Patent Application
20230411851
The present disclosure relates to an antenna substrate, an antenna structure, and an antenna production method.
In order to protect an antenna from corrosive atmosphere, moisture, and so on, a method is adopted in which a coating agent is applied to an antenna substrate so as to make the antenna substrate moisture-proof and protect the antenna substrate.
However, for a product that requires gluing or soldering work in assembling an antenna, a moisture-proof process needs to be performed after the antenna is assembled. Therefore, if the antenna has a complex structure, the moisture-proof process is difficult.
Patent Literature 1: JP 2011-215641 A
Patent Literature 1 discloses a surface light emitter that is composed of a bendable substrate including electrical wiring, a plurality of light emitting diode (LED) elements to be placed almost regularly on the substrate, and a top film to be stretched over the surface of the LED elements, where the top film is stretched over the surface of the placed LED elements on the bendable substrate.
According to this disclosure, since the film is attached only to the top face of the substrate, there is a risk that water will enter from the edge of the substrate, and there is also a problem that the film tends to peel off due to a difference in thermal expansion between the substrate and the film.
An object of the present disclosure is to provide an antenna substrate and an antenna structure that can prevent water from entering from the surface and edge portion of the substrate and can reduce a risk that a film will peel off by attaching, to the antenna substrate, a film that is suitably fitted to pits and projections on the substrate and the shape of the substrate.
An antenna substrate according to the present disclosure includes
An antenna structure according to the present disclosure includes
In an antenna substrate and an antenna structure according to the present disclosure, a film that is suitably fitted to pits and projections on the substrate is attached to the antenna substrate, so that it is possible to prevent water from entering from the surface and edge portion of the substrate and reduce a risk that the film will peel off.
In the antenna structure and the antenna substrate according to the present disclosure, the film covers the substrate and the side faces of a housing of the antenna structure or covers the antenna substrate, so that it is relatively easy to secure waterproofness. In addition, according to the present disclosure, the film covers the edge portion of the substrate, so that this has the effect of reducing water entry into the substrate and moisture absorption of the substrate. Furthermore, the film is wrapped to the back face of a support or the back face of the antenna substrate, so that the present disclosure has the effect of reducing a risk that the film will peel off.
In the description and drawings of embodiments, the same elements and corresponding elements are denoted by the same reference sign. The description of elements denoted by the same reference sign will be suitably omitted or simplified.
This embodiment will be described in detail below with reference to the drawings.
Although not illustrated, the antenna structure 1 is typically attached to an antenna mounting member 22 of a main apparatus or the like. The wiring substrate 2 and the antenna element 3 will be collectively called an antenna substrate 23.
The antenna structure 1 includes a structure surface, a plurality of structure side faces, and a structure back face. The structure surface is a face that includes a radio wave emitting face. The plurality of structure side faces are faces that are in contact with the structure surface. The structure back face is a face that is opposite to the structure surface and in contact with the plurality of structure side faces, and is also called the antenna structure 1 back face.
The wiring substrate 2 is a substrate on which electrical wiring is formed and includes the antenna element 3. In this example, the number of side faces of the wiring substrate 2 is four, but the number of side faces is not limited to four. A side face refers to a face located in a lateral direction, and refers to a face other than the radio wave emitting face and a substrate back face. The lateral direction is a direction perpendicular to an upward direction. The directions of an X axis and a Y axis are specific examples of the lateral direction. The direction of a Z axis is a specific example of the upward direction. The substrate back face is a face that is opposite to the radio wave emitting face and located in a downward direction, and is also called the wiring substrate 2 back face or the antenna substrate 23 back face. The wiring substrate 2 includes the radio wave emitting face, the substrate back face, and a plurality of substrate side faces. The substrate side faces are faces that are in contact with the radio wave emitting face. The substrate back face is a face that is in contact with the plurality of substrate side faces.
