JP2002076720A - High frequency coaxial line connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high frequency coaxial line connection structure which has a high degree of reliability against temperature fluctuation hysteresis by increasing the degree of deformation on a first circuit substrate 2 and a second circuit substrate 3 against expansion and contraction of a center conductor 4 accompanying the fluctua tion of the ambient temperature. SOLUTION: The high frequency coaxial line connection structure comprises a first organic material substrate 21 which has metalized areas on both surface and which forms the first high frequency circuit, of a second organic material substrate 31 which has metalized areas on both surfaces which forms the second high frequency circuit. And the organic material substrate 21 and the organic material substrate 31 are each bonded on one and the other side surface of a base substrate 1 which forms a through hole starting from the organic material substrate 21 through the substrate 1 reaching to the organic material substrate 31. The base conductor 4 is deployed coaxially within the through hole and conductively connected each ends to the first and second high frequency circuits. The through holes are comprised of a first through hole 8 which formed on the base substrate 1 and a second through hole 9 formed on the organic material substrate 21 and the organic material substrate 31, and the diameter d1 of the first through hole 8 is formed bigger than the diameter d2 of the second through hole 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency coaxial line connection structure, and more particularly to a first organic material substrate having a high-frequency circuit formed on both sides of a base substrate and a second organic material substrate having another high-frequency circuit formed thereon. And a high-frequency coaxial line connection structure in which a through-hole is formed from the first organic material substrate to the second organic material substrate through the base substrate and reaches the second organic material substrate, and two high-frequency circuits are coupled by a central conductor coaxially arranged in the through-hole. .

[0002]

2. Description of the Related Art Conventionally, a first organic material substrate on which a high-frequency circuit is formed and a second organic material substrate on which another high-frequency circuit is formed are bonded to both sides of a base substrate, and the first organic material substrate is passed through the base substrate. A high-frequency coaxial line connection structure in which a through-hole reaching the second organic material substrate is formed, and two high-frequency circuits are coupled by a center conductor coaxially arranged in the through-hole,
It is used in high-frequency transmission / reception devices of automotive radars and the like, and one example thereof is a high-frequency transmission / reception device disclosed in JP-A-2000-59140.

FIG. 7 is a sectional view showing the structure of a high-frequency coaxial line connection structure disclosed in Japanese Patent Application Laid-Open No. 2000-59140.

In FIG. 7, 31 is a base board, 32 is an antenna circuit board, 33 is a transmitting / receiving circuit board, 34 is an antenna pattern conductor, 35 is a transmitting / receiving circuit pattern conductor, 3
6, 37 are ground conductors, 38 is a center conductor, 39 is a dielectric, 40 and 41 are lands, 42 and 43 are plating layers,
Reference numerals 4 and 45 are solders.

In this case, the antenna circuit board 32 is provided with an antenna pattern conductor 34 on one surface and a ground conductor 36 on the other surface, and constitutes an antenna circuit portion as a whole. Similarly, the transmission / reception circuit board 33 is provided with a transmission / reception circuit pattern conductor 35 on one surface and a ground conductor 37 on the other surface, and constitutes a transmission / reception circuit unit as a whole.
An antenna circuit board 32 forming an antenna circuit unit is joined to one surface of the base board 31, and the base board 3
A transmission / reception circuit board 33 constituting a transmission / reception circuit unit is bonded to the other surface of the transmission / reception circuit unit 33. A hole (no symbol) from the antenna circuit board 32 to the transmission / reception circuit board 33 through the base board 31 is provided, and a center conductor 38 is coaxially arranged in this hole. The center conductor 3 is provided in the hole of the base substrate 31.
8 is filled with a dielectric 39. A plating layer 42 is provided on the peripheral surface of the hole of the antenna circuit board 32, and solder 44 is embedded between one end of the center conductor 38 and the plating layer 42, and one end of the center conductor 38 is placed in the hole of the antenna circuit board 32. Fixed to. Similarly, the transmission / reception circuit board 3
3, a plating layer 43 is provided on the peripheral surface of the hole. Solder 45 is embedded between the other end of the center conductor 38 and the plating layer 43, and the other end of the center conductor 38 is placed in the hole of the transmission / reception circuit board 33. Fix it. At this time, the lands 40 and 41 prevent the plating layers 42 and 43 from peeling off.

