package is reduced; and then carrying out secondary plastic packaging on the wafer on the basis of the primary plastic packaging, filling the surface of the primary plastic packaging and the cutting channel with a plastic packaging material, wrapping the whole wafer by a secondary plastic packaging layer, and finally reducing the warpage of the wafer after the plastic packaging by thinning the second plastic packaging layer, thereby facilitating the subsequent bonding and back process. In addition, one of the key points of the technical scheme of the invention is that the second plastic package material and the first plastic package material have different plastic package internal stresses relative to the wafer-level adapter plate by selecting proper first and second plastic package materials, so that the internal stress of the whole plastic package reconstruction structure can be at least partially balanced, and the warping problem of the wafer after plastic package is remarkably reduced. According to the secondary plastic package structure and the manufacturing method thereof, a mode of twice plastic package is adopted, the first plastic package is used for filling and wrapping the chip, the plastic package area is small, the chip patch area is mainly wrapped, the wafer warpage after the plastic package is reduced by reducing the plastic package area, and the plastic package on the back of the chip is removed by plastic package thinning, so that the wafer warpage is controlled within a certain range; the second plastic package selects a proper plastic package material, so that warping caused by mismatching of the first plastic package material is balanced, the whole wafer is wrapped in the plastic package area, the edge of the wafer is protected, and the wafer is prevented from being damaged by a subsequent process; through the balance of the two times of plastic packaging, the wafer is less warped after the plastic packaging and thinning, and the subsequent bonding process and the back process are utilized.

Drawings

To further clarify the above and other advantages and features of embodiments of the present invention, a more particular description of embodiments of the invention will be rendered by reference to the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. In the drawings, the same or corresponding parts will be denoted by the same or similar reference numerals for clarity.

Fig. 1 shows a schematic cross-sectional view of a secondary plastic package structure 100 according to an embodiment of the invention.

Fig. 2A to 2K are schematic cross-sectional views illustrating a process of forming the secondary plastic package structure 100 according to an embodiment of the invention.

Fig. 3 illustrates a flow chart 300 for forming such a secondary plastic encapsulated package structure 100, in accordance with an embodiment of the present invention.

Detailed Description

In the following description, the invention is described with reference to various embodiments. One skilled in the relevant art will recognize, however, that the embodiments may be practiced without one or more of the specific details, or with other alternative and/or additional methods, materials, or components. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of embodiments of the invention. Similarly, for purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the embodiments of the invention. However, the invention may be practiced without specific details. Further, it should be understood that the embodiments shown in the figures are illustrative representations and are not necessarily drawn to scale.

Reference in the specification to "one embodiment" or "the embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

It should be noted that, in the embodiments of the present invention, the process steps are described in a specific order, however, this is only for convenience of distinguishing the steps, and the order of the steps is not limited, and in different embodiments of the present invention, the order of the steps may be adjusted according to the adjustment of the process.

The invention provides a secondary plastic package packaging structure and a manufacturing method thereof, wherein first plastic package is carried out after chip surface mounting is finished on a wafer-level adapter plate, a plastic package layer is thinned and a plastic package area is cut after plastic package, the whole plastic package layer is divided into plastic package units, and the wafer warpage after the first plastic package is reduced; and then carrying out secondary plastic packaging on the wafer on the basis of the primary plastic packaging, filling the surface of the primary plastic packaging and the cutting channel with a plastic packaging material, wrapping the whole wafer by a secondary plastic packaging layer, and finally reducing the warpage of the wafer after the plastic packaging by thinning the second plastic packaging layer, thereby facilitating the subsequent bonding and back process. In addition, one of the key points of the technical scheme of the invention is that the second plastic package material and the first plastic package material have different plastic package internal stresses relative to the wafer-level adapter plate by selecting proper first and second plastic package materials, so that the internal stress of the whole plastic package reconstruction structure can be at least partially balanced, and the warping problem of the wafer after plastic package is remarkably reduced. According to the secondary plastic package structure and the manufacturing method thereof, a mode of twice plastic package is adopted, the first plastic package is used for filling and wrapping the chip, the plastic package area is small, the chip patch area is mainly wrapped, the wafer warpage after the plastic package is reduced by reducing the plastic package area, and the plastic package on the back of the chip is removed by plastic package thinning, so that the wafer warpage is controlled within a certain range; the second plastic package selects a proper plastic package material, so that warping caused by mismatching of the first plastic package material is balanced, the whole wafer is wrapped in the plastic package area, the edge of the wafer is protected, and the wafer is prevented from being damaged by a subsequent process; through the balance of the two times of plastic packaging, the wafer is less warped after the plastic packaging and thinning, and the subsequent bonding process and the back process are utilized.

