Embedded fan-out packaging method and packaging structure thereof
By using a co-fired ceramic embedded substrate and a through-cavity design, the problems of heat dissipation and complex wiring in embedded fan-out packaging are solved, achieving efficient interlayer interconnection and chip front-side flushing, improving the design flexibility of the packaging structure and simplifying the process.
Patent Information
- Application Number
- CN202511051794.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-09
- Publication Date
- 2025-11-25
AI Technical Summary
Existing embedded fan-out packages suffer from poor heat dissipation, complex interlayer interconnection and double-sided wiring packaging processes, and high difficulty in achieving a chip front flush with the embedded substrate surface.
Using a co-fired ceramic embedding substrate as the embedding substrate, a stable encapsulation of the chip and cover plate is achieved through the through cavity design and the use of filler adhesive. Single or multiple fan-out rewiring is fabricated in the package structure, and the interconnection of conductive adhesive and ground metal structure is combined to ensure that the front of the chip is flush with the surface of the substrate.
It improves heat dissipation performance, simplifies interlayer interconnection and double-sided wiring packaging, reduces process difficulty and equipment precision requirements, increases design flexibility, and achieves flushing of the chip front with the substrate surface.
Smart Images
Figure CN121011572A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of microelectronic packaging, and particularly relates to a fan-out packaging method and a packaging structure thereof. BACKGROUND
[0002] Fan-out packaging has the advantages of low profile, small volume, low cost, high wiring density, etc., and is increasingly widely used in the field of electronic packaging. At present, the process routes of fan-out packaging mainly include the following: chip first and die face down, chip first and die face up, chip last (also called RDL first), and embedded fan-out process. The embedded fan-out process refers to a packaging process in which a chip is embedded into a substrate, and then a RDL is used to realize fan-out. Compared with the traditional non-embedded process, the embedded fan-out process has the advantages of suppressing warping and suppressing chip drift during molding.
[0003] The embedded substrate used in the embedded fan-out process includes silicon, glass, PCB, etc. Among them, the glass and PCB substrates have low thermal conductivity, which affects heat dissipation. The silicon and glass substrates have high costs for manufacturing interlayer interconnection holes (TSV or TGV), and it is difficult to realize double-sided wiring and packaging. SUMMARY
[0004] The present application aims to solve the problems of poor heat dissipation performance, complex interlayer interconnection and double-sided wiring packaging process, and high difficulty in realizing the flatness of the embedded chip front surface (active surface) and the embedded substrate surface in the existing embedded fan-out packaging. A fan-out packaging method and a packaging structure thereof are provided. The embedded fan-out packaging method provided by the present application uses a co-fired ceramic embedded substrate (including low-fired ceramic LTCC and high-fired ceramic HTCC) as the embedded substrate, which has the advantages of good heat dissipation performance, easy realization of interlayer interconnection and double-sided wiring packaging, and easy realization of the flatness of the embedded chip front surface and the embedded substrate surface.
[0005] To achieve the above-mentioned purpose, the technical solution of the present application is as follows: An embedded fan-out packaging method, characterized in that it comprises the following steps: S1: manufacturing a co-fired ceramic embedded substrate, the co-fired ceramic embedded substrate is provided with an upper surface metal interconnection, a lower surface metal interconnection, and internal two sides are provided with vertical interconnection through holes and substrate internal metal interconnections; the co-fired ceramic embedded substrate is further provided with a plurality of through cavities penetrating the co-fired ceramic embedded substrate, the through cavities include a through cavity upper part and a through cavity lower part which are connected in series, the through cavity lower part has a thickness greater than that of a chip, and is used for placing the chip; the through cavity upper part has an area greater than that of the through cavity lower part, and has a thickness same as that of a cover plate, and is used for placing the cover plate; S2: bonding the co-fired ceramic embedded substrate on a temporary bonding substrate using a temporary bonding film; S3: attaching the chip in the through cavity lower part, and the chip front surface is attached to the temporary bonding film; S4: injecting one or more filling glues into the through cavity, and the total height of the injected filling glue is greater than the height of the through cavity lower part and is lower than the height of the through cavity upper part; S5: placing the cover plate into the through cavity upper part, extruding the filling glue, and filling the gap between the cover plate and the through cavity with the filling glue, so that the co-fired ceramic embedded substrate, the chip, the cover plate and the filling glue form a stable packaging structure; S6: debonding, so that the packaging structure is separated from the temporary bonding film; S7: preparing a single-layer or multi-layer fan-out redistribution line on the lower surface of the packaging structure; S8: packaging components on the upper surface of the packaging structure, and planting solder balls on the lower surface.