The radio wave emitting face is the face including the antenna element 3 of the wiring substrate 2. Unless otherwise stated, the antenna structure 1, the antenna substrate 23, and so on will be described assuming that the radio wave emitting face is the face located in the upward direction.
The antenna element 3 is an element with an antenna function. In this example, the number of the antenna elements 3 is nine, but the number of the antenna elements 3 is not limited to nine. The shape of the antenna element is not limited to a disc-like shape, hemisphere, or the like.
The film 4 is a single film, and is attached to at least the radio wave emitting face, the plurality of structure side faces, and an edge portion of an outer peripheral portion of the support 5 back face. The film 4 is attached so as to cover the top face, the side faces, and part of the bottom face of the antenna structure 1. The film 4 is also called a first film.
The film 4 is attached to the surface of the antenna substrate 23. Therefore, a material with low permittivity and a low-loss dissipation factor is desirable as the material of the film 4. As a specific example, the film 4 is a cycloolefin film or a polyethylene film.
The film 4 may be one that can be attached to the antenna substrate 23 and the support 5 by self-fusion of the film 4, or may be one that can be attached to the antenna substrate 23 and the support 5, using a pressure-sensitive adhesive, adhesive, or the like.
In order to reduce the influence on the antenna characteristics, it is desirable to attach the film 4 to the radio wave emitting face by self-fusion of the film.
The support 5 supports at least the outer peripheral portion of the wiring substrate 2 back face. The support 5 may support an area other than the outer peripheral portion. In this embodiment, it is assumed that the support 5 is attached so as to cover the outer peripheral portion of the wiring substrate 2 and supports the outer peripheral portion.
The antenna substrate 23 is composed of the wiring substrate 2 and the antenna element 3 and is fixed to the support 5.
The antenna structure 1 is formed by attaching the film 4 from the radio wave emitting face of the antenna substrate 23 so as to wrap the side faces of the antenna substrate 23 to the outer peripheral portion of the support 5 back face. That is, the film 4 is attached so as to cover the entire face of the radio wave emitting face of the antenna substrate 23, the entire faces of all the side faces of the antenna substrate 23, and the edge portion of the outer peripheral portion of the support 5 back face, and the film 4 does not have any separated portions.
In practice, the film 4 is attached to the entire face of the radio wave emitting face. Note that the entire face means the whole surface of a face. However, for convenience of description, the film 4 is omitted in this diagram.
The support 5 supports only the outer peripheral portion of the wiring substrate 2. Therefore, there is an opening portion of the support 5, that is, an area where the support 5 does not exist in the antenna structure 1 back face.
The film 4 is attached only to the edge portion of the support 5 back face, so that there is an opening portion of the film 4, that is, an area where the film 4 does not exist in the antenna structure 1 back face. The film 4 may be attached to the entire face of the support 5 back face, or may wrap the support 5 back face and be attached to the inner wall of the support 5.
The connector 6 is placed on the antenna substrate 23 back face, and electrically connects the antenna substrate 23 and the antenna mounting member 22 or the like.
In this figure, there seems to be a gap between the film 4 and each of the wiring substrate 2, the antenna element 3, and the support 5. However, the gap is for clearly indicating the film 4, and there is actually no such gap. The same as in this figure also applies to other side cross-sectional diagrams. There may be a slight gap between the film 4 and a boundary between the wiring substrate 2 and the antenna element 3 or the like.
In order to waterproof the opening portion of the support 5, a gap between the opening portion or an area around the opening portion of the support 5 and the antenna mounting member 22 is filled. Specific examples of waterproofing the opening portion of the support 5 will be presented below.
This figure illustrates an example in which the opening portion of the support 5 is waterproofed by placing packing 7 in the entire area of a surrounding area of the peripheral portion of the opening portion of the support 5, where this area is between the support 5 back face and the antenna mounting member 22, so as to cause the antenna structure 1 and the antenna mounting member 22 to be in close contact.
