JP2005064986A - Quasi-optical coupling type module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate a bonding process for mounting an antenna integrated element on a flat surface of a silicon hemispherical lens, to improve the positioning accuracy of the antenna integrated element, and to avoid an influence of a stress at the time of the mounting. <P>SOLUTION: A submount 4 is disposed on the flat surface of the silicon hemispherical lens 2, and the antenna integrated element 3 is mounted on the submount 4. The submount 4 is made of a silicon plane of the same material as that of the lens 2, its top is superimposed on the flat surface periphery edge of the lens 2, and a mark 9 indicating a mounting position of the element 3 is formed on its top surface. The lens 2 is joined in the mounting hole 1a of a casing 1 with an adhesive 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a module having a structure for quasi-optically coupling a millimeter wave or submillimeter wave and an antenna integrated element.

  Ultra-high frequency signals such as millimeter waves and submillimeter waves are used in various fields such as communication and measurement. An antenna is generally used to radiate or detect a high-frequency signal. The size of the antenna is proportional to the wavelength of the signal to be handled, and is extremely small, 10 mm or less for millimeter waves and 1 mm or less for submillimeter waves. In such a frequency region, a so-called quasi-optical coupling system is used alongside the waveguide technology. In the quasi-optical coupling system, a dielectric lens is often used because propagation of radio waves is handled by geometric optics similar to visible light.

FIG. 9 is a diagram of a conventional example showing a relationship between silicon hemispherical lenses 51 and 51A as dielectric lenses and a micro-sized antenna integrated element (an oscillator or a detector having an antenna) 52 in which antennas are integrated. In FIG. 9A, a plane wave can be input / output to / from the antenna integrated element 52 by the silicon hemispherical lens 51. In FIG. 9B, the silicon hemispherical lens 51A can input and output radio waves having a certain spread angle with respect to the antenna integrated element 52. Specifically, for example, in the element described in Non-Patent Document 1, an element in which an antenna and a photodiode are integrated is used as an antenna integrated element 52 as shown in FIG. It is mounted on the lens 51 to output a millimeter wave.
Ahirata et al., “Design and Characterization of 120 GHz Millimeter-Wave Antennas for Integrated Photonic Transmitters”, IEEE Bulletin on Microwave Theory and Technology, Vol. 49, No. 11, 2157-2162, November 2001 (A. Hirata, et al "Design and Characterization of a 120-GHz Millimeter-Wave Antenna for Integrated Photonic Transmitters", IEEET Trans. Microwave Theory and Techniques, pp.2157-2162, VOL.49, NO.11, NOVEMBER 2001 )

  However, several problems have been encountered so far in producing a quasi-optically coupled module having the above configuration. First, because of a problem in processing technology, it is difficult to form a mark for determining the position of the antenna integrated element 52 directly on the plane of the silicon hemispherical lens 51. It has been difficult to accurately place in the center of the 51 plane.

  In addition, as shown in FIG. 10B, a so-called wire bonding technique is used to connect the wiring 53 to the antenna integrated element 52 having such a small size. Due to its thickness, it is difficult to mount such a module on a normal wire bonding apparatus.

  Further, as shown in FIG. 10B, the silicon hemispherical lens 51 is usually fixed to the lower portion of the mounting hole 55a of the housing 55 with an adhesive 54. However, the adhesive portion peels off due to stress applied during mounting. There was a problem that.

  An object of the present invention is to solve the above-described problems in the prior art, which facilitates a bonding process when mounting an antenna integrated element on a plane of a dielectric hemispherical lens, and positioning the antenna integrated element. It is an object of the present invention to provide a quasi-optically coupled module that can improve accuracy and avoid the influence of stress during mounting.

The invention according to claim 1 includes at least a dielectric hemispherical lens mounted on a housing, a submount disposed on a plane of the dielectric hemispherical lens, and an antenna integrated element mounted on the submount. A quasi-optically coupled module in which an input or output electromagnetic wave is quasi-optically coupled to the antenna of the antenna integrated element via the dielectric hemispherical lens, wherein the submount includes the dielectric hemispherical lens Is formed of a flat plate of the same material as that of the dielectric hemispherical lens, and includes the apex or the outer perimeter having a dimension that overlaps with the outer perimeter of the planar portion of the dielectric hemispherical lens, and indicates the mounting position of the antenna integrated element on one surface. A mark is formed.
According to a second aspect of the present invention, in the quasi-optically coupled module according to the first aspect, the dielectric hemispherical lens is configured so that the casing supports a force in a direction from the flat portion to the hemispherical portion of the dielectric hemispherical lens. It has a joining means which supports to the above-mentioned case.

