Module based on three-dimensional stacking structure and preparation method thereof

Abstract

The present invention proposes a module based on a three-dimensional stacking structure and a preparation method thereof, wherein the structure comprises: an upper circuit substrate, an intermediate layer, a lower circuit substrate and a shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure; the intermediate layer is composed of a filling material and a solder ball array, the solder ball array is vertically interconnected between the upper circuit substrate and the lower circuit substrate, and the upper circuit substrate and the lower circuit substrate are covered with a filling material; if the filling material is a conductive material, an annular prefabricated block for preventing signal mutual interference between solder balls and preventing non-grounded solder ball signal short circuit is provided outside the non-grounded solder ball. The present invention fills conductive material between two circuit substrates of a module based on a three-dimensional stacking structure, so that the grounding of the upper circuit substrate is better and the radio frequency performance is high, and the isolation between the circuit substrates is ensured by using the solder ball array, thereby improving the module's ability to suppress electromagnetic interference.

Description

Technical Field

[0001] The present invention relates to the technical field of stacked structures, and in particular to a module based on a three-dimensional stacked structure and a preparation method thereof. Background Art

[0002] With the rapid development of modern electronic technology, electronic devices are required to be increasingly miniaturized and high-density in order to reduce the manufacturing cost of electronic devices while meeting performance requirements. However, due to the continuous improvement of the functional and performance requirements of electronic devices, it is difficult to improve the integration level by relying solely on conventional two-dimensional planar circuit substrates, and electronic devices cannot be further miniaturized. In related technologies, stacking integration technology is usually used to vertically interconnect two functional circuit substrates through ball planting, so that the two functional circuit substrates are stacked together to form a module with a three-dimensional stacking structure, thereby forming an integrated circuit with higher performance, higher integration, and smaller size, so as to make electronic devices more miniaturized.

[0003] However, in the module of the three-dimensional stacked structure, the circuit substrates at each position cannot all be electromagnetically isolated, resulting in electromagnetic interference problems based on the three-dimensional stacked structure. In addition, the circuit substrates are interconnected by BGA (Ball Grid Array Package) solder balls, which makes the upper circuit board prone to poor grounding, resulting in poor RF signal transmission performance. In addition, due to the long heat dissipation path of the three-dimensional stacked structure and the low thermal conductivity of the circuit substrate, heat is easily accumulated, resulting in difficulties in heat dissipation and low thermal reliability of the three-dimensional stacked structure, making it impossible to apply it to scenarios with high heat consumption, limiting the application scope of the three-dimensional stacked structure. Summary of the invention

[0004] The present invention provides a module based on a three-dimensional stacking structure to solve the technical problems existing in the prior art; and also provides a method for preparing the module based on the three-dimensional stacking structure.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] In the first aspect, the present invention provides a module based on a three-dimensional stacking structure, comprising: an upper circuit substrate, a lower circuit substrate, an intermediate layer and a shell substrate, wherein the upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure; the intermediate layer is composed of a filling material and a solder ball array, the solder ball array is vertically interconnected between the upper circuit substrate and the lower circuit substrate, and the upper circuit substrate and the lower circuit substrate are covered with the filling material; the filling material is an insulating material or a conductive material, and if the filling material is a conductive material, then a ring-shaped prefabricated block is provided outside the non-grounded solder balls in the solder ball array to prevent signal interference between solder balls and prevent the non-grounded solder ball signals from short-circuiting.

[0007] In one embodiment of the present invention, the non-grounded solder ball located at the center of the solder ball array is used as the middle solder ball. If the filling material is a conductive material, the middle solder ball sleeved by the annular prefabricated block, the grounded solder balls around the middle solder ball and the filling material constitute a coaxial structure; if the filling material is an insulating material, the middle solder ball and the grounded solder balls around the middle solder ball constitute a quasi-coaxial structure.

[0008] In one embodiment of the present invention, the height of the annular prefabricated block matches the solder ball array, and the inner diameter of the annular prefabricated block is larger than the diameter of the solder balls in the solder ball array.

[0009] In one embodiment of the present invention, the intermediate layer further includes a flow channel shaped prefabricated block, the flow channel shaped prefabricated block is distributed in the filling material, and the flow channel of the flow channel shaped prefabricated block covers at least a portion of the solder balls in the solder ball array.

[0010] In one embodiment of the present invention, the lower circuit substrate is provided with a first liquid through hole, which is communicated with the area where the channel shape prefabricated block is located, and the shell substrate is provided with a second liquid through hole, which is communicated with the first liquid through hole.

[0011] In one embodiment of the present invention, the channel shape prefabricated block is made of a sacrificial material, and the channel shape prefabricated block in the middle layer is dissolved by injecting a corrosive liquid into the second liquid hole to form the channel in the middle layer.

[0012] In one embodiment of the present invention, a plurality of metal holes are disposed on the bottom surface of the upper circuit substrate, and the metal holes are connected to the middle layer.

[0013] In one embodiment of the present invention, the top surface of the upper circuit substrate and the top surface of the lower circuit substrate respectively include at least one cavity, in which a device is disposed. The device is installed in the cavity by bonding, bonding or welding, and partition beams are provided between the plurality of cavities, and the partition beams are higher than the height of the device.

