PCB module on package

Abstract

Aspects of the present disclosure provide a printed circuit board (PCB) system, which includes an integrated circuit (IC) package, a first PCB, and a PCB module. The IC package has a package substrate and an IC chip coupled to the top surface of the package substrate. The first PCB is configured to be electrically coupled to a first contact structure arranged on the bottom surface of the package substrate. The PCB module includes a second PCB and one or more electronic components electrically coupled to the second PCB. The PCB module is configured to be electrically coupled to a second contact structure arranged on the top surface of the package substrate.

Description

[0001] Incorporated by Reference

[0002] This disclosure claims the benefit of U.S. Provisional Application No. 62 / 625,808, filed on February 2, 2018, “MODULE ON PACKAGE (MOP)”, which is incorporated herein by reference in its entirety. Background Art

[0003] The background description provided herein is for the purpose of generally presenting the background of the present disclosure. The work of the inventors currently mentioned within the scope of the work described in this background technology section, as well as various aspects of the description that may not be prior art at the time of filing, are neither explicitly nor implicitly admitted as prior art against the present disclosure.

[0004] A printed circuit board (PCB) is typically formed of one or more patterned copper layers stacked on and / or between non-conductive sheets. PCBs use patterned copper layers to mechanically support and electrically connect electronic components such as integrated circuit (IC) packages, resistors, diodes, capacitors, transistors, etc. Summary of the invention

[0005] Aspects of the present disclosure provide a printed circuit board (PCB) system, which includes an integrated circuit (IC) package, a first PCB, and a PCB module. The IC package has a package substrate and an IC chip coupled to the top surface of the package substrate. The first PCB is configured to be electrically coupled to a first contact structure arranged on the bottom surface of the package substrate. The PCB module includes a second PCB and one or more electronic components electrically coupled to the second PCB. The PCB module is configured to be electrically coupled to a second contact structure arranged on the top surface of the package substrate.

[0006] In an example, the second contact structure is arranged on the top surface of the package substrate, in a peripheral area surrounding the IC chip.

[0007] In an embodiment, the PCB system includes an interposer that interconnects the PCB module with a second contact structure arranged on a top surface of the package substrate. In an example, the interposer is configured to provide a compression contact on at least one side of the interposer. For example, the PCB system includes a force component that is configured to apply a compressive force to the first PCB and the PCB module to interconnect the PCB module with the second contact structure of the IC package via the interposer.

[0008] According to aspects of the present disclosure, power is provided from the first PCB to the IC package via a first contact structure in a first contact structure on a bottom surface of the package substrate, and power is provided from the IC package to the PCB module via a second contact structure in a second contact structure on a top surface of the package substrate.

[0009] In an example, the second contact structure has a different density than the first contact structure. For example, the second contact structure has a higher density than the first contact structure.

[0010] In another example, a distance between the first PCB and the second PCB is less than a thickness of the IC package.

[0011] Aspects of the present disclosure provide a method for manufacturing a PCB system. The method includes mounting an integrated circuit (IC) package to a first PCB to electrically couple a first contact structure on a bottom surface of a package substrate of the IC package to a trace on the first PCB. Then, the method includes fastening a PCB module to the IC package and the first PCB. The PCB module includes a second PCB and one or more electronic components electrically coupled to the second PCB. Then, the trace on the second PCB is electrically coupled to a second contact structure on a top surface of the package substrate.

[0012] Aspects of the present disclosure also provide a printed circuit board (PCB) module. The PCB module includes a PCB substrate configured to have a first surface and a second surface opposite to the first surface. The PCB module includes electronic components mounted on the first surface of the PCB substrate, and includes a contact interface formed on the second surface of the PCB substrate to couple an integrated circuit (IC) package having a first contact structure and a second contact structure, the first contact structure being arranged on the bottom surface of the package substrate, and the second contact structure being arranged on the top surface of the package substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Various embodiments of the present disclosure, presented as examples, will be described in detail with reference to the following drawings, in which like reference numerals represent like elements, and in which:

[0014] Figure 1A-Figure 1C A printed circuit board (PCB) system 100 is shown according to an embodiment of the present disclosure.