  According to the first aspect of the invention, since the submount is used, the positioning accuracy of the antenna integrated element on the plane of the dielectric hemispherical lens can be improved, and the bonding step when mounting the antenna integrated element is possible. According to the invention of claim 2, it is possible to avoid the influence of stress at the time of mounting, and both have the effect of improving the production technique of the quasi-optically coupled module.

  In the present invention, the antenna integrated element is not directly mounted on the plane of the silicon hemispherical lens, but a planar silicon submount is provided on the plane of the silicon hemispherical lens, and the apex or outer periphery thereof is the plane of the silicon hemispherical lens. It is mounted so as to overlap the outer peripheral edge, and the antenna integrated element is mounted at the position of the mark formed on the submount, thereby improving the mounting position accuracy of the antenna integrated element and performing the wiring bonding process of the antenna integrated element. make it easier. Moreover, the influence of the stress at the time of mounting is avoided by providing the joining means for supporting the silicon hemispherical lens on the housing so that the housing supports the force in the direction from the flat part to the hemispherical part of the silicon hemispherical lens. Examples of the present invention will be described in detail below.

  FIG. 1 is a cross-sectional view showing the structure of a quasi-optically coupled module of Example 1 that converts an ultrahigh-frequency optical signal into a millimeter-wave radio signal. In FIG. 1, 1 is a housing, 2 is a silicon hemispherical lens mounted in the mounting hole 1a of the housing 1, 3 is an antenna integrated light receiving element in which an antenna, a photodiode, etc. are integrated, and 4 is a rectangular submount made of a silicon flat plate. is there. Reference numerals 5 to 7 denote lens systems for allowing optical signals to enter the antenna integrated light receiving element 3, 5 denotes a lens, 6 denotes a lens holding component, and 7 denotes an optical fiber. Reference numeral 8 denotes a casing lid that closes the upper portion of the casing 1, 9 is a wire to be wire-bonded, and 10 is an adhesive that joins the mounting hole 1 a and the silicon hemispherical lens 2. The ultra-high frequency optical signal introduced from the optical fiber 7 is irradiated to the photodiode of the antenna integrated light receiving element 3 by the lens 5, photoelectrically converted there, radiated from the antenna as a millimeter wave radio signal, and emitted from the silicon hemisphere lens 2. The

  Here, the lens holding component 6 has a configuration in which the position of the lens 5 can be adjusted in the triaxial direction using a coaxial sleeve. I do not care. Note that a connector portion for taking out the wiring 9 from the antenna integrated light receiving element 3 to the outside of the housing 1 is omitted.

  FIG. 2 is a view showing the upper surface of the silicon hemispherical lens 2, and each vertex of the rectangular submount 4 is formed to have a dimension that coincides with the outer peripheral edge of the planar portion of the silicon hemispherical lens 2. An alignment mark 11 for mounting the antenna integrated light receiving element 3 is formed near the center of the submount 4. The formation of the mark 11 can be performed with submicron accuracy by using a normal semiconductor process for the submount 4. In order not to affect the input / output of radio waves, this mark 11 is preferably realized by forming a groove or the like by etching a dielectric film or the silicon substrate itself instead of a metal film. After a large number of such marks 11 are formed on the silicon substrate in advance, the silicon substrate is cut and separated into the submounts 4 by a normal dicing process.

  Next, as shown in FIG. 2, the antenna integrated light receiving element 3 is mounted on the submount 4 under a stereomicroscope, and wire bonding of the wiring 9 is performed on the connection terminal portion 12 provided in this state. This process is the same as the wire bonding for an element formed on a normal silicon substrate, and can be executed without modifying the apparatus or preparing a special jig.