In the high-frequency coaxial cable connection structure having such a configuration, the antenna circuit and the transmitting / receiving circuit are connected to the center conductor 38.
It is capable of transmitting and receiving microwave signals between the antenna circuit unit and the transmission / reception circuit by using a high-frequency coaxial line having a structure. And miniaturization can be achieved.

[0007]

The above-mentioned Japanese Patent Application Laid-Open No. 2000-5
The high-frequency coaxial cable connection structure disclosed in Japanese Patent No. 9140 can reduce the number of components and reduce the size compared to a known high-frequency coaxial cable connection structure of this type. One end of the antenna circuit board 3
2 is soldered in the entire depth direction of the hole, and the other end is similarly soldered to the transmitting / receiving circuit board 3.
3 is soldered in the entire depth direction of the hole, so that if the ambient temperature of the high-frequency coaxial cable connection structure greatly changes, the antenna circuit board 32 and the center conductor 38 are not connected. And transmission / reception circuit board 33
In some cases, a large thermal stress may be generated between the central conductor 38 and the central conductor 38, and sufficient consideration has not been given to measures for the thermal stress.

The present invention has been made in view of such a technical background, and an object of the present invention is to provide a first organic material substrate and a second organic material substrate with respect to expansion and contraction of a center conductor due to a change in ambient temperature. An object of the present invention is to provide a high-frequency coaxial cable connection structure having a high degree of freedom in deformation and having a high degree of reliability with respect to the history of thermal fluctuation.

[0009]

In order to achieve the above object, a high-frequency coaxial line connection structure according to the present invention comprises a first organic material substrate having a first high-frequency circuit formed of metallized regions on both surfaces and a metallized region on both surfaces. And a second organic material substrate on which a second high-frequency circuit is formed, is bonded to one surface and the other surface of the base substrate with a bonding material to form a through hole reaching the second organic material substrate from the first organic material substrate through the base substrate. And a center conductor coaxially disposed in the through-hole and having both ends conductively connected to the first high-frequency circuit and the second high-frequency circuit, wherein the through-hole and the first through-hole formed in the base substrate are connected to each other. A first organic material substrate and a second through hole formed in a second organic material substrate;
Means are provided in which the diameter of the through hole is formed to be larger than the diameter of the second through hole.

[0010] As one constitutional means of the above means,
In the high-frequency coaxial line connection structure, the bonding material for bonding the first organic material substrate and the base substrate and the bonding material for bonding the second organic material substrate and the base substrate are deeper than the diameter of the first through hole of the base substrate. It is retracted to the position where it was.

As another constitutional means of the above means, the high-frequency coaxial line connection structure is configured such that the diameter of the second through holes formed in the first organic material substrate and the second organic material substrate is largest on the base substrate side. It is formed in a stepped or tapered shape.

As another configuration means of the above means, the high-frequency coaxial line connection structure is characterized in that the metallized region of the first organic material substrate and the metallized region of the second organic material substrate are based on the metallized region on the base substrate side. The substrate is retracted to the position where the first through hole is formed in the substrate.

In another aspect of the present invention, the high-frequency coaxial line connection structure includes a metallized region of the first organic material substrate and a metallized region of the second organic material substrate on the side electrically conductively connected to the center conductor. The region is arranged so as to bend and extend to the middle portion of the inner peripheral surface of the second through hole, and both ends of the center conductor are conductively connected to the bent and extended metallized region.

According to each of the above means, the diameter of the first through-hole is defined between the first through-hole formed in the base substrate and the second through-hole formed in the first organic material substrate and the second organic material substrate. It is formed so as to be larger than the diameter of the second through hole, so that the end regions of the first organic material substrate and the second organic material substrate on the side of the second through hole are closer to the center conductor with respect to the first through hole. Because it protrudes, when the center conductor expands and contracts due to fluctuations in ambient temperature,
The end regions of the first organic material substrate and the second organic material substrate are deformed with a relatively large degree of freedom in response to the expansion and contraction of the center conductor, and the deformation allows thermal stress to be absorbed. A high-frequency coaxial line connection structure having high reliability with respect to the history of heat fluctuation can be obtained.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an example of the configuration of a millimeter wave radar using the high-frequency coaxial line connection structure according to the present invention.

