1. Field of Invention
The invention relates to a three-dimensional (3D) chip-stack package structure. In particular, it relates to a structure of embedded active components having TSVs (through silicon via).
2. Related Art
In order to create larger space and to enhance the functions of the module within a limited substrate area, shrunk or embedded passive components are often used to minimize the circuit layout and to reduce the signal transmission distance. Thus, more space is left for installing active components and enhancing the overall performance. Therefore, substrates with passive components such as embedded resistors, capacitors, and inductors are developed.
In order to more effectively minimize the packaging of the components, methods of embedding active components (such as IC chips) on a substrate have been developed. The substrate with an embedded IC module as disclosed in the U.S. Pat. No. 5,497,033 has a plurality of chips installed thereon. A molding plate is first used to enclose the chips to be the embedded components. A molding material then covers the chips using the conventional molding method. The chips are thus embedded in the molding material after curing. However, this method completes the whole process of embedding components on the substrate. It is likely to damage other components not to be embedded. The finished substrate is not flexible and has limited applications.
In the U.S. Pat. No. 6,027,958, a transferring manufacturing method for the flexible IC components is taught. A semiconductor substrate with silicon on insulator (SOI) structure is provided to form the required IC thereon. An adhesive layer is used to attach another flexible substrate on the IC. Finally, etching is employed to remove the semiconductor substrate, thereby transferring the IC onto the surface of the flexible substrate.
In US Patent Publication No. 2007/0222050 (hereafter called as Pub. '050), a stack package utilizing through vias and re-distribution lines, introduces a stack package. The stack package includes a printed circuit board (PCB), at least two semiconductor chips stacked on the PCB, first and second solder balls, a molding material, and third solder balls. Each of the chips has first re-distribution lines formed on the upper surface thereof and connected to bonding pads, TSVs (through silicon vias) formed therethrough and connected to the first re-distribution lines, and second re-distribution lines formed on the lower surface thereof and connected the TSVs. The first and second solder balls interposed between the first and second re-distribution lines which face each other and between the first re-distribution lines of the lowermost semiconductor chip and electrode terminals of the PCB. The molding material is for molding the upper surface of the PCB. The third balls attach to ball lands formed on the lower surface of the PCB.
As described above, the Pub. '050 discloses a re-distribution structure of 3D chip-stack package to gain more space and better distribution of bonding pads. Although Pub. '050 re-distributes the bonding pads by several stacked ICs, the bonding strength is not good enough. The reason is that the materials between the semiconductor chip and PCB are different. CT (coefficient of thermo expansion) is thus different. In other words, CT of the chip mismatches that of the PCB. Accordingly, thermo stress is incurred at the solder balls between the chip and the PCB when ambient temperature changes. This will cause cracks and bad electrical connections.
Hence, re-distribution (fan-out) of bonding pads of stacked ICs as well as less thermo stress between the PCB and stacked IC are eager to be reached in the IC package field.
In view of the foregoing, an objective of the invention is to provide 3D chip-stack package adapted to be disposed on a PCB with less thermo stress therebetween. The thermo stress problem in subsequence can be solved.
The 3D chip-stack package comprises a component-embedded plate and a side IC (integrated circuit). The PCB has a plurality of conductive contacts. The component-embedded plate comprises a dielectric layer; an active an active component embedded in the dielectric layer, one surface of each active component exposed outside the dielectric layer, the active components having a plurality of TSVs (Through Silicon Via), one ends of the TSVs exposed outside the exposed surface, the other ends of the TSVs corresponding to the conductive contacts of the PCB; and an electrical circuit on the dielectric layer and in electrical connection between the other ends of the TSVs of the active component and the corresponding conductive contacts of the PCB, respectively. The side IC has a plurality of pads. The pads are electrically connected with the exposed ends of the TSVs of the active component.
The pitches between the TSVs of the active component are smaller than the pitches between the conductive contacts of the PCB. Therefore, the 3D chip-stack package achieves the results of re-distribution (fan-out) of bonding pads of stacked ICs and less thermo stress between the PCB and stacked IC.
Another objective of the invention is to provide a structure of active component on a flexible substrate.
The structure of active component on a flexible substrate comprises a component-embedded plate and a flexible substrate. The component-embedded plate comprises a dielectric layer, an active component, and an electrical circuit. The dielectric layer has a first surface, a second surface and a plurality of conductive holes. The conductive holes penetrate the dielectric layer and are connected between the first surface and the second surface. The active component is embedded in the dielectric layer. One surface of active component exposed outside the first surface of the dielectric layer. The active component has a plurality of TSVs (Through Silicon Via). One ends of the TSVs are exposed outside the exposed surface of the active component. The other ends of the TSVs are connected with a part of the conductive holes. The electrical circuit is on the dielectric layer and in electrical connection between the other ends of the TSVs of the active component and the other part of the conductive holes through the part of the conductive holes The flexible substrate has a plurality of conductive contacts corresponding to and electrically connected with both the exposed ends of the TSVs and the other part of the through holes.