This figure illustrates an example of waterproofing the opening portion of the support 5 by placing the packing 7 between the inner walls of the opening portion of the support 5 and the side faces of the protruding portion of the antenna mounting member 22 so as to cause the antenna structure 1 and the antenna mounting member 22 to be in close contact.
In addition to the above examples, filling the entire opening portion of the support 5 with resin, or attaching a lid to the opening portion of the support 5 may be pointed out as means for waterproofing the opening portion of the support 5.
A film attachment process according to this embodiment will be described below. The film attachment process is a series of steps to attach the film 4 to the antenna structure 1 to which the film 4 has not been attached.
In the film attachment process, as a specific example, a forming method using an apparatus that utilizes gas pressure to attach a skin material to the surface of an attachment target 12 is used. An antenna production method is a method for producing the antenna substrate 23 or the antenna structure 1 using the apparatus. As a specific example of the apparatus, a three-dimensional surface decoration forming machine may be pointed out. The film attachment process using the three-dimensional surface decoration forming machine will be described below.
The film forming jig 18 is placed on the stage 17, and the antenna structure 1 to which the film has not been attached is placed on the film forming jig 18.
The outer shape of the top face of the film forming jig 18 is smaller than the outer shape of the antenna substrate 23 or the antenna structure 1 back face to which the film has not been attached. That is, the outer shape of the top face of the film forming jig 18 is contained within the outer shape of the bottom face of the antenna substrate 23 or the antenna structure 1. The antenna structure 1 can be placed on the top face of the film forming jig 18 with the radio wave emitting face facing upward so that at least the entire edge portion of the outer peripheral portion of the antenna structure 1 back face is not in contact with the top face of the film forming jig 18. With this arrangement, when the film 4 is attached to the antenna structure 1, the film 4 can be wrapped to the side faces of the film forming jig 18. After the film 4 is wrapped to the side faces of the film forming jig 18, the film 4 is trimmed along the boundary of the side faces of the film forming jig 18 and the antenna structure 1. As a result, the antenna structure 1 to which the film 4 has been attached, as illustrated in
The film forming jig 18 is placed on the stage 17, and the antenna structure 1, which is the attachment target 12, is placed on the film forming jig 18.
Then, the three-dimensional surface decoration forming machine lowers the stage 17 so that the entirety of the antenna structure 1 is contained within the lower chamber 14.
The film 4 is placed so as to block the entire area of a hole formed by the frame 16. The hole is a space surrounded by the frame 16.
The three-dimensional surface decoration forming machine closes the upper chamber 13 and the lower chamber 14. As a result, the space on the side of the upper chamber 13 and the space on the side of the lower chamber 14 are separated with the frame 16 and the film 4 as a boundary.
The three-dimensional surface decoration forming machine uses the vacuum pump 20 to pull air from the upper chamber 13 and the lower chamber 14.
The heater 15 heats the film 4. When the film 4 reaches a temperature that allows forming, the three-dimensional surface decoration forming machine proceeds to the next step.
The three-dimensional surface decoration forming machine causes the attachment target 12 to be in contact with the film 4. That is, the three-dimensional surface decoration forming machine raises the stage 17 to press the antenna structure 1 against the film 4.
The three-dimensional surface decoration forming machine uses the compressor 19 to inject compressed air only into the upper chamber 13 so as to pressurize the upper chamber 13. While compressed air is injected into the space in the upper chamber 13, the space in the lower chamber 14 is maintained in a vacuum state. Therefore, the film 4 is attached around the antenna structure 1 without any gap. In this step, the three-dimensional surface decoration forming machine attaches the film 4 to the surface of the antenna structure 1 by causing the pressure under the film 4 to be lower than the pressure above the film 4. With this process, the film 4 that is suitably fitted to pits and projections on the substrate and the shape of the substrate can be attached to the attachment target 12.
The three-dimensional surface decoration forming machine may choose whether or not to carry out this step.