In FIG. 1, 1 is a base board, 2 is an antenna circuit board, 3 is a high-frequency circuit board, 10 is a cover,
1 is a semiconductor chip (MMIC), 12 is a case, 13 is a radome, 14 is a signal processing circuit, 15 is a connection line, 16 is a harness, 17 is a connection pin, 18 is a bush, 19 is a microwave connector, and 20 is a connection line. , A is a high-frequency coaxial line connection structure. In this case, the base substrate 1, the antenna circuit substrate 2, and the high-frequency circuit substrate 3 constitute an RF module, and the case 12 and the radome 13 constitute a housing.

The base substrate 1 has an antenna circuit substrate 2 bonded to the upper surface thereof with an adhesive (not shown in FIG. 1), and an RF circuit substrate 3 and a semiconductor chip 11 bonded to the lower surface thereof (FIG. 1). (Not shown). The case 12 and the radome 13 are sealed and fixed by screws (not shown in FIG. 1) to form a housing. Base substrate 1
Is screwed to the case 12 by a screw (not shown in FIG. 1). The cover 10 is mounted on the lower surface side of the base substrate 1 and hermetically seals the high-frequency circuit board 3. The signal processing circuit 14 is divided into a plurality of signal processing circuit boards 14 in order to reduce the layout area.
Are stacked in the case 12 so as to be separated from each other by the bush 18. The connection line 15 is directly connected between the high-frequency circuit board 3 and the uppermost signal processing circuit board 14 and between the high-frequency circuit board 3 and the uppermost signal processing circuit board 14 via a harness 16. Connected to. The connection pins 17 are arranged so as to penetrate through the bush 18 and electrically connect between the signal processing circuit boards 14.
The microwave connector 19 is mounted and disposed outside the case 12, in the illustrated example, below the case 12, and is conductively connected to the lowermost signal processing circuit board 14 through a connection line 20 penetrating the case 12. Further, as will be described in detail later, the high-frequency coaxial line connection structure A has a through hole (not shown in FIG. 1) extending from the antenna circuit board 2 to the high-frequency circuit board 3 through the base substrate 1 and a through hole. A patch antenna pattern (not shown in FIG. 1) on the antenna circuit board 2 side and a high-frequency circuit pattern (not shown in FIG. 1) on the antenna circuit board 2 side are provided. 1 (not shown) are conductively connected through this central conductor.

This millimeter wave radar operates roughly as follows.

Driving power is supplied from the microwave connector 19 to the signal processing circuit 14 through the connection line 20, and at the same time, the signal processing circuit 14 supplies a predetermined driving power to the high-frequency circuit board 3 through the harness 16. When driving power is supplied to the high-frequency circuit board 3, the microwave oscillator configured by the semiconductor chip 11 generates a millimeter wave having a frequency of 76 GHz, and the generated millimeter wave is an amplifier (not shown in FIG. 1).
After being amplified in the antenna circuit board 1, the signal is supplied to the high-frequency coaxial line connection structure A and transmitted from the high-frequency circuit board 3 to the antenna circuit board 1 through the glass coaxial line. (Not shown). When the transmitted millimeter wave is reflected by the target, the patch antenna pattern receives the reflected wave at a predetermined timing, and supplies the received millimeter wave to the semiconductor chip 11 through the high-frequency coaxial line connection structure A. The chip 11 mixes with the transmitting millimeter wave to generate an IF signal. This IF signal is transmitted from the high-frequency circuit board 3 to the connection line 15 and the harness 16.
The signal is supplied to the signal processing circuit 14 through. The signal processing circuit 14 uses the IF signal to calculate speed information, distance information, angle information, and the like representing the relative speed between the vehicle or the like on which the millimeter-wave radar is mounted and the target. And supplied to the microwave connector 19, and from the microwave connector 19 to the utilization device.

Next, FIG. 2 is a sectional view showing the configuration of the first embodiment of the high-frequency coaxial line connection structure according to the present invention.

