JP2005020046A - Electromagnetic apparatus and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic apparatus wherein the excess or deficiency of a joining material such as solder does not affect the electric characteristics of a waveguide, and a manufacturing method thereof. <P>SOLUTION: In the electromagnetic apparatus, a carrier member having a carrier member opening which can be connected to the waveguide and a board which has joining pads and on which electronic components are mounted are joined by a joining material layer such as solder or a conductive adhesive. The joining pads and the joining layer form a connection opening which is communicated with the carrier member opening to electromagnetically connect the carrier member opening and the board. Each joining pad is provided with a slit which is communicated with the connection opening and has a width of 1/4 of the wavelength of an electromagnetic wave or below to absorb the excess or deficiency of the amount of the joining material. Each slit is a dead end slit or a grating slit provided over the all joining pads. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic device and a manufacturing method thereof, and more particularly to an electromagnetic device having a joint structure in which a carrier member that can be connected to a waveguide and a substrate on which an electronic component is mounted and a manufacturing method thereof.
[0002]
[Prior art]
In a microwave circuit, a microwave device formed on one surface of a dielectric or semiconductor substrate, a coupling hole provided in the ground conductor of the microwave device, and a waveguide in a metal housing A metal cover that covers the metal housing and the microwave device by opposing and electromagnetically coupling the waveguide coupling hole provided on the H surface, integrating the ground conductor and the metal housing with solder or a conductive adhesive Are integrated with solder or an adhesive (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
JP-A-7-202520 [0004]
[Problems to be solved by the invention]
In such a conventional microwave circuit, when the semiconductor substrate and the waveguide coupling hole of the ground conductor are joined by solder, if the ground conductor or the substrate is warped or tilted, it will melt. The amount of solder changes from place to place and is not uniform. If the molten solder is insufficient, the substrate is exposed and a cavity is formed in this portion of the waveguide coupling hole. If the molten solder is excessive, solder protrudes into the waveguide coupling hole. The wave tube will be deformed at this point. Such deformation causes leakage and reflection of electromagnetic waves supplied through the waveguide, and adversely affects electrical characteristics.
[0005]
Conventionally, in order to eliminate such inconvenience due to the deformation of the waveguide, after the joining work by soldering is completed, it is necessary to rework the solder to replenish the solder shortage portion or to remove the solder from the excessive solder portion. Therefore, improvement of the joining structure and joining method in the production of electromagnetic devices such as microwave circuits is desired, and an electromagnetic device having an improved joining structure is desired.
[0006]