JP4524706B2 - Soldering method for patch antenna feed pin - Google Patents

Description

The present invention relates to a patch antenna, in particular, it relates to a soldering method of the feed pin of the antenna in a suitable patch antenna mounted on a vehicle such as an automobile.

  As is well known in this technical field, various antennas are currently mounted on vehicles such as automobiles. For example, such antennas include a GPS (Global Positioning System) antenna and an SDARS (Satellite Digital Radio Service) antenna.

  GPS (Global Positioning System) is a satellite positioning system using artificial satellites. The GPS receives radio waves (GPS signals) from four GPS satellites out of 24 artificial satellites (hereinafter referred to as “GPS satellites”) orbiting the earth, and a mobile object is received from the received radio waves. The position and altitude of the moving object on the map can be calculated with high accuracy based on the principle of triangulation by measuring the positional relationship and time error between the GPS satellite and the GPS satellite.

  In recent years, GPS has been widely used in car navigation systems that detect the position of a traveling vehicle. The car navigation device includes a GPS antenna for receiving the GPS signal, a processing device for processing the GPS signal received by the GPS antenna to detect the current position of the vehicle, and a position detected by the processing device. Is displayed on a map. A planar antenna such as a patch antenna is used as the GPS antenna.

  On the other hand, SDARS (Satellite Digital Audio Radio Service) is a service based on digital broadcasting using a satellite in the United States (hereinafter referred to as “SDARS satellite”). That is, in the United States, digital radio receivers that receive satellite waves or terrestrial waves from SDARS satellites and can listen to digital radio broadcasts have been developed and put into practical use. Currently, in the United States, two broadcasting stations, XM and Sirius, offer a total of more than 250 channels of radio programs nationwide. This digital radio receiver is generally mounted on a moving body such as an automobile, and can receive radio waves by receiving radio waves having a frequency of about 2.3 GHz. That is, the digital radio receiver is a radio receiver capable of listening to mobile broadcasts. Since the frequency of the received radio wave is about 2.3 GHz, the reception wavelength (resonance wavelength) λ at that time is about 128.3 mm. The terrestrial wave is a satellite wave that is once received by the earth station, then slightly shifted in frequency, and retransmitted with linearly polarized waves. That is, the satellite wave is a circularly polarized wave, whereas the ground wave is a linearly polarized wave. As the SDARS antenna, a planar antenna such as a patch antenna is used in the same manner as the GPS antenna.

  The antenna device for XM satellite radio receives circularly polarized radio waves from two geostationary satellites, and receives radio waves from the ground linear polarization equipment in the dead zone. On the other hand, the antenna device for Sirius satellite radio receives circularly polarized radio waves from three orbiting satellites (synchronous type), and receives radio waves by the ground linear polarization equipment in the dead zone.

  As digital radio receivers, there are those installed in automobiles, stationary types installed indoors, and portable types that can be carried using a battery as a power source.

  A conventional patch antenna 10 will be described with reference to FIGS. 1 to 3. FIG. 1 is a perspective view of the patch antenna 10. 2, (A) is a plan view of the patch antenna 10, (B) is a front view of the patch antenna 10, (C) is a left side view of the patch antenna 10, and (D) is a bottom view of the patch antenna 10. . FIG. 3 is a cross-sectional view taken along line III-III in FIG.

  The patch antenna 10 includes a substantially rectangular parallelepiped dielectric substrate 12, an antenna radiation electrode (radiation element) 14, a ground electrode (ground conductor) 16, and a rivet-shaped feed pin 18. The antenna radiation electrode 14 is also called a reception electrode or a patch electrode.

  The dielectric substrate 12 is made of a ceramic material having a high dielectric constant made of, for example, barium titanate. The dielectric substrate 12 has a top surface (front surface) 12u and a bottom surface (back surface) 12d, and a side surface 12s that face each other. In the illustrated example, the corners of the side surface 12s of the dielectric substrate 12 are chamfered. The dielectric substrate 12 is provided with a substrate through-hole 12a penetrating from the top surface 12u to the bottom surface 12d at a position where a feeding point 15 described later is installed.

  The antenna radiation electrode (radiation element) 14 is made of a conductor and is formed on the top surface 12 u of the dielectric substrate 12. The antenna radiation electrode (radiation element) 12 has a substantially square shape. The antenna radiation electrode (radiation element) 12 is formed by, for example, silver pattern printing.