In FIG. 2, 2₁Is the first organic material substrate, 2
_TwoIs the patch antenna pattern, 2_ThreeIs the ground pattern, 2
_FourIs the non-ground (patch antenna pattern) side metal foil, 2_Five
Is the ground (ground pattern) side metal foil, 2₆Is non-ground side adhesive
Agent layer, 2₇Is the ground side adhesive layer, 3₁Is the second organic material substrate,
3_TwoIs the high frequency circuit pattern, 3_ThreeIs the ground pattern, 3 _Four
Is the non-ground (high frequency circuit pattern) side metal foil, 3_FiveIs ground
(Ground pattern) side metal foil, 3₆Is the non-ground side adhesive layer,
3₇Is a ground side adhesive layer, 4 is a center conductor, 5 is an adhesive layer,
6 is a dielectric holding part, 7 is a solder connection part, and 8 is a first through hole.
, 9 is a second through hole, and other shown in FIG.
The same reference numerals are used for the same components as
I am.

[0023] Then, the antenna circuit board 2 comprises a first organic material substrate 2 ₁ consisting of Teflon substrate having a low dielectric constant, on one surface thereof, made of a copper foil ungrounded metal foil 2 ₄ ungrounded side adhesive together joined by a layer 2 _6, a patch antenna pattern 2 ₂ to the non-adhesive surface of the non-grounded metallic foil 2 ₄ deposited forming, on the other face, the ground side metal foil 2 made of copper foil
₅ with bonding by the ground-side adhesive layer 2 _7, is obtained by depositing form ground pattern 2 ₃ to the non-adhesive face side of the ground-side metal foil 2 _5. Similarly, the high-frequency circuit board 3 comprises a second organic material substrate 3 ₁ made of Teflon substrate having a low dielectric constant, on one surface thereof, non-grounded metallic foil 3 ₄ ungrounded side adhesive layer 3 made of copper foil together joined by _6, the high-frequency circuit pattern 3 ₂ to the non-adhesive surface of the non-grounded metallic foil 3 ₄
Was deposited and formed, on the other side, a ground side metal foil ₃₅ made of copper foil with bonding by the ground-side adhesive layer 3 _7, the ground side metal foil 3 non-adhesive surface to the ground pattern 3 _{3 5}
Is formed. In this case, the antenna circuit board 2 and the high-frequency circuit board 3 each have a second diameter d2.
A through hole 9 is formed.

The base substrate 1 has a first through hole 8 having a diameter d1 larger than a diameter d2 of the second through hole 9.
There are formed, on one surface thereof, an antenna circuit board 2 by an adhesive layer 5 made of silver epoxy adhesive, so that the ground pattern 2 ₃ side becomes adhesive surface, and the center axis of the first through-hole 8 and the 2 are joined such that the center axis of the through hole 9 matches, other surfaces, an adhesive layer 5 made of silver epoxy adhesive frequency circuit board 3, so that the ground pattern 3 ₃ side becomes adhesive surface, and The first through hole 8 and the second through hole 9 are joined so that the central axis thereof coincides with the central axis of the second through hole 9. In the first through-hole 8 and the second through-hole 9, the central conductor 4 made of a conductive glass coaxial line is arranged along each central axis. The portion of the center conductor 4 inside the first through hole 8 is held coaxially with the first through hole 8 by the cylindrical dielectric holding portion 6, and the portion inside the second through hole 9 of the center conductor 4. Is
The respective solder connection portion 7, one of which is conductively bonded to the non-grounded metallic foil 2 ₄ patch antenna pattern 2 ₂ antenna circuit board 2 ends and the other high frequency circuit board 3 ends the high-frequency circuit patterns 3 ₂ and non It is conductively bonded to the ground metal foil _35.

In the high-frequency coaxial line connection structure according to the first embodiment having the above-described structure, the diameter d1 of the first through hole 8 formed in the base substrate 1 is reduced by the first organic material made of Teflon material having a small Young's modulus. the antenna circuit board 2 and the high-frequency circuit board 3 including a substrate 2 ₁ and the second organic material substrate 3 ₁
The diameters d2 of the second through holes 9 formed on the antenna circuit board 2 and the end regions on the second through hole 9 side of the high-frequency circuit board 3 with respect to the first through holes 8 are made of conductive glass coaxial lines. When the center conductor 4 thermally expands and contracts due to a sudden change in ambient temperature or the like, the end regions of the antenna circuit board 2 and the high-frequency circuit board 3 Bending deformation occurs around the center of the through hole 9 and the center conductor 4
Since the distortion caused by the thermal fluctuation is absorbed, no excessive stress is generated in the solder connection portion 7. And since an excessive stress is not applied to the solder connection portion 7,
It is not necessary to use a large amount of solder when forming the solder connection part 7, and it is possible to reduce the high-frequency transmission loss of the solder connection part 7, and to obtain a high-frequency coaxial line connection structure having high reliability as a whole. Can be.

