THERMALLY ENHANCED SEMICONDUCTOR ASSEMBLY WITH THREE DIMENSIONAL INTEGRATION AND METHOD OF MAKING THE SAME
20170243803 · 2017-08-24
Inventors
Cpc classification
H01L2225/1082
ELECTRICITY
H01L2924/19105
ELECTRICITY
H01L2221/68359
ELECTRICITY
H01L2224/131
ELECTRICITY
H01L2225/06517
ELECTRICITY
H01L23/49816
ELECTRICITY
H01L2224/131
ELECTRICITY
H01L2224/8385
ELECTRICITY
H01L2225/0651
ELECTRICITY
H01L2924/16251
ELECTRICITY
H01L23/16
ELECTRICITY
H01L23/49833
ELECTRICITY
H01L2924/00014
ELECTRICITY
H01L25/50
ELECTRICITY
H01L23/3128
ELECTRICITY
H01L21/568
ELECTRICITY
H01L2924/165
ELECTRICITY
H01L2225/1058
ELECTRICITY
H01L2224/16235
ELECTRICITY
H01L2223/54486
ELECTRICITY
H01L2224/4847
ELECTRICITY
H01L24/73
ELECTRICITY
H01L21/4853
ELECTRICITY
H01L2924/00012
ELECTRICITY
H01L2225/06506
ELECTRICITY
H01L2224/81203
ELECTRICITY
H01L2224/92225
ELECTRICITY
H01L24/97
ELECTRICITY
H01L2224/48101
ELECTRICITY
H01L2224/32225
ELECTRICITY
H01L2224/48463
ELECTRICITY
H01L2224/32225
ELECTRICITY
H01L2224/2929
ELECTRICITY
H01L2924/00
ELECTRICITY
H01L2224/2929
ELECTRICITY
H01L2224/16227
ELECTRICITY
H01L2924/00
ELECTRICITY
H01L2924/1533
ELECTRICITY
H01L23/36
ELECTRICITY
H01L2221/68381
ELECTRICITY
H01L2224/97
ELECTRICITY
H01L2225/06568
ELECTRICITY
H01L2924/00014
ELECTRICITY
H01L2924/00012
ELECTRICITY
H01L2924/15153
ELECTRICITY
H01L2225/06572
ELECTRICITY
H01L21/481
ELECTRICITY
H01L2224/97
ELECTRICITY
H01L2224/8385
ELECTRICITY
H01L23/544
ELECTRICITY
International classification
H01L21/48
ELECTRICITY
H01L25/00
ELECTRICITY
Abstract
A thermally enhanced semiconductor assembly with three dimensional integration includes a semiconductor chip electrically coupled to a wiring board by bonding wires. A heat spreader that provides an enhanced thermal characteristic for the semiconductor chip is disposed in a through opening of a wiring structure. Another wiring structure disposed on the heat spreader not only provides mechanical support, but also allows heat spreading and electrical grounding for the heat spreader by metallized vias. The bonding wires provide electrical connections between the semiconductor chip and the wiring board for interconnecting the semiconductor chip to terminal pads provided in the wiring board.
Claims
1. A method of making a thermally enhanced semiconductor assembly with three dimensional integration, comprising: providing a wiring board, including: inserting a heat spreader into a through opening of a first wiring structure, with a backside surface of the heat spreader being substantially coplanar with a first surface of the first wiring structure, and forming a second wiring structure on the backside surface of the heat spreader and the first surface of the first wiring structure, wherein the second wiring structure is electrically coupled to the first wiring structure and thermally conductible to the heat spreader through metallized vias; disposing a first semiconductor chip in the through opening of the first wiring structure and over the heat spreader; and providing a plurality of bonding wires that electrically couple the first semiconductor chip to a second surface of the first wiring structure opposite to the first surface.
2. The method of claim 1, further comprising a step of providing a second semiconductor chip stacked over the first semiconductor chip by an adhesive and electrically coupled to the first wiring structure by a plurality of additional bonding wires.