[0015] Figure 2 A flow chart outlining a process example 200 according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0016] Aspects of the present disclosure provide a printed circuit board (PCB) system, which includes at least one first PCB and at least one second PCB. At least one second PCB is configured as a PCB module. As used in the present disclosure, a PCB module refers to a PCB substrate to which an integrated circuit (IC) or other electronic component is appropriately coupled. According to an embodiment, the ICs are not directly attached to the PCB, but the ICs are packaged in an IC package, which is then coupled to the PCB. The IC package includes a package substrate for mechanical support and for improving the electrical connectivity of one or more IC chips included in the IC package. In an embodiment, the IC chip coupled to the package substrate is also packaged to form an IC package. The package substrate has a first surface (also referred to as a bottom surface) and a second surface (also referred to as a top surface) opposite to the first surface. The IC package includes a first contact structure such as a contact pad, a solder ball, etc., the first contact structure is formed on a first surface (e.g., a bottom surface) of the package substrate, and also includes a second contact structure formed on a second surface (e.g., a top surface) of the package substrate. The IC package is electrically connected to the first PCB via the first contact structure on the first surface of the IC package, and the IC package is electrically connected to the PCB module via the second contact structure on the second surface of the IC package. In some embodiments, an interposer is used to couple, for example, a PCB module and a second contact structure of an IC package.

[0017] Figure 1A-Figure 1C Different views of a PCB system 100 are shown according to some embodiments of the present disclosure. Figure 1A shows a perspective view of a PCB system 100, Figure 1B A cross-sectional view of a PCB system 100 is shown, and Figure 1C FIG. 1 shows a top view of the PCB system 100. Figure 1A The PCB system 100 shown in FIG. 1 includes a first PCB 110 (also referred to as a main PCB), a PCB module 140 (also referred to as a module on a package when coupled to an IC package 120 (also referred to as a bottom package)). The IC package 120 encapsulates one or more IC chips (such as an IC chip 121 encapsulated in the IC package 120) and forms a main PCB module when coupled to the first PCB 110. The IC package 120 includes contacts electrically connected to the first PCB 110 or the PCB module 140.

[0018] The IC package 120 includes a package substrate 122 having a first surface 123 (also referred to as a bottom surface) and a second surface 124 (also referred to as a top surface) opposite to the first surface 123. The package substrate 122 is made of, for example, a suitable insulating material (also referred to as a dielectric material, such as an epoxy-based laminate substrate, a resin-based bismaleimide-triazine (BT) substrate, etc.). The package substrate 122 is relatively rigid to provide mechanical support to the IC chip 121. The IC chip 121 is arranged on a surface such as the second surface 124 of the package substrate 122. In addition, in some examples, in an embodiment, the IC package 120 includes a metal cover 125, which covers the IC chip 121, for example to protect the IC chip 121 and facilitate rapid heat dissipation during operation when the IC chip 121 is powered on. Figure 1A A close-up view is shown when the metal cover 125 is open and the IC chip 121 is exposed.

[0019] The package substrate 122 also provides electrical support for the IC chip 121, such as electrical connection for the IC chip, so as to facilitate the coupling of the IC chip with the PCB. In some examples, the package substrate 122 includes multiple layers of metal traces (such as copper wires, etc., with insulating materials therebetween). In various embodiments, the metal traces on different layers are connected by conductive vias. In addition, contact structures are formed on both the first surface 123 and the second surface 124 to electrically connect the IC chip 121 in the IC package 120 to electronic components (such as the first PCB 110 and the PCB module 140, etc.) outside the IC package 120.

[0020] IC chip 121 can be any suitable integrated circuit chip, such as, for example, an integrated circuit processor, a controller, a transceiver, a switch device, a system on chip, etc. IC chip 121 includes various circuits for providing computing and / or processing functions. In some examples, IC chip 121 receives suitable signals (such as analog signals, digital signals, control signals, data signals, etc.) from components outside IC package 120, and processes the received signals. In some examples, IC chip 121 generates suitable signals (such as analog signals, digital signals, control signals, data signals, etc.), and outputs the generated signals to components outside IC package 120.