FIG. 3 is a sectional view showing the configuration of a second embodiment of the high-frequency coaxial line connection structure according to the present invention.

In FIG. 3, the same components as those shown in FIG. 2 are denoted by the same reference numerals.

The difference between the high-frequency coaxial line connection structure of the first embodiment (hereinafter, referred to as the former) and the high-frequency coaxial line connection structure of the second embodiment (hereinafter, the second) is as follows. the configuration of the end area of the second through hole 9 side of the antenna circuit board 2 and the high-frequency circuit board 3, the former, the ground pattern 2 _3, the ground side metal foil 2 _5, the ground-side adhesive layer 2 _7, and the ground pattern 3 _3, ground side metal foil _35, the formation position of the ground-side adhesive layer 3 ₇ are arranged in the second through hole 9 position, i.e. the first organic material substrate 2 ₁ and the second
While being formed to the same position as the position of the end face of the organic material substrate 3 _1, the latter 2 is a only in that their formation positions are retracted to a position aligned with the first through-hole 9,
In addition, there is no structural difference between the former and the latter 2.
For this reason, further description of the configuration of the latter 2 is omitted.

The operation of the latter 2 and the obtained effects are
Qualitatively the same as the former action and the effect obtained
However, the latter 2 is composed of an antenna circuit board 2 and a high-frequency circuit board 3
The ground pattern 2 is formed in the end region on the side of the second through hole 9.
_Three, Ground side metal foil 2_Five, Ground side adhesive layer 2₇And contact
Ground pattern 3_Three, Ground side metal foil 3_Five, Ground side adhesive layer 3
₇Is not provided, the first organic material substrate 2
₁And second organic material substrate 3 ₁The bending stiffness of each of the above components
Is slightly lower due to lack of
If the center conductor 4 thermally expands and contracts due to sudden fluctuations, etc.
Antennas, the antennas
The end regions of the circuit board 2 and the high-frequency circuit board 3 are the second through.
It becomes easy to bend around the center of the hole 9. So
As a result, the latter 2 has a larger thermal fluctuation of the center conductor 4 than the former.
Of the solder joint 7
Has a slightly higher reliability than the former.
A high-frequency coaxial line connection structure can be obtained.

FIG. 4 is a sectional view showing the configuration of a third embodiment of the high-frequency coaxial line connection structure according to the present invention.

In FIG. 4, the same components as those shown in FIG. 2 are denoted by the same reference numerals.

The high-frequency coaxial line connection structure according to the first embodiment (hereinafter referred to as the former) and the high-frequency coaxial line connection structure according to the third embodiment (hereinafter referred to as the third).
The difference between the first and second embodiments is that the adhesive layer 5 has a configuration in which the end position of the adhesive layer 5 on the side of the center conductor 4 is the same as the diameter d1 of the first through hole 8 of the base substrate 1. On the other hand, in the latter 3, the terminal position of the adhesive layer 5 on the side of the center conductor 4 is retracted to a position deeper than the diameter d1 of the first through hole 8 of the base substrate 1, and the retracted position is the first position. Diameter d3 larger than diameter d1 of through hole 8
Only the former and the latter 3
There is no structural difference between the two. For this reason, further description of the configuration of the latter 3 is omitted.