  The ground electrode (ground conductor) 16 is made of a conductor and is formed on the bottom surface 12 d of the dielectric substrate 12. The ground electrode (ground conductor) 16 has a ground opening 16a that is substantially concentric with the substrate through hole 12a and has a diameter larger than the diameter of the substrate through hole 12a.

  A feeding point 15 is provided at a position displaced from the center of the antenna radiation electrode 12 in the x-axis direction and the y-axis direction. The upper end portion 18 a of the power supply pin 18 is connected to the power supply point 15. The power supply pin 18 is led to the lower side separated from the ground electrode (ground conductor) 16 through the substrate through hole 12a and the ground through hole 16a.

  Here, solder is used as the feeding point 15. Therefore, the feeding point 15 has a convex shape that rises upward from the main surface of the antenna radiation electrode 14.

  The illustrated power supply pin 18 includes a rivet pin having a head 181 provided at the upper end 18a and a rod-shaped body 182 extending from the upper end 18a to the lower end 18b. In this case, the head 181 of the rivet pin 18 is joined to the antenna radiation electrode 14 by soldering with the head 181 of the rivet pin 18 protruding from the main surface of the antenna radiation electrode 14. Therefore, this joint portion has a convex shape as the feeding point 15.

  Various methods are employed as a soldering method (mounting method) of the power supply pin 18. For example, there is a method of soldering the power supply pin 18 using a soldering iron with a human hand. However, this method has a problem that the amount of solder is not constant. Therefore, the capacitance value (capacitance) applied around the power supply pin 18 changes. As a result, there is a problem that the tuning frequency of the patch antenna 10 is affected.

  Another power supply pin soldering method (mounting method) is disclosed in Patent Document 1, for example. In this method of attaching a power feed pin disclosed in Patent Document 1, a predetermined amount of annular solder (solder paste) is placed on the antenna radiation electrode (patch electrode) 12 around the substrate through-hole 12a. Then, the power supply pin 18 is inserted and pushed into the substrate through-hole 12a from the lower end portion 18b, and then the solder (solder paste) is heated and melted to cover the upper end portion (head) 181 of the power supply pin 18 with solder. The antenna radiation electrode (patch electrode) 12 and the feed pin 18 are electrically connected.

  In the power supply pin soldering method (mounting method) disclosed in Patent Document 1, a predetermined amount of solder paste is first applied to the antenna radiation electrode (patch electrode) before inserting the power supply pin 18 into the dielectric substrate 12. ) It is mounted on 12. However, Patent Document 1 does not disclose or suggest how to place a predetermined amount of solder paste on the antenna radiation electrode (patch electrode) 12.

  Next, a conventional power supply pin soldering method by reflow will be described with reference to FIG. In FIG. 4, the ground electrode (ground conductor) 16 formed on the bottom surface 12d of the dielectric substrate 12 is omitted.

  First, as shown in FIG. 4A, the body portion 182 of the power feed pin 18 is inserted into the substrate through hole 12 a of the dielectric substrate 12. At this time, since the diameter of the head 181 of the power feed pin 18 is larger than the diameter of the substrate through hole 12 a, the head 181 of the power feed pin 18 is placed on the antenna radiation electrode (reception electrode) 14.

  Next, as shown in FIG. 4B, the mask 20 is mounted on the antenna radiation electrode (reception electrode) 14 and the paste solder 15 is applied. The thickness of the mask 20 is thicker than the thickness (height) of the head 181 of the power supply pin 18. The mask 20 has a circular opening 20 a that surrounds the head 181 of the power supply pin 18. The diameter of the circular opening 20 a is larger than the diameter of the head 181 of the power supply pin 18. When the mask 20 is mounted on the antenna radiation electrode (reception electrode) 14, the center line of the circular opening 20a of the mask 20 and the center line of the feed pin 18 (substrate through hole 12a) are aligned with each other. The The paste solder 15 is applied by removing unnecessary portions so as not to protrude from the circular opening 20a. Accordingly, a predetermined amount of paste solder 15 is applied over the entire circumference on the head 181 of the power supply pin 18 in the circular opening 20a.

  Subsequently, the mask 20 is peeled off from the antenna radiation electrode (reception electrode) 14, and the paste solder 15 is melted by reflow in an electric furnace. As a result, as shown in FIG. 4C, the entire circumference of the head 181 of the power feed pin 18 is covered with the solder 15, and the antenna radiation electrode (reception electrode) 14 and the power feed pin 18 are conductively connected.

