JP2002009537A - Antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna with reliability, durability and a long service life without deteriorating the performance and the quality even when a thermal shock or a heat cycle is exerted to the antenna. SOLUTION: An antenna unit 5 radiation electrode 2 of which is formed on the front side of a dielectric board 1 and a feeding pin 13 of which used to supply power to the radiation electrode 2 penetrates through the dielectric board 1 and projected from the rear side of the dielectric board 1 is placed on a printed circuit board 10 in a way that the rear side of the antenna unit overlaps one side of the printed circuit board 10 and the end of the feeding pin 13 is soldered to a through-hole section 14 of the printed circuit board in this antenna, and an air escape path 20 that permits air to escape in the through-hole section 14 externally is formed on the overlapping part of the printed circuit board 10 and the antenna unit 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a GPS (Global Pos
The present invention relates to a back-feeding type antenna used for a switching system, for example, a planar patch antenna.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for high-frequency radio equipment such as a navigation system using GPS.
A back-fed antenna, for example, a planar patch antenna, has been used for these high-frequency wireless devices.

Conventionally, this type of antenna has a structure as shown in FIG. 5 is an antenna unit, for example,
A rectangular radiation electrode 2 is formed on the surface of a rectangular flat dielectric substrate 1 made of epoxy resin or the like.
A rectangular ground electrode 3 is formed on the back surface of the
A small diameter through hole 4 for inserting a power supply pin is provided from the power supply point 2a to the ground electrode 3.

A circuit board 10 has a rectangular ground electrode 7 formed on one surface of a rectangular flat insulating substrate 6 made of epoxy resin or the like, and a microstrip line or the like formed on the other surface of the insulating substrate 6. A high-frequency circuit 8 is formed, and a through-hole portion 14 is provided through the insulating substrate 6. The through-hole portion 14 is provided with a small-diameter through-hole 9 for inserting a power supply pin.

[0005] Between the ground electrode 3 of the antenna unit 5 and the ground electrode 7 of the circuit board 10, for example, as shown in FIG. 6, a small-diameter through hole (through portion) 11 for inserting a feed pin is provided at a predetermined position. The antenna unit 5 and the circuit board 10 are joined by the adhesive force of the double-sided tape 12 having a rectangular shape.

The antenna unit 5, the double-sided tape 12, and the through holes 4, 11, 9 of the circuit board 10 have:
A conductive power supply pin 13 (including a wire) made of copper, a copper alloy, or the like is inserted, and one end 13 a of the power supply pin 13 is electrically connected to the power supply point 2 a of the radiation electrode 2 by solder 25. On the other hand, the other end portion 13b of the power supply pin 13 into which the above members are inserted is inserted into the through hole 9 of the through hole portion 14 of the circuit board 10, and is fixed to a conductor layer formed therearound by solder 25. Thereby, it is electrically connected to the high frequency circuit 8.
The conventional antenna has the above configuration.

[0007]

When assembling a conventional antenna, the feed pin 13 is inserted into the through hole 4 of the antenna unit 5 and one end 13a thereof is electrically connected to the radiation electrode 2 by solder 25. , Through hole 1 of double-sided tape 12
1, the power supply pin 13 is inserted, and the double-sided tape 12 is attached. Thereafter, the power supply pin 13 is inserted into the through hole 9 of the circuit board 10, and the other end 13 b of the power supply pin 13 is connected to the circuit board 10.
Is fixed to the other surface of the insulating substrate 6 with solder 25.

By the way, the feeder pin insertion side of the through hole 4 in the antenna unit 5 is sealed with solder 25, and the periphery of the through hole 11 is also closed by the inner wall surface of the double-sided tape 12. The air is almost hermetically sealed.

Therefore, when fixing the other end 13b of the power supply pin 13 to the other surface of the insulating substrate 6 with the solder 25,
However, as shown in FIG. As a result, the power supply pin 13 and the through-hole portion 14 may be soldered on the other surface side of the insulating substrate 6 and may not be soldered on the side where the antenna unit 5 is arranged. When the antenna in such a state receives a thermal change during a thermal shock test or during use, a portion 2b along the outer periphery of the head (one end 13a) of the feed pin 13 of the radiation electrode 2
Cracks are likely to occur.

The present inventors consider the cause as follows. That is, in the part where the power supply pin 13 and the through-hole part 14 are not soldered, the large expansion and contraction of the insulating substrate 6 is not suppressed. Feed pin 1
3 and the radiation electrode 2 of the antenna unit 5 are in strong contact with each other.
The radiation electrode 3a and the radiation electrode 2 of the antenna unit 5 attempt to separate from each other. When this change is repeated, cracks occur in the radiation electrode 2 around the one end 13a of the power supply pin 13. The dielectric substrate 1 is formed of an epoxy resin composition containing a ceramic filler, and its expansion and contraction is sufficiently smaller than that of the circuit board 10. When the radiation electrode 2 is cracked in this way, the performance and quality of the antenna deteriorate.