The operation and the effect of the latter 3 are essentially the same as the operation and the effect of the former, except that the terminal position of the adhesive layer 5 on the side of the center conductor 4 is the first. When the center conductor 4 is thermally expanded and contracted at a position having a diameter d3 larger than the diameter d1 of the through hole 8, the second through hole 9 in the end region of the antenna circuit board 2 and the high-frequency circuit board 3 is formed. Is more likely to be bent around the central portion of the adhesive layer 5, the latter 3 in which the terminal position of the adhesive layer 5 on the side of the center conductor 4 is retracted is compared with the former in which the same terminal position is not retracted. Become big. As a result, the latter 3 has higher reliability than the former, because the degree of absorption of the strain due to the thermal fluctuation of the center conductor 4 is slightly increased as compared with the former, and the stress applied to the solder connection portion 7 is reduced. A high frequency coaxial line connection structure can be obtained.

FIG. 5 is a sectional view showing the configuration of a fourth embodiment of the high-frequency coaxial line connection structure according to the present invention.

[0035] In FIG. 5, the 2 ₈ antenna circuit board 2
The stepped portion provided in the second through hole 9 side end region 3 ₈ is a tapered portion provided in the second through hole 9 side end region in the high-frequency circuit board 3, the other, shown in FIG. 2 The same components as those described above are denoted by the same reference numerals.

The high-frequency coaxial line connection of the first embodiment
Connection structure (hereinafter referred to as the former) and the fourth implementation
High-frequency coaxial line connection structure (hereinafter referred to as the latter 4)
The difference between the two is that the antenna circuit board 2 and the high-frequency circuit
Regarding the configuration of the end region on the second through hole 9 side of the substrate 3
The latter 4 is located in the end area on the antenna circuit board 2 side.
And the first organic material substrate 2₁Of the ground putter
2_ThreeAnd ground side metal foil 2_FiveAnd ground side adhesive layer 2₇Reduce
Stepped part 2₈And the high-frequency circuit board 3 side
In the end region, the second organic material substrate 3₁Sequentially thinner
Lost, ground pattern 3_ThreeAnd ground side metal foil 3_FiveAnd the ground side
Adhesive layer 3₇Tapered part 3 with reduced size ₈have
On the other hand, the former is located in the end area of the antenna circuit board 2.
Step-like part 2 like₈Without high frequency circuit board
The tapered portion 3 in the end region₈Have
There is only one point, and between the former and the latter 4
There is no difference in configuration. Therefore, the configuration of the latter 4
Will not be described any further.

The operation of the latter 4 and the operation and effect obtained are essentially the same as those of the former and the operation and effect obtained, but the latter 4 is different from the end region of the antenna circuit board 2 and the end of the high-frequency circuit board 3. since part region has a stepped portion 2 ₈ and tapered portion 3 _8, when the center conductor 4 attempts stretch thermally, the at the end region of the antenna circuit board 2 and the high-frequency circuit board 3 2 resulting ease of the center and the bending deformation of the center portion of the through hole 9, the latter 4 has a stepped portion 2 ₈ and tapered portion 3 _8, such stepped portion 2 ₈ and tapered portion 3 It is much larger than the former without ₈ . As a result, the latter 4 has a much higher degree of absorption of the strain due to the thermal fluctuation of the center conductor 4 than the former, and the stress applied to the solder connection portion 7 is considerably smaller. And a high-frequency coaxial line connection structure having

It should be noted, the latter 4, a stepped portion 2 ₈ provided on the antenna circuit board 2 side, while indicating example in which a tapered portion 3 ₈ in the high-frequency circuit board 3 side, on the contrary ,
A tapered portion may be provided on the antenna circuit board 2 side and a step-shaped portion may be provided on the high-frequency circuit board 3 side, and a step-shaped portion may be provided on both the antenna circuit board 2 side and the high-frequency circuit board 3 side. Alternatively, tapered portions may be provided on both the antenna circuit board 2 side and the high-frequency circuit board 3 side.

FIG. 6 is a sectional view showing the configuration of a fourth embodiment of the high-frequency coaxial line connection structure according to the present invention.

In FIG. 6, the same components as those shown in FIG. 2 are denoted by the same reference numerals.

