printing screen

Abstract

The application relates to the technical field of PCBA board manufacturing, in particular to a printing net, which comprises a printing net body, at least one solder printing through hole is formed in the printing net body, the solder printing through hole corresponds to a pad position on a PCB, the solder printing through hole is used for printing solder onto the corresponding pad, and the pad is used for fixing the pins of a to-be-mounted patch electronic component; the printing net body is provided with an avoiding structure at the solder printing through hole, the avoiding structure is arranged at a position corresponding to the arrangement position of a micro hole at the pad, the avoiding structure blocks the solder from being printed into the micro hole, so that the solder is printed onto the pad and avoids the micro hole position. In the application, the avoiding structure offsets the solder printing position from the micro hole, so that the solder flows to the micro hole position after being melted. The flowing process provides a time window for waste gas exhaust, significantly reduces the waste gas residual probability, reduces cavities, and improves the welding quality.

Description

Technical Field

[0001] This application relates to the field of PCBA board manufacturing technology, and more specifically, to printed circuit boards. Background Technology

[0002] The development of electronic technology has led to the widespread application of printed circuit boards (PCBs). High-density interconnect (HDI) technology is one of the key technologies in modern PCB design. Microvia technology, as its core process, significantly impacts the electrical performance and reliability of multilayer PCBs. Microvia fabrication and soldering processes are crucial in high-density PCB manufacturing. Current PCB microvia soldering commonly uses reflow soldering or wave soldering, requiring flux. However, the high-temperature evaporation of flux and the formation of gas from residual air within the microvias when heated are particularly problematic. In high-density microvia arrays, this gas is more easily trapped within the solder joints. Although existing processes employ measures to address this, gas escape remains difficult for micron-sized PCB microvias. Residual gas forms voids, reducing the mechanical strength of solder joints, affecting electrical connection reliability, and even leading to open circuits or signal transmission failures. Utility Model Content

[0003] The purpose of this application is to provide a printed mesh that can significantly reduce the probability of residual exhaust gas, reduce voids, and improve welding quality.

[0004] To achieve the above objectives, this utility model provides a printing screen, including a printing screen body, wherein at least one solder printing through hole is provided on the printing screen body, the solder printing through hole corresponds to the position of the pad on the PCB board, the solder printing through hole is used to print solder onto the corresponding pad, and the pad is used to fix the pins of the surface mount electronic components to be mounted.

[0005] The solder printing through-hole on the printing screen body has an avoidance structure. The position of the avoidance structure corresponds to the position of the micro-hole on the pad. The avoidance structure blocks the solder from being printed onto the micro-hole so that the solder avoids the position of the micro-hole when it is printed onto the pad.

[0006] In an optional embodiment, the position of the avoidance structure at the solder printing through-hole on the printing screen body corresponds to the position of one of the micro-holes on the pad.

[0007] In an optional embodiment, the location of the avoidance structure corresponds to the location of the microvia located at the center of the pad.

[0008] In an optional embodiment, the location of the avoidance structure corresponds to the location of the microvia offset at the center of the pad.

[0009] In an optional embodiment, the avoidance structure is positioned on the printed screen body in a manner corresponding to the positions of at least two of the micro-holes on the solder pad, and divides the solder printing through-hole into at least two printed sub-through-holes.

[0010] In an optional embodiment, the positions of the at least two micropores corresponding to the positions of the avoidance structure are distributed sequentially at intervals along a straight trajectory.

[0011] In an optional embodiment, the avoidance structure is positioned on the printed screen body in a manner corresponding to the positions of at least three micro-holes on the solder pad, and divides the solder printed through-hole into at least two printed sub-through-holes. The at least three micro-holes are divided into at least two groups, with at least one group of micro-holes distributed along a first trajectory and at least one group of micro-holes distributed along a second trajectory.

[0012] In an optional embodiment, the minimum spacing between two adjacent printed sub-holes is L, where 0 < L ≤ 0.15 mm.