An object of the present invention is to solve the above-mentioned problems, and to provide a long-life antenna which is reliable and durable without deterioration in performance and quality even when a thermal shock or heat cycle acts. I do.

[0012]

According to the present invention, a radiation electrode is formed on a surface of a dielectric substrate, and a power supply pin for supplying power to the radiation electrode passes through the dielectric substrate. Antenna unit protruded from the rear surface of the circuit board, the rear surface thereof is disposed so as to overlap with one surface of the circuit board, and an end of the power supply pin is fixed to a through hole of the circuit board by soldering. An air escape path is formed at a position where the circuit board and the antenna unit are overlapped to each other to allow the air in the through hole to escape to the outside.

Since the antenna of the present invention is configured as described above, when the other end of the power supply pin is fixed to the other surface of the insulating substrate of the circuit board by soldering in the process of assembling the antenna, the solder is When the air flows into the through hole of the circuit board, the air in the through hole is discharged to the outside of the antenna through an air escape path formed between the antenna unit and the circuit board. For this reason, the solder flows smoothly through the through hole and is filled over the entire length of the through hole. As a result, the power supply pins are firmly fixed to the circuit board.

Even when the antenna is heated and cooled by a thermal shock test or a heat cycle acting during use, the antenna is filled with solder over the entire length of the through hole of the through hole of the circuit board. In the portion, the amount of thermal expansion in the thickness direction is greatly suppressed, and the relative position between one end of the feed pin and the radiation electrode of the antenna unit is stabilized. For this reason, distortion, deformation, and cracks are less likely to occur on the radiation electrode of the antenna unit, the reliability of the fixed portion of the power supply pin is improved, the performance and quality of the antenna are improved, and the life is prolonged.

[0015]

(Embodiment 1) Next, Embodiment 1 of the antenna according to the present invention will be described in detail with reference to the drawings. Note that the same reference numerals are used for components having the same configurations and functions as those shown in the related art. The antenna of this embodiment is an example of a back-fed flat patch antenna unit. In FIG. 1, reference numeral 5 denotes an antenna unit. For example, a rectangular radiation electrode 2 is formed on the surface of a rectangular flat dielectric substrate 1 made of an epoxy resin composition or the like, and a rectangular radiation electrode 2 is formed on the back surface of the dielectric substrate 1. A ground electrode 3 is formed, and a small-diameter through hole 4 for inserting a feed pin is provided from the feed point 2 a of the radiation electrode 2 to the ground electrode 3.

Numeral 10 is a circuit board, on which a rectangular ground electrode 7 is formed on one surface of a rectangular flat insulating substrate 6 made of epoxy resin or the like, and a microstrip line or the like is formed on the other surface of the insulating substrate 6. A high-frequency circuit 8 is formed, and the insulating substrate 6 is provided with a small-diameter through hole 9 for inserting a power supply pin.

A double-sided tape 17 is interposed between the ground electrode 3 of the antenna unit 5 and the ground electrode 7 of the circuit board 10, and the two ground electrodes 3, 7 are joined by the adhesive force of the double-sided tape 17. . The double-sided tape 17 is, for example, as shown in FIG.
As shown in the figure, one square-shaped double-sided tape piece 18
A substantially U-shaped through portion 1 for inserting a power supply pin at a predetermined position
9, and further, the tape piece is cut linearly from the penetrating portion 19 to one side edge, for example, with a width of about the outer diameter of the power supply pin 13 so as to communicate with the penetrating portion 19. The air escape path 20 is formed. Double-sided tape piece 18
Is, for example, as shown in FIG.
8a and a rubber-based pressure-sensitive adhesive layer 18b, if necessary,
Is used, which is formed by laminating the layers through the intermediary layer, so that both sides have adhesiveness. The air escape path 20 is
As will be described later, when the other end 13b of the power supply pin 13 is fixed to the circuit board 10 with the solder 25, at least the air in the through hole 9 is removed from the ground electrode 3 of the antenna unit 5 and the circuit board 10
And has the function of escaping outward through the space between the ground electrode 7.

In the antenna unit 5, the double-sided tape 17, the through-hole 4, the through-hole 19 and the through-hole 9 of the circuit board 10, conductive feeding pins 13 (including a wire) such as copper and copper alloy are provided. It is inserted, and one end 13 a thereof is electrically connected to the feeding point 2 a of the radiation electrode 2 by solder 25. On the other hand, the other end 13 of the power supply pin 13 through which the above members are inserted.
b protrudes from the other surface of the circuit board 10, and solders 25 to the conductor layer of the through-hole portion 14 having the through-hole 9.
And is electrically connected to the high-frequency circuit 8 via this. During the soldering operation, the solder 25 flows into the through-hole 9 of the circuit board 10, and accordingly, the air in the through-hole 9 passes through the air escape path 20 formed on the double-sided tape 17 and the antenna 25 It is discharged outside.