The high-frequency coaxial line connection structure of the first embodiment (hereinafter, referred to as the former) and the high-frequency coaxial line connection structure of the fifth embodiment (hereinafter, referred to as the 5).
The difference between the two configurations is that the antenna circuit board 2 and the high-frequency circuit board 3 have the end regions on the second through-hole 9 side, the former being the patch antenna pattern 2 ₂ , the non-ground side metal foil 2 ₄ , side adhesive layer 2 _6, and a high frequency circuit pattern 3 _2, non-grounded metallic foil 3 _4, non-grounded adhesive layer 3
Position the forming position of ₆ are arranged in the second through-hole 9, respectively, i.e. the first organic material substrate 2 ₁ and the second organic material substrate 3
Is formed to the same position as the _first end surface location, the patch antenna pattern 2 ₂ by one end of the central conductor 4 is soldered joint 7
And is conductively bonded to each end of the ungrounded metal foil 2 _4, conductively joined to each end by the other end portion of the central conductor 4 is soldered joint 7 to the high-frequency circuit patterns 3 ₂ and ungrounded metal foil 3 ₅ On the other hand, in the latter case, the second through-hole is bent and extended to a position where the formation position exceeds the position aligned with the second through-hole 9 and reaches the inner peripheral surface intermediate portion of the second through-hole 9. A metallized area is formed on the inner peripheral surface of the hole 9, and only one end and the other end of the center conductor 4 are conductively joined to the metallized area by the solder joint 7. There is no structural difference between the fifth embodiment and the fifth embodiment. Therefore, further description of the configuration of the latter 5 will be omitted.

The operation and the effect of the latter 5 are essentially the same as the operation and the effect of the former, but the latter 5 forms a metallized region on the inner peripheral surface of the second through hole 9. Since the solder joint 7 is provided between the metallized region and one end and the other end of the center conductor 4, the solder joint 7 is provided between the solder joint 7 and the metallized region, and one end of the center conductor 4. In addition, the bonding area between the other end and the solder joint 7 is increased, and accordingly, the bonding strength at the solder joint 7 is improved, and a high-frequency coaxial line connection structure that can ensure high reliability for the solder joint 7 is provided. Obtainable.

Here, the high-frequency coaxial line of each of the above embodiments
An example of the dimensions of each part used in the road connection structure
When presented, the first organic material substrate 2 made of a Teflon substrate
₁Is larger than 63 mm × 63 mm × 127 μm,
Second organic material substrate 3 made of Teflon substrate₁Is 50mm ×
More than 15mm × 127μm, each copper foil
Ungrounded metal foil and grounded metal foil 2_Four, 2_Five, 3
_Four, 3_FiveIs copper / nickel having a thickness of more than 18 μm
/ Patch antenna pattern 2 consisting of each layer of gold _TwoAnd high lap
Wave circuit pattern 3_TwoHas a thickness of 18 μm / 4 ~
10μm / 0.3-0.5μm or more, silver epoxy
The adhesive layer 5 made of an adhesive has a thickness of 20 to 30 μm or more.
The second through hole 9 has a diameter of 300 μm or more.
The center conductor 4 made of a conductive glass coaxial wire has a diameter of
It is 200 μm or more.

In the description of the high-frequency coaxial line connection structure of each of the above embodiments, the constituent materials used for each constituent element indicate the preferable constituent materials for each constituent element. The constituent material used for each component in the high-frequency coaxial line connection structure of the present invention is not limited to the above-described example, and other than such a suitable constituent material, a constituent material having similar characteristics may be used. Of course it is good.

[0045]

As described above, according to the present invention, between the first through hole formed in the base substrate and the second through hole formed in the first organic material substrate and the second organic material substrate,
The diameter of the first through-hole is formed to be larger than the diameter of the second through-hole, so that the end regions of the first organic material substrate and the second organic material substrate on the second through-hole side are formed by the first through-hole. When the center conductor expands and contracts due to a change in the ambient temperature, the first organic material substrate and the second organic material substrate correspond to the expansion and contraction of the center conductor. Since the end region is deformed with a relatively large degree of freedom and the deformation makes it possible to absorb the thermal stress, it is possible to obtain a high-frequency coaxial cable connection structure having high reliability with respect to the history of heat fluctuation. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of the configuration of a millimeter wave radar using a high-frequency coaxial line connection structure according to the present invention.

FIG. 2 is a sectional view showing a configuration of a first embodiment of a high-frequency coaxial line connection structure according to the present invention.

FIG. 3 is a sectional view showing a configuration of a high-frequency coaxial line connection structure according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing the configuration of a third embodiment of the high-frequency coaxial line connection structure according to the present invention.