[0013] In an optional embodiment, when the printed sub-hole is configured as a circular through-hole, its size satisfies: R / 2T > 0.66;

[0014] When the printed sub-hole is set as a rectangular through hole, its size satisfies: (K*W) / (2*(K+W)*T)>0.66;

[0015] Where K is the length of the rectangular through hole;

[0016] W is the width of the rectangular through hole;

[0017] T represents the thickness of the rectangular or circular through-hole.

[0018] R is the radius of the circular through hole.

[0019] In an optional implementation, the avoidance structure is configured as a circular solid structure, a polygonal solid structure, or a combination of both.

[0020] In this application, the avoidance structure offsets the solder printing position from the micro-orifice, so that the solder will flow to the micro-orifice position after melting. This flow process provides a time window for exhaust gas discharge, significantly reducing the probability of exhaust gas residue, reducing voids, and improving welding quality.

[0021] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figures 1 to 5 Schematic diagrams of several different embodiments of the printed mesh provided in this application, wherein the micropores are offset at the center of the pads;

[0024] Figures 6 to 11 Schematic diagrams of several different embodiments of the printed mesh provided in this application, wherein the micropores are located at the center of the pads;

[0025] Figure 12 , Figure 17 , Figures 21 to 23 Schematic diagrams of several different embodiments of the printing screen provided in this application;

[0026] Figures 13 to 16 , Figures 18 to 20 This is a comparison chart showing the effects.

[0027] icon:

[0028] 100 - Printing screen body; 110 - Avoidance structure; 120 - Solder printing through hole; 122 - Printing sub-through hole;

[0029] 200 - Pad; 210 - Microvia; 220 - Solder;

[0030] 300 - First trajectory; 310 - Second trajectory. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] In the description of this application, it should be noted that the terms "inner" and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0034] In relevant PCB manufacturing technologies, voids often appear during the soldering process of PCB pads, resulting in poor soldering quality. The causes of voids can be roughly attributed to the waste gas generated during the soldering of micro-holes at the pads on the PCB board and the waste gas generated by the volatilization of flux. These waste gases cannot be discharged from the molten pool in time, resulting in voids in the pads.

[0035] Embodiments of this application provide a printing screen for defining the printing area of ​​solder 220 on pad 200. The melted solder 220 is used to attach the leads of surface-mount electronic components to the pad 200. Figure 1 As shown, the printing screen includes a printing screen body 100, and at least one solder printing through hole 120 is provided on the printing screen body 100. The solder printing through hole 120 corresponds to the position of the pad 200 on the PCB board. The solder printing through hole 120 is used to print solder 220 onto the corresponding pad 200. During use, the solder 220 passes through the solder printing through hole 120 and is printed onto the pad 200.

[0036] Pad 200 is used to fix the pins of the surface mount electronic components to be mounted.

[0037] like Figure 1As shown, the solder printing through-hole 120 on the printing screen body 100 has an avoidance structure 110. The avoidance structure 110 is a solid structure that can prevent the solder 220 from passing through the avoidance structure 110. The position of the avoidance structure 110 corresponds to the position of the micro-hole 210 on the pad 200. The avoidance structure 110 blocks the solder 220 from being printed onto the micro-hole 210, so that the solder 220 avoids the position of the micro-hole 210 when it is printed onto the pad 200. In the prior art, when the solder 220 directly covers the micro-hole 210, the waste gas (such as flux volatiles and air inside the micro-hole 210) in the molten state is trapped in the molten pool and forms a cavity after cooling. In this application, the avoidance structure 110 offsets the solder 220 printing position from the micro-hole 210, so that the solder 220 will flow to the position of the micro-hole 210 after melting. This flow process provides a time window for exhaust gas to be discharged from the micropores 210, significantly reducing the probability of exhaust gas residue.