3. The method of claim 1, further comprising a step of providing a semiconductor device stacked over and electrically coupled to the first wiring structure or the second wiring structure.
4. The method of claim 1, further comprising a step of stacking a lens over the first wiring structure, wherein the lens is optically transparent to at least one range of light wavelengths and covers the first semiconductor chip.
5. The method of claim 1, further comprising steps of: providing an array of vertical connecting elements disposed on and electrically coupled to the first wiring structure; and providing an encapsulant that covers the first semiconductor chip and the bonding wires and surrounds the vertical connecting elements.
6. The method of claim 5, further comprising a step of providing a semiconductor device stacked over the encapsulant and electrically coupled to the vertical connecting elements.
7. The method of claim 1, wherein the step of providing the wiring board further includes forming a metal layer that covers sidewalls of the through opening of the first wiring structure and contacts the heat spreader and is electrically coupled to the second wiring structure by the metallized vias in contact with the backside surface of the heat spreader.
8. The thermally enhanced semiconductor assembly with three dimensional integration, which is prepared by a method that comprises steps of: providing a wiring board, including: inserting a heat spreader into a through opening of a first wiring structure, with a backside surface of the heat spreader being substantially coplanar with a first surface of the first wiring structure, and forming a second wiring structure on the backside surface of the heat spreader and the first surface of the first wiring structure, wherein the second wiring structure is electrically coupled to the first wiring structure and thermally conductible to the heat spreader through metallized vias; disposing a first semiconductor chip in the through opening of the first wiring structure and over the heat spreader; and providing a plurality of bonding wires that electrically couple the first semiconductor chip to a second surface of the first wiring structure opposite to the first surface.
9. The semiconductor assembly of claim 8, wherein the method further comprises a step of providing a second semiconductor chip stacked over the first semiconductor chip by an adhesive and electrically coupled to the first wiring structure by a plurality of additional bonding wires.
10. The semiconductor assembly of claim 8, wherein the method further comprises a step of providing a semiconductor device stacked over and electrically coupled to the first wiring structure or the second wiring structure.
11. The semiconductor assembly of claim 8, wherein the method further comprises a step of stacking a lens over the first wiring structure, wherein the lens is optically transparent to at least one range of light wavelengths and covers the first semiconductor chip.
12. The semiconductor assembly of claim 8, wherein the method further comprises steps of: providing an array of vertical connecting elements disposed on and electrically coupled to the first wiring structure; and providing an encapsulant that covers the first semiconductor chip and the bonding wires and surrounds the vertical connecting elements.
13. The semiconductor assembly of claim 12, wherein the method further comprises a step of providing a semiconductor device stacked over the encapsulant and electrically coupled to the vertical connecting elements.
14. The semiconductor assembly of claim 8, wherein the step of providing the wiring board further includes forming a metal layer that covers sidewalls of the through opening of the first wiring structure and contacts the heat spreader and is electrically coupled to the second wiring structure by the metallized vias in contact with the backside surface of the heat spreader.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The following detailed description of the preferred embodiments of the present invention can best be understood when read in conjunction with the following drawings, in which:
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] Hereafter, examples will be provided to illustrate the embodiments of the present invention. Advantages and effects of the invention will become more apparent from the following description of the present invention. It should be noted that these accompanying figures are simplified and illustrative. The quantity, shape and size of components shown in the figures may be modified according to practical conditions, and the arrangement of components may be more complex. Other various aspects also may be practiced or applied in the invention, and various modifications and variations can be made without departing from the spirit of the invention based on various concepts and applications.
Embodiment 1
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[0055] At this stage, a wiring board 10 is accomplished and includes a first wiring structure 11, a heat spreader 15 and a second wiring structure 16. As the depth of the through opening 115 is more than the thickness of the heat spreader 15, the exterior surface of the heat spreader 15 and the sidewall surface of the through opening 115 of the first wiring structure 11 forms a cavity 116 in the through opening 115 of the first wiring structure 11. As a result, the heat spreader 15 can provide thermal dissipation for a device accommodated in the cavity 116, whereas the combination of the first wiring structure 11 and the second wiring structure 16 offers electrical contacts for next connection from two opposite sides of the wiring board 10.
