Preparation method of fan-out type stacked packaging structure and fan-out type stacked packaging structure

Abstract

The invention discloses a fan-out type stacked packaging structure preparation method and structure, and relates to the technical field of chip packaging, and the method comprises the steps: preparing a glass substrate, and punching a plurality of through holes in the glass substrate; filling the through holes with metal to form metal columns, and flattening the surface of the glass substrate after metal filling; cutting the glass substrate into a plurality of glass substrate units, and arranging the first bare chip and each glass substrate unit between the two rewiring layers on the substrate layer; and inversely mounting a second bare chip on the upper rewiring layer, carrying out bottom filling between the second bare chip and the integral structure, then packaging and grinding the bare chips in sequence, and finally removing a new substrate layer. The fan-out stacked packaging structure solves the problems that copper columns of an existing fan-out stacked packaging structure are prone to collapse, and the quality of through holes cannot be independently tested before assembly. According to the invention, the stability and the yield of the fan-out stacked packaging structure are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging, and particularly to a method for preparing a fan-out stacked packaging structure and the structure thereof. Background Art

[0002] In the existing fan-out stacked packaging structure, TMV copper pillars are usually used for packaging inside. During the packaging process, due to high-temperature pressing and injection molding, the copper pillars may collapse, deform or have poor contact due to mechanical stress or thermal expansion. In addition, since the TMV copper pillars are completed synchronously with the chip packaging, it is impossible to separately test the quality of the TMV copper pillar through holes before assembly. If there are defects in the through holes, such as open circuits or short circuits, they can only be detected after the packaging is completed. At this time, the entire package cannot be repaired, resulting in the entire package being a defective product.

[0003] Therefore, a method for preparing a fan-out stacked packaging structure and the structure thereof are developed to solve the above problems. Summary of the Invention

[0004] The present invention provides a method for preparing a fan-out stacked packaging structure and the structure thereof to solve the problems that the copper pillars of the existing fan-out stacked packaging structure are prone to collapse and the quality of the through holes cannot be separately tested before assembly.

[0005] The present invention achieves the above object through the following technical solutions: A method for preparing a fan-out stacked packaging structure of the present invention includes: Preparing a glass substrate and drilling a plurality of through holes in the glass substrate; Filling each of the through holes with metal to form metal pillars, and then planarizing the surface of the glass substrate filled with metal; Cutting the glass substrate into a plurality of glass substrate units, and arranging a first bare chip and each glass substrate unit between two layers of redistribution layers on a substrate layer; Flip-chip bonding a second bare chip on the upper redistribution layer, and performing underfill between the second bare chip and the overall structure. Then, encapsulating and grinding the bare chips in sequence, and finally removing the new substrate layer.

[0006] Further, solder balls are connected to the lower redistribution layer at the bottom of the overall structure after removing the substrate layer.

[0007] Further, the overall structure after removing the substrate layer is cut, integrated with passive devices, and singulated.

[0008] Further, cutting the glass substrate into a plurality of glass substrate units, and arranging a first bare chip and each glass substrate unit between two layers of redistribution layers on a substrate layer includes: Make solder balls on the bottom surface of the metal posts, and then cut the glass substrate with the solder balls made thereon into a plurality of glass substrate units; Prepare a substrate layer, which includes a glass plate layer, an antireflection coating, and a physically vapor deposited metal layer arranged from bottom to top; Set a first redistribution layer on the upper surface of the substrate layer, arrange each glass substrate unit on the first redistribution layer through solder balls, and set a first bare chip on the first redistribution layer through flip-chip bonding technology; Encapsulate and grind the first bare chip and all glass substrate units; Set a second redistribution layer on the upper surface of the ground overall structure, then flip the overall structure and remove the substrate layer, and then set the lower surface of the flipped overall structure on a new substrate layer.

[0009] Further, flip the second bare chip on the first redistribution layer of the flipped overall structure, perform underfill between the second bare chip and the overall structure, then encapsulate and grind the bare chips in sequence, and finally remove the new substrate layer.

[0010] Further, cut the glass substrate into a plurality of glass substrate units, and arrange the first bare chip and each glass substrate unit between two redistribution layers on the substrate layer, including: Cut the glass substrate into a plurality of glass substrate units; Prepare a substrate layer, which includes a glass plate layer and an antireflection coating arranged from bottom to top; Set the first bare chip and each glass substrate unit on the substrate layer, and bond the back of the first bare chip and the lower surface of each glass substrate unit to the upper surface of the substrate layer; Encapsulate and grind the first bare chip and each glass substrate; Set a first redistribution layer on the upper surface of the ground overall structure; Flip the overall structure after setting the first redistribution layer, and then remove the substrate layer; Set the lower surface of the flipped overall structure on a new substrate layer, and grind or planarize the upper surface of the flipped overall structure; Set a second redistribution layer on the upper surface of the planarized or ground overall structure.

[0011] Further, flip the second bare chip on the second redistribution layer, perform underfill between the second bare chip and the overall structure, then encapsulate and grind the bare chips in sequence, and finally remove the new substrate layer.