[0014] In one embodiment of the present invention, the module based on the three-dimensional stacking structure also includes a packaging component, which includes an inner cover plate, a surrounding frame and an outer cover plate. The inner cover plate is bonded to the top of the upper circuit substrate, the lower end of the surrounding frame is welded to the four sides of the top surface of the outer shell substrate, and the upper end of the surrounding frame is welded to the outer cover plate.

[0015] In one embodiment of the present invention, the inner cover plate is provided with an opening, and the opening is located directly above the partition beam in the upper circuit substrate. The top surface of the partition beam corresponding to the opening area is provided with a metal pad, and the metal pad is used to weld the inner cover plate to the top surface of the upper circuit substrate.

[0016] In a second aspect, the present invention provides a method for preparing a module based on a three-dimensional stacking structure, the method comprising: providing an upper circuit substrate, a lower circuit substrate, a shell substrate, a solder ball array, an annular prefabricated block and a filling material; welding one end of the solder ball array to the bottom surface of the upper circuit substrate or the top surface of the lower current substrate, wherein if the filling material is a conductive material, the annular prefabricated block is used to surround the non-grounded solder balls in the solder ball array, the annular prefabricated block is an insulating material, matches the height of the solder ball array, and the inner circle diameter of the annular prefabricated block is larger than the diameter of the solder balls in the solder ball array; the solder ball array is used to connect the bottom surface of the upper circuit substrate and the top surface of the lower circuit substrate, so that the upper circuit substrate and the lower circuit substrate are vertically interconnected; the filling material is filled between the upper circuit substrate and the lower circuit substrate to form an intermediate layer, and the upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure; or,

[0017] Provide the upper circuit substrate, the lower circuit substrate, the shell substrate, the solder ball array and the filling material; solder one end of the solder ball array to the bottom surface of the upper circuit substrate or the top surface of the lower circuit substrate; if the filling material is an insulating material, use the solder ball array to connect the bottom surface of the upper circuit substrate and the top surface of the lower circuit substrate, so that the upper circuit substrate and the lower circuit substrate are vertically interconnected; fill the filling material between the upper circuit substrate and the lower circuit substrate to form an intermediate layer, and the upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure.

[0018] In a third aspect, the present invention also provides a method for preparing a module based on a three-dimensional stacking structure, the method comprising: providing an upper circuit substrate, a lower circuit substrate, a shell substrate, a solder ball array, an annular prefabricated block, a flow channel shape prefabricated block and a filling material; welding one end of the solder ball array to the bottom surface of the upper circuit substrate or the top surface of the lower current substrate, wherein if the filling material is a conductive material, the annular prefabricated block is used to surround the non-grounded solder balls in the solder ball array, the annular prefabricated block is an insulating material, matches the height of the solder ball array, and the inner circle diameter of the annular prefabricated block is larger than the diameter of the solder balls in the solder ball array; after the flow channel shape prefabricated block is nested in at least a part of the solder balls in the solder ball array, use The solder ball array connects the bottom surface of the upper circuit substrate and the top surface of the lower circuit substrate, so that the upper circuit substrate and the lower circuit substrate are vertically interconnected; the filling material is filled between the upper circuit substrate and the lower circuit substrate to form an intermediate layer, and the upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure; liquid holes communicating with the area of ​​the flow channel shape prefabricated block are respectively provided in the lower circuit substrate and the shell substrate; a corrosive liquid is injected into the area of ​​the flow channel shape prefabricated block through the liquid hole to dissolve the flow channel shape prefabricated block, and a prefabricated flow channel is formed in the intermediate layer, and the flow channel shape prefabricated block is made of a sacrificial material; or,

[0019] The upper circuit substrate, the lower circuit substrate, the shell substrate, the solder ball array, the flow channel shape prefabricated block and the filling material are provided; one end of the solder ball array is welded to the bottom surface of the upper circuit substrate or the top surface of the lower circuit substrate; if the filling material is an insulating material, the flow channel shape prefabricated block is nested in at least a part of the solder balls in the solder ball array; the solder ball array is used to connect the bottom surface of the upper circuit substrate and the top surface of the lower circuit substrate, so that the upper circuit substrate and the lower circuit substrate are vertically interconnected; the filling material is welded to ... A filling material is filled between the upper circuit substrate and the lower circuit substrate to form an intermediate layer, and the upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure; liquid holes communicating with the region of the flow channel shape prefabricated block are respectively arranged in the lower circuit substrate and the shell substrate; a corrosive liquid is injected into the region of the flow channel shape prefabricated block through the liquid holes to dissolve the flow channel shape prefabricated block, and a prefabricated flow channel is formed in the intermediate layer, and the flow channel shape prefabricated block is made of a sacrificial material.

[0020] Beneficial effects of the present invention:

[0021] First, the upper circuit substrate, the middle layer, the lower circuit substrate and the shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure. The middle layer is composed of a filling material and a solder ball array. The solder ball array is vertically interconnected between the upper circuit substrate and the lower circuit substrate, so that a cavity is formed between the upper circuit substrate and the lower circuit substrate, thereby ensuring the isolation between the upper circuit substrate and the lower circuit substrate, forming electromagnetic isolation, and improving the module's ability to suppress electromagnetic interference.