[0038] For example, in this embodiment, the thickness of the avoidance structure 110 is not limited, as long as it can prevent the solder 220 from being printed onto the micro-hole 210. The arrangement of the avoidance structure 110 is also not limited; it is integrally formed with the printing screen body 100. When setting the solder printing through-hole 120, it can be created by removing material from the printing screen body 100. For example, if a 270° fan-shaped solder printing through-hole 120 is created on the printing screen, the avoidance structure 110 is a 110° fan-shaped solid structure. Alternatively, if the solder printing through-hole 120 is a 275° fan-shaped through-hole, the avoidance structure 110 is a 105° fan-shaped solid structure. Material removal methods include laser cutting, electrochemical machining, CNC drilling, or photolithography and nanoimprinting. The solder printing through-hole 120 can also be created using additive manufacturing methods such as 3D machining.

[0039] This embodiment does not limit the specific shape of the solder printing through-hole 120, as long as it can ensure that the solder 220 can be printed onto the corresponding pad 200.

[0040] This embodiment does not limit the specific type of solder 220, as long as it ensures that the pad 200 and the pins of the surface mount electronic component can be electrically connected. For example, solder 220 can be solder paste.

[0041] like Figure 1 or Figure 12 As shown, in one embodiment, the avoidance structure 110 is configured as a circular solid structure, a polygonal solid structure, or a combination of both.

[0042] like Figure 1As shown, in one embodiment, the avoidance structure 110 is a fan-shaped structure, and the setting position of the avoidance structure 110 corresponds to the setting position of a micro-hole 210. The micro-hole 210 is biased at the center of the solder pad 200; the solder printing through hole 120 is a fan-shaped structure.

[0043] like Figure 2 As shown, in one embodiment, the avoidance structure 110 is a solid structure composed of two fan-shaped structures, wherein the two fan-shaped structures constituting the avoidance structure 110 are connected, and the position of one of the fan-shaped solid structures corresponds to the position of the micro-hole 210, which is offset at the center of the solder pad 200. The solder printing via 120 is a structure composed of two fan-shaped vias.

[0044] like Figure 3 As shown, in one embodiment, the avoidance structure 110 is a fan-shaped solid structure formed by being cut in an arc shape, and the solder printing through hole 120 is a fan-shaped through hole structure formed by being cut in an arc shape. The setting position of the avoidance structure 110 corresponds to the setting position of a micro hole 210, and the micro hole 210 is offset at the center of the pad 200.

[0045] like Figure 4 As shown, in one embodiment, the solder printing through-hole 120 is a circular through-hole, and the avoidance structure 110 is disposed in the solder printing through-hole 120 and is a combination of an arc-shaped entity and a rectangular entity. The position of the avoidance structure 110 corresponds to the position of a micro-hole 210, which is offset at the center of the pad 200.

[0046] like Figure 5 As shown, in one embodiment, the solder printing through-hole 120 is a circular through-hole, and the avoidance structure 110 is disposed in the solder printing through-hole 120 and is a combination of an arc-shaped entity and a triangular entity. The position of the avoidance structure 110 corresponds to the position of a micro-hole 210, which is offset at the center of the pad 200.

[0047] like Figure 6 As shown, in one embodiment, the avoidance structure 110 is a solid structure composed of two fan-shaped structures, which are separately arranged. The position of one of the fan-shaped structures corresponds to the position of the micro-hole 210, which is located at the center of the pad 200. The solder printing via 120 is a structure composed of two fan-shaped vias, which are connected.

[0048] like Figure 7 As shown, in one embodiment, the avoidance structure 110 is a circular structure with part of the solid removed to form a fan-shaped solid structure. The setting position of the avoidance structure 110 corresponds to the setting position of a micro-hole 210. The micro-hole 210 is located at the center of the pad 200, and the solder printing through hole 120 is a fan-shaped structure.

[0049] like Figure 8 As shown, in one embodiment, the avoidance structure 110 is a combination of a fan-shaped solid structure and a circular solid structure, the solder printing through hole 120 is a partially annular structure, the setting position of the avoidance structure 110 corresponds to the setting position of a microhole 210, and the microhole 210 is located at the center of the pad 200.