[0012] The present invention also provides a fan-out stacked packaging structure, and the fan-out stacked packaging structure is obtained by preparing according to any one of the preparation methods of the fan-out stacked packaging structure.

[0013] The beneficial effects of the present invention are as follows: The preparation method and structure of the fan-out stacked packaging structure proposed by the present invention solve the problems that the copper pillars in the existing fan-out stacked packaging structure are prone to collapse and the via hole quality cannot be tested separately before assembly. The stability and yield rate of the fan-out stacked packaging structure are improved by the present invention. Description of the Drawings

[0014] Figure 1 It is one of the method flowcharts of the preparation method of the fan-out stacked packaging structure of the present application.

[0015] Figure 2 It is the second method flowchart of the preparation method of the fan-out stacked packaging structure of the present application.

[0016] Figure 3 It is the structural schematic diagram of the fan-out stacked packaging structure of the present application.

[0017] In the figure: 1 - the first redistribution layer; 2 - the second redistribution layer; 3 - the glass substrate unit; 4 - the first bare chip; 5 - the second bare chip; 6 - the solder ball. Detailed Embodiments

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the present invention claimed, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0020] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0021] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "inner", "outer", "left", "right", etc. are based on the orientation or positional relationships shown in the drawings, or the orientation or positional relationships in which the inventive product is customarily placed during use, or the orientation or positional relationships commonly understood by those skilled in the art. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention.

[0022] In addition, the terms "first", "second", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0023] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, terms such as "set", "connect" should be understood in a broad sense. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] The following will describe in detail the specific embodiments of the present invention with reference to the drawings.

[0025] As Figure 1 and Figure 2 shown, a method and a structure for manufacturing a fan-out stacked package structure include: A method for manufacturing a fan-out stacked package structure according to the present invention is characterized by including: Prepare a glass substrate, and punch a plurality of through holes on the glass substrate, and the through holes are realized by laser drilling; Fill each of the through holes with metal to form metal pillars, and then planarize the surface of the glass substrate after metal filling. Metal filling is carried out by electroplating or chemical plating, and chemical plating is electroless plating; Cut the glass substrate into a plurality of glass substrate units, and arrange the first bare chip and each glass substrate unit between two layers of redistribution layers on the substrate layer; Flip-chip the second bare chip on the upper redistribution layer, and perform underfill between the second bare chip and the overall structure, and then encapsulate and grind the bare chips in sequence, and finally remove the new substrate layer.

[0026] In one embodiment, solder balls are connected to the lower redistribution layer at the bottom of the overall structure after removing the substrate layer.

[0027] In one embodiment, the overall structure after removing the substrate layer is cut, integrated with passive devices, and singulated.

[0028] In the specific implementation manners, the present application provides two ways to dispose the first bare chip and each glass substrate unit between two layers of redistribution layers: The first way is as Figure 1 shown. The glass substrate is cut into a plurality of glass substrate units, and the first bare chip and each glass substrate unit are disposed between two layers of redistribution layers on the substrate layer, including: Bump balls are fabricated on the bottom surface of the metal pillars, and then the glass substrate after fabricating the bump balls is cut into a plurality of glass substrate units; Prepare a substrate layer, which includes a glass plate layer, an anti-reflection coating, and a physical vapor deposition metal layer disposed from bottom to top; Dispose a first redistribution layer on the upper surface of the substrate layer, dispose each glass substrate unit on the first redistribution layer through the bump balls, and dispose the first bare chip on the first redistribution layer through flip-chip bonding technology; Encapsulate and grind the first bare chip and all glass substrate units; Dispose a second redistribution layer on the upper surface of the ground overall structure, then turn over the overall structure and remove the substrate layer, and then dispose the lower surface of the turned-over overall structure on a new substrate layer; Flip the second bare chip on the first redistribution layer of the turned-over overall structure, perform underfill between the second bare chip and the overall structure, then encapsulate and grind the bare chips in sequence, and finally remove the new substrate layer.

[0029] The second way is as Figure 2 shown. The glass substrate is cut into a plurality of glass substrate units, and the first bare chip and each glass substrate unit are disposed between two layers of redistribution layers on the substrate layer, including: Cut the glass substrate into a plurality of glass substrate units; Prepare a substrate layer, which includes a glass plate layer and an anti-reflection coating disposed from bottom to top; Dispose the first bare chip and each glass substrate unit on the substrate layer, and bond the back of the first bare chip and the lower surface of each glass substrate unit to the upper surface of the substrate layer; Encapsulate and grind the first bare chip and each glass substrate; Dispose a first redistribution layer on the upper surface of the ground overall structure; Turn over the overall structure after disposing the first redistribution layer, and then remove the substrate layer; Set the lower surface of the flipped overall structure on a new substrate layer, and grind or planarize the upper surface of the flipped overall structure; Set a second redistribution layer on the upper surface of the planarized or ground overall structure.

[0030] In one embodiment, flip-chip mount a second bare die on the second redistribution layer, perform underfill between the second bare die and the overall structure, then encapsulate and grind the bare die in sequence, and finally remove the new substrate layer.

