Millimeter wave waveguide and method for manufacturing millimeter wave waveguide

Abstract

To inexpensively provide a millimeter wave waveguide having such a structure that a conductor layer is formed on the inner surface of a resin pipe, which has excellent transmission characteristics.SOLUTION: A millimeter wave waveguide (10) constitutes a waveguide by an internal space (14) surrounded by a first member (11) and a second member (12) which are joined to each other by a solder (13). The first member has a first member body (110) made of a resin, and a first conductor layer (111) which is formed on the surface of the first member body (110) and contains copper. The second member has a second member body (120) made of a resin, and a second conductor layer (121) which is formed on the surface of the second member body (120) and contains copper. The first conductor layer and the second conductor layer are coated with coating layers (112 and 122) having rust preventive effects. The coating layers are provided on the whole surface of an inner wall surface (141) of the internal space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a millimeter-wave waveguide and a method for manufacturing the same. [Background technology]

[0002] A known waveguide has a structure in which a conductive layer made of metal plating or the like is formed on the inner surface of a resin tube (see, for example, Patent Document 1). By using resin as the material, it is possible to reduce the weight and cost of the waveguide.

[0003] Specifically, the waveguide described in Patent Document 1 has two tubular members that are combined with each other in the vertical direction. The tubular members have a resin portion and a metal fitting held by the resin portion. A conductor layer is formed over the entire inner surface of the resin portion. The resin portion has a bottom portion that faces the opposite tubular member in the vertical direction and a side portion located at the edge of the bottom. The conductor layer is formed not only on the inner surface of the resin portion but also on the opposing surface of the side portion, which is the surface facing the direction in which the two tubular members are combined. With this structure, when the two tubular members are combined, the conductor layer formed on the opposing surface of one tubular member comes into contact with the conductor layer formed on the opposing surface of the other tubular member. As a result, the difference in potential between the conductor layer formed on one tubular member and the conductor layer formed on the other tubular member can be more effectively reduced. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-145503 Summary of the Invention [Problem to be solved by the invention]

[0005] In this type of waveguide, by forming the conductor layer formed on the resin member from inexpensive copper or copper alloy instead of expensive gold or silver, manufacturing costs can be further reduced. However, if copper rust occurs on the inner wall of the waveguide, transmission characteristics are significantly reduced. Furthermore, even if gaps occur at joints, transmission characteristics are significantly reduced due to radio wave leakage. The present invention has been made in consideration of the above-mentioned circumstances. That is, the present invention provides a technology that makes it possible to provide, at low cost, a millimeter-wave waveguide having a structure in which a conductor layer is formed on the inner surface of a resin tube, which has excellent transmission characteristics. [Means for solving the problem]

[0006] The millimeter wave waveguide (10) according to claim 1 comprises: The first member (11) and the second member (12) are joined with solder (13) to form a waveguide in an internal space (14) surrounded by the first member and the second member, The first member has a first member body (110) made of resin, and a copper-containing conductor layer (111) provided along at least surfaces (116, 118) facing the internal space and a surface (117) facing the second member for joining with the second member, The second member has a second member body (120) made of resin, and a copper-containing conductor layer (121) provided along at least surfaces (126, 128) facing the internal space and a surface (127) facing the first member for joining with the first member, the first conductor layer and the second conductor layer are covered with a coating layer (112, 122) having a rust prevention effect; The coating layer is provided on the entire inner wall surface (141) of the internal space. A method for manufacturing a millimeter wave waveguide (10) according to claim 6 is a method for manufacturing a millimeter wave waveguide having a structure in which a first member (11) and a second member (12) are joined with solder (13) to form a waveguide in an internal space (14) surrounded by the first member and the second member, a first conductor layer (111) containing copper is formed on a surface of a resin body (110) of the first member; a second conductor layer (121) containing copper is formed on the surface of the resin body (120) of the second member; The first conductor layer and the second conductor layer are coated with coating layers (112, 122) made of an organic anticorrosive material, A solder material (131) containing a solder alloy and which may also contain flux (161) is applied to the first member or the second member so that the solder material (131) is sandwiched between the first conductor layer and the second conductor layer when the first member and the second member are superimposed; the first member and the second member are overlapped with each other with the solder material sandwiched therebetween and heated to join the first member and the second member; At least the entire inner wall surface (141) of the internal space is re-coated with the coating layer.