A secondary plastic package structure according to an embodiment of the invention is described in detail below with reference to fig. 1. Fig. 1 shows a schematic cross-sectional view of a secondary plastic package structure 100 according to an embodiment of the invention. As shown in fig. 1, the secondary plastic package structure 100 further includes an interposer 110, a conductive through-silicon via 120, a first chip 130, a second chip 140, a first plastic package layer 150, a second plastic package layer 160, a metal wiring layer 170, and external solder balls 180.

The interposer 110 is a supporting structure of the secondary plastic package structure 100, and is typically a silicon interposer. In one embodiment of the present invention, the interposer 110 is a wafer level silicon interposer having a thickness of about 50 microns to about 150 microns. In another embodiment of the present invention, the interposer 110 may also be a PCB substrate or a glass substrate.

The conductive through-silicon-via 120 penetrates the interposer 110. In an embodiment of the present invention, the conductive through silicon via 120 is formed by TSV via, conductive metal filling, and backside exposure, and further, the conductive metal may be copper.

The first chip 130 is flip-chip bonded to the front surface of the interposer 110. In an embodiment of the present invention, the first chip 130 may be a logic chip such as a processor, an FPGA, an MCU, etc., or a memory chip such as an EPROM, a FLASH, a DRAM, etc., or a radio frequency chip, a MEMS sensor, or other discrete devices. In another embodiment of the present invention, the first chip 130 is flip-chip bonded to the front surface of the interposer 110 through a bonding structure 131 such as a BGA solder ball or a conductive copper pillar disposed on the front surface of the first chip 130, and electrically connected to the conductive through silicon via 120, and an underfill 132 is further disposed between the first chip 130 and the interposer for insulation and mechanical protection. In yet another embodiment of the present invention, the front surface of the interposer 110 may further include one or more metal wiring layers, and a chip pad (not shown) is disposed on the upper metal wiring layer, and the first chip 130 is flip-chip bonded on the corresponding chip pad.

The second chip 140 is flip-chip bonded to the front surface of the interposer 110, similar to the first chip. In an embodiment of the present invention, the second chip 140 may be a logic chip such as a processor, an FPGA, an MCU, or the like, a memory chip such as an EPROM, a FLASH, a DRAM, or a radio frequency chip, a MEMS sensor, or other discrete devices, and the second chip 140 may be the same chip as the first chip or a different chip. In another embodiment of the present invention, the second chip 140 is flip-chip bonded to the corresponding position on the front surface of the interposer 110 through a bonding structure 141 such as a BGA solder ball or a conductive copper pillar disposed on the front surface of the second chip 140, and electrically connected to the conductive through silicon via 120, and an underfill 142 is further disposed between the second chip 140 and the interposer for insulation and mechanical protection. In yet another embodiment of the present invention, the front surface of the interposer 110 may further include one or more metal wiring layers, a chip pad (not shown) is disposed on the upper metal wiring layer, and the second chip 140 is flip-chip bonded on the corresponding chip pad.

The first molding compound layer 150 is disposed on the front surface of the interposer 110 and surrounds the first chip 130 and the second chip 140. In one embodiment of the present invention, the first mold layer 150 is disposed only near the chip areas of the first and second chips 130 and 140, and the back surfaces of the first and second chips 130 and 140 leak from the first mold layer 150.