[0021] In an embodiment, the IC package 120 is used in a high-speed network switching device for packet switching. For example, the IC chip 121 includes a core circuit for packet processing, and a peripheral circuit for interface (input / output) processing, such as receiving and / or transmitting a signal carrying a packet. In an example, the IC chip 121 includes one or more packet processors configured to perform packet processing (including but not limited to packet forwarding). The IC chip 121 also includes interface circuits, such as modulation / demodulation circuits, memory circuits for queuing packets, etc. In an example, the IC chip 121 includes a serializer / deserializer (SERDES) configured to convert data between serial data and parallel data. In addition, in an example, the IC chip 121 includes a modulation / demodulation circuit with a suitable modulation technology (such as pulse amplitude modulation (PAM)-4, PAM-8, etc.). In addition, in an example, the IC chip 121 includes a coding / decoding circuit with a suitable coding technology (such as non-return to zero (NRZ), non-return to zero inverse (NRZI), return to zero (RZ), etc.).

[0022] The package substrate 122 provides interconnections from the input / output of the IC chip 121 to the contact structures formed on the first surface 123 and the second surface 124 of the IC package 120. In the example, the IC chip 121 is a flip chip. The IC chip 121 includes an input / output (I / O) pad (not shown) electrically connected to the internal circuit formed on the IC chip 121. Then, solder bumps are deposited on the I / O pads by a suitable manufacturing process to form a protruding structure on the surface of the flip chip. The second surface 124 of the package substrate 122 includes solder bumps (not shown) that match the protruding structure on the IC chip 121. In the example, the IC chip 121 is arranged on the second surface 124 so that the protruding structure on the IC chip 121 is aligned with the solder bumps on the second surface 124 of the package substrate 122. Then, a reflow process is performed to form a connection between the protruding structure and the solder bumps.

[0023] Note that in another example, the IC chip 121 may be wire bonded to form an electrical connection with the package substrate 122 .

[0024] exist Figure 1A-Figure 1C In the example shown, package substrate 122 includes first contact structures 126 formed on first surface 123 and second contact structures 127 formed on second surface 124. In addition, package substrate 122 includes metal traces (not shown) that electrically connect solder bumps to first contact structures 126 and second contact structures 127.

[0025] According to aspects of the present disclosure, the second contact structure 127 and the IC chip 121 are arranged on the same surface side of the package substrate 122. In some embodiments, the second contact structure 127 is arranged at a peripheral area around the IC chip 121 (such as, the area between the metal cover 125 for the IC chip 121 and the edge of the second surface 124).

[0026] The first contact structure 126 and the second contact structure 127 may be any suitable contact structures. In an embodiment, the IC package 120 is a ball grid array (BGA) package, and each of the first contact structure 126 and the second contact structure 127 includes a pad and a solder ball deposited on the pad. In another embodiment, the IC package 120 is a land grid array (LGA) package, and each of the first contact structure 126 and the second contact structure 127 includes a pad. In another embodiment, the IC package 120 is a pin grid array (PGA) package, and each of the first contact structure 126 and the second contact structure 127 includes a pin.

[0027] It should be noted that in some embodiments, the second contact structure 127 is implemented using a different technology than the first contact structure 126. For example, the first contact structure 126 is implemented using a pad and a solder ball, and the second contact structure 127 is implemented using only a pad.

[0028] exist Figure 1A In the example of FIG. 1 , the second contact structure 127 is shown as a circle. In some examples, the first contact structure 126 and the second contact structure 127 have other suitable shapes, such as a sphere, a square, a needle, etc.

[0029] According to aspects of the present disclosure, the first contact structure 126 and the second contact structure 127 are respectively configured to use appropriate techniques to achieve electrical connection with other components. In an example, the first contact structure 126 is configured to use a soldering technique to achieve electrical connection with the first PCB 110. For example, when the IC package 120 is mounted on the first PCB 110, a solder reflow process is performed to form solder joints, so that the first contact structure 126 is connected to the corresponding contact structure on the first PCB 110.

[0030] In addition, in an embodiment, the second contact structure 127 is configured to achieve electrical connection with the PCB module 140 via the interposer 130. Specifically, the PCB module 140 includes a contact interface 142 at a surface facing the interposer 130 and the first PCB 110, such as by Figure 1A The contact interface 142 includes a plurality of contact structures 141 corresponding to the second contact structures 127 .