[0022] Second, the upper circuit substrate and the lower circuit substrate are covered with a filling material; the filling material is an insulating material or a conductive material. By filling the conductive material between the two circuit substrates, the grounding of the upper circuit board is better, the radio frequency performance of the signal transmission between the circuit substrates is high, and the non-grounded solder balls in the solder ball array are provided with an annular prefabricated block outside for preventing signal interference between solder balls and preventing non-grounded solder ball signal short circuit, so as to avoid signal interference between the solder balls.

[0023] In addition, by setting a flow channel in the middle layer to transfer the heat accumulated in the circuit substrate to the outside of the module in time, the heat dissipation capacity of the module based on the three-dimensional stacking structure is improved, and the performance of each device on the circuit substrate is prevented from being affected by the temperature rise. The reliability of each device is high, so that the module can be used in scenarios with high heat consumption, expanding the application range of modules based on the three-dimensional stacking structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a cross-sectional schematic diagram of a module based on a three-dimensional stacking structure shown in an exemplary embodiment of the present invention;

[0025] Figure 2 is a top view showing an annular prefabricated block sleeved on a non-grounded solder ball according to an exemplary embodiment of the present invention;

[0026] Figure 3 is a cross-sectional schematic diagram of a module with a flow channel based on a three-dimensional stacking structure according to an exemplary embodiment of the present invention;

[0027] Figure 4 is a top view of a flow channel shaped prefabricated block sleeved on a solder ball according to an exemplary embodiment of the present invention;

[0028] Figure 5 is a flow chart of a method for preparing a module based on a three-dimensional stacking structure shown in an exemplary embodiment of the present invention;

[0029] Figure 6 is a flow chart showing another method for preparing a module based on a three-dimensional stacking structure according to an exemplary embodiment of the present invention;

[0030] Among them, 1-outer cover plate; 2-inner cover plate; 3-opening; 4-cavity of upper circuit substrate; 5-heat-conducting metal hole; 6-metal pad; 7-surrounding frame; 8-upper circuit substrate; 9-solder ball array; 10-lower circuit substrate; 11-shell substrate; 12-cavity of lower circuit substrate; 13-filling material; 14-annular prefabricated block; 15-first liquid hole; 16-second liquid hole; 17-channel shape prefabricated block; 18-solder ball for transmitting ground signal; 19-solder ball for transmitting high-frequency signal; 20-solder ball for transmitting low-frequency signal. DETAILED DESCRIPTION

[0031] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers.

[0032] The diagram provided in the following embodiments only illustrates the basic conception of the present invention in a schematic manner, and only the components related to the present invention are shown in the diagram, so that people familiar with this technology can understand and read, and are not drawn according to the number, shape and size of components during actual implementation, so there is no substantial technical significance. The pattern, quantity and ratio of each component during its actual implementation can be a kind of arbitrary change, and its component layout pattern may also be more complicated, without affecting the effect that the present invention can produce and the purpose that can be achieved, all should still fall within the scope that the technical content disclosed by the present invention can cover. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" etc. quoted in this specification are also only for the convenience of narration, rather than for limiting the scope that the present invention can implement, and the change or adjustment of its relative relationship is also regarded as the scope that the present invention can implement without substantially changing the technical content.

[0033] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any methods, equipment and materials of the prior art similar or equivalent to the methods, equipment and materials described in the embodiments of the present invention can also be used to implement the present invention.

[0034] See also Figure 1 , is a cross-sectional schematic diagram of a module based on a three-dimensional stacking structure shown in an exemplary embodiment of the present invention.

[0035] This embodiment provides a module based on a three-dimensional stacking structure, such as Figure 1 As shown, the module based on the three-dimensional stacking structure at least includes an upper circuit substrate 8, a lower circuit substrate 10, an intermediate layer and a shell substrate 11, an upper circuit substrate 8; wherein the intermediate layer, the lower circuit substrate 10 and the shell substrate 11 are stacked in sequence to form a module based on the three-dimensional stacking structure; the intermediate layer is composed of a filling material 13 and a solder ball array 9, the solder ball array 9 is vertically interconnected between the upper circuit substrate 8 and the lower circuit substrate 10, and the upper circuit substrate 8 and the lower circuit substrate 10 are covered with a filling material 13; the filling material 13 is an insulating material or a conductive material. If the filling material 13 is a conductive material, an annular prefabricated block 14 is provided outside the non-grounded solder balls in the solder ball array 9 for preventing signal interference between solder balls and preventing non-grounded solder ball signal short circuit.

[0036] Specifically, the solder ball array 9 is soldered between the upper circuit substrate 8 and the lower circuit substrate 10 by means of ball planting. The upper circuit substrate 8 forms a cavity with the lower circuit substrate 10 through the solder ball array 9, thereby improving the isolation of the lower circuit substrate 10, so that the lower circuit substrate 10 forms electromagnetic isolation, and reduces signal interference such as crosstalk and stray interference. Among them, the solder ball 9 array can be fully distributed or partially distributed, and the specific structure and size of the solder ball array 9 can be adaptively changed according to actual needs.

[0037] In this embodiment, the non-grounded solder ball located at the center of the solder ball array 9 is used as the middle solder ball. If the filling material 13 is a conductive material, the middle solder ball sleeved with the annular prefabricated block 14, the grounded solder balls around the middle solder ball and the filling material 13 constitute a coaxial structure; if the filling material 13 is an insulating material, the middle solder ball and the grounded solder balls around the middle solder ball constitute a quasi-coaxial structure.