The second plastic package layer 160 is disposed on the front surface of the interposer 110 and entirely surrounds and wraps the first plastic package layer 150, wherein the plastic package material of the second plastic package layer 160 and the plastic package material of the first plastic package layer 150 have different plastic package internal stresses relative to the interposer 110 and/or the chip, so that the internal stresses of the whole plastic package reconfiguration package structure can be at least partially balanced, and the warpage of the wafer after plastic package is reduced. In an embodiment of the present invention, the plastic molding material of the first plastic molding layer 150 has a tensile stress with respect to the interposer 110 after plastic molding, and the plastic molding material of the second plastic molding layer 160 has a compressive stress with respect to the interposer 110 after plastic molding, so as to perform a stress balancing function.

A metal wiring layer 170 is disposed on the back surface of the interposer 110 and electrically connected to the conductive through-silicon-vias 120. In an embodiment of the present invention, the number of metal layers of the metal wiring layer 170 may be a single layer or multiple layers, wherein an external pad is further disposed on the outermost layer, and a dielectric layer 171 is further disposed between metal wirings of the same layer and between adjacent metal layers.

The external solder balls 180 are electrically connected to the metal wiring layer 170, and serve as electrical and/or signal connections for the package structure to an external system.

The process of forming the secondary plastic package structure 100 is described in detail below with reference to fig. 2A to 2K and fig. 3. Fig. 2A to 2K are schematic cross-sectional views illustrating a process of forming such a secondary plastic package structure 100 according to an embodiment of the invention; fig. 3 illustrates a flow chart 300 for forming such a secondary plastic encapsulated package structure 100, in accordance with an embodiment of the present invention.

First, in step 301, as shown in fig. 2A, a wafer 210 with non-exposed conductive through silicon vias 220 is provided. Wherein, the wafer 210 may be a 200mm or 300mm silicon wafer, and the thickness is about 150um to 1000 um; the conductive through silicon vias 220 are blind vias that do not penetrate the wafer 210, and the filling metal is mainly copper, and the depth/height thereof is about 50um to 150 um. In an embodiment of the present invention, the sidewall of the conductive through silicon via 220 contacting the wafer 210 may further have a barrier metal layer to prevent copper contamination of the wafer 210, wherein the barrier metal layer may be titanium nitride, titanium, chromium, or the like.

Next, in step 302, as shown in fig. 2B, the first chip 230 and the second chip 240 are mounted on the front surface of the wafer 210. In one embodiment of the present invention, the first chip 230 and/or the second chip 240 are flip-chip bonded on the front side of the wafer 210 by the first chip bonding structure 231 and/or the second chip bonding structure 241 disposed on the first chip 230 and/or the second chip 240, and the first chip bonding structure 231 and/or the second chip bonding structure 241 are electrically connected with the conductive through silicon via 220. In a further embodiment of the present invention, a first underfill 232 and/or a second underfill 242 are further disposed between the first chip 230 and/or the second chip 240 and the wafer 210. In a further embodiment of the present invention, the front surface of the wafer 210 is further provided with a metal wiring layer (not shown), and the first chip 230 and the second chip 240 are flip-chip bonded to corresponding chip pads of the metal wiring layer.

Then, in step 303, as shown in fig. 2C, a first molding compound layer 250 covering the first chip 230 and the second chip 240 is formed on the front surface of the wafer 210. The material of the first molding compound layer 250 may be conventional molding compound such as resin, or specially modified, so that the molding compound has a specific stress with respect to the wafer 210.

Next, in step 304, as shown in fig. 2D, the first molding compound layer 250 is thinned, the back surfaces of the first chip 230 and the second chip 240 are exposed, and the thinned first molding compound layer 250 is divided to form a plurality of first molding compound layer units. In one embodiment of the invention, the segmentation may be performed by etching, photolithographic etching, mechanical grooving, or the like.

Then, in step 305, as shown in fig. 2E, a second molding compound layer 260 covering the first molding compound layer 250 and the back surfaces of the first chip 230 and the second chip 240 is formed on the front surface of the wafer 210. The plastic package material of the second plastic package layer 260 and the plastic package material of the first plastic package layer 250 have different internal stresses relative to the wafer 210, so that the internal stress of the whole plastic package reconfiguration packaging structure can be at least partially balanced, and the warping of the wafer after plastic package is reduced. In an embodiment of the invention, the plastic packaging material of the first plastic packaging layer 250 has a tensile stress relative to the wafer 210 after plastic packaging, and the plastic packaging material of the second plastic packaging layer 260 has a compressive stress relative to the wafer 210 after plastic packaging, so that a stress balance effect can be achieved. .