JP-A-9-260933 (FIG. 1)

  However, in the conventional power supply pin soldering method (mounting method) disclosed in Patent Document 1 or illustrated in FIG. 4, the entire head 181 (whole circumference) of the power supply pin 18 is covered with the solder 15, and the antenna Since the radiation electrode (reception electrode) 14 and the feed pin 18 are conductively connected, it is difficult to reduce the amount of solder 15.

  On the other hand, if the amount of the solder 15 is excessively reduced, the bonding strength between the antenna radiation electrode (reception electrode) 14 and the feed pin 18 is lowered. As a result, the feed pin 18 may come off from the patch antenna, leading to strength deterioration.

Accordingly, an object of the present invention, without deteriorating the bonding strength can be as much as possible reduce the amount of solder is to provide a feed pin soldering method of the patch antenna.

According to the onset bright, has a top surface opposite to each other (12u) and bottom (12d), the substrate through hole penetrating from the top surface at a predetermined position to the bottom surface (12a) is bored, dielectric A substrate (12); an antenna radiation electrode (14) made of a conductor and formed on the top surface of the dielectric substrate; and a ground electrode (16) made of a conductor and formed on the bottom surface of the dielectric substrate; A power supply pin (18) comprising a head (181) provided at the upper end (18a) and a rod-shaped body (182) extending from the upper end to the lower end (18b), A patch antenna (10A; 10B) having a feed pin (18) having a head connected to the antenna radiation electrode at a predetermined position and a lower end led to the bottom surface side of the dielectric substrate through the substrate through-hole. Solder the power supply pin (18) to the antenna radiation electrode (14) That a method, separated from each other, and N provided in rotational symmetry with respect to the center line of the substrate through hole (12a) (N is an integer of 2 or more) have number of openings (20Aa) feed pin ( 18) mounting a mask (20A) having a thickness smaller than the height of the head (181) on the antenna radiation electrode (14), and using this mask (20A), N paste solders (15A) ) On the antenna radiation electrode (14) and on the position where the head (181) of the feed pin (18) rests, and the feed pin (18) from the top surface of the dielectric substrate to the substrate through hole (12a). ) And placing the head (181) of the power supply pin on the N paste solders, and melting the N paste solders (15A) by reflow and soldering the power supply pins. Patch antenna characterized by including Feed pin soldering method is obtained.

In feed pin soldering method of the patch antenna according to the aforementioned present onset bright, as mask, an N-number of arcuate openings can the N openings by dividing the virtual ring to N (20Aa), A mask (20A) may be used. In this case, the inner diameter of the virtual ring is smaller than the diameter of the head (181) of the power supply pin (18), and the outer diameter of the virtual ring is larger than the diameter of the head of the power supply pin (18). preferable.

  In addition, the code | symbol in the said parenthesis is attached | subjected in order to make an understanding of this invention easy, and it is only an example, and of course is not limited to these.

  In the present invention, the solder for connecting the head of the power feed pin and the antenna radiation electrode are separated from each other and a plurality of solder portions provided in rotational symmetry with respect to the center line of the substrate through hole of the dielectric substrate Therefore, the amount of solder can be reduced as much as possible without deteriorating the bonding strength.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  With reference to FIG. 5, the patch antenna 10A and its feed pin soldering method according to the first embodiment of the present invention will be described. FIG. 5 is a diagram showing steps of the patch antenna 10A and its power supply pin soldering method. In FIG. 5, the ground electrode (ground conductor) 16 formed on the bottom surface 12d of the dielectric substrate 12 is omitted.

  The illustrated patch antenna 10A has the same configuration as the conventional patch antenna 10 except that the method of applying solder is different from that shown in FIG. 4 as will be described later. Accordingly, the reference numeral 15A is attached to the solder. Components having the same functions as those shown in FIG. 4 are denoted by the same reference numerals.

  The illustrated patch antenna 10A is used as a GPS antenna that receives radio waves from GPS satellites or an SDARS antenna that receives radio waves from SDARS satellites.

  Before inserting the body portion 182 of the power supply pin 18 into the substrate through hole 12a of the dielectric substrate 12, first, as shown in FIG. 5A, the mask 20A is placed on the antenna radiation electrode (reception electrode) 14. Mount and apply paste solder 15A.