The invention will become more fully understood from the detailed description given hereinbelow illustration only, and thus are not limitative of the present invention, and wherein:
The steps of the disclosed method are shown in
When the dielectric layer is a polymer layer, it can be a preprocessed or existing polymer layer, such as the Ajinomoto build-up film (ABF) or the resin coated copper foil (RCC). The above process also includes the step of embossing to embed active components into the polymer layer or the step of coating a polymer solution followed by curing to form the dielectric layer. The latter includes the steps of: covering a polymer solution on the active components by spraying, spin-coating, or printing; and curing the polymer solution to form a polymer layer.
Step 140 in
The process in an embodiment of the invention is further described in detail with reference to
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The structure of embedded active components formed using the process of the disclosed embodiment is shown in
The disclosed structure of embedded active components can be installed with an arbitrary substrate, such as the semiconductor substrate, flexible substrate, or glass substrate. Since the active components have fixed relative positions, only one alignment is required to fix the positions of all the active components. This can greatly lower the difficulty in subsequent processes and increase the product yield.
Please refer to
The three-dimensional (hereafter called as 3D) chip-stack package 50 is adapted to be disposed on a printed circuit board 60 (hereafter called as PCB). The PCB 60 has a plurality of conductive contacts 62, 64 and a plurality of circuits 66, 68. The circuits 66, 68 are connected to the conductive contacts 62, 64 for specific functions, respectively. The circuits 66, 68 can comprise a plurality of conductive through holes (not shown in drawings).
The 3D chip-stack package 50 comprises a component-embedded plate 52 and a side integrated circuit 58 (hereafter called as IC).
The component-embedded plate 52 comprises a dielectric layer 53, an active component 54 and an electrical circuit 55. The dielectric layer 53 is similar to the polymer layer 300 in
The active component 54 is embedded in the dielectric layer 53 and one surface of active component 54 is exposed outside the dielectric layer 53. The active component 54 has a plurality of TSVs (Through Silicon Via) 540, 542. One ends of the TSVs 540, 542 (the bottom ends of TSVs shown in
The TSVs 540, 542 are vertical electrical connection passing completely through the active component 54, just like a conductive through holes on a PCB 60.
The electrical circuit 55 is on the dielectric layer 53 and in electrical connection between the other ends of the TSVs 540, 542 of the active component 54 and the corresponding conductive contacts 62, 64 of the PCB 60, respectively. As shown in
The side IC 58 has a plurality of conductive pads 580, 582. The pads 580, 582 are electrically connected with the exposed ends of the TSVs 540, 542 of the active component 54 to form a 3D chip-stack package.
The active component 54 and the side IC 58 have integrated electrical circuits inside for performing specific functions. In addition, the side IC 58 can be a regular IC or an IC with TSVs.
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The 3D chip-stack package 50 is adapted to be disposed on a PCB 60 which is the same as the PCB in
The sandwiched IC 56 has a plurality of TSVs 560, 562. The sandwiched IC 56 is sandwiched between the active component 54 and the side IC 58 so that the pads 580, 582 of the side IC 58 are electrically connected with the exposed ends of the TSVs 540, 542 of the active component 54 through the TSVs 560, 562 of the sandwiched IC 56.
In this embodiment, there is only one sandwiched IC 56 in the 3D chip-stack package 50. However, in practical application, it is possible to have more than one sandwiched IC 56 in the 3D chip-stack package for limited space consideration.
The active component 54, sandwiched IC 56 and the side IC 58 have integrated electrical circuits inside for performing specific functions. In addition, the side IC 58 in this embodiment is an IC with TSVs 584, 586. The side IC 58 has a plurality of TSVs 584, 586. The TSVs 584, 586 are corresponding to and electrically connected with the conductive pads 580, 582.
The materials of both the dielectric layer 52 and the PCB 60 are organic. For example, the PCB 60 can be, but not limited to, FR-4 (Flame Retardant Type 4) epoxy laminate or polyimide. The dielectric layer 52 can be polymer layer. Therefore, coefficients of thermo expansion (CT) of both the dielectric layer 52 and the PCB 60 are close. Accordingly, thermo stress between the dielectric layer 52 and PCB 60 is reduced.
In addition, please refer to
The structure of active component on a substrate comprises a component-embedded plate 70 and a flexible substrate 80.
The component-embedded plate 70 comprises a dielectric layer 72, an active component 74 and an electrical circuit 76. The dielectric layer 72 has a first surface 720, a second surface 722 and a plurality of conductive holes 724, 725, 726, 727. The conductive holes 724, 725, 726, 727 penetrate the dielectric layer 72 and connected between the first surface 720 and the second surface 722.