Next, in step 306, as shown in fig. 2F, thinning the second molding compound 260 leaks out of the first molding compound 250 and the back surfaces of the first chip 230 and the second chip 240. In one embodiment of the invention, the corresponding thinning may be performed by mechanical grinding in combination with a Chemical Mechanical Polishing (CMP) process.

Then, in step 307, as shown in fig. 2G, a carrier plate 270 is temporarily bonded to the second molding layer 260 and the back surfaces of the first chip 230 and the second chip 240. In an embodiment of the present invention, the carrier 270 is a light-transmitting carrier, and the carrier 270 is bonded to the back surfaces of the second molding layer 260 and the first and second chips 230 and 240 by a laser detachable bonding material.

Next, in step 308, as shown in fig. 2H, the back surface of the wafer 210 is thinned, so as to expose the back surface of the conductive through silicon via 220. In one embodiment of the present invention, the back side thinning of the wafer 210 is achieved by a mechanical thinning combined with a Chemical Mechanical Polishing (CMP) process.

Then, in step 309, as shown in fig. 2I, a metal wiring layer 280 and external solder balls 290 are formed on the back side of the thinned wafer 210. In one embodiment of the present invention, a single-layer or multi-layer metal wiring layer 280 is formed by patterned plating, a dielectric layer 285 is further formed between metal lines of the same layer and between adjacent metal layers to perform an insulating and mechanical supporting function, and an external connection pad (not shown) is further formed in the outermost metal wiring layer 280, and an external connection solder ball 290 is formed outside the external connection pad. In another embodiment of the present invention, the external solder ball 290 may be a lead-free solder ball formed by electroplating, reflow process or ball-mounting process, or may be a conductive copper pillar formed by electroplating process.

Next, at step 310, the temporary bond carrier 270 is removed, as shown in fig. 2J. In an embodiment of the present invention, the carrier 270 is a transparent carrier, and is temporarily bonded to the back of the plastic package layer and the chip by a detachable bonding adhesive, and the carrier 270 is peeled off by laser irradiation, and then the bonding adhesive is removed by a cleaning process.

Finally, in step 311, as shown in fig. 2K, the secondary plastic package structure is obtained by dividing.

According to the secondary plastic package structure and the manufacturing method thereof, firstly, after chip mounting is completed on the wafer-level adapter plate, primary plastic package is performed, thinning of a plastic package layer and cutting of a plastic package area are performed after plastic package, the whole plastic package layer is divided into plastic package units, and wafer warping after primary plastic package is reduced; and then carrying out secondary plastic packaging on the wafer on the basis of the primary plastic packaging, filling the surface of the primary plastic packaging and the cutting channel with a plastic packaging material, wrapping the whole wafer by a secondary plastic packaging layer, and finally reducing the warpage of the wafer after the plastic packaging by thinning the second plastic packaging layer, thereby facilitating the subsequent bonding and back process. In addition, one of the key points of the technical scheme of the invention is that the second plastic package material and the first plastic package material have different plastic package internal stresses relative to the wafer-level adapter plate by selecting proper first and second plastic package materials, so that the internal stress of the whole plastic package reconstruction structure can be at least partially balanced, and the warping problem of the wafer after plastic package is remarkably reduced. According to the secondary plastic package structure and the manufacturing method thereof, a mode of twice plastic package is adopted, the first plastic package is used for filling and wrapping the chip, the plastic package area is small, the chip patch area is mainly wrapped, the wafer warpage after the plastic package is reduced by reducing the plastic package area, and the plastic package on the back of the chip is removed by plastic package thinning, so that the wafer warpage is controlled within a certain range; the second plastic package selects a proper plastic package material, so that warping caused by mismatching of the first plastic package material is balanced, the whole wafer is wrapped in the plastic package area, the edge of the wafer is protected, and the wafer is prevented from being damaged by a subsequent process; through the balance of the two times of plastic packaging, the wafer is less warped after the plastic packaging and thinning, and the subsequent bonding process and the back process are utilized.