[0007] In the millimeter-wave waveguide described in claim 1 having such a configuration, the first member and the second member are joined by soldering to form a waveguide in the internal space surrounded by the first member and the second member. Here, the first member has a resin first member body and a copper-containing conductor layer provided along at least a surface facing the internal space and a surface facing the second member for joining with the second member. The second member has a resin second member body and a copper-containing conductor layer provided along at least a surface facing the internal space and a surface facing the first member for joining with the first member. The first and second conductor layers provided on the first and second members are coated with a rust-preventing coating layer. The coating layer is provided on the entire inner wall surface of the internal space. Therefore, the conductor layer provided along the internal space constituting the waveguide is covered with the rust-preventing coating layer, thereby effectively suppressing the occurrence of copper rust. This effectively suppresses the degradation of transmission characteristics due to the occurrence of copper rust on the inner wall surface of the millimeter-wave waveguide. Therefore, with this configuration, it is possible to provide a millimeter wave waveguide having a structure in which a conductor layer is formed on the inner surface of a resin tube, which has excellent transmission characteristics, at a low cost.

[0008] In the method for manufacturing a millimeter-wave waveguide according to claim 5, a first conductor layer containing copper is formed on the surface of the resin body of the first member, and the first conductor layer is coated with a coating layer made of an organic rust-preventive material, thereby forming the first member. Similarly, a second conductor layer containing copper is formed on the surface of the resin body of the second member, and the second conductor layer is coated with a coating layer made of an organic rust-preventive material, thereby forming the second member. A solder material containing a solder alloy and possibly flux is applied to the first member or the second member. The first member and the second member are then heated while overlapping each other so that the solder material is sandwiched between the first and second conductor layers, thereby joining the first and second members. At least the entire inner wall surface of the internal space is then coated with a coating layer. The conductor layer provided along the internal space is thereby coated with a coating layer having a rust-preventive effect, thereby effectively suppressing the occurrence of copper rust. This effectively suppresses the deterioration of transmission characteristics due to the occurrence of copper rust on the inner wall surface of the millimeter-wave waveguide. Therefore, according to this manufacturing method, it is possible to provide a millimeter wave waveguide having a structure in which a conductor layer is formed on the inner surface of a resin tube, which has excellent transmission characteristics, at a low cost.

[0009] In addition, in each section of the application documents, each element may be given a reference symbol in parentheses. However, such reference symbol merely indicates an example of the correspondence between the element and the specific means described in the embodiment described below. Therefore, the present invention is not limited in any way by the above-mentioned reference symbols. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a side cross-sectional view showing a schematic configuration of a millimeter wave waveguide according to a first embodiment of the present invention. [Figure 2] 2 is an exploded side cross-sectional view showing the upper member and the lower member shown in FIG. 1 in a state before they are joined together. FIG. [Figure 3] 3 is a perspective view showing an example of a manner in which a solder material is applied to the lower member shown in FIG. 2. FIG. [Figure 4] 3 is a perspective view showing another example of a manner in which the solder material is applied to the lower member shown in FIG. 2. FIG. [Figure 5] 3 is a side view showing a schematic configuration of a solder reflow machine used in the step of joining the upper member and the lower member shown in FIG. 2. FIG. [Figure 6] 10 is a graph showing the results of a high-temperature, high-humidity test of a millimeter-wave waveguide in a state where a coating layer made of an organic anticorrosive material is not provided on a conductor layer formed on a resin member. [Figure 7] 3 is a side cross-sectional view showing an outline of a process for joining the upper member and the lower member shown in FIG. 2. FIG. [Figure 8] 3 is a side cross-sectional view showing an outline of a process for joining the upper member and the lower member shown in FIG. 2. FIG. [Figure 9] 3 is a side cross-sectional view showing an outline of a process for joining the upper member and the lower member shown in FIG. 2. FIG. [Figure 10] FIG. 10 is a side cross-sectional view showing a joining state when the gap at the joining portion between the upper member and the lower member is approximately a design value. [Figure 11] 10 is a side cross-sectional view showing a joining state when the gap at the joining portion between the upper member and the lower member is smaller than the design value. FIG. [Figure 12] 10 is a side cross-sectional view showing a joining state when the gap at the joining portion between the upper member and the lower member is larger than the design value. FIG. [Figure 13] 13 is a cross-sectional side view showing a joining state when the gap at the joining portion between the upper member and the lower member is larger than the design value, as in the case of FIG. 12, in a configuration in which two or more waveguide structures run in parallel. [Figure 14] 3 is an enlarged side cross-sectional view showing an outline of the configuration of a joint between an upper member and a lower member in the first embodiment of the present invention. FIG. [Figure 15] 3 is an enlarged side cross-sectional view showing an example of the structure of a joint between an upper member and a lower member in the first embodiment of the present invention. FIG. [Figure 16] 10 is an enlarged side cross-sectional view showing another example of the configuration of the joint between the upper member and the lower member in the first embodiment of the present invention. FIG. [Figure 17]FIG. 10 is an enlarged side cross-sectional view showing a main part of a lower member according to a second embodiment of the present invention. [Figure 18] FIG. 10 is a side cross-sectional view showing an enlarged view of a joint between an upper member and a lower member in a third embodiment of the present invention. [Figure 19] FIG. 10 is a side cross-sectional view showing an enlarged view of a joint between an upper member and a lower member in a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Embodiment) Hereinafter, exemplary embodiments and specific examples of the present invention will be described with reference to the accompanying drawings. The same reference numerals are used to designate identical or equivalent parts in multiple embodiments. Therefore, with regard to components having the same reference numerals as components in a previously described embodiment, the description of the previously described embodiment may be used in a subsequent embodiment, unless there is a technical contradiction or a special additional explanation.