[0006] Further, the step S7 further includes preparing a single-layer or multi-layer redistribution line on the upper surface of the packaging structure.
[0007] Further, the through cavity in the step S1 has a grounding metal structure, and the chip is planted with gold balls on the back surface, and the upper surface of the gold ball is not higher than the height of the through cavity lower part. The filling glue in the step S4 includes two parts, the first injected filling glue is plastic packaging glue, the height of which is higher than that of the chip and is lower than the upper surface of the gold ball; and the second injected filling glue is conductive glue, which covers the gold ball and is interconnected with the grounding metal structure in the through cavity.
[0008] Based on the same inventive concept, the application further provides a co-fired ceramic embedded substrate embedded fan-out packaging structure, which is characterized in that the co-fired ceramic embedded substrate is provided with an upper surface metal interconnection, a lower surface metal interconnection, and internal two sides are provided with vertical interconnection through holes and substrate internal metal interconnections, and the co-fired ceramic embedded substrate is further provided with a plurality of through cavities penetrating the substrate, the through cavities are divided into a through cavity lower part and a through cavity upper part, and the through cavity upper part has an area greater than that of the through cavity lower part. The through cavity lower part has a chip with a chip pad facing down, and the thickness of the chip is less than the through cavity lower part; The through cavity upper part has a cover plate, and the height of the cover plate is the same as that of the through cavity upper part; The space in the through cavity, except for the chip and the cover plate, is filled with filling glue; The co-fired ceramic embedded substrate, the chip, the cover plate and the filling glue form a package structure, and the lower surface of the package structure has single-layer or multi-layer fan-out redistribution lines, the bottom has solder balls, and the top is packaged with a plurality of components.
[0009] Preferably, the co-fired ceramic embedded substrate embedded fan-out package structure has the following characteristics: the upper surface of the package structure has single-layer or multi-layer redistribution lines; Preferably, the co-fired ceramic embedded substrate embedded fan-out package structure has the following characteristics: the through cavity has a grounding metal structure, the chip is provided with gold balls on the back surface, the upper surface of the gold balls does not exceed the height of the through cavity lower part, the filling glue includes two parts, the lower filling glue is plastic packaging glue, the height of which exceeds the chip and is lower than the upper surface of the gold ball, and the upper conductive glue fills the remaining gaps in the through cavity and is interconnected with the grounding metal structure in the through cavity; Compared with the prior art, the application has the following advantages and positive effects: The co-fired ceramic embedded substrate (including low-temperature co-fired ceramic (LTCC) and high-temperature co-fired ceramic (HTCC)) is used as the embedded substrate, which has the advantages of good heat dissipation performance, easy realization of interlayer interconnection, easy realization of double-sided wiring packaging and stacked packaging, and the internal interconnection lines of the co-fired ceramic embedded substrate can reduce the complexity and number of layers of the surface redistribution lines; During the pouring process, the co-fired ceramic embedded substrate and the front surface (pad surface) of the chip are in close contact with the temporary bonding film, which facilitates the realization of the flushness of the front surface of the embedded chip and the surface of the co-fired ceramic embedded substrate, reduces the process difficulty and equipment precision requirement; Since the co-fired ceramic process is a multi-piece lamination co-firing, the cavity depth has a discrete type, and it is also difficult to polish the bare chip shelf product to control the thickness. The use of the upper and lower parts of the through cavity and the cover plate in cooperation makes the fan-out packaging scheme have the advantages of increasing design flexibility, reducing the amount of glue filling, reducing process difficulty, and ensuring the flushness of the upper surface of the package. The preferred scheme plants gold balls on the back surface of the chip and uses conductive glue to interconnect with the grounding metal structure inside the through cavity, which can realize the grounding requirement of the back surface of the chip. BRIEF DESCRIPTION OF DRAWINGS
[0010] Figure 1 The co-fired ceramic embedded substrate embedded fan-out package structure in Embodiment 1 of the application is shown in the schematic diagram. Figure 2Process flow chart of the packaging method in embodiment 2 of the present application; Figure 3 Schematic diagram of the co-fired ceramic embedded substrate embedded fan-out packaging structure in embodiment 2 of the present application; Figure 4 Process flow chart of the packaging method in embodiment 2 of the present application; Legend of reference signs: 1: ceramic core board; 11: internal conductive line; 12: internal via; 13: core board surface conductive line; 2: build-up wiring layer; 21: build-up dielectric layer; 22: build-up via; 23: build-up conductive line; 24: upper fixing screw hole; 3: intermediate bonding layer; 31: photoresist; 4: carrier board. 1: co-fired ceramic embedded substrate 11: vertical interconnection via; 12: upper surface metal interconnection; 13: lower surface metal interconnection; 14: substrate internal metal interconnection; 15: through cavity; 151: through cavity lower part; 152: through cavity upper part; 16: cover plate; 17: ground metal structure; 2: temporary bonding film; 3: temporary bonding substrate; 4: chip; 41: chip pad; 42: gold ball; 5: filling adhesive; 51: plastic encapsulation adhesive; 52: conductive adhesive; 61: upper surface re-wiring; 62: lower surface re-wiring; 7: component; 8: solder ball. DETAILED DESCRIPTION
[0011] The embedded fan-out packaging method and packaging structure of the present application are further described in detail below in combination with the accompanying drawings and specific embodiments. The advantages and features of the present application will be more apparent according to the following description.