  Here, the thickness of the mask 20 </ b> A is thinner than the thickness (height) of the head 181 of the power supply pin 18. The mask 20A has four arcuate openings 20Aa that can be divided (separated) into four virtual rings. That is, the four arcuate openings 20Aa are spaced apart from each other and are rotationally symmetrical (equal angular intervals) with respect to the center line of the virtual ring. The inner radius of each arcuate opening 20Aa is smaller than the radius of the head 181 of the feed pin 18, and the outer radius of each arcuate opening 20Aa is larger than the radius of the head 181 of the feed pin 18. In other words, the inner diameter of the virtual ring is smaller than the diameter of the head 181 of the power supply pin 18, and the outer diameter of the virtual ring is larger than the diameter of the head 181 of the power supply pin 18.

  When the mask 20A is mounted on the antenna radiation electrode (reception electrode) 14, the center line of the virtual ring of the mask 20A and the center line of the substrate through hole 12a of the dielectric substrate 12 are aligned with each other. The

  The paste solder 15A is applied to the four arcuate openings 20Aa while removing unnecessary portions. Therefore, the thickness (height) of the applied paste solder 15 </ b> A is lower than the thickness (height) of the head 181 of the power supply pin 18.

  Next, as shown in FIG. 5B, the mask 20 </ b> A is peeled off from the antenna radiation electrode (reception electrode) 14, and the body portion 182 of the feed pin 18 is inserted into the substrate through hole 12 a of the dielectric substrate 12. As a result, the head 181 of the power supply pin 18 is placed on the four paste solders 15A.

  Finally, the paste solder 15A is melted by reflow in an electric furnace. As a result, as shown in FIG. 5C, the head portion 181 of the power feed pin 18 is covered with the solder 15A at the four locations, and the antenna radiation electrode (reception electrode) 14 and the power feed pin 18 are conductively connected. . The solder 15A joins the antenna radiation electrode (reception electrode) 14 and the head 181 of the feed pin 18 in a fillet shape.

  In the patch antenna 10A manufactured as described above, the solder is composed of four solder portions 15A that are spaced apart from each other and provided rotationally symmetrically with respect to the center line of the feed pin 18 (substrate through hole 12a).

  As described above, in this embodiment, the paste solder 15A is applied onto the antenna radiation electrode (reception electrode) 14 by mechanical printing using the mask 20A, so that the amount of solder 15A to be applied is constant. can do. Thereby, a change in capacity can be suppressed. In addition, since the solder portions 15A are attached at four equiangular intervals instead of the entire circumference of the head 181 of the power supply pin 18, the amount of the solder 15A can be reduced. Therefore, the cost of the patch antenna 10A can be reduced. Furthermore, since the antenna radiation electrode (reception electrode) 14 and the head 181 of the power feed pin 18 are joined by the fillet-shaped solder 15A, the antenna radiation electrode (reception electrode) 14 and the head 181 of the power feed pin 18 are connected. It is possible to ensure the bonding strength between the two. In other words, since the stress is dispersed, it is possible to prevent the feed pin 18 from coming off.

  In the embodiment shown in FIG. 5, the head 181 of the feed pin 18 is joined to the antenna radiation electrode (reception electrode) 14 with solder 15A at four positions (equal angular intervals) at rotationally symmetric positions. Of course, the present invention is not limited to this. That is, in general, the head 181 of the power supply pin 18 is soldered to the antenna radiation electrode (reception electrode) 14 at N (N is an integer equal to or greater than 2) N (equal angular intervals) at rotationally symmetric positions. May be joined.

  FIG. 6 shows a second embodiment of the present invention in which the head 181 of the feed pin 18 is joined to the antenna radiation electrode (reception electrode) 14 by solder 15A at six positions (equal angular intervals) at rotationally symmetric positions. It is a figure for demonstrating the patch antenna 10B by the form of this, and its feed pin mounting method. 6A is an exploded perspective view showing the patch antenna 10B before being joined with the solder 15A, and FIG. 6B is a plan view showing the patch antenna 10B after being joined with the solder 15A.

  In this case, the solder 15A is composed of six solder portions 15A that are spaced apart from each other and provided rotationally symmetrically with respect to the center line of the power feed pin 18 (substrate through hole 12a).