[0031] As Figure 3 shown, in one embodiment, a fan-out stacked package structure includes a first redistribution layer 1; a second redistribution layer 2; a glass substrate unit 3; a first bare die 4; a second bare die 5; solder balls 6, and the fan-out stacked package structure is prepared according to the preparation method of any one of the fan-out stacked package structures described above.

[0032] The preparation method, structural materials and structure of a fan-out stacked package structure proposed by the present invention have the following advantages compared with the prior art: 1. Stability: The glass substrate unit has high mechanical strength and good thermal stability. The vias are made by etching glass and filling with conductive materials. Compared with the molded copper pillars of TMV, the structure of the glass substrate unit is more stable and is not easily deformed or collapsed.

[0033] 2. Can be tested separately: Before encapsulation, electrical tests can be performed on the glass vias on the glass substrate to ensure that the via quality is qualified before subsequent assembly.

[0034] 3. Mount the chips that have been tested and confirmed to be good on the glass substrate unit first, avoiding introducing defective chips and vias into the encapsulation process at the same time. This "double screening" greatly reduces the risk of composite defects.

[0035] 4. Risk forward shift: By eliminating defective substrates and chips in advance and only putting known good components into encapsulation, material waste is reduced, and phased testing is allowed. First, test the vias, and then test the chips.

[0036] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for fabricating a fan-out stacked packaging structure, characterized in that, Including: Prepare a glass substrate and drill a number of through holes in the glass substrate; Fill each of the through holes with metal to form metal pillars, and then planarize the surface of the glass substrate after metal filling; Cut the glass substrate into a number of glass substrate units, and dispose a first bare chip and each glass substrate unit between two layers of redistribution layers on a substrate layer; Flip-chip a second bare chip on the upper redistribution layer, perform underfill between the second bare chip and the overall structure, and then encapsulate and grind the bare chips in sequence, and finally remove the new substrate layer.

2. The preparation method of a fan-out stacked packaging structure according to claim 1, wherein Connect solder balls to the lower redistribution layer at the bottom of the overall structure after removing the substrate layer.

3. The manufacturing method of a fan-out stacked packaging structure according to claim 1, wherein, Cut, integrate passive devices, and separate single chips for the overall structure after removing the substrate layer.

4. The method for manufacturing a fan-out stacked packaging structure according to claim 1, wherein Cut the glass substrate into a number of glass substrate units, and dispose a first bare chip and each glass substrate unit between two layers of redistribution layers on a substrate layer, including: Fabricate solder balls on the bottom surface of the metal pillars, and then cut the glass substrate with fabricated solder balls into a number of glass substrate units; Prepare a substrate layer, where the substrate layer includes a glass plate layer, an anti-reflection coating, and a physical vapor deposition metal layer arranged from bottom to top; Dispose a first redistribution layer on the upper surface of the substrate layer, dispose each glass substrate unit on the first redistribution layer through solder balls, and dispose the first bare chip on the first redistribution layer through flip-chip bonding technology; Encapsulate and grind the first bare chip and all glass substrate units; Dispose a second redistribution layer on the upper surface of the ground overall structure, then flip the overall structure and remove the substrate layer, and then dispose the lower surface of the flipped overall structure on a new substrate layer.

5. The preparation method of a fan-out stacked packaging structure according to claim 4, wherein Flip-chip the second bare chip on the first redistribution layer of the flipped overall structure, perform underfill between the second bare chip and the overall structure, and then encapsulate and grind the bare chips in sequence, and finally remove the new substrate layer.

6. The method for manufacturing a fan-out stacked packaging structure according to claim 1, wherein Cut the glass substrate into a number of glass substrate units, and dispose a first bare chip and each glass substrate unit between two layers of redistribution layers on a substrate layer, including: Cut the glass substrate into a number of glass substrate units; Prepare a substrate layer, where the substrate layer includes a glass plate layer and an anti-reflection coating arranged from bottom to top; Dispose a first bare chip and each glass substrate unit on the substrate layer, and bond the back of the first bare chip and the lower surface of each glass substrate unit to the upper surface of the substrate layer; Encapsulate and grind the first bare chip and each glass substrate; Dispose a first redistribution layer on the upper surface of the ground overall structure; Flip the overall structure with the first redistribution layer disposed thereon, and then remove the substrate layer; Dispose the lower surface of the flipped overall structure on a new substrate layer, and grind or planarize the upper surface of the flipped overall structure; Dispose a second redistribution layer on the upper surface of the planarized or ground overall structure.

7. The method for manufacturing a fan-out stacked packaging structure according to claim 6, wherein Flip-chip a second bare chip on the second redistribution layer, perform underfill between the second bare chip and the overall structure, and then encapsulate and grind the bare chips in sequence, and finally remove the new substrate layer.

8. A fan-out stacked packaging structure, characterized in that, The fan-out type stacked packaging structure described above is prepared by the preparation method of the fan-out type stacked packaging structure according to any one of claims 1-7.

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