[0012] (First embodiment: configuration) 1, a millimeter-wave waveguide 10 according to this embodiment includes an upper member 11, a lower member 12, and solder 13 for joining these members together. The millimeter-wave waveguide 10 has a structure in which an internal space 14 surrounded by the upper member 11 and the lower member 12 constitutes a waveguide. Note that the expressions "upper member 11" and "lower member 12" used here are concepts of upper and lower used for the sake of convenience in the illustrated state of FIG. 1, and do not represent concepts of upper and lower in the actual state in which the millimeter-wave waveguide 10 is used.

[0013] 2 shows an exploded view of the upper member 11 and the lower member 12 before they are joined with the solder 13. The state shown in FIG. 1, in which the upper member 11 and the lower member 12 are stacked with the solder 13 sandwiched therebetween and joined with the solder 13, is referred to as the "joined state." In contrast, the state before they are joined with the solder 13 is referred to as the "separated state." Hereinafter, a schematic configuration of a millimeter-wave waveguide 10 according to this embodiment will be described with reference to FIGS. 1 and 2.

[0014] The upper member 11, which corresponds to the "first member" of the present invention, has a resin upper member body 110 that forms the main body, an upper conductor layer 111 that coats the upper member body 110, and an upper coating layer 112 that coats the upper conductor layer 111. The upper member body 110, which corresponds to the "first member body" of the present invention, is integrally formed by injection molding. The upper conductor layer 111, which corresponds to the "first conductor layer" of the present invention, is a conductor layer containing copper, and is formed on the surface of the upper member body 110 by vapor deposition, plating, or the like. The upper coating layer 112, which corresponds to the "first coating layer" of the present invention, is a coating layer with anti-rust properties and is formed from an organic anti-rust material such as imidazole.

[0015] The upper member 11 has an upper flat plate portion 113 and a plurality of upper protrusions 114. The upper flat plate portion 113 is formed in a flat plate shape with a thickness direction along the height direction in the figure, which is the joining direction between the upper member 11 and the lower member 12. The upper protrusions 114, which correspond to the "first protrusions" of the present invention, protrude downward in the figure from the upper flat plate portion 113 toward the lower member 12. The plurality of upper protrusions 114 are arranged along an in-plane direction (i.e., the left-right direction in FIG. 1) that is perpendicular to the joining direction and perpendicular to the extension direction of the internal space 14. A recess that constitutes part of the internal space 14 is formed between a pair of adjacent upper protrusions 114 in the in-plane direction.

[0016] As shown in FIG. 2 , the upper member 11 has an upper outer facing surface 115, an upper inner facing surface 116, an upper protruding end surface 117, an upper inner side surface 118, and an upper outer side surface 119. The upper outer facing surface 115 is located on the outermost side in the in-plane direction of the surface facing the lower member 12, i.e., the surface facing downward in the figure. That is, the upper outer facing surface 115 is the surface of the upper flat plate portion 113 facing the lower member 12 that does not face the internal space 14 in the joined state. The upper inner facing surface 116 is located on the inner side in the in-plane direction of the surface of the upper flat plate portion 113 facing the lower member 12. That is, the upper inner facing surface 116 is the surface of the upper flat plate portion 113 facing the lower member 12 that faces the internal space 14 in the joined state. The upper inner facing surface 116 is formed as a flat plane parallel to the in-plane direction.