[0038] See also Figure 2 , which is a top view of the annular prefabricated block being sleeved on the non-grounded solder ball.

[0039] like Figure 2 As shown, the middle solder ball is used for transmitting RF signals. Figure 2 The solder ball 19 in the middle transmits high-frequency signals, and the ground solder balls surrounding the middle solder ball are used as signal ground, that is, Figure 2 The six solder balls 18 for transmitting ground signals surrounding the solder ball 19 for transmitting high frequency signals serve as signal grounds. If the filling material 13 is an insulating material, then the ground solder balls are independent of each other. Figure 2The solder balls 19 for transmitting high-frequency signals and the solder balls 18 for transmitting ground signals form a quasi-coaxial structure; if the filling material 13 is a conductive material, the grounding solder balls will be connected to each other, so that the grounding of the upper circuit substrate is better, and Figure 2 The solder ball 19 for transmitting high frequency signals and the solder ball 18 for transmitting ground signals will form a coaxial structure, further improving the ability of radio frequency signal transmission.

[0040] Specifically, when the filling material 13 is a conductive material, the annular prefabricated block 14 is an insulating material, and the height of the annular prefabricated block 14 matches the solder ball array, and the inner circle diameter of the annular prefabricated block 14 is larger than the diameter of the solder balls in the solder ball array.

[0041] It should be understood that when the filling material 13 is a conductive material, the solder balls in the solder ball array 9 are connected to each other, which will cause signal interference between the solder balls and the solder balls used to transmit the ground signal will be short-circuited. Therefore, in order to avoid this situation, the annular prefabricated block 14 is sleeved outside the non-grounded solder balls in the solder ball array 9.

[0042] Continue reading Figure 2 The outside of the solder balls 19 transmitting high-frequency signals and the solder balls 20 transmitting low-frequency signals are both sleeved with an annular prefabricated block 14, and in order to ensure the density between the solder balls 20 transmitting low-frequency signals, the annular prefabricated block 14 sleeved on the outside of the solder balls 20 transmitting low-frequency signals is different from the annular prefabricated block 14 sleeved on the solder balls 19 transmitting high-frequency signals. One annular prefabricated block can be used to simultaneously surround multiple solder balls 20 transmitting low-frequency signals, while each solder ball 19 transmitting high-frequency signals is surrounded by a separate annular prefabricated block 14.

[0043] See also Figure 3 , is a cross-sectional schematic diagram of a module with a flow channel based on a three-dimensional stacking structure according to an exemplary embodiment of the present invention. Figure 3 As shown, in this embodiment, the middle layer further includes a flow channel shape prefabricated block 17 , which is distributed in the filling material 13 , and the flow channel of the flow channel shape prefabricated block covers at least a portion of the solder balls in the solder ball array 9 .

[0044] Specifically, see Figure 4 , is a top view of a flow channel shaped prefabricated block sleeved on a solder ball, showing an exemplary embodiment of the present invention. Figure 4 As shown, the flow channel shape prefabricated block 17 is provided with a plurality of holes for surrounding the solder balls, for example Figure 4 There are multiple solder balls 18 for transmitting ground signals.

[0045] Continue to refer to Figure 3In this embodiment, the lower circuit substrate 10 is provided with a first liquid through hole 15, which is communicated with the area where the flow channel shape prefabricated block 17 is located, and the shell substrate 11 is provided with a second liquid through hole 16, which is communicated with the first liquid through hole 15. In addition, the flow channel shape prefabricated block 17 is made of sacrificial material, and the flow channel shape prefabricated block in the middle layer is dissolved by injecting etching liquid into the second liquid through hole to form a flow channel in the middle layer.

[0046] In this embodiment, the sacrificial material includes a high temperature resistant water-soluble material, a photoresist, etc., and the etching liquid includes water, acetone, etc., which are not limited to this.

[0047] Specifically, the area where the flow channel shape prefabricated block 17 is located, the first liquid hole 15 embedded in the lower circuit substrate 10, and the second liquid hole 16 embedded in the shell substrate 11 are connected in sequence, so that the flow channel shape prefabricated block 17 is dissolved by the corrosive liquid, so that the area where the annular prefabricated block 17 is located no longer constitutes a closed area, and the refrigerant can flow normally in the flow channel through the first liquid hole 15 and the second liquid hole 16, and the heat accumulated when the device on the circuit substrate (upper circuit substrate 8 and lower circuit substrate 11) is working is transferred to the outside in time, so that the three-dimensional stacking structure has heat dissipation ability, and the performance of each device on the circuit substrate is prevented from being affected by the temperature rise. The reliability of each device is high, so that the three-dimensional stacking structure can be applied to high heat consumption scenes, and the application range of the three-dimensional stacking structure is expanded. In addition, because the flow channel is in indirect or direct contact with the bottom surface of the upper circuit substrate 8, the top surface of the lower circuit substrate 10 and the solder ball array, its heat dissipation area is large, and heat can be dissipated more quickly. It should be understood that the refrigerant is a fluid used to complete the work of transferring heat energy and producing a freezing effect.