[0031] In addition, the interposer 130 includes a plurality of interconnect structures 131 to interconnect the corresponding contact structures 141 of the PCB module 140 and the second contact structures 127 of the IC package 120. Each interconnect structure 131 is configured to make a first connection with the second contact structure 127 and a second connection with the contact structure 141 using a suitable technique. In an embodiment, each interconnect structure 131 is a double compression structure using a compression connection for the first connection and the second connection. In another embodiment, each interconnect structure 131 is a single compression structure with solder balls, which uses solder balls for the first connection and a compression connection for the second connection.

[0032] Figure 1A A close-up view of one side of an interconnect structure 131 configured for a compression connection. The interconnect structure 131 includes a metal tongue 132 that protrudes from a surface of the interposer 130 and can be pushed into the surface under a compressive force.

[0033] In an embodiment, the PCB system 100 includes a force generating component that can apply a compressive force to cause the interposer 130 to interconnect the PCB module 140 with the second contact structure 127. For example, the first PCB 110 and the PCB module 140 are designed and manufactured with holes that can be aligned for arranging bolts. After the IC package 120 is mounted on the first PCB 110, the interposer 130 and the PCB module 140 are aligned and stacked. It should be noted that a suitable spacer 111 can be inserted to keep the PCB module 140 horizontal on the first PCB 110. The bolts 112 and 114 are then tightened to the corresponding nuts 113 and 115 to lock the first PCB 110, the interposer 130 and the PCB module 140 in place, and a compressive force is applied to cause the interposer 130 to interconnect the contact structure 141 of the PCB module 140 with the second contact structure 127 of the IC package 120.

[0034] According to aspects of the present disclosure, the PCB module 140 includes a PCB (also referred to as a second PCB) and electronic components (such as resistors, diodes, capacitors, transistors, integrated circuit (IC) packages, etc.) that have been mounted on the PCB. The first PCB 110 and the second PCB in the PCB module 140 are configured similarly. For example, the first PCB 110 and the second PCB respectively include multi-layer metal traces (such as copper wires, etc.) arranged on a multi-layer sandwich structure of a dielectric material. In some examples, the first PCB 110 and the second PCB have different numbers of metal layers. For example, the first PCB 110 has more metal layers and is the main PCB of the PCB system 100. The second PCB provides additional electrical connection support for any suitable electronic components (such as integrated circuit (IC) packages, resistors, diodes, capacitors, transistors, etc. that can be mounted on the second PCB to form the PCB module 140).

[0035] exist Figure 1A-Figure 1C In the example of FIG. 1 , a conventional IC package 150 (also referred to as an upper package) is mounted on an upper surface of the second PCB (e.g., opposite to a surface facing the first PCB 110) to form a PCB module 140. The conventional IC package 150 includes a contact structure on one side of the package substrate, rather than on both sides of the package substrate.

[0036] According to aspects of the present disclosure, the interposer 130 has high density and low profile. In an example, the interposer 130 has a pitch grid of 0.80 mm (e.g., less than the solder ball pitch) and has a body height of 1 mm (0.33 mm height for the shortest signal path). Therefore, in an example, the distance between the two PCB modules 110 and 140 is less than the height of the IC package 120.

[0037] In an embodiment, the pitch grid of interposer 130 is less than the solder ball pitch requirement. In an example, the density of second contact structures 127 is higher than the density of first contact structures 126. IC package 120 uses both sides of the package substrate to provide input / output (IO) and can be implemented with a reduced package size.

[0038] In another embodiment, the electrical connection from the second contact structure 127 of the IC package 120 to, for example, the upper package 150 is through the interposer 130, which provides a relatively short signal path compared to other interconnect technologies, such as package plated through hole (PTH) vias, PCB PTH, PCB, etc. Therefore, the electrical connection from the second contact structure 127 to the upper package 150 via the interposer 130 has less attenuation than other interconnect technologies, and thus can be used for high-speed signal transmission, such as (but not limited to) data rates exceeding 50 Gbps.

[0039] In another embodiment, power supply is provided from the first PCB 110 to the PCB module 140 via the IC package 120 (eg, via one of the first contact structures 126 , some metal traces in the package substrate 122 , and one of the second contact structures 127 ) and the interposer 130 .

[0040] Figure 2 A flow chart outlining a process example 200 according to an embodiment of the present disclosure is shown. In an example, the process 200 is used to form a PCB system, such as the PCB system 100. The process starts at S201 and proceeds to S210.