[0017] The upper protrusion end surface 117 is the end surface of the upper protrusion 114, i.e., the tip surface in the protruding direction, and is formed as a flat plane parallel to the in-plane direction. The upper inner side surface 118 is one side surface of the upper protrusion 114 and is located at a position continuous with the upper inner facing surface 116. In other words, the upper inner side surface 118 is the side surface of the upper protrusion 114 that faces the internal space 14 in the joined state. The upper outer side surface 119 is the other side surface of the upper protrusion 114 and is located at a position continuous with the upper outer facing surface 115. In other words, the upper outer side surface 119 is the side surface of the upper protrusion 114 that does not face the internal space 14 in the joined state.

[0018] The upper conductor layer 111 is provided along at least the upper inner facing surface 116 and the upper inner side surface 118 of the upper member 11, which are surfaces facing the internal space 14, and the upper protrusion end surface 117, which is a surface facing the lower member 12 for bonding with the lower member 12. Specifically, in this embodiment, the upper conductor layer 111 is provided so as to cover the entire surface of the upper member 11. Then, as shown in FIG. 2 , the upper covering layer 112 is provided so as to cover the entire surface of the upper conductor layer 111 in a separated state.

[0019] The lower member 12, which corresponds to the "second member" of the present invention, has a resin lower member body 120 that forms the main body, a lower conductor layer 121 that coats the lower member body 120, and a lower coating layer 122 that coats the lower conductor layer 121. The lower member body 120, which corresponds to the "second member body" of the present invention, is integrally formed by injection molding. The lower conductor layer 121, which corresponds to the "second conductor layer" of the present invention, is a conductor layer containing copper and is formed on the surface of the lower member body 120 by vapor deposition, plating, or the like. The lower coating layer 122, which corresponds to the "second coating layer" of the present invention, is a coating layer with anti-rust properties and is formed from an organic anti-rust material such as imidazole. In this embodiment, the lower coating layer 122 is formed from the same material as the upper coating layer 112.

[0020] The lower member 12 has a lower flat plate portion 123 and a plurality of lower protrusions 124. The lower flat plate portion 123 is formed in a flat plate shape with a thickness direction along the joining direction. The lower protrusions 124, which correspond to the "second protrusions" of the present invention, protrude upward in the figure from the lower flat plate portion 123 toward the upper member 11. The plurality of lower protrusions 124 are arranged in an in-plane direction. The lower protrusions 124 are also arranged at positions corresponding to the upper protrusions 114 in the in-plane direction. In other words, the lower protrusions 124 are arranged so as to face the upper protrusions 114. A recess that constitutes part of the internal space 14 is formed between a pair of lower protrusions 124 adjacent to each other in the in-plane direction.

[0021] As shown in FIG. 2 , the lower member 12 has a lower outer facing surface 125, a lower inner facing surface 126, a lower protruding end surface 127, a lower inner side surface 128, and a lower outer side surface 129. The lower outer facing surface 125 is located on the outermost side in the in-plane direction of the surface facing the upper member 11, i.e., the surface facing upward in the figure. That is, the lower outer facing surface 125 is the surface of the lower flat plate portion 123 facing the upper member 11 that does not face the internal space 14 in the joined state. The lower inner facing surface 126 is located on the inner side in the in-plane direction of the surface of the lower flat plate portion 123 facing the upper member 11. That is, the lower inner facing surface 126 is the surface of the lower flat plate portion 123 facing the upper member 11 that faces the internal space 14 in the joined state. The lower inner facing surface 126 is formed as a flat plane parallel to the in-plane direction.

[0022] The lower protrusion end surface 127 is the end surface of the lower protrusion 124, i.e., the tip surface in the protruding direction, and is formed as a flat plane parallel to the in-plane direction. The lower inner side surface 128 is one side surface of the lower protrusion 124 and is located at a position continuous with the lower inner facing surface 126. In other words, the lower inner side surface 128 is the side surface of the lower protrusion 124 that faces the internal space 14 in the joined state. The lower outer side surface 129 is the other side surface of the lower protrusion 124 and is located at a position continuous with the lower outer facing surface 125. In other words, the lower outer side surface 129 is the side surface of the lower protrusion 124 that does not face the internal space 14 in the joined state.