[0050] like Figure 9 As shown, in one embodiment, the solder printing through-hole 120 is a circular through-hole, and the avoidance structure 110 is disposed in the solder printing through-hole 120 and is a solid structure formed by a combination of circles and rectangles. The position of the avoidance structure 110 corresponds to the position of a micro-hole 210, which is located at the center of the pad 200.

[0051] like Figure 10 As shown, in one embodiment, the solder printing through-hole 120 is a circular through-hole, and the avoidance structure 110 is disposed in the solder printing through-hole 120 and is a combination of an arc-shaped entity and a rectangular entity. The position of the avoidance structure 110 corresponds to the position of a micro-hole 210, which is located at the center of the pad 200.

[0052] like Figure 11 As shown, in one embodiment, the solder printing through-hole 120 is a circular through-hole, and the avoidance structure 110 is disposed in the solder printing through-hole 120 and is a combination of an arc-shaped entity and a triangular entity. The position of the avoidance structure 110 corresponds to the position of a micro-hole 210, which is located at the center of the pad 200.

[0053] Unlike the above embodiment where the location of the avoidance structure 110 corresponds to the location of a microhole 210, in other embodiments, such as... Figure 12 and Figure 21 As shown, the location of the avoidance structure 110 corresponds to the location of at least two micropores 210.

[0054] For example, the at least two micropores 210 are distributed at equal intervals along a straight trajectory.

[0055] like Figure 12 As shown, in one embodiment, the avoidance structure 110 is a T-shaped solid structure formed by combining two rectangles. The setting position of one of the rectangular solids corresponds to the setting position of at least two micro-holes 210, and the at least two micro-holes 210 are distributed sequentially at intervals along a straight line trajectory. For example, the setting position of the rectangular solid can correspond to five micro-holes 210 distributed sequentially at intervals along a straight line trajectory. Of course, the setting position of the rectangular solid can correspond to other numbers of micro-holes 210 distributed sequentially at intervals along a straight line trajectory, such as three, four, or six.

[0056] For example, the solder printed via 120 is divided into two printed sub-vias 122, which are formed by a combination of semicircles and rectangles. The two printed sub-vias 122 of the solder printed via 120 are symmetrically arranged, and the minimum interval between two adjacent printed sub-vias 122 is L, where 0 < L ≤ 0.15 mm.

[0057] Figure 13 and Figure 14 The welding effect when L > 0.15mm is demonstrated. Figure 13 and Figure 14 N is greater than 0; from Figure 13 and Figure 14 As can be seen, there is no clearance structure 110 at the solder-printed through-hole 120, and the solder 220 can be directly printed onto the micro-via 210. If L > 0.15mm or L = 0, the pad 200 will easily exhibit issues such as... Figure 13 and Figure 14 The intervals or holes shown, Figure 13 and Figure 14 The black area in the middle is pad 200. The white area in pad 200 is a void. The void on pad 200 occupies more than 30% of the area, indicating poor soldering quality.

[0058] when Figure 12 When L = 0.15mm, the welding effect is as follows: Figure 15 As shown, the void area is less than 30%, and although there is a void at pad 200, the soldering quality is better than expected. Figure 13 and Figure 14 The situation shown.

[0059] when Figure 12 When L = 0.10mm, the welding effect is as follows: Figure 16 As shown, when the void area is less than 30%, the welding quality is better. Of course, L can also be set to other values, such as L = 0.05mm, etc.

[0060] like Figure 17 As shown, in one embodiment, the avoidance structure 110 is a T-shaped solid structure formed by combining two rectangles. The setting position of one of the rectangular solids corresponds to the setting position of at least two micro-holes 210, and the at least two micro-holes 210 are distributed sequentially at intervals along a straight line trajectory. For example, the setting position of the rectangular solid can correspond to five micro-holes 210 distributed sequentially at intervals along a straight line trajectory. Of course, the setting position of the rectangular solid can correspond to other numbers of micro-holes 210 distributed sequentially at intervals along a straight line trajectory, such as three, four, or six.