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[0058] Accordingly, as shown in
[0059] The heat spreader 15 of the wiring board 10 is thermally conductible to and covers the first semiconductor chip 22 from below. The first wiring structure 11 laterally surrounds peripheral edges of the first semiconductor chip 22 and the heat spreader 15, and is electrically coupled to the first semiconductor chip 22 by the bonding wires 31. The second wiring structure 16 covers the first wiring structure 11 and the heat spreader 15 from below, and is electrically coupled to the first wiring structure 11 and thermally conductible to the heat spreader 15 through metallized vias 164. As a result, the first wiring structure 11 and the second wiring structure 16 can provide fan-out routing for the first semiconductor chip 22.
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Embodiment 2
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[0066] For purposes of brevity, any description in Embodiment 1 above is incorporated herein insofar as the same is applicable, and the same description need not be repeated.
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[0070] Accordingly, as shown in
[0071] The heat spreader 15 covers the inactive surface of the first semiconductor chip 22 and is thermally conductible to the first semiconductor chip 22, whereas the metal layer 17 surrounds peripheral edges of the first semiconductor chip 22 and contacts the heat spreader 15. The first wiring structure 11 is electrically coupled to the first semiconductor chip 22 through bonding wires 31. The second wiring structure 16 covers the first wiring structure 11 and the heat spreader 15 from below, and is electrically coupled to the first wiring structure 11 for signal routing and to the heat spreader 15 for ground connection through metallized vias 164. Accordingly, the combination of the first wiring structure 11 and the second wiring structure 16 can provide fan-out routing for the first semiconductor chip 22 and electrical contacts for next-level connection, whereas the combination of the heat spreader 15 and the metal layer 17, electrically connected to the second wiring structure 16 through metallized vias 164, provides thermal dissipation and EMI (electromagnetic interference) shielding for the first semiconductor chip 22.
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Embodiment 3
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[0077] For purposes of brevity, any description in Embodiments above is incorporated herein insofar as the same is applicable, and the same description need not be repeated.
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Embodiment 4
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[0085] The semiconductor assembly 410 is similar to that illustrated in
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Embodiment 5
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[0093] The semiconductor assembly 510 is similar to that illustrated in
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Embodiment 6
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[0097] The semiconductor assembly 610 is similar to that illustrated in
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[0100] The semiconductor assemblies described above are merely exemplary. Numerous other embodiments are contemplated. In addition, the embodiments described above can be mixed-and-matched with one another and with other embodiments depending on design and reliability considerations. For instance, the first wiring structure may have multiple through openings in an array and each first semiconductor chip is accommodated in its corresponding through opening. Also, the first wiring structure of the wiring board can include additional conductive traces to receive and route additional first semiconductor chips.
[0101] For the convenience of below description, the direction in which the first surface of the first wiring structure faces is defined as the first direction, and the direction in which the second surface of the first wiring structure faces is defined as the second direction.
[0102] As illustrated in the aforementioned embodiments, a distinctive semiconductor assembly is configured by providing a first wiring structure, then inserting a heat spreader into a through opening of the first wiring structure, and then forming a second wiring structure on the heat spreader and the first wiring structure. Accordingly, the semiconductor assembly includes a first semiconductor chip electrically coupled to a wiring board by bonding wires. The wiring board includes a heat spreader, a first wiring structure and a second wiring structure. The first wiring structure includes electrical contacts at its second surface for chip connection and next-level connection from the second direction, whereas the second wiring structure includes electrical contacts at its exterior surface for next-level connection from the first direction. The heat spreader is laterally surrounded by the first wiring structure and covered by the second wiring structure from the first direction, and can provide a thermal dissipation pathway for the first semiconductor chip. Additionally, a second semiconductor chip may be stacked over first semiconductor chip by an adhesive and electrically coupled to the first wiring structure by a plurality of additional bonding wires. Optionally, an encapsulant may be further provided to cover the bonding wires.