[0023] The lower conductor layer 121 is provided along at least a lower inner facing surface 126 and a lower inner side surface 128 of the lower member 12, which are surfaces facing the internal space 14, and a lower protrusion end surface 127, which is a surface facing the lower member 12 for bonding with the lower member 12. Specifically, in this embodiment, the lower conductor layer 121 is provided so as to cover the entire surface of the lower member 12. As shown in FIG. 2 , the lower covering layer 122 is provided so as to cover the entire surface of the lower conductor layer 121 in a separated state.

[0024] 1, in the joined state, the entire space inner wall surface 141, which is the inner wall surface of the internal space 14, is covered with the anti-rust coating layer that constitutes the upper coating layer 112 and the lower coating layer 122. In other words, the anti-rust coating layer formed by the upper coating layer 112 and the lower coating layer 122 is provided on the entire space inner wall surface 141 so as not to expose the upper conductor layer 111 or the lower conductor layer 121 in the internal space 14.

[0025] (First embodiment: manufacturing method) Next, an outline of a method for manufacturing the millimeter wave waveguide 10 having the above configuration will be described, along with the configuration of the millimeter wave waveguide 10 and the effects achieved by the manufacturing method.

[0026] First, the upper member 11 and the lower member 12 are formed. The upper member 11 is formed by forming an upper conductor layer 111, which is a conductor layer containing copper, on the surface of a resin upper member body 110, and coating this upper conductor layer 111 with an upper coating layer 112 made of an organic anti-corrosive material. The lower member 12 is formed by forming a lower conductor layer 121, which is a conductor layer containing copper, on the surface of a resin lower member body 120, and coating this lower conductor layer 121 with a lower coating layer 122 made of an organic anti-corrosive material.

[0027] Next, as shown in FIGS. 3 and 4, solder material 131 containing a solder alloy is applied to the upper component 11 or the lower component 12. In the examples of FIGS. 3 and 4, the solder material 131 is applied to the lower protrusion end surface 127, which is the tip surface of the lower protrusion 124. Specifically, for example, as shown in FIG. 3, ball-shaped solder material 131 having a predetermined diameter can be applied by a dispenser so as to be arranged at equal intervals. Alternatively, for example, as shown in FIG. 4, strip- or line-shaped solder material 131 can be applied with a dispenser or by printing in a single stroke with a uniform thickness. As a result, when the upper component 11 and the lower component 12 are superimposed, the solder material 131 is sandwiched between the upper conductor layer 111 provided along the upper protrusion end surface 117 and the lower conductor layer 121 provided along the lower protrusion end surface 127. 3 and 4 show an example in which the solder material 131 is applied to the lower component 12, but the solder material 131 may also be applied to the upper component 11, i.e., to the upper protrusion end surface 117, which is the tip surface of the upper protrusion portion 114. Differences in effect depending on the application method will be described later.

[0028] After applying solder material 131, upper member 11 and lower member 12 are joined together. This joining process is performed by overlapping upper member 11 and lower member 12 with solder material 131 sandwiched between them and heating them. FIG. 5 shows an overview of the joining process and a solder reflow machine 200 used therein. In this embodiment, solder reflow machine 200 has a configuration in which belt conveyor 201 is disposed between a pair of upper and lower heaters 202. Then, with upper member 11 and lower member 12 overlapping each other, multiple pins 203 are used to position upper member 11 and lower member 12, and the upper member 11 and lower member 12 are placed on belt conveyor 201 while being weighted by weights 204, and are heated by heaters 202. The effects of using pins 203 and weights 204 will be described later.

[0029] Figure 6 shows the results of a high-temperature, high-humidity test using a waveguide configured with a metal conductor film formed on the inner surface of a resin tube. The temperature and humidity conditions were 85°C and 85% humidity. The millimeter-wave frequency was 77 GHz. In Figure 6, the black dots indicate the case where the metal conductor film was copper, the white dots indicate the case where the metal conductor film was a nickel-chromium film formed on a copper film, and the square dots indicate the case where the metal conductor film was silver.

[0030] As shown in Figure 6, when the metal conductor film was silver, the millimeter-wave transmission characteristics hardly deteriorated even after the storage time had passed, and no rust was found on the surface of the metal conductor film. In contrast, when copper was used, the millimeter-wave transmission characteristics deteriorated significantly in the early stages of storage time, and then gradually deteriorated. When the surface of the metal conductor film was observed, black rust was found to have developed over almost the entire surface. In the case of nickel chromium / copper, as with copper, the millimeter-wave transmission characteristics deteriorated significantly in the early stages of storage time, and then gradually deteriorated, but the extent of this deterioration was smaller than in the case of copper. When the surface of the metal conductor film was observed, rust was found to have developed.