[0012] Embodiment 1 Reference Figure 1 A co-fired ceramic embedded substrate embedded fan-out packaging structure, the co-fired ceramic embedded substrate 1 is provided with an upper surface metal interconnection 12 and a lower surface metal interconnection 13 on the surface, and is provided with a vertical interconnection via 11 and a substrate internal metal interconnection 14 on the two sides inside, and is further provided with a through cavity 15 penetrating through the substrate, the through cavity is divided into a through cavity lower part 151 and a through cavity upper part 152, and the area of the through cavity upper part 152 is greater than that of the through cavity lower part 151; The through cavity lower part is provided with a chip 4 with the chip pad 41 facing downward, and the thickness of the chip is less than that of the through cavity lower part 151; The through cavity upper part is provided with a cover plate 16, and the height of the cover plate is the same as that of the through cavity upper part 152; The space in the through cavity except for the chip 4 and the cover plate 16 is filled with a filling adhesive 5; The co-fired ceramic embedded substrate 1, the chip 4, the cover plate 16 and the filling adhesive 5 constitute a packaging body structure, the lower surface of the packaging body structure is provided with a single-layer or multi-layer fan-out re-wiring 62 and a solder ball 8, and the top is encapsulated with a plurality of components 7.
[0013] Preferably, the upper surface of the package structure has a single layer or multiple layers of redistribution layer 62.
[0014] Embodiment 2 Referring to Figure 2 An embedded fan-out packaging method, comprising the following steps: Referring to Figure 2 (a), (c) and (e), S1: manufacturing a co-fired ceramic embedded substrate 1, the co-fired ceramic embedded substrate 1 is provided with an upper surface metal interconnection 12, a lower surface metal interconnection 13, internal two sides are provided with vertical interconnection through holes 11 and substrate internal metal interconnections 14, the co-fired ceramic embedded substrate 1 is also provided with a plurality of through-substrate through cavities 15, the lower part 151 of the through cavity is thicker than the thickness of the chip 4, used for placing the chip 4, the upper part 152 of the through cavity is larger than the lower part 151 of the through cavity in area, and the thickness is the same as that of the cover plate 16, used for placing the cover plate 16; Referring to Figure 2 (b), S2: bonding the co-fired ceramic embedded substrate 1 on the temporary bonding substrate 3 using the temporary bonding film 2; Referring to Figure 2 (c), S3: pasting the chip 4 in the through cavity 15, the front surface of the chip, i.e. the pad 41, is closely attached to the temporary bonding film 2; Referring to Figure 2 (d), S4: injecting the filling glue 5 in the through cavity 15, the height of the filling glue 5 is greater than the height of the lower part 151 of the through cavity, and is lower than the height of the upper part 152 of the through cavity; Referring to Figure 2 (e), S5: placing the cover plate 16 in the upper part 152 of the through cavity, and extruding the filling glue 5, so that the filling glue 5 fills the gap between the cover plate 16 and the through cavity 15, and the co-fired ceramic embedded substrate, the chip, the cover plate and the filling glue form a stable package structure; Referring to Figure 2 (f), S6: debonding, so that the package structure is separated from the temporary bonding film 2; Referring to Figure 2 (g), S7: preparing a single layer or multiple layers of fan-out redistribution layer 62 on the lower surface of the package structure; Referring to Figure 2 (h) (i), S8: packaging components 7 on the upper surface of the package structure, including components without leads, chips, and soldering balls 8 on the lower surface.
[0015] Preferably, in step S7, a single layer or multiple layers of redistribution layer 61 is prepared on the upper surface of the package structure.