The active component 74 is embedded in the dielectric layer 72. One surface of active component 74 is exposed outside the first surface 720 of the dielectric layer 72. The active component 74 has a plurality of TSVs 740, 742. One ends of the TSVs 740, 742 are exposed outside the exposed surface of the active component 74. The other ends of the TSVs 740, 742 are connected with a part of the conductive holes 726, 727.
The electrical circuit 76 is on the dielectric layer 72 and in electrical connection between the other ends of the TSVs 740, 742 of the active component 74 and the other part of the conductive holes 724, 725 through the part of the conductive holes 726, 727.
The flexible substrate 80 has a plurality of conductive contacts 82, 84 corresponding to and electrically connected with both the exposed ends of the TSVs 740, 742 and the other part of the through holes 724, 725. The flexible substrate 80 is made of polymer. The polymer is FR-4 (Flame Retardant Type 4) epoxy laminate or polyimide. The dielectric layer 72 is a polymer layer.
The flexible substrate 80 can a heat-dissipating substrate for dissipating heat generated by the active component 74 as well as conducted from conductive holes 724, 725, 726, 727.
Further, please refer to
The component-embedded plate 70a is further stacked by a side IC 79. The side IC 79 has a plurality of conductive pads 790, 791. The pads 790, 791 are electrically connected with the electrical circuit 76. The active component 74a and the side IC 79 have integrated electrical circuits inside for performing specific functions. In addition, the side IC 59 can be a regular IC or an IC with TSVs.
The side IC 79 can be, but not limited to, made by a flexible material. Accordingly, the component-embedded plate 70a and the side IC 79 is bendable and flexible for flexible electronics.
Furthermore, please refer to
The second component-embedded plate 70b comprises a dielectric layer 73′, an active component 74b and an electrical circuit 76′. The dielectric layer 72′ has a first surface 720′, a second surface 722′ and a plurality of conductive holes 724′, 725′, 726′, 727′. The conductive holes 724′, 725′, 726′, 727′ penetrate the dielectric layer 72′ and connected between the first surface 720′ and the second surface 722′.
The active component 74b is embedded in the dielectric layer 72′. One surface of active component 74b is exposed outside the first surface 720′ of the dielectric layer 72′. The active component 74b has a plurality of TSVs 740′, 742′. One ends of the TSVs 740′, 742′ are exposed outside the exposed surface of the active component 74b. The other ends of the TSVs 740′, 742′ are connected with a part of the conductive holes 726′, 727′.
The electrical circuit 76′ is on the dielectric layer 72′ and in electrical connection between the other ends of the TSVs 740′, 742′ of the active component 74b and the other part of the conductive holes 724′, 725′ through the part of the conductive holes 726′, 727′.
The second component-embedded plate 70b is disposed upon and electrically connected with the first component-embedded plate 70a. The exposed TSVs 740′, 742′ and the other part of the conductive holes 724′, 725′ of the second component-embedded plate 70b are in electrical connection with the electrical circuit 76 of the first component-embedded plate 70a. Therefore, the active components 74a, 74a are electrically connected for performing some specific functions.
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The component-embedded plate 70 comprises a dielectric layer 72, an active component 74 and an electrical circuit 76. The dielectric layer 72 has a first surface 720, a second surface 722 and a plurality of conductive holes 726, 727. The conductive holes 726, 727 penetrate the dielectric layer 72 and connected between the second surface 722 and the active component 74. The active component 74, dielectric layer 72 and the heat-dissipating substrate 86 are bendable and flexible for flexible electronics. The heat-dissipating substrate 86 is contact with both the exposed surface of the active component 74 and the first surface 720 for dissipating heat generated by the active component 74. The heat-dissipating substrate 86 can be, but not limited to, a metal foil or a flexible heat sink. The active component 74 is a thinned (or laminated) and flexible active component. According to said another embodiment of active component on a substrate, heat generated by the active component 74 can be effectively dissipated owing to the contact between the heat-dissipating substrate 86 and the active component 74.
Certain variations would be apparent to those skilled in the art, which variations are considered within the spirit and scope of the claimed invention.
Number | Date | Country | Kind |
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93135743 | Nov 2004 | TW | national |
The present application is a continuation-in-part of parent application Ser. No. 11/252,572, filed Oct. 19, 2005, which claims the benefit of Taiwan Patent Application No. 093135743, filed on Nov. 19, 2004. The parent application and the Taiwan application are hereby incorporated by reference for all purposes as if fully set forth herein.
Number | Date | Country | |
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Parent | 11252572 | Oct 2005 | US |
Child | 12232019 | US |