The three-dimensional surface decoration forming machine re-heats the film 4 with the heater 15. By this step, adhesion between the film 4 and the antenna structure 1 can be improved.
The three-dimensional surface decoration forming machine restores the air pressure in both of the space inside the upper chamber 13 and the space in the lower chamber 14 to atmospheric pressure.
The antenna structure 1 is extracted from the three-dimensional surface decoration forming machine.
The film 4 may be trimmed before the antenna structure 1 is extracted from the three-dimensional surface decoration forming machine, or may be trimmed using another machine or the like after the antenna structure 1 is extracted.
The film 4 is attached to the antenna structure 1 as described above, so that waterproofness is secured on the radio wave emitting face and all the side faces of the antenna substrate 23 and between the antenna substrate 23 and the support 5.
The film 4 is attached to the antenna structure 1 as described above, so that the film that is wrapped from the side faces of the antenna substrate 23 to the edge portion of the outer peripheral portion of the support 5 back face acts as an anchor. This reduces a risk that the film 4 will peel off due to deformation caused by thermal expansion of at least one of the wiring substrate 2 and the support 5, deformation caused by a difference in thermal expansion between the wiring substrate 2 and the support 5, or the like.
The film 4 is wrapped from the side faces of the antenna substrate 23 to the edge portion of the outer peripheral portion of the support 5 back face, so that a waterproof distance can be lengthened, resulting in enhanced waterproofness. The waterproof distance is the shortest distance from the end of a member for waterproofing to an area that needs to be waterproofed. In the antenna structure 1, the member for waterproofing is the film 4, the packing 7, or the like, and the area that needs to be waterproofed is an exposed portion of the antenna substrate 23 or the like. The waterproof distance in this embodiment is the distance from the end of the film 4 in the support 5 back face to the bottom edge of each of the side faces of the antenna substrate 23.
When the film is attached by self-bonding of the film or an adhesive, generally if the film peels off after the film has been attached once, the adhesiveness of the film is not maintained, and it is difficult to restore the adhesiveness of the film without a process such as re-heating the film. Therefore, self-bonding of the film or an adhesive leads to a higher risk that the film will peel off when compared with a pressure-sensitive adhesive.
However, according to this embodiment, since the film 4 is wrapped to the support 5 back face and the film 4 shrinks when the film 4 is attached, and also due to effects caused by these, the adhesion of the film 4 to the antenna substrate 23 and the support 5 is enhanced, and a risk that the film 4 will peel off from the antenna substrate 23 and the support 5 is reduced.
Even when self-bonding of the film is used, a risk that the film 4 will peel off from the antenna substrate 23 and the support 5 is reduced because the film 4 is arranged to be wrapped to the support 5 back face.
Part of each of the antenna elements 3 may be placed inside the wiring substrate 2, or part of the antenna elements 3 may be placed inside the wiring substrate 2.
A method for producing the antenna structure 1 illustrated in this figure will be briefly described. Before the film 4 is attached to the antenna structure 1, the screws 9 are inserted and installed from the top face side of the antenna substrate 23 to fasten the antenna substrate 23 to the support 5. Then, the film 4 is attached from the top faces and side faces of the screws 9 and the entire face of the radio wave emitting face so as to wrap the side faces of the antenna substrate 23 to the edge portion of the outer peripheral portion of the support 5 back face.
In this case, the fastening sections of the screws 9 are waterproofed by the film 4. Therefore, it is not necessary to waterproof these fastening sections using a different method.
The film 4 is attached from the entire face of the radio wave emitting face of the antenna substrate 23 so as to wrap the side faces of the antenna substrate 23 to the edge portion of the outer peripheral portion of the support 5 back face.
In this variation, since the screws 9 are inserted from the support 5 back face side so as to fasten the antenna substrate 23 and the support 5, the waterproof distance is shortened when the fastening sections of the screws 9 are covered by the film 4. The waterproof distance here is the shortest distance from the end of the film 4 attached to the antenna structure 1 to the through holes of the screws 9. Therefore, it is desirable to separately waterproof the fastening sections of the screws 9 with resin or the like.