[0061] For example, the solder printed via 120 is divided into two printed sub-vias 122, which are formed by rectangular combinations. The two printed sub-vias 122 of the solder printed via 120 are symmetrically arranged, and the minimum interval between the two printed sub-vias 122 is L, where 0 < L ≤ 0.15 mm.

[0062] Figure 18 To adopt such Figure 17 The soldering effect diagram of the illustrated embodiment shows that although there is residual solder at the end of pad 200, the soldering effect is better than expected. Figure 19 The welding effect shown is achieved by using... Figure 20 It can be obtained Figure 19 The welding effect in the middle, Figure 20 Without the use of the avoidance structure 110, the solder 220 can be directly printed onto the micro-hole 210 of the pad 200; for example Figure 19 As shown, the voids occupy more than 30% of the area, indicating poor welding quality.

[0063] In one embodiment, such as Figure 21 As shown, the avoidance structure 110 is a cross-shaped solid structure formed by combining two rectangles. The position of one of the rectangular solids corresponds to the position of at least two micro-holes 210, and the at least two micro-holes 210 are distributed sequentially at intervals along a straight line trajectory. For example, the position of the rectangular solid can correspond to five micro-holes 210 distributed sequentially at intervals along a straight line trajectory. Of course, the position of the rectangular solid can correspond to other numbers of micro-holes 210 distributed sequentially at intervals along a straight line trajectory, such as three, four, or six.

[0064] In one embodiment, such as Figure 22 As shown, the avoidance structure 110 is positioned to correspond to at least three micro-holes 210. These at least three micro-holes 210 are divided into at least two groups. At least one group of micro-holes 210 is distributed along the first trajectory 300, and at least one group of micro-holes 210 is distributed along the second trajectory 310. The first trajectory 300 and the second trajectory 310 are arranged in a T-shape. The avoidance structure 110 is a T-shaped solid structure formed by combining two rectangles. The position of one rectangular solid of the avoidance structure 110 corresponds to the position of the micro-hole 210 on the first trajectory 300, and the position of the other rectangular solid of the avoidance structure 110 corresponds to the position of the micro-hole 210 on the second trajectory 310. Figure 22 As shown, five microholes 210 are provided on the first track 300 and four microholes 210 are provided on the second track 310. Of course, other numbers of microholes 210 on the first track 300 and microholes 210 on the second track 310 can also be provided, such as three or six.

[0065] In one embodiment, the location of the avoidance structure 110 corresponds to at least three micro-holes 210. These at least three micro-holes 210 are divided into at least two groups. At least one group of micro-holes 210 is distributed along the first trajectory 300, and at least one group of micro-holes 210 is distributed along the second trajectory 310. The first trajectory 300 and the second trajectory 310 are arranged in a cross shape. The avoidance structure 110 is a cross-shaped solid structure formed by combining two rectangles. The location of one of the rectangular solids of the avoidance structure 110 corresponds to the location of the micro-holes 210 on the first trajectory 300, and the location of the other rectangular solid of the avoidance structure 110 corresponds to the location of the micro-holes 210 on the second trajectory 310.

[0066] Of course, in other embodiments, the first trajectory 300 and the second trajectory 310 are not only arranged perpendicularly, but can also be at other angles, such as 30°, 45° or 75°.

[0067] In one embodiment, such as Figure 23 As shown, at least two solder printing through holes 120 are provided. For example, the printing screen body 100 has six solder printing through holes 120, two of which are fan-shaped through holes, and the other four are through holes formed by a combination of fan-shaped and rectangular through holes. Of course, the printing screen body 100 can also have other numbers of solder printing through holes 120, such as two, three, or four, and their shape can be circular, rectangular, or a combination thereof.

[0068] In one embodiment, when the printed sub-hole 122 is configured as a circular through-hole, its size satisfies: R / 2T > 0.66. It is understood that since sector-shaped, annular, etc., also have a radius dimension, the circular printed sub-hole 122 includes a complete circular through-hole, a sector-shaped through-hole, and an annular through-hole, etc.