[0048] Specifically, the lower circuit substrate 10 is provided with two first liquid holes 15. That is to say, the shell substrate 11 is also provided with two second liquid holes 16, which are respectively arranged below the two first liquid holes 15 in the vertical direction, and are respectively used to inject the coolant into the flow channel and discharge the coolant from the flow channel, so as to perform cyclic heat dissipation, improve the heat dissipation capacity of the module based on the three-dimensional stacking structure, keep its temperature within a suitable range, and stabilize the performance of the device set on the circuit substrate.

[0049] It should be noted that the first liquid through hole 15 and the second liquid through hole 16 can be an integrated through hole or two independent through holes. In addition, while the lower circuit substrate 10 and the shell substrate 11 are dissipating heat through the flow channel, the refrigerant flows through the first liquid through hole 15 and the second liquid through hole 16, and the contact area with the lower circuit substrate 10 is larger, which accelerates the heat dissipation of the lower circuit substrate 11 and the shell substrate 12, and further improves the heat dissipation speed of the module based on the three-dimensional stacking structure.

[0050] In this embodiment, a plurality of metal holes 5 are provided on the bottom surface of the upper circuit substrate 8 , and the metal holes 5 are connected to the middle layer.

[0051] Specifically, in order to speed up the heat dissipation of the upper circuit substrate 8, a plurality of metal holes 5 are provided at the bottom of the upper circuit substrate 8. When the metal hole 5 is located directly above the flow channel for heat conduction, the metal hole 5 is a grounding hole, and the metal hole 5 and the solder ball array 9 in the flow channel can be connected together by welding. On the one hand, the heat generated by part of the upper circuit substrate 8 can be transmitted to the solder ball array 9 in the flow channel through the metal hole 5, and then the heat in the flow channel is extracted through heat exchange between the refrigerant and the solder ball array 9, thereby improving the heat dissipation speed of the module based on the three-dimensional stacking structure; on the other hand, the upper circuit board substrate 8 forms a good electrical connection with the lower circuit substrate 10 through the welding array 9. Compared with the conventional microchannel design, the welding array 9 can achieve better grounding performance, and at the same time, the microchannel structure obtains better support, so that the mechanical strength is higher and the microchannel is not easy to collapse.

[0052] More specifically, in addition to being used for heat conduction, if the metal hole 5 is connected to the solder ball 19 in the solder ball array 9 that transmits high-frequency signals, the metal hole 5 is used to transmit high-frequency signals; if the metal hole 5 is connected to the solder ball 20 in the solder ball array 9 that transmits low-frequency signals, the metal hole 5 is used to transmit low-frequency signals; if the metal hole 5 is connected to the solder ball 18 in the solder ball array 9 that transmits ground signals, the metal hole 5 is used for ground signals; if the metal hole 5 is connected to the flow channel, the metal hole 5 is used for heat dissipation.

[0053] Based on the above embodiments, the module based on the three-dimensional stacking structure realizes liquid cooling by using the flow channel, and has a large heat dissipation area and a fast heat dissipation speed, thereby greatly improving the heat dissipation performance of the module based on the three-dimensional stacking structure.

[0054] Continue to refer to Figure 1 or Figure 3 In this embodiment, the top surface of the upper circuit substrate 8 and the top surface of the lower circuit substrate 10 respectively include at least one cavity (cavity 4 of the upper circuit substrate 8 and cavity 12 of the lower circuit substrate 10), and devices are arranged in the cavity. The devices are installed in the cavity by bonding, bonding or welding, and partition beams are provided between the multiple cavities, and the partition beams are higher than the height of the devices.

[0055] Specifically, the depth of the cavity is higher than the height of the device, that is, the partition beams around the cavity are higher than the height of the device, so that there is space above the device, and the cavity can be divided according to the actual circuit function requirements, and the number of devices can also be set according to actual needs. The number of cavities and the number of devices in the cavity are not limited here. Figure 1 or Figure 3For example, the upper circuit substrate 8 is divided into three cavities 4, and the lower circuit substrate 10 is divided into two cavities 14; in the upper circuit substrate 8, the number of devices in the cavities 4 on both sides is 1, and the number of devices in the middle cavity 4 is 2. In addition, because the top surface of the upper circuit substrate 8 is fixed with an inner cover plate 2, that is, the inner cover plate 2 will be bonded above the partition beams around the cavity 4 to further isolate each cavity, the combination of the inner cover plate 2 and the partition beams improves the isolation between each cavity 4 and reduces the interference of crosstalk and stray.

[0056] Continue to refer to Figure 1 and Figure 3 In this embodiment, the module based on the three-dimensional stacking structure also includes a packaging component, which includes an inner cover plate 2, a surrounding frame 7 and an outer cover plate 1. The inner cover plate 2 is bonded to the upper circuit substrate 8, the lower end of the surrounding frame 7 is welded to the top surface of the outer shell substrate 11, and the upper end of the surrounding frame 7 is welded to the outer cover plate 1.

[0057] Specifically, the outer cover plate 1 and the surrounding frame 7 can be welded by parallel seam welding or laser sealing, and the module based on the three-dimensional stacking structure is encapsulated by the outer cover plate 1 and the surrounding frame 7 to achieve electromagnetic shielding of the entire module based on the three-dimensional stacking structure, thereby improving the overall crosstalk and spurious suppression capability of the module based on the three-dimensional stacking structure. The top surface of the upper circuit substrate 8 is exposed copper and gold-plated, so that the upper circuit substrate 8 uses the metal pad 6 to weld the top surface to the inner cover plate 2, thereby improving the isolation of the upper circuit substrate 8, forming the electromagnetic isolation of the upper circuit substrate 8, and preventing electromagnetic leakage.