Instead of covering the fastening sections of the screws 9 by the film 4, a waterproof process may be separately performed for the fastening sections, such as installing the packing 7 in
The film 4 is attached from the entire face of the radio wave emitting face of the antenna substrate 23 so as to wrap the side faces of the antenna substrate 23 to the edge portion of the outer peripheral portion of the support 5 back face.
The antenna substrate 23 and the support 5 may be fixed using both the screws 9 and the adhesive 8. The substrate back face may be fixed to the support 5 that covers the outer peripheral portion of the substrate back face with at least one of the screws 9 and the adhesive 8.
Differences from the above embodiment will be mainly described below with reference to the drawings.
The film 4 is attached to at least the radio wave emitting face, the plurality of substrate side faces, and the edge portion of the outer peripheral portion of the substrate back face. The film 4 is attached so as to cover at least the side faces, the top face, and part of the bottom face of the antenna substrate 23, and is not attached to the support 5.
The packing 7 is installed between the edge portion of the outer peripheral portion of the wiring substrate 2 back face and the edge portion of the outer peripheral portion of the surface of the support 5.
The film 4 is attached from the entire face of the radio wave emitting face so as to wrap the entire face of each of the side faces of the antenna substrate 23 to the edge portion of the outer peripheral portion of the antenna substrate 23 back face.
The packing 7 is installed so as to bridge between the film 4 attached to the antenna substrate 23 back face and the top face of the support 5. A groove corresponding to the width of the packing 7 may be provided on the top face of the support 5, and part of the packing 7 may be fitted into the groove. The groove may be omitted. At least part of the packing 7 may be in contact with the antenna substrate 23.
Between the antenna substrate 23 back face and the top face of the support 5, there is a gap whose height is the thickness of the packing 7 or a gap whose height is slightly narrower than this thickness. A height is a length in the upward direction.
The film attachment process according to this embodiment is substantially the same as the film attachment process according to Embodiment 1. In the film attachment process according to this embodiment, the film 4 is attached to the antenna substrate 23 instead of the antenna structure 1. The antenna substrate 23 to which at least one of the films to be attached has not been attached may be simply called the antenna substrate 23.
The description of the film attachment process according to this embodiment is one where the antenna structure 1 and each constituent element of the antenna structure 1 in the description of the film attachment process according to Embodiment 1 is suitably interpreted as the antenna substrate 23 or each constituent element of the antenna substrate 23 and also the description related to the antenna structure 1 is suitably omitted.
As described above, according to this embodiment, the packing 7 is placed between the film 4 attached to the edge portion of the outer peripheral portion of the antenna substrate 23 back face and the support 5. Therefore, the waterproofness of the antenna structure 1 is secured.
The film 4 is attached as described above, so that the film 4 that is wrapped from the side faces of the antenna substrate 23 to the edge portion of the outer peripheral portion of the antenna substrate 23 back face acts as an anchor, and this can reduce a risk that the film 4 will peel off due to deformation caused by thermal expansion of the wiring substrate 2 or the like.
The film 4 is wrapped from the side faces of the antenna substrate 23 to the edge portion of the outer peripheral portion of the antenna substrate 23 back face, so that the waterproof distance can be lengthened, and as a result, the waterproofness of the antenna structure 1 is enhanced.
The fastening sections of the screws 9 may be waterproofed by placing packing between the screws 9 and the support 5. A waterproof process such as filling resin into the fastening sections of the screws 9 on the support 5 back face may be performed.
The adhesive 8 is applied to at least part of an area between the wiring substrate 2 and the support 5 where the packing 7 is not installed.
Differences from the above embodiments will be mainly described below with reference to the drawings.
The film 11 is a single film, and is attached to at least the substrate back face and the plurality of substrate side faces so as to cover at least part of the first film. The film 11 is also called a second film.