  Then, the submount 4 is fixed to the flat portion of the silicon hemispherical lens 2 with an adhesive or the like. At this time, each vertex of the submount 4 is formed to have a dimension that coincides with the outer peripheral edge of the planar portion of the silicon hemispherical lens 2, so that each vertex of the submount 4 comes to the outer peripheral edge of the planar portion of the silicon hemispherical lens 2. By simply adjusting the position as described above, the antenna integrated light receiving element 3 can be disposed at the center of the plane of the silicon hemispherical lens 2, and the alignment accuracy is remarkably improved. Here, since the submount 4 is made of the same silicon material as that of the silicon hemispherical lens 2, problems such as reflection of radio waves due to a difference in dielectric constant at the junction interface between them do not occur. Note that the focal position of the silicon hemispherical lens 2 may be corrected by the thickness of the submount 4. As described above, according to the first embodiment, the bonding process for the antenna integrated light receiving element 3 can be easily executed by a normal apparatus, the alignment accuracy of the antenna integrated light receiving element 3 can be improved, and the stress at the time of mounting can be improved. The influence of can be avoided.

  The shape of the submount 4 is a polygon such as a hexagon shown in FIG. 3A, a circle shown in FIG. 3B, a part of the arc shown in FIG. Alternatively, a combination thereof may be used. Among them, a square and a rectangle are preferable because they can be easily and efficiently cut with a dicing saw.

  After the above, wiring is performed from the connection terminal portion 12 of the submount 4 to the electrode terminal (shown in the figure) on the housing 1, but if the output side electrode on the connection terminal portion 12 is enlarged, wire bonding is performed. Wiring can be done in a process such as normal soldering without using it. Finally, the optical system such as the lens 5 is welded to complete the quasi-optical coupling type module.

  FIG. 4 is a cross-sectional view showing the structure of a quasi-optically coupled module of Example 2 that converts millimeter-wave radio signals into electrical signals. In FIG. 4, 21 is a housing, 22 is a silicon hemispherical lens, 23 is an integrated antenna detection element integrated with an antenna, a Schottky diode, etc., 24 is a submount made of a silicon flat plate, and 28 is a housing lid that closes the top of the housing 21. , 29 is a wire to be wire-bonded, and 30 is an adhesive for bonding the silicon hemispherical lens 22 to the upper edge of the mounting hole 21a of the housing 21. The millimeter wave radio signal incident on the silicon hemisphere lens 22 is received by the antenna of the antenna integrated detection element 23 and detected by the Schottky diode.

  Here, the shape of the silicon hemispherical lens 22 is different from that of the silicon hemispherical lens 2 of the first embodiment. In addition, since a Schottky diode is used as the antenna integrated detection element 23 for detecting millimeter waves and submillimeter waves, there is no light incident optical system shown in the first embodiment.

  As shown in FIG. 5, the silicon hemispherical lens 22 is formed with a flange 22 a that supports the housing 21 against a force that pushes the hemispherical part (lens) from the plane part direction. The flange 22a is joined to the upper edge of the mounting hole 21a of the casing 21, so that the influence of stress during mounting can be reduced. If a dedicated jig is used, it is possible to realize wire bonding of the wiring 29 after the submount 24 on which the antenna integrated detection element 23 is mounted in advance on the planar portion of the silicon hemispherical lens 22. At the same time, the wiring 29 can be directly bonded to an electrode terminal (not shown) installed in the housing 21 without providing a connection terminal portion on the submount 24.

  In this embodiment, as the alignment mark on the submount 24, as shown in FIG. 6, four scribing lines 31 scribed by a dicing saw are used. The marking line 31 can be formed by making the dicing saw teeth touch the surface of the silicon substrate which becomes the submount 24 only slightly. By doing in this way, the special mark formation process on a silicon substrate can be skipped. The antenna integrated detector 23 is mounted on the central square portion of the marking line 31 formed on the submount 24, and then the submount 24 is fixed on the silicon hemispherical lens 22. Finally, wire bonding of the wiring 29 is performed. Here, it goes without saying that wire bonding may be performed with the submount 24 alone. As described above, by using the second embodiment, as in the first embodiment, the bonding process for the antenna integrated detection element 23 can be easily performed with a normal apparatus, and the alignment accuracy of the antenna integrated detection element 23 is improved. In addition, the influence of stress during mounting can be avoided.

  In the second embodiment, the connector portion for taking out the wiring 29 to the outside of the housing is not shown. Further, as shown in FIG. 7, the silicon hemispherical lens 22 is replaced with a silicon hemispherical lens 22A having a plurality of engaging recesses 22b on the outer peripheral surface of the lens, and the engaging recesses 22b are provided in the mounting holes 21a of the housing 21. The silicon hemispherical lens 22 </ b> A may be supported by the housing 21 by engaging with the engaging convex portion 21 b. As described above, various forms can be used as the joining means of the silicon hemispherical lenses 22 and 22A and the casing 21.