[0058] In this way, by bonding the inner cover plate 2 directly above the upper circuit substrate 8, electromagnetic isolation of the upper circuit substrate 8 is achieved, and the components inside the upper circuit substrate 8 are isolated by partition beams, further improving the overall electromagnetic interference performance of the module based on the three-dimensional stacked structure.

[0059] Continue to refer to Figure 1 and Figure 3 In this embodiment, the inner cover plate 2 is provided with an opening 3, and the opening 3 is located directly above the partition beam in the upper circuit substrate 8, and a metal pad 6 is provided on the top surface of the partition beam corresponding to the area of ​​the opening 3.

[0060] Specifically, the top surface of the upper circuit substrate 8 and the inner cover 2 need to be tightly bonded to ensure the airtightness and electromagnetic shielding of the upper circuit substrate 8. Figure 1For example, two openings 3 are set at corresponding positions above the two partition beams when the inner cover plate 2 is located in the upper circuit substrate 8, and then blocked with metal pads 6. In order to further prevent the inner cover plate 2 and the upper circuit substrate 8 from having gaps at the edges when they are bonded, thereby causing electromagnetic leakage, the size of the inner cover plate 2 is designed to be slightly smaller than the upper circuit substrate 8, and then the metal pads 6 are used to cover the position where the top surface of the upper circuit substrate 8 does not contact the inner cover plate 2 due to the size of the inner cover plate 2 being smaller than the upper circuit substrate 8, that is, Figure 1 The metal pad 6 is located around the top surface of the upper circuit substrate 8 to block the gap. It should be understood that the metal pad 6 can also be replaced by conductive glue and other materials. Conductive glue is an adhesive with certain conductive properties after curing or drying. It usually has a base resin and a conductive filler, that is, conductive particles as the main components. The conductive particles are combined together by the bonding effect of the base resin to form a conductive path to achieve conductive connection of the bonded materials. It is often used in the assembly of various microelectronics.

[0061] See also Figure 5 , is a flow chart of a method for preparing a module based on a three-dimensional stacking structure according to an exemplary embodiment of the present invention. Figure 5 As shown, in an exemplary embodiment, the method for preparing a module based on a three-dimensional stacking structure includes at least steps S510 to S540, which are described in detail as follows:

[0062] Step S510, providing an upper circuit substrate, a lower circuit substrate, a housing substrate, a solder ball array, a ring-shaped prefabricated block and a filling material;

[0063] Step S520, soldering one end of the solder ball array to the bottom surface of the upper circuit substrate or the top surface of the lower current substrate, wherein if the filling material is a conductive material, a ring-shaped prefabricated block is used to surround the non-grounded solder balls in the solder ball array, the ring-shaped prefabricated block is made of insulating material, matches the height of the solder ball array, and the inner circle diameter of the ring-shaped prefabricated block is larger than the diameter of the solder balls in the solder ball array;

[0064] Step S530, connecting the bottom surface of the upper circuit substrate and the top surface of the lower circuit substrate using a solder ball array, so that the upper circuit substrate and the lower circuit substrate are vertically interconnected;

[0065] Step S540, filling the filling material between the upper circuit substrate and the lower circuit substrate to form an intermediate layer, and stacking the upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate in sequence to form a module based on a three-dimensional stacking structure.

[0066] or, providing an upper circuit substrate, a lower circuit substrate, a housing substrate, a solder ball array, and a filling material;

[0067] Solder one end of the solder ball array to the bottom surface of the upper circuit substrate or the top surface of the lower circuit substrate. If the filling material is an insulating material, the solder ball array is used to connect the bottom surface of the upper circuit substrate and the top surface of the lower circuit substrate, so that the upper circuit substrate and the lower circuit substrate are vertically interconnected.

[0068] Filling material is filled between the upper circuit substrate and the lower circuit substrate to form an intermediate layer. The upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure.

[0069] See also Figure 6 , is a flow chart of another method for preparing a module based on a three-dimensional stacking structure according to an exemplary embodiment of the present invention. Figure 6 As shown, in an exemplary embodiment, the method for preparing a module based on a three-dimensional stacking structure includes at least steps S610 to S660, which are described in detail as follows:

[0070] Step S610, providing an upper circuit substrate, a lower circuit substrate, a housing substrate, a solder ball array, a ring-shaped prefabricated block, a flow channel-shaped prefabricated block, and a filling material;

[0071] Step S620, soldering one end of the solder ball array to the bottom surface of the upper circuit substrate or the top surface of the lower current substrate, wherein if the filling material is a conductive material, a ring-shaped prefabricated block is used to surround the non-grounded solder balls in the solder ball array, the ring-shaped prefabricated block is made of insulating material, matches the height of the solder ball array, and the inner circle diameter of the ring-shaped prefabricated block is larger than the diameter of the solder balls in the solder ball array;

[0072] Step S630, after the flow channel shape prefabricated block is nested in at least a portion of the solder balls in the solder ball array, the solder ball array is used to connect the bottom surface of the upper circuit substrate and the top surface of the lower circuit substrate, so that the upper circuit substrate and the lower circuit substrate are vertically interconnected;

[0073] Step S640, filling a filling material between the upper circuit substrate and the lower circuit substrate to form an intermediate layer, and stacking the upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate in sequence to form a module based on a three-dimensional stacking structure;

[0074] Step S650, respectively providing liquid through holes in communication with the area of ​​the flow channel shape prefabricated block on the lower circuit substrate and the housing substrate;

[0075] Step S660, injecting a corrosive liquid into the region of the channel shape prefabricated block through the liquid through-hole to dissolve the channel shape prefabricated block and form a prefabricated channel in the middle layer, wherein the channel shape prefabricated block is made of a sacrificial material.