[0041] At S210, the IC package is mounted to the first PCB by coupling the first contact structure of the IC package to the first PCB, thereby forming a first PCB module. For example, the IC package 120 is mounted on the first PCB 110. Specifically, the first contact structure 126 is aligned with the corresponding contact structure on the first PCB 110 and mounted on the first PCB 110. In an example, a solder reflow process is performed to form a solder joint that forms an electrical connection between the IC package and the first PCB 110, wherein the contact structure 126 is connected to the corresponding contact structure on the first PCB 110.

[0042] At S220, the interposer and the second PCB module are stacked and aligned with the IC package of the first PCB module. In an example, the PCB module 140 is preformed by mounting the upper IC 150 on the second PCB. The interposer 130 is arranged on the second contact structure 127 and aligned with the second contact structure 127. The PCB module 140 is arranged on the interposer 130, and the contact structure 141 is aligned with the relative interconnection structure 131 of the interposer 130. In some embodiments, the spacer 111 can be inserted to make the PCB module 140 level on the first PCB 110.

[0043] At S230, the second PCB module is fastened to the first PCB module to apply a compressive force on the interposer. For example, the first PCB 110 and the second PCB in the PCB module 140 are designed and manufactured with holes that can be aligned to arrange bolts or other suitable fasteners. Bolts 112 and 114 are then fastened to corresponding nuts 113 and 115 to lock the first PCB 110, the interposer 130 and the PCB module 140 in place, and apply a compressive force to allow the interposer 130 to interconnect the contact structure 141 of the PCB module 140 with the second contact structure 127 of the IC package 120. Then, the process proceeds to S299 and terminates.

[0044] It should be noted that in various embodiments, other suitable process steps may be performed for manufacturing semiconductor devices before process 200, between steps in process 200, and / or after process 200. In an example, before S220, the upper package 150 is mounted on the second PCB to form the PCB module 140.

[0045] Although aspects of the present disclosure have been described in conjunction with the specific embodiments of the present disclosure proposed as examples, the examples may be replaced, modified, and varied. Therefore, the embodiments set forth herein are intended to be illustrative rather than restrictive. Changes may be made without departing from the scope of the claims set forth below.

Claims

1. A printed circuit board (PCB) system, comprising: a first integrated circuit package having a package substrate and an IC chip coupled to a top surface of the package substrate, the package substrate having an edge; a first PCB configured to be electrically coupled to a first contact structure disposed on a bottom surface of the package substrate, the first PCB having a first number of layers; a PCB module comprising a second PCB and one or more electronic components electrically coupled to the second PCB, the one or more electronic components comprising a second integrated circuit package mounted on the second PCB, wherein the second PCB comprises a second number of layers less than the first number of layers, the PCB module being configured to be electrically coupled to a second contact structure arranged on the top surface of the package substrate, the second PCB extending beyond the edge of the package substrate and being located above the first PCB; and A plurality of compression interconnect structures are configured to interconnect the PCB module with the second contact structure arranged on the top surface of the packaging substrate, and the plurality of compression interconnect structures are configured to form contacts maintained by compression force between the second contact structure and the corresponding contact structure on the PCB module on at least one side of the compression interconnect structure.

2. The PCB system according to claim 1, wherein: The second contact structure is arranged on the top surface of the packaging substrate in a region between the IC chip and the edge of the packaging substrate.

3. The PCB system according to claim 1, wherein: The plurality of compression interconnect structures are arranged in an interposer configured to interconnect the PCB module with the second contact structure arranged on the top surface of the package substrate. 4 . The PCB system of claim 3 , wherein the interposer is configured to provide compression contacts on at least one side of the interposer.

5. The PCB system according to claim 4, further comprising: A force component is configured to apply a compressive force to the first PCB and the PCB module to interconnect the PCB module with the second contact structure of the first integrated circuit package via the interposer.

6. The PCB system according to any one of claims 1 to 5, wherein: Power supply is provided from the first PCB to the first integrated circuit package via the first contact structure in the first contact structure on the bottom surface of the packaging substrate, and the power supply is provided from the first integrated circuit package to the PCB module via the second contact structure in the second contact structure on the top surface of the packaging substrate.

7. The PCB system according to any one of claims 1 to 5, wherein The second contact structure has a different density than the first contact structure.

8. The PCB system of claim 7, wherein the second contact structure has a higher density than the first contact structure.