[0016] Embodiment 3 Referring to Figure 3A co-fired ceramic embedded substrate embedded fan-out package structure, the co-fired ceramic embedded substrate 1 is provided with an upper surface metal interconnection 12 and a lower surface metal interconnection 13 on the surface, and is provided with vertical interconnection through holes 11 and substrate internal metal interconnections 14 on both sides of the interior, and is further provided with a plurality of through cavities 15 penetrating the substrate, the through cavities are divided into a through cavity lower portion 151 and a through cavity upper portion 152, and the area of the through cavity upper portion 152 is greater than that of the through cavity lower portion 151; The through cavity lower portion is provided with a chip 4 with a chip pad 41 facing downward, and the thickness of the chip 4 is less than that of the through cavity lower portion 151, and the through cavity 15 is provided with a grounding metal structure 17, and the chip 4 is provided with gold balls 42 on the back surface, and the upper surface of the gold balls 42 does not exceed the height of the through cavity lower portion 151; The through cavity upper portion 152 is provided with a cover plate 16, and the height of the cover plate 16 is the same as that of the through cavity upper portion 152; In the through cavity, the space other than the chip 4 and the cover plate 16 is filled with filling glue, including plastic encapsulating glue 51 and conductive glue 52, the lower layer filling glue is plastic encapsulating glue 51, the height of which exceeds that of the chip 4 and is lower than the upper surface of the gold ball 42, and the upper layer conductive glue 52 fills the remaining gaps in the through cavity and is interconnected with the grounding metal structure 17 in the through cavity; The co-fired ceramic embedded substrate 1, the chip 4, the cover plate 16, the plastic encapsulating glue 51 and the conductive glue 52 constitute a package structure, the lower surface of the package structure is provided with single-layer or multi-layer fan-out redistribution layers 62 and solder balls 8, and the top of the package structure is provided with a plurality of components 7, including chips, passive components and stacked substrates, etc.
[0017] Preferably, the upper surface of the package structure is provided with single-layer or multi-layer redistribution layers 62.
[0018] Embodiment 4 Referring to Figure 2 An embedded fan-out packaging method, comprising the following steps: Referring to Figure 4 (a), (c) and (e), S1: manufacturing a co-fired ceramic embedded substrate 1, the co-fired ceramic embedded substrate 1 is provided with an upper surface metal interconnection 12 and a lower surface metal interconnection 13 on the surface, and is provided with vertical interconnection through holes 11 and substrate internal metal interconnections 14 on both sides of the interior, and is further provided with a plurality of through cavities 15 penetrating the substrate, the through cavity lower portion 151 is thicker than the thickness of the chip 4, and is used for placing the chip 4, the through cavity upper portion 152 is larger than the through cavity lower portion 151 in area, and is the same as the cover plate 16 in thickness, and is used for placing the cover plate 16; Referring to Figure 4 (b), S2: bonding the co-fired ceramic embedded substrate 1 on a temporary bonding substrate 4 using a temporary bonding film 2; Referring to Figure 4(c), S3: the chip 4 is pasted in the through cavity 15, the chip front face, i.e. the pad 41 face, is closely attached to the temporary bonding film 2, and the chip 4 is planted with gold balls 42 on the back face, the upper surface of the gold balls 42 does not exceed the height of the lower part 151 of the through cavity; Referring to Figure 4 (d), S4: the plastic sealing glue 51 is injected into the through cavity 15, the height of the plastic sealing glue 51 exceeds the back face of the chip 4 and is lower than the upper surface of the gold balls 42, the conductive glue 52 is further injected, the height of the conductive glue 52 is higher than the upper edge of the lower part 151 of the through cavity and is lower than the upper edge of the upper part 152 of the through cavity, and the conductive glue 52 is connected with the ground metal structure 17; Referring to Figure 4 (e), S5: the cover plate 16 is placed in the upper part 152 of the through cavity, the conductive glue 52 is extruded so as to fill the gap between the cover plate 16 and the through cavity 15, and the co-fired ceramic embedded substrate, the chip, the cover plate and the filling glue form a stable package structure; Referring to Figure 4 (f), S6: the package structure is separated from the temporary bonding film 2 by debonding; Referring to Figure 4 (g), S7: a single-layer or multi-layer fan-out redistribution layer 62 is prepared on the lower surface of the package structure; Referring to Figure 4 (h)(i), S8: the package components 7, including the borderless components, chips and stacked substrates, etc. are packaged on the upper surface of the package structure, and the solder balls 8 are planted on the lower surface.