  As the antenna integrated elements mounted on the silicon hemispherical lenses 2, 22, 22A, in addition to the antenna integrated light receiving element 3 and the antenna integrated detection element 23 in which the antenna and the photodiode, the Schottky diode and the like are integrated, the antenna and other elements are integrated. An integrated element in which an element, for example, an electronic circuit such as a multiplier and an oscillator, a mixer, and the like are integrated may be used.

  Further, as the design of the planar position of the silicon hemispherical lenses 2, 22, 22A, as described with reference to FIG. 9A, the focal position is determined so that the input / output radio wave becomes a plane wave, or FIG. As described above, it is possible to realize a desired function by determining a focal position so that light is focused on a certain point. Furthermore, not only a plane passing through the center of the sphere but also a so-called super hemisphere lens having a plane passing through a position beyond the hemisphere may be used.

  Moreover, although the example for determining the center position was shown about the mark position on the plane of the submounts 4 and 24, as shown in FIG. 8, according to the objective, it shifted | deviated only by the desired dimension from the center position. It can also be used to determine the position.

  Further, as the material of the silicon hemispherical lenses 2, 22, 22A and the submounts 4, 24, other dielectric materials such as Teflon and polyethylene can be used in addition to silicon. It is also preferable to apply a non-reflective coating to the surfaces of the silicon hemispherical lenses 2, 22, 22A.

FIG. 3 is a cross-sectional view of the quasi-optically coupled module of Example 1. 3 is a top view of a silicon hemispherical lens of the quasi-optically coupled module of Example 1. FIG. (a)-(c) is explanatory drawing of the modification of the submount of the semi- optical coupling type module of Example 1. FIG. 6 is a cross-sectional view of a quasi-optically coupled module of Example 2. FIG. 6 is a perspective view of a silicon hemispherical lens of the quasi-optical coupling module of Example 2. FIG. FIG. 6 is a perspective view of a submount of a quasi-optical coupling module according to Embodiment 2. It is explanatory drawing of another example of the engagement relation of the silicon hemisphere lens of the semi-optical coupling type module of Example 2, and a box. 6 is an explanatory diagram of a silicon hemispherical lens of a quasi-optically coupled module of Example 3. FIG. (a), (b) is explanatory drawing of the silicon hemispherical lens used for the conventional quasi-optical coupling type module, and the antenna integrated element mounted there. (a) is explanatory drawing of the silicon hemispherical lens used for the conventional quasi-optical coupling type module, and the antenna integrated element mounted in it, (b) is sectional drawing which mounted | wore the silicon hemispherical lens in the housing.

Explanation of symbols

1: Housing 1a: Mounting hole 2: Silicon hemispherical lens 3: Antenna integrated light receiving element 4: Submount 5: Lens 6: Lens holding component 7: Optical fiber 8: Housing lid 9: Wiring 10: Adhesive 11: Mark 12 : Connection terminal component 21: Housing, 21a: Mounting hole, 21b: Engaging projection 22, 22A: Silicon hemisphere lens, 22a: Flange, 22b: Engaging recess 23: Antenna integrated detector 24: Submount 28: Housing lid 29: Wiring 30: Adhesive 31: Marking wire

Claims (2)

An electromagnetic wave to be input or output includes at least a dielectric hemispherical lens mounted on a housing, a submount disposed on a plane of the dielectric hemispherical lens, and an antenna integrated element mounted on the submount. A quasi-optical coupling module that is quasi-optically coupled to the antenna of the antenna integrated element via the dielectric hemispherical lens;
The submount is made of a flat plate made of the same material as the dielectric hemispherical lens, includes the apex or outer perimeter having a dimension such that the apex or outer perimeter overlaps the outer perimeter of the flat portion of the dielectric hemispherical lens, and one surface The quasi-optical coupling module is characterized in that a mark indicating the mounting position of the antenna integrated element is formed on the quasi-optical coupling module. The quasi-optically coupled module according to claim 1,
A quasi-optically coupled module comprising a joining means for supporting the dielectric hemispherical lens on the casing so that the housing supports a force in a direction from the flat portion to the hemispherical portion of the dielectric hemispherical lens. .

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