FIG. 5 is a sectional view showing the configuration of a fourth embodiment of the high-frequency coaxial line connection structure according to the present invention.

FIG. 6 is a sectional view showing the configuration of a fifth embodiment of the high-frequency coaxial line connection structure according to the present invention.

FIG. 7 is a sectional view showing an example of the configuration of a known high-frequency coaxial line connection structure.

[Description of Signs] 1 Base substrate 2 Antenna circuit substrate 2 ₁ First organic substrate 2 ₂ Patch antenna pattern 2 ₃ Ground pattern 2 ₄ Non-ground side metal foil 2 ₅ Ground-side metal foil 2 ₆ Non-ground side adhesive layer 2 ₇ Ground side adhesive layer 2 ₈ Stepped portion 3 High frequency circuit board 3 ₁ Second organic substrate 3 ₂ High frequency circuit pattern 3 ₃ Ground pattern 3 ₄ Non-ground side metal foil 3 ₅ Ground side metal foil 3 ₆ Non-ground side adhesive layer 3 ₇ Ground side adhesive layer 3 ₈ Tapered part 4 Center conductor 5 Adhesive layer 6 Dielectric holding part 7 Solder connection part 8 First through hole 9 Second through hole 10 Cover 11 Semiconductor chip (MMIC) 12 Case 13 Radome 14 signal processing circuit 15 connection line 16 harness 17 connection pin 18 bush 19 microwave connector 20 connection line A high frequency coaxial line connection structure antenna

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadashi Isono 2477 Takaba, Hitachinaka-shi, Ibaraki Pref.Hitachi Car Engineering Co., Ltd. Within the Automotive Equipment Group (72) Inventor Shiro Ouchi, Hitachi, Ibaraki Pref., 2520 Oji Takaba Co., Ltd.Hitachi, Ltd. F-term in the Automobile Group of Mfg. Co., Ltd.

Claims (6)

[Claims] 1. A first organic material substrate having a first high-frequency circuit formed of a metallized region on both surfaces and a second organic material substrate having a second high-frequency circuit formed of a metallized region formed on both surfaces. Joined to the surface with a joining material,
A through hole is formed from the first organic material substrate to the second organic material substrate through the base substrate, and is coaxially arranged in the through hole and both ends are electrically connected to the first high-frequency circuit and the second high-frequency circuit. A high-frequency coaxial line connection structure having a center conductor formed therein, wherein the through-hole is formed in a first through-hole formed in the base substrate and a second through-hole formed in the first organic material substrate and the second organic material substrate.
A high-frequency coaxial cable connection structure comprising a through hole, wherein the diameter of the first through hole is formed to be larger than the diameter of the second through hole. 2. A bonding material for bonding the first organic material substrate and the base substrate and a bonding material for bonding the second organic material substrate and the base substrate have a diameter of a first through hole of the base substrate. 2. The high-frequency coaxial cable connection structure according to claim 1, wherein the high-frequency coaxial cable connection structure is disposed so as to be retracted to a position deeper than the inner surface. 3. The method according to claim 1, wherein the diameters of the second through holes formed in the first organic material substrate and the second organic material substrate are stepped or tapered so that the diameter of the second through hole is largest on the base substrate side. The high-frequency coaxial cable connection structure according to claim 1, wherein: 4. The metallized region of the first organic material substrate and the metallized region of the second organic material substrate are arranged such that the metallized region on the side of the base substrate is recessed from a position where a first through hole is formed in the base substrate. 2. The high-frequency coaxial cable connection structure according to claim 1, wherein 5. The metallized region of the first organic material substrate and the metallized region of the second organic material substrate are such that the metallized region on the side conductively connected to the central conductor extends to the middle of the inner peripheral surface of the second through hole. It is arranged to bend and extend,
2. The high-frequency coaxial cable connection structure according to claim 1, wherein both ends of the center conductor are conductively connected to the bent and extended metallized region. 6. The first through hole of the base substrate is filled with a dielectric that holds the center conductor, and a distance at which the dielectric holds the center conductor is greater than a depth of the first through hole. The high-frequency coaxial cable connection structure according to any one of claims 1 to 5, wherein the connection structure is short.