[0019] Preferably, in step S7, the single-layer or multi-layer redistribution layer 61 is prepared on the upper surface of the package structure.
[0020] The embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the above-described embodiments. Even if various changes are made to the present application, if the changes fall within the scope of the claims of the present application and equivalent technologies thereof, they still fall within the protection scope of the present application.
Claims
1. A method of embedded fan-out packaging, the method comprising: The method comprises the following steps: S1： Manufacture a co-fired ceramic embedded substrate, which is provided with upper surface metal interconnection, lower surface metal interconnection, vertical interconnection through hole and substrate internal metal interconnection on both sides; the co-fired ceramic embedded substrate is further provided with a plurality of through cavities penetrating through the co-fired ceramic embedded substrate, the through cavities comprise through cavity upper part and through cavity lower part, the thickness of the through cavity lower part is greater than the thickness of the chip, and the through cavity lower part is used for placing the chip; the area of the through cavity upper part is greater than that of the through cavity lower part, and the thickness of the through cavity upper part is the same as that of the cover plate, and the through cavity upper part is used for placing the cover plate; S2: bonding the co-fired ceramic embedded substrate on the temporary bonding substrate by using a temporary bonding film; S3: attaching the chip in the through cavity lower part, and the front surface of the chip is attached to the temporary bonding film; S4: injecting one or more filling glues into the through cavity, and the total height of the injected filling glue is greater than the height of the through cavity lower part and is lower than the height of the through cavity upper part; S5: placing the cover plate in the through cavity upper part, extruding the filling glue, and filling the gap between the cover plate and the through cavity with the filling glue, so that the co-fired ceramic embedded substrate, the chip, the cover plate and the filling glue form a stable package structure; S6: debonding, so that the package structure is separated from the temporary bonding film; S7: preparing single-layer or multi-layer fan-out redistribution lines on the lower surface of the package structure; S8: packaging components on the upper surface of the package structure, and planting solder balls on the lower surface.
2. The method of claim 1, wherein, The step S7 further comprises preparing single-layer or multi-layer redistribution lines on the upper surface of the package structure.
3. The method of claim 1, wherein, The through cavity in the step S1 is provided with a grounding metal structure, and the chip is planted with gold balls on the back surface, and the upper surface of the gold ball is not higher than the height of the through cavity lower part; The filling glue in the step S4 comprises two parts, the first injected filling glue is plastic encapsulation glue, the height of which is higher than that of the chip and is lower than the upper surface of the gold ball; and the second injected filling glue is conductive glue, which covers the gold ball and is interconnected with the grounding metal structure in the through cavity.
4. A package structure for performing the method of claim 1-3, wherein, The co-fired ceramic embedded substrate is provided with upper surface metal interconnection, lower surface metal interconnection, vertical interconnection through hole and substrate internal metal interconnection on both sides; the co-fired ceramic embedded substrate is further provided with a plurality of through cavities penetrating through the co-fired ceramic embedded substrate, the through cavities comprise through cavity upper part and through cavity lower part, the thickness of the through cavity lower part is greater than the thickness of the chip, and the through cavity lower part is used for placing the chip; the area of the through cavity upper part is greater than that of the through cavity lower part, and the thickness of the through cavity upper part is the same as that of the cover plate, and the through cavity upper part is used for placing the cover plate; The through cavity lower part is provided with a chip with the chip pad facing downward, and the thickness of the chip is less than that of the through cavity lower part; The through cavity upper part is provided with a cover plate, and the height of the cover plate is the same as that of the through cavity upper part; The space in the through cavity, except for the chip and the cover plate, is filled with filling glue; The co-fired ceramic embedded substrate, the chip, the cover plate and the filling glue constitute a package structure, the lower surface of the package structure is provided with single-layer or multi-layer fan-out redistribution lines, the bottom is provided with solder balls, and the top is packaged with a plurality of components.
5. The co-fired ceramic-embedded-substrate-embedded fan-out package structure of claim 4, wherein, The upper surface of the package structure is provided with single-layer or multi-layer redistribution lines.
6. The co-fired ceramic-embedded-substrate-embedded fan-out package structure of claim 4, wherein, The through cavity has a grounding metal structure, the chip is planted with gold balls on the back surface, the upper surface of the gold balls does not exceed the height of the lower part of the through cavity, the filling glue comprises two parts, the lower filling glue is plastic sealing glue, the height exceeds the chip and is lower than the upper surface of the gold ball, the upper conductive glue fills the remaining gaps in the through cavity and is interconnected with the grounding metal structure in the through cavity.