[0031] In order to manufacture the millimeter-wave waveguide 10 inexpensively, it is preferable to use copper or a copper alloy, rather than gold or silver, for the upper conductor layer 111 and the lower conductor layer 121. However, as shown in FIG. 6 , if copper rust occurs on the space inner wall surface 141, which is the inner wall surface of the tubular structure of the millimeter-wave waveguide 10, the transmission characteristics will be significantly degraded. Therefore, one possible solution is to coat the upper conductor layer 111 and the lower conductor layer 121 with an organic anticorrosive material layer. Specifically, the upper conductor layer 111 is coated with the upper coating layer 112, which is an organic anticorrosive material layer, and the lower conductor layer 121 is coated with the lower coating layer 122, which is also an organic anticorrosive material layer.

[0032] 7 to 9 show a step-by-step outline of solder bonding between an upper member 11 in which the upper conductor layer 111 is coated with an upper coating layer 112, which is an organic anticorrosive material layer, and a lower member 12 in which the lower conductor layer 121 is coated with a lower coating layer 122, which is also an organic anticorrosive material layer. First, as shown in FIG. 7, the upper member 11 is superimposed on the lower member 12 to which a solder material 131 has been applied. The state before thermal reflow, in which the upper member 11 and the lower member 12 are superimposed with the solder material 131 sandwiched therebetween, is referred to as a "polymerized state."

[0033] By heating the components in a polymerized state, the upper and lower components 11 and 12 are joined by solder 13, as shown in FIG. 8. At this time, flux 161 contained in the solder material 131 seeps out around the solder 13. As a result, the upper and lower coating layers 112 and 122, which are organic anticorrosive layers, dissolve into the flux 161 through a chemical reaction. Therefore, when the flux 161 is washed away, exposed portions 162 are generated around the solder 13, as shown in FIG. 9, where the organic anticorrosive layer has been removed and the metal film surface is exposed. If such exposed portions 162 are generated on the inner wall surface 141 of the space shown in FIG. 1, there is a concern that rust may occur, significantly degrading transmission characteristics.

[0034] FIG. 10 shows the bonded state when the gap between the upper and lower components 11 and 12 is approximately the design value. In this case, the seepage of flux 161, which results in the formation of exposed portions 162 that expose the upper and lower conductor layers 111 and 121 to the internal space 14, occurs within a very small area around the solder 13, as shown in FIG. 10 . Meanwhile, the upper and lower component bodies 110 and 120 are integrally formed by injection molding. Therefore, due to manufacturing errors in the resin thickness, variations occur in the protruding heights of the upper and lower protrusions 114 and 124, making it difficult to ensure high flatness at the bonded surfaces. Furthermore, warping may occur on one or both of the upper and lower components 11 and 12 when they are bonded.

[0035] In this regard, as shown in Figure 11, if the gap at the joint is smaller than the design value, the amount of solder will be excessive, causing solder 13 and flux 161 to seep onto the inner wall surface 141 of the space, resulting in a deviation in the characteristic impedance, and increasing the exposed amount of the upper conductor layer 111 and the lower conductor layer 121, resulting in a deterioration in millimeter-wave transmission characteristics due to copper rust. Conversely, as shown in Figure 12, if the gap at the joint is larger than the design value, the solder 13 will not wet the joint surface, reducing the occlusion of the internal space 14 and potentially causing radio waves to leak to the outside. In particular, as shown in Figure 13, in a configuration in which two or more waveguide structures run parallel to each other, if the two parallel internal spaces 14 are connected by a gap, radio waves will leak from one to the other. The excessive solder amount situation shown in Fig. 11 and the non-wetting solder situation shown in Fig. 12 and Fig. 13 can also occur due to variations in ball diameter and application interval when ball-shaped solder material 131 is applied discontinuously, as shown in Fig. 3. These situations can also occur due to warping when upper member 11 and lower member 12 are joined.

[0036] Therefore, in this embodiment, the amount of solder material 131 applied is made uniform in the application process prior to the joining process. Specifically, for example, as shown in Fig. 4, the solder material 131 is applied in a uniform thickness by printing or in one stroke using a dispenser. This makes it possible to properly optimize the amount of solder at the joining portion.