In this manner, as shown in FIG. 3, the solder 25 is sufficiently filled over the entire length of the through hole 9. Therefore, a gap is not generated in the through hole 9 as in the related art, and the other end 13 b of the power supply pin 13 is connected to the circuit board 1.
It is firmly fixed to 0. Further, the antenna is heated and
Even when cooled, the dimensional change due to thermal expansion in the thickness direction of the through-hole portion 14 of the circuit board 10 is greatly suppressed, so that the stress applied to the joint between the radiation electrode and the feed pin 13 is reduced.

(Embodiment 2) Next, Embodiment 2 of the antenna according to the present invention will be described. The antenna of this embodiment is a double-sided tape used in the first embodiment as shown in FIG.
In this embodiment, a double-sided tape 21 having the structure shown in FIG. 1 is used, and the other structures and functions are the same as those of the first embodiment. The double-sided tape 21 used in this embodiment is configured by arranging two rectangular double-sided tape pieces 22 and 22 in parallel with a gap slightly larger than the outer diameter of the power supply pin 13. The material of the double-sided tape piece 22 is, for example, the same as the double-sided tape piece 18 used in the first embodiment.

In this double-sided tape 21, a through portion 23 for inserting a power supply pin and an air escape path 24 are formed by utilizing a gap formed between the double-sided tape pieces 22, 22. That is, a predetermined intermediate position in the length direction of the gap becomes the penetrating portion 23, and the gap portion on both sides thereof becomes the air escape path 24. Thereby, the penetration portion 23 and the air escape path 24 are in communication with each other,
The air in the penetrating portion 23 is outside from between the ground electrode 3 of the antenna unit 5 and the ground electrode 7 of the circuit board 10, that is,
It is discharged into the atmosphere outside the antenna.

The double-sided tape 21 is formed by placing one side of the double-sided tape pieces 22 constituting the double-sided tape 21 in the above-described arrangement state in advance on the ground electrode 3 side of the antenna unit 5 or the circuit board 1.
The antenna unit 5 and the circuit board 10 are bonded to each other with the double-sided tape 21 interposed therebetween by attaching the antenna unit 5 to the ground electrode 7 side. The other configuration is substantially the same as that of the first embodiment, and the description is omitted.

[0023]

As described above, in the antenna according to the present invention, since the air escape path is formed between the antenna unit and the circuit board to allow the air in the through hole of the circuit board to escape to the outside, the feed pin is provided. The flow of the solder for fixing the other end to the circuit board is not disturbed by the air in the through hole, flows smoothly into the through hole, and is filled over the entire length of the through hole. Therefore, even if a thermal shock or a heat cycle acts on the antenna, obstacles such as cracks are less likely to occur in the radiation electrode of the antenna unit, and the performance of the antenna, particularly high-frequency characteristics, quality, and durability are improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing Embodiment 1 of the present invention.

FIG. 2 is a double-sided tape used in the first embodiment,
(A) is a plan view, and (B) is a cross-sectional view taken along line XX of (A).

FIG. 3 is a cross-sectional view illustrating a situation in which the other end of the power supply pin is fixed to the other surface of the circuit board by soldering in the first embodiment.

FIG. 4 is a plan view showing a double-sided tape used in Embodiment 2 of the present invention.

FIG. 5 is a sectional view showing a conventional antenna.

FIG. 6 is a front view of a double-sided tape used in a conventional antenna.

FIG. 7 is a cross-sectional view showing a state in which the other end of the feed pin is fixed to the other surface of the circuit board by soldering in the conventional antenna.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Dielectric substrate 2 Radiation electrode 2a Feeding point 2a Portion of radiation electrode along one end of feeder pin 3, 7 Ground electrode 4, 9, 11 Through hole 5 Antenna unit 6 Insulating substrate 8 High frequency circuit 10 Circuit board 12 Double-sided tape 13 Power supply pin 13a One end 13b Other end 14 Through hole 15 Void 17, 21 Double-sided tape 18, 22 Double-sided tape piece 18a Acrylic adhesive layer 18b Rubber-based adhesive layer 18c Base 19, 23 Penetration 20, 24 Air escape Road 25 Solder

Continued on the front page F term (reference) 5J045 AA01 AB06 AB07 DA10 EA07 HA06 NA01 5J046 AA05 AB13 PA07

Claims (1)

[Claims] 1. An antenna unit having a radiation electrode formed on a surface of a dielectric substrate, and a power supply pin for supplying power to the radiation electrode penetrating the dielectric substrate and projecting from the rear surface thereof. In an antenna which is arranged so as to overlap one surface of the substrate and the end of the feed pin is fixed to a through-hole portion of the circuit board by soldering, the through-hole is provided at a position where the circuit board and the antenna unit are overlapped. An antenna characterized in that an air escape path for escaping the air in the hall portion to the outside is formed.