[0076] Or, provide an upper circuit substrate, a lower circuit substrate, a shell substrate, a solder ball array, a flow channel shape prefabricated block and a filling material; weld one end of the solder ball array to the bottom surface of the upper circuit substrate or the top surface of the lower current substrate, and if the filling material is an insulating material, embed the flow channel shape prefabricated block in at least a part of the solder balls in the solder ball array; use the solder ball array to connect the bottom surface of the upper circuit substrate and the top surface of the lower circuit substrate, so that the upper circuit substrate and the lower circuit substrate are vertically interconnected; fill the filling material between the upper circuit substrate and the lower circuit substrate to form an intermediate layer, and the upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure; set liquid holes that communicate with the area of ​​the flow channel shape prefabricated block on the lower circuit substrate and the shell substrate respectively; inject a corrosive liquid into the area of ​​the flow channel shape prefabricated block through the liquid hole to dissolve the flow channel shape prefabricated block, and form a prefabricated flow channel in the intermediate layer, and the flow channel shape prefabricated block is made of sacrificial material.

[0077] The above preparation method steps are merely illustrative and are not intended to be specific limitations of the present application.

[0078] Based on the above embodiments, first, an upper circuit substrate, an intermediate layer, a lower circuit substrate and a shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure, wherein the intermediate layer is composed of a filling material and a solder ball array, and the solder ball array is vertically interconnected between the upper circuit substrate and the lower circuit substrate, so that a cavity is formed between the upper circuit substrate and the lower circuit substrate, thereby ensuring the isolation between the upper circuit substrate and the lower circuit substrate, forming electromagnetic isolation, and improving the module's ability to suppress electromagnetic interference.

[0079] Second, the upper circuit substrate and the lower circuit substrate are covered with a filling material; the filling material is an insulating material or a conductive material. By filling the conductive material between the two circuit substrates, the grounding of the upper circuit board is better, the radio frequency performance of the signal transmission between the circuit substrates is high, and the non-grounded solder balls in the solder ball array are provided with an annular prefabricated block outside for preventing signal interference between solder balls and preventing non-grounded solder ball signal short circuit, so as to avoid signal interference between the solder balls.

[0080] In addition, by setting a flow channel in the middle layer to transfer the heat accumulated in the circuit substrate to the outside of the module in time, the heat dissipation capacity of the module based on the three-dimensional stacking structure is improved, and the performance of each device on the circuit substrate is prevented from being affected by the temperature rise. The reliability of each device is high, so that the module can be used in scenarios with high heat consumption, expanding the application range of modules based on the three-dimensional stacking structure.

[0081] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A module based on a three-dimensional stacking structure, characterized in that: include: An upper circuit substrate, a lower circuit substrate, an intermediate layer and a shell substrate, wherein the upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure; The middle layer is composed of a filling material and a solder ball array, the solder ball array is vertically interconnected between the upper circuit substrate and the lower circuit substrate, and the filling material covers the space between the upper circuit substrate and the lower circuit substrate; The filling material is an insulating material or a conductive material. If the filling material is a conductive material, an annular prefabricated block is provided outside the non-grounded solder balls in the solder ball array to prevent signal interference between the solder balls and prevent the non-grounded solder ball signals from short-circuiting. If the filling material is an insulating material, the middle layer also includes a flow channel shape prefabricated block, the flow channel shape prefabricated block is distributed in the filling material, and the flow channel of the flow channel shape prefabricated block covers at least a portion of the solder balls in the solder ball array, and the flow channel is formed by dissolving the flow channel shape prefabricated block using a corrosive liquid.

2. The module based on the three-dimensional stacking structure according to claim 1, characterized in that: The non-grounded solder ball located at the center of the solder ball array is used as the middle solder ball. If the filling material is a conductive material, the middle solder ball sleeved with the annular prefabricated block, the grounded solder balls around the middle solder ball and the filling material constitute a coaxial structure; if the filling material is an insulating material, the middle solder ball and the grounded solder balls around the middle solder ball constitute a quasi-coaxial structure.

3. The module based on the three-dimensional stacking structure according to claim 1, characterized in that: The height of the annular prefabricated block matches the solder ball array, and the inner circle diameter of the annular prefabricated block is larger than the diameter of the solder balls in the solder ball array.

4. The module based on the three-dimensional stacking structure according to claim 1, characterized in that: If the filling material is a conductive material, the intermediate layer further includes the flow channel shaped prefabricated block.

5. The module based on the three-dimensional stacking structure according to claim 1, characterized in that: The lower circuit substrate is provided with a first liquid through hole, which is communicated with the area where the flow channel shape prefabricated block is located, and the shell substrate is provided with a second liquid through hole, which is communicated with the first liquid through hole.