[0037] 5, in the joining step, the upper member 11 and the lower member 12 are positioned using pin 203 in a state where they are overlapped, and weight is applied using weight 204. This effectively prevents warping of the upper member 11 or the lower member 12 during joining.

[0038] Furthermore, in this embodiment, after the joining process, at least the entire inner wall surface 141 of the internal space 14 is recoated with a coating layer made of an organic rust-preventive material. The upper coating layer 112 and the lower coating layer 122 around the solder 13, which were removed due to the seepage and cleaning of the flux 161, are then recoated as shown in FIG. 14 . This effectively prevents deterioration of millimeter-wave transmission characteristics due to the generation of copper rust. For ease of explanation, in the following description, the portion of the upper coating layer 112 and the lower coating layer 122 shown in FIG. 14 that is recoated in the exposed portion 162 in FIG. 9 is referred to as the solder vicinity portion 151. Meanwhile, the portion of the upper coating layer 112 and the lower coating layer 122 remaining around the exposed portion 162 in FIG. 9 that is "recoated" by the recoating process is referred to as the overlapping coating portion 152.

[0039] Depending on the processing conditions of the second coating process, a step or film thickness difference may occur between the solder-proximate portion 151 and the overlapping coating portion 152, as shown in FIG. 15, or a difference in the number of layers may occur when analyzing the cross section, as shown in FIG. 16. That is, the overlapping coating portion 152 may be thicker or have more layers than the solder-proximate portion 151. On the other hand, as shown in FIG. 14, the solder-proximate portion 151 and the overlapping coating portion 152 may be integrated to the extent that they are difficult to distinguish from each other. However, in either case, the second coating process applies an organic anticorrosive to the area adjacent to the solder 13, creating a contact interface between the solder 13 and the upper coating layer 112 or the lower coating layer 122. Therefore, even if the step shown in FIG. 15 or the multilayer structure in the cross section shown in FIG. 16 do not occur, it is possible to confirm whether a second coating process has been performed by observing or analyzing the cross section.

[0040] Second Embodiment As shown in FIG. 17, a groove 171 may be provided on a lower protrusion end surface 127, which is the surface on which the solder material 131 is applied in the lower protrusion 124. With this configuration, even if a large amount of solder material 131 is applied, the excess is accommodated in the groove 171, so that the seepage of the solder 13 or flux 161 onto the space inner wall surface 141 as shown in FIG. 11 can be effectively suppressed. The shape of the groove 171 is not particularly limited, and it may be a V-groove as shown in FIG. 17 or a U-groove. The groove 171 may also be provided on the upper member 11 side.

[0041] (Third embodiment) As shown in Fig. 18, the upper coating layer 112 and the lower coating layer 122 may be made of a nickel-chromium thin film. In this case, the upper coating layer 112 and the lower coating layer 122 made of a nickel-chromium thin film are not corroded by the flux 161. Therefore, even if the flux 161 is washed away, exposure of the upper conductor layer 111 and the lower conductor layer 121 can be effectively prevented. After the flux 161 is removed, an additional coating layer 181 made of an organic anticorrosive material may be provided, as shown in Fig. 19.

[0042] (Variation) The present invention is not limited to the above-described embodiments and specific examples. Therefore, the above-described embodiments and the like can be modified as appropriate. Representative modifications will be described below. In the following description of the modifications, differences from the above-described embodiments and the like will be mainly described. Furthermore, the same reference numerals are used for parts that are identical or equivalent to each other in the above-described embodiments and the following modifications. Therefore, in the following description of the modifications, the explanations in the above-described embodiments and the like can be used as appropriate for components that have the same reference numerals as the above-described embodiments and the like, unless there is a technical contradiction or special additional explanation.

[0043] The present invention is not limited to the specific device configurations shown in the above embodiments. That is, for example, the millimeter-wave waveguide 10 is not limited to a configuration in which two members, an upper member 11 and a lower member 12, are joined together. Specifically, the millimeter-wave waveguide 10 may have a configuration in which three or more members are joined together. More specifically, for example, with reference to FIG. 1 , the upper member 11 may be composed of only an upper flat plate portion 113 and may be joined to another plate-like member corresponding to the upper protrusion portion 114. The same applies to the lower member 12. In this case, the "first member" and the "second member" in the present invention may be recognized as one and the other of a pair of members that are adjacent in the vertical direction and joined together using solder 13.