  The patch antenna 10B having such a configuration has the same effect as the patch antenna 10A shown in FIG. That is, since the paste solder 15A is applied onto the antenna radiation electrode (receiving electrode) 14 by mechanical printing using a mask (not shown), the amount of solder 15A to be applied can be made constant. Thereby, a change in capacity can be suppressed. Further, since the solder portions 15A are attached not at the entire circumference of the head portion 181 of the power supply pin 18 but at six equiangular intervals, the amount of the solder 15A can be reduced. Therefore, the cost of the patch antenna 10B can be reduced. Furthermore, since the antenna radiation electrode (reception electrode) 14 and the head 181 of the power feed pin 18 are joined by a fillet-like solder 15A, the antenna radiation electrode (reception electrode) 14 and the head 181 of the power feed pin 18 are connected to each other. It is possible to ensure the bonding strength between the two. In other words, since the stress is dispersed, it is possible to prevent the feeding pin 18 from coming off the patch antenna 10B.

  Although the present invention has been described above with reference to preferred embodiments, it is needless to say that the present invention is not limited to the above-described embodiments. For example, in the above embodiment, the antenna radiation electrode has a square shape, but it is needless to say that it may have a circular shape. Further, the material of the dielectric substrate is not limited to the ceramic material, and may be composed of a resin material. Of course, the opening formed in the mask is not limited to the arcuate opening as shown in FIG. 5, and various shapes may be used. Furthermore, the patch antenna according to the present invention is suitable for a GPS antenna or a SDARS antenna, but is not limited thereto, and is an antenna for mobile communication for receiving other satellite waves and terrestrial waves. It is also applicable.

It is a perspective view of the 1st conventional patch antenna. 2A and 2B are diagrams illustrating the patch antenna illustrated in FIG. 1, in which FIG. 1A is a plan view, FIG. 1B is a front view, FIG. 1C is a left side view, and FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. It is process drawing for demonstrating the conventional feeder pin soldering method by reflow. It is process drawing which shows the process of the patch antenna which concerns on the 1st Embodiment of this invention, and its feed pin soldering method. The patch antenna according to the second embodiment of the present invention, in which the heads of the power supply pins are joined to the antenna radiation electrodes (reception electrodes) by soldering at six rotationally symmetrical positions (equal angular intervals) and the power supply thereof It is a figure for demonstrating the pin soldering method.

Explanation of symbols

10A, 10B Patch antenna 12 Dielectric substrate 12u Top surface (surface)
12d Bottom (back)
12a Substrate through hole 14 Antenna radiation electrode (receiving electrode)
15A Solder (Paste solder, solder part)
16 Ground electrode 16a Ground opening 18 Power supply pin (rivet pin)
18a Upper end portion 18b Lower end portion 181 Head portion 182 Body portion 20A Mask 20Aa Arc-shaped opening

Claims (3)

A dielectric substrate having a top surface and a bottom surface facing each other, and having a substrate through-hole penetrating from the top surface to the bottom surface at a predetermined position; and comprising a conductor; An antenna radiation electrode formed on the top surface; a ground electrode formed of a conductor and formed on the bottom surface of the dielectric substrate; a head portion provided on an upper end portion; and extending from the upper end portion to the lower end portion And a rod-shaped body portion, wherein the head is connected to the antenna radiation electrode at the predetermined position, and the lower end portion of the dielectric substrate via the substrate through-hole. A method of soldering the feed pin of a patch antenna led to the bottom surface side to the antenna radiation electrode;
There are N (N is an integer of 2 or more) openings that are spaced apart from each other and rotationally symmetrical with respect to the center line of the substrate through-hole , and the thickness is higher than the height of the head of the power feed pin. Mounting a thin mask on the antenna radiation electrode;
Using the mask , applying N paste solders on the antenna radiation electrode at a position where the head of the feed pin rests ;
Pressing the power feed pin from the top surface of the dielectric substrate into the substrate through hole, and placing the head of the power feed pin on the N paste solders;
Melting the N paste solders by reflow and soldering the power supply pins;
A method of soldering a feed pin of a patch antenna, comprising: As the mask, the a N-divided pieces of opening a virtual ring into N (separation) and the N arcuate openings which can be characterized by the use of a mask, according to claim 1 Method of soldering the feed pin of the patch antenna. 3. The patch antenna according to claim 2 , wherein an inner diameter of the virtual ring is smaller than a diameter of a head of the power feed pin, and an outer diameter of the virtual ring is larger than a diameter of a head of the power feed pin. Power supply pin soldering method.

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