The film 11 is attached so as to overlap at least part of the first film. As a specific example, the film 11 is attached from the entire face of the back face of the antenna substrate 23 so as to wrap the side faces of the antenna substrate 23 to the edge portion of the outer peripheral portion of the top face of the antenna substrate 23, so as to overlap part of the film 4. In this figure, the film 11 is attached so as to overlap part of the film 4, but the film 11 may be attached so that the film 4 covers the film 11.
The portion of the film 11 to enclose the connector 6 is opened by trimming. This allows the connector 6 to be connected to the antenna substrate 23.
The film 4 is attached to the antenna substrate 23, as in the film attachment process according to Embodiment 2.
In order for the top face of the antenna substrate 23 to which the film 4 has been attached to be in contact with the top face of the film forming jig 18, the antenna substrate 23 is placed with the top face facing downward on the film forming jig 18.
Then, the film 11 is attached to the antenna substrate 23, as in the first film attachment process. The description of this process is one where the film 4 in the description of the first film attachment process is suitably interpreted as the film 11.
As described above, according to this embodiment, the waterproofness of the antenna structure 1 is secured by inserting the packing 7 between the film 11 and the support 5 on the back face side of the antenna substrate 23.
According to this embodiment, the antenna substrate 23 is covered with the film 4 and the film 11, so that the enhanced waterproofness of the antenna substrate 23 can be secured. In addition, attaching the two layers of films to the side faces of the antenna substrate 23 reduces a risk that the film 4 will peel off at the edge portion of the antenna substrate 23 and reduces a risk that the film 4 will rupture.
In this figure, the substrate taps 10 are installed by making holes at part of the film 11. The areas around the boundaries between the substrate taps 10 and the antenna substrate 23 may be waterproofed by resin or the like. The substrate taps 10 may be installed on the film 11.
The adhesive 8 may be applied on the film 11.
Differences from the above embodiments will be mainly described below with reference to the drawings.
The film 4 is attached from the entire face of the radio wave emitting face of the antenna substrate 23 so as to wrap the edge portion of the top face of the support 5 and the side faces of the support 5 to the edge portion of the outer peripheral portion of the support 5 back face, so as to form the antenna structure 1.
The film attachment process according to this embodiment is substantially the same as the film attachment process according to Embodiment 1.
As described above, according to this embodiment, the side faces of the antenna substrate 23 are covered by the support 5, so that the edge portion of the antenna substrate 23 is protected.
According to this embodiment, the film 4 is attached from the entire face of the radio wave emitting face of the antenna substrate 23 so as to wrap the edge portion of the top face of the support 5 and the side faces of the support 5 to the edge portion of the outer peripheral portion of the support 5 back face. As a result, the film 4 acts as an anchor, and this reduces a risk that the film 4 will peel off due to deformation caused by thermal expansion of the wiring substrate 2 or the like.
The film 4 is attached from the entire face of the radio wave emitting face of the antenna substrate 23 so as to wrap the edge portion of the surface of the support 5 and the side faces of the support 5 to the edge portion of the outer peripheral portion of the support 5 back face.
The above embodiments can be freely combined, or any constituent element of each of the embodiments can be modified. Alternatively, in each of the embodiments, any constituent element can be omitted.
The embodiments are not limited to those presented in Embodiments 1 to 4, and various modifications can be made as needed. The procedures described using the flowcharts or the like may be suitably modified.
1: antenna structure, 2: wiring substrate, 3: antenna element, 4: film, 5: support, 6: connector, 7: packing, 8: adhesive, 9: screw, 10: substrate tap, 11: film, 12: attachment target, 13: upper chamber, 14: lower chamber, 15: heater, 16: frame, 17: stage, 18: film forming jig, 19: compressor, 20: vacuum pump, 21: pipe, 22: antenna mounting member, 23: antenna substrate, 30: machine housing, 31: elevating section.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/042942 | 11/18/2020 | WO |