[0044] The upper conductor layer 111 and the upper covering layer 112 do not have to be provided on other surfaces as long as they are provided on at least the upper inner facing surface 116, the upper protrusion end surface 117, and the upper inner side surface 118, which face the solder joint and the internal space 14. The same applies to the lower conductor layer 121 and the lower covering layer 122. There are no particular limitations on the number and arrangement of the internal spaces 14 provided in the millimeter-wave waveguide 10.

[0045] It goes without saying that the elements constituting the above-described embodiments are not necessarily essential unless expressly stated as essential or clearly considered essential in principle. Furthermore, when numerical values ​​such as the number, value, amount, and range of components are mentioned, the present disclosure is not limited to those specific numbers unless expressly stated as essential or clearly limited to a specific number in principle. Similarly, when the shape, direction, positional relationship, etc. of components are mentioned, the present disclosure is not limited to those shapes, directions, positional relationships, etc. unless expressly stated as essential or clearly limited to a specific shape, direction, positional relationship, etc. in principle.

[0046] The variations are not limited to the above examples. For example, all or part of one of the multiple embodiments may be combined with all or part of another embodiment, provided that there is no technical inconsistency. Similarly, all or part of one of the multiple variations may be combined with all or part of another embodiment, provided that there is no technical inconsistency. [Explanation of symbols]

[0047] 10 Millimeter Waveguide 11 Upper member (first member) 111 Upper conductor layer 112 Upper coating layer (coating layer) 12 Lower member (second member) 121 Lower conductor layer 122 Lower coating layer (coating layer) 13 Solder 14 Interior Space 141 Inner wall of space

Claims

1. A millimeter wave waveguide (10), The first member (11) and the second member (12) are joined with solder (13) to form a waveguide in an internal space (14) surrounded by the first member and the second member, The first member has a first member body (110) made of resin, and a copper-containing conductor layer (111) provided along at least surfaces (116, 118) facing the internal space and a surface (117) facing the second member for joining with the second member; The second member has a second member body (120) made of resin, and a copper-containing conductor layer (121) provided along at least surfaces (126, 128) facing the internal space and a surface (127) facing the first member for joining with the first member; the first conductor layer and the second conductor layer are covered with a coating layer (112, 122) having a rust prevention effect; The coating layer is provided on the entire inner wall surface (141) of the internal space, Millimeter wave waveguide.

2. The coating layer is made of an organic rust inhibitor.

2. The millimeter wave waveguide according to claim 1.

3. The coating layer has a solder vicinity portion (151) located around the solder and an overlapping coating portion (152) located outside the solder vicinity portion, The overlapping coating portion is formed to have a thicker film and / or multiple layers than the solder vicinity portion.

3. The millimeter wave waveguide according to claim 2.

4. The first member has a first protrusion (114) protruding toward the second member, The second member has a second protrusion (124) protruding toward the first member, The second protrusion has a groove (171) that opens toward the first protrusion, The solder is provided in the groove. The millimeter wave waveguide according to any one of claims 1 to 3.

5. The coating layer is made of a nickel chromium thin film. The millimeter wave waveguide according to any one of claims 1 to 3.

6. A method for manufacturing a millimeter wave waveguide (10) having a structure in which a first member (11) and a second member (12) are joined with solder (13) to form a waveguide in an internal space (14) surrounded by the first member and the second member, A first conductor layer (111) containing copper is formed on the surface of the resin body (110) of the first member, A second conductor layer (121) containing copper is formed on the surface of the resin body (120) of the second member, The first conductor layer and the second conductor layer are coated with a coating layer (112, 122) made of an organic anticorrosive material, A solder material (131) containing a solder alloy and which may also contain flux (161) is applied to the first member or the second member so that the solder material (131) is sandwiched between the first conductor layer and the second conductor layer when the first member and the second member are superimposed; the first member and the second member are overlapped with each other with the solder material sandwiched therebetween and heated to join the first member and the second member; At least the entire inner wall surface (141) of the internal space is re-coated with the coating layer. Method for manufacturing millimeter wave waveguides.

7. The solder material is applied to a uniform thickness by printing. The method for manufacturing the millimeter wave waveguide according to claim 6 .

8. The solder material is applied in a single stroke using a dispenser to a uniform thickness. The method for manufacturing the millimeter wave waveguide according to claim 6 .

9. With the first member and the second member overlapped, the first member and the second member are positioned using a pin (203); The first member and the second member are joined together by heating while applying a weight using a weight (204). A method for manufacturing a millimeter wave waveguide according to any one of claims 6 to 8.

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