[0069] In one embodiment, when the printed sub-hole 122 is configured as a rectangular through-hole, its size satisfies: K*W / (2*(K+W)*T)>0.66.

[0070] Where K is the length of the rectangular through hole.

[0071] W is the width of the rectangular through hole.

[0072] T represents the thickness of the rectangular or circular through-hole.

[0073] R is the radius of the circular through hole.

[0074] In this application, the thickness T is the thickness at the printed sub-hole 122 on the printing screen body 100, and the thickness T is not necessarily equal to the average thickness of the printing screen body 100.

[0075] In one embodiment, such as Figure 9As shown, the solder printing through-hole 120 is a combination of circular printed through-hole 122 and rectangular printed through-hole 122. The circular printed through-hole 122 needs to satisfy R / 2T>0.66, and the rectangular printed through-hole 122 needs to satisfy K*W / (2*(K+W)*T)>0.66.

[0076] It should be noted that, where there is no conflict, the features in the embodiments of this application can be combined with each other.

[0077] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A printing screen, characterized in that... The PCB includes a printing screen body (100), on which at least one solder printing through hole (120) is provided. The solder printing through hole (120) corresponds to the position of the pad (200) on the PCB board. The solder printing through hole (120) is used to print solder (220) onto the corresponding pad (200). The pad (200) is used to fix the pins of the surface mount electronic components to be mounted. The solder printing through-hole (120) on the printing screen body (100) has an avoidance structure (110). The position of the avoidance structure (110) corresponds to the position of the micro-hole (210) on the pad (200). The avoidance structure (110) blocks the solder (220) from being printed onto the micro-hole (210) so that the solder (220) avoids the position of the micro-hole (210) when it is printed onto the pad (200).

2. The printing screen according to claim 1, characterized in that... The position of the avoidance structure (110) at the solder printing through hole (120) on the printing screen body (100) corresponds to the position of one of the micro holes (210) on the pad (200).

3. The printing screen according to claim 2, characterized in that... The location of the avoidance structure (110) corresponds to the location of the microhole (210) located at the center of the pad (200).

4. The printing screen according to claim 2, characterized in that... The location of the avoidance structure (110) corresponds to the location of the microhole (210) which is offset at the center of the pad (200).

5. The printing screen according to claim 1, characterized in that... The avoidance structure (110) is positioned on the printed screen body (100) in a manner corresponding to the positions of at least two micro-holes (210) on the solder pad (200), and divides the solder printing through-hole (120) into at least two printed sub-through-holes (122).

6. The printing screen according to claim 5, characterized in that... The positions of at least two micropores (210) corresponding to the positions of the avoidance structure (110) are distributed sequentially at intervals along a straight trajectory.

7. The printing screen according to claim 1, characterized in that... The avoidance structure (110) is positioned on the printed screen body (100) in a manner corresponding to the positions of at least three micro-holes (210) on the solder pad (200), and divides the solder printing through-hole (120) into at least two printed sub-through-holes (122). The at least three micro-holes (210) are divided into at least two groups, with at least one group of micro-holes (210) distributed along a first trajectory (300) and at least one group of micro-holes (210) distributed along a second trajectory (310).

8. The printing screen according to any one of claims 5 to 7, characterized in that... The minimum spacing between two adjacent printed sub-holes (122) is L, where 0 < L < 0.15 mm.

9. The printing screen according to any one of claims 5 to 7, characterized in that... When the printed sub-hole (122) is set as a circular through hole, its size satisfies: R / 2T>0.66; When the printed sub-through hole (122) is set as a rectangular through hole, its size satisfies: (K*W) / (2*(K+W)*T)>0.66; Where K is the length of the rectangular through hole; W is the width of the rectangular through hole; T represents the thickness of the rectangular or circular through-hole. R is the radius of the circular through hole.

10. The printing screen according to claim 1, characterized in that... The avoidance structure (110) is configured as a circular solid structure, a polygonal solid structure, or a combination of both.

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