9. The PCB system according to any one of claims 1 to 5, wherein A distance between the first PCB and the second PCB is smaller than a thickness of the first integrated circuit package.

10. A method for manufacturing a printed circuit board (PCB) system, comprising: mounting the integrated circuit package to a first PCB to electrically couple a first contact structure on a bottom surface of a package substrate of the first integrated circuit package to a trace on the first PCB, the first PCB having a first number of layers and the package substrate having an edge; as well as A PCB module is fastened to the integrated circuit package and the first PCB, the PCB module comprising a second PCB and one or more electronic components electrically coupled to the second PCB, the second PCB having a second number of layers less than the first number of layers, the one or more electronic components comprising a second integrated circuit package mounted on the second PCB, wherein traces on the second PCB are electrically coupled to second contact structures on the top surface of the package substrate through a plurality of compression interconnect structures, the plurality of compression interconnect structures being configured to form contacts maintained by compression force between the second contact structures arranged on the top surface of the package substrate and corresponding contact structures on the second PCB on at least one side of the compression interconnect structures, wherein after the PCB module is fastened to the first integrated circuit package and the first PCB, the second PCB extends beyond the edge of the package substrate and is located above the first PCB.

11. The method of claim 10, wherein fastening the PCB module to the integrated circuit package and the first PCB further comprises: An interposer is disposed between the PCB module and the second contact structure, the interposer including a plurality of interconnect structures to interconnect the PCB module with the second contact structure disposed on the top surface of the package substrate.

12. The method according to claim 11, further comprising: A compressive force is applied to the interposer to interconnect the PCB module with the second contact structure of the integrated circuit package.

13. The method according to claim 12, further comprising: Tighten the bolts to apply the compressive force.

14. The method according to any one of claims 10 to 13, further comprising: A power supply is provided from the first PCB to the PCB module via at least a first one of the first contact structures on the bottom surface of the packaging substrate and a second one of the second contact structures on the top surface of the packaging substrate.

15. A printed circuit board (PCB) module, configured to be electrically coupled to a first integrated circuit (IC) package having a package substrate with an edge, the package substrate having a first contact structure arranged on a bottom surface of the package substrate and a second contact structure arranged on a top surface of the package substrate, the first contact structure arranged on the bottom surface of the package substrate being used to electrically couple to a main PCB having a first number of layers, the PCB module comprising: A PCB substrate, configured to have a first surface and a second surface opposite to the first surface, the PCB substrate including a second number of layers less than the first number of layers; an electronic component mounted on the first surface of the PCB substrate, the electronic component comprising a second IC mounted on the first surface of the PCB substrate; as well as A contact interface is formed on the second surface of the PCB substrate to couple the integrated circuit IC, the contact interface has a plurality of third contact structures, the plurality of third contact structures are configured to be coupled to the second contact structures arranged on the top surface of the package substrate, so that when the third contact structures are coupled to the second contact structures arranged on the top surface of the package substrate, the PCB substrate extends beyond the edge of the package substrate and is located above the main PCB, wherein the plurality of third contact structures of the contact interface are configured to be coupled with a plurality of compression interconnect structures, the plurality of compression interconnect structures are configured to form contacts maintained by compression force on at least one side of the compression interconnect structure, between the second contact structures arranged on the top surface of the package substrate and the corresponding contact structures on the PCB module.

16. The PCB module according to claim 15, wherein the plurality of third contact structures of the contact interface are configured to be coupled with the second contact structures arranged in a peripheral area surrounding an IC chip, and the IC chip is coupled on the top surface of the packaging substrate.

17. The PCB module of claim 15, wherein the contact interface is configured to couple with an interposer, the plurality of compression interconnect structures being disposed on the interposer.

18. The PCB module of claim 15, wherein a plurality of compression structures are disposed on an interposer interconnecting the PCB module with the second contact structure disposed on the top surface of the package substrate.

19. The PCB module according to claim 18, wherein: The PCB substrate defines a hole structure configured to receive a bolt for tightening to exert a compressive force on the interposer.

20. The PCB module according to any one of claims 16 to 19, wherein: One of the third contact structures of the contact interface is positioned to accept a power supply, which is provided from the main PCB, via one of the first contact structures on the bottom surface of the packaging substrate, and via one of the second contact structures on the top surface of the packaging substrate.

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