[0103] The first wiring structure has a through opening extending from its first surface to its second surface to accommodate the heat spreader and the first semiconductor chip therein. The first wiring structure is not limited to a particular structure, and may be a multi-layered routing circuitry that laterally surround peripheral edges of the first semiconductor chip and the heat spreader. For instance, the first wiring structure may include an interconnect substrate, a first buildup circuitry and a second buildup circuitry. The first and second buildup circuitries are disposed on both opposite sides of the interconnect substrate. The interconnect substrate can include a core layer, first and second routing layers respectively on both opposite sides of the core layer, and metallized through vias formed through the core layer to provide electrical connection between the first and second routing layers. Each of the first and second buildup circuitries typically includes a dielectric layer and one or more conductive traces. The dielectric layers of the first and second buildup circuitries are respectively deposited on opposite sides of the interconnect substrate. The conductive traces extend laterally on the dielectric layer and include conductive vias in contact with first and second routing layers of the interconnect substrate. Further, the first and second buildup circuitries can include additional dielectric layers, additional via openings, and additional conductive traces if needed for further signal routing. Accordingly, the outmost conductive traces at both the first and second surfaces of the first wiring structure can provide electrical contacts for the chip connection and next-level connection from its second surface and for the second wiring structure connection from its first surface, and are electrically connected to each other.
[0104] The heat spreader is disposed in the through opening of the first wiring structure and has a thickness less than that of the first wiring structure so that a cavity is formed in the wiring board to accommodate the first semiconductor chip therein. Further, the heat spreader has peripheral edges adjacent to and attached to sidewalls of the through opening of the first wiring structure, and thus no electrical contacts are provided at the bottom of the cavity. In a preferred embodiment, the heat spreader is a metal layer that completely covers an inactive surface of the first semiconductor chip from the first direction to provide effective thermal dissipation and vertical EMI shielding for the first semiconductor chip attached thereto using a thermally conductive material. Further, the cavity may have metallic sidewalls by forming a metal layer that covers sidewalls of the through opening of the first wiring structure and is electrically coupled to the second wiring structure by the metallized vias in contact with the backside surface of the heat spreader. Preferably, the metal layer contacts sidewalls of the through opening of the first wiring structure, and completely covers sidewalls of the first semiconductor chip to provide effective lateral EMI shielding for the first semiconductor chip.
[0105] The second wiring structure may be a multi-layered routing circuitry and laterally extends to peripheral edges of the first wiring structure. Preferably, the second wiring structure is formed by direct build-up process on the first wiring structure and the heat spreader and electrically coupled to the heat spreader and the first wiring structure by metallized vias embedded in a dielectric layer of the second wiring structure and in contact with the backside surface of the heat spreader and the first surface of the first wiring structure. More specifically, the second wiring structure can be a multi-layered buildup circuitry without a core layer, and includes dielectric layers and conductive traces in repetition and alternate fashion. The innermost dielectric layer covers the backside surface of the heat spreader and the first surface of the first wiring structure. The conductive traces include metallized vias in the dielectric layer and extend laterally on the dielectric layer. Accordingly, the heat spreader, covered by the dielectric layer of the second wiring structure from the first direction, can be mechanically supported by the second wiring structure and electrically coupled to the second wiring structure by the metallized vias for ground connection.
[0106] The outmost conductive traces of the first and second wiring structures can respectively accommodate conductive joints, such as solder balls or bonding wires, for electrical communication and mechanical attachment with an assembly, an electronic device, an additional heat spreader or others. For instance, a semiconductor device may be a semiconductor chip and mounted over and electrically coupled to the second wiring structure through a plurality of bonding wires, or be a ball grid array package or a bumped chip and mounted over and electrically coupled to the first wiring structure or the second wiring structure through a plurality of solder balls. For the aspect of the semiconductor device being flip-chip mounted on the second wiring structure, an additional heat spreader may be mounted over the second wiring structure, and the semiconductor device can be disposed in a cavity of the additional heat spreader and thermally conductible to the additional heat spreader through a thermally conductive material. Further, the additional heat spreader may be electrically coupled to the second wiring structure for ground connection by, for example, solder balls in contact with the additional heat spreader and the outmost conductive traces of the second wiring structure. Additionally, when the first semiconductor chip or/and the optional second semiconductor chip is an optical chip, a lens optically transparent to at least one range of light wavelengths may be stacked over the first semiconductor chip and the optional second semiconductor chip, and mounted on the first wiring structure of the wiring board.