6. The module based on the three-dimensional stacking structure according to claim 5, characterized in that: The flow channel shape prefabricated block is made of a sacrificial material, and the flow channel is formed in the middle layer by injecting a corrosive liquid into the second liquid hole to dissolve the flow channel shape prefabricated block in the middle layer.

7. The module based on the three-dimensional stacking structure according to claim 6, characterized in that: The bottom surface of the upper circuit substrate is provided with a plurality of metal holes, and the metal holes are connected with the middle layer.

8. The module based on the three-dimensional stacking structure according to claim 1, characterized in that: The top surface of the upper circuit substrate and the top surface of the lower circuit substrate respectively include at least one cavity, in which a device is arranged. The device is installed in the cavity by bonding, bonding or welding. Partition beams are arranged between the multiple cavities, and the partition beams are higher than the height of the device.

9. The module based on the three-dimensional stacking structure according to claim 8, characterized in that: The module based on the three-dimensional stacking structure also includes a packaging component, which includes an inner cover plate, a surrounding frame and an outer cover plate. The inner cover plate is bonded directly above the upper circuit substrate, the lower end of the surrounding frame is welded to the four sides of the top surface of the outer shell substrate, and the upper end of the surrounding frame is welded to the outer cover plate.

10. The module based on the three-dimensional stacking structure according to claim 9, characterized in that: The inner cover plate is provided with an opening, and the opening is located directly above the partition beam in the upper circuit substrate. The top surface of the partition beam corresponding to the opening area is provided with a metal pad, and the metal pad is used to weld the inner cover plate to the top surface of the upper circuit substrate.

11. A method for preparing a module based on a three-dimensional stacking structure, characterized in that: The method comprises: Providing an upper circuit substrate, a lower circuit substrate, a housing substrate, a solder ball array, a ring-shaped prefabricated block and filling materials; Soldering one end of the solder ball array to the bottom surface of the upper circuit substrate or the top surface of the lower circuit substrate, wherein if the filling material is a conductive material, the non-grounded solder balls in the solder ball array are surrounded by the annular prefabricated block, the annular prefabricated block is an insulating material, matches the height of the solder ball array, and the inner circle diameter of the annular prefabricated block is larger than the diameter of the solder balls in the solder ball array; Connecting the bottom surface of the upper circuit substrate and the top surface of the lower circuit substrate by using the solder ball array to vertically interconnect the upper circuit substrate and the lower circuit substrate; The filling material is filled between the upper circuit substrate and the lower circuit substrate to form an intermediate layer. The upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate are stacked in sequence to form a module based on a three-dimensional stacking structure.

12. A method for preparing a module based on a three-dimensional stacking structure, characterized in that: The method comprises: Providing an upper circuit substrate, a lower circuit substrate, a housing substrate, a solder ball array, a ring-shaped prefabricated block, a flow channel shape prefabricated block and filling materials; Soldering one end of the solder ball array to the bottom surface of the upper circuit substrate or the top surface of the lower circuit substrate, wherein if the filling material is a conductive material, the non-grounded solder balls in the solder ball array are surrounded by the annular prefabricated block, the annular prefabricated block is an insulating material, matches the height of the solder ball array, and the inner circle diameter of the annular prefabricated block is larger than the diameter of the solder balls in the solder ball array; After the flow channel shape prefabricated block is nested in at least a portion of the solder balls in the solder ball array, the solder ball array is used to connect the bottom surface of the upper circuit substrate and the top surface of the lower circuit substrate, so that the upper circuit substrate and the lower circuit substrate are vertically interconnected; Filling the filling material between the upper circuit substrate and the lower circuit substrate to form an intermediate layer, and stacking the upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate in sequence to form a module based on a three-dimensional stacking structure; Liquid holes communicating with the area of ​​the flow channel shape prefabricated block are respectively provided on the lower circuit substrate and the shell substrate; Injecting a corrosive liquid into the region of the channel shape prefabricated block through the liquid through hole to dissolve the channel shape prefabricated block and form a prefabricated channel in the middle layer, wherein the channel shape prefabricated block is made of a sacrificial material; or, Providing the upper circuit substrate, the lower circuit substrate, the housing substrate, the solder ball array, the flow channel shape prefabricated block and the filling material; Soldering one end of the solder ball array to the bottom surface of the upper circuit substrate or the top surface of the lower circuit substrate, and if the filling material is an insulating material, embedding the flow channel shape prefabricated block in at least a part of the solder balls in the solder ball array; Connecting the bottom surface of the upper circuit substrate and the top surface of the lower circuit substrate by using the solder ball array to vertically interconnect the upper circuit substrate and the lower circuit substrate; Filling the filling material between the upper circuit substrate and the lower circuit substrate to form an intermediate layer, and stacking the upper circuit substrate, the intermediate layer, the lower circuit substrate and the shell substrate in sequence to form a module based on a three-dimensional stacking structure; Liquid holes communicating with the area of ​​the flow channel shape prefabricated block are respectively provided on the lower circuit substrate and the shell substrate; The corrosive liquid is injected into the region of the channel shape prefabricated block through the liquid through hole to dissolve the channel shape prefabricated block and form a prefabricated channel in the middle layer. The channel shape prefabricated block is made of sacrificial material.

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