[0107] The bonding wires provide electrical connections between the first semiconductor chip and the first wiring structure and between the optional second semiconductor chip and the first wiring structure. In a preferred embodiment, the bonding wires contact and are attached to an active surface of the first/second semiconductor chip exposed from the through opening of the first wiring structure and the second surface of the first wiring structure. As a result, the first semiconductor chip and the optional second semiconductor chip can be electrically connected to the wiring board for external connection through the bonding wires.
[0108] Optionally, an array of vertical connecting elements may be further provided in electrical connection with the wiring board for next-level connection. Preferably, the vertical connecting elements contact and are electrically coupled to the first wiring structure from the second surface of the first wiring structure. The vertical connecting elements can include metal posts, solder balls or others, and may be laterally covered by an encapsulant. As the vertical connecting elements have a selected portion not covered by the encapsulant, a semiconductor device can be further provided to be electrically coupled to the vertical connecting elements.
[0109] The term “cover” refers to incomplete or complete coverage in a vertical and/or lateral direction. For instance, in a preferred embodiment, the heat spreader covers the first semiconductor chip in the first direction regardless of whether another element such as the thermally conductive material is between the first semiconductor chip and the heat spreader.
[0110] The phrases “attached to”, “attached on”, “mounted to” and “mounted on” includes contact and non-contact with a single or multiple element(s). For instance, in a preferred embodiment, the peripheral edges of the heat spreader are attached to the sidewalls of the through opening regardless of whether the peripheral edges of the heat spreader contact the sidewalls of the through opening or are separated from the sidewalls of the through opening by an adhesive.
[0111] The phrases “electrical connection”, “electrically connected” and “electrically coupled” refer to direct and indirect electrical connection. For instance, in a preferred embodiment, the bonding wires directly contact and are electrically connected to the first wiring structure, and the first semiconductor chip is spaced from and electrically connected to the first wiring structure by the bonding wires.
[0112] The “first direction” and “second direction” do not depend on the orientation of the semiconductor assembly, as will be readily apparent to those skilled in the art. For instance, the first surface of the first wiring structure faces the first direction and the second surface of the first wiring structure faces the second direction regardless of whether the semiconductor assembly is inverted. Thus, the first and second directions are opposite one another and orthogonal to the lateral directions. Furthermore, the first direction is the upward direction and the second direction is the downward direction when the outer surface of the second wiring structure faces in the upward direction, and the first direction is the downward direction and the second direction is the upward direction when the outer surface of the second wiring structure faces in the downward direction.
[0113] The semiconductor assembly according to the present invention has numerous advantages. For instance, as the first semiconductor chip is connected to the first wiring structure of the wiring board by bonding wires, not by direct build-up process, the simplified process steps result in lower manufacturing cost. The heat spreader can provide thermal dissipation, electromagnetic shielding and moisture barrier for the first semiconductor chip. The second wiring structure can provide mechanical support for the heat spreader and dissipate heat from the heat spreader. The semiconductor assembly made by this method is reliable, inexpensive and well-suited for high volume manufacture.
[0114] The manufacturing process is highly versatile and permits a wide variety of mature electrical and mechanical connection technologies to be used in a unique and improved manner. The manufacturing process can also be performed without expensive tooling. As a result, the manufacturing process significantly enhances throughput, yield, performance and cost effectiveness compared to conventional techniques.
[0115] The embodiments described herein are exemplary and may simplify or omit elements or steps well-known to those skilled in the art to prevent obscuring the present invention. Likewise, the drawings may omit duplicative or unnecessary elements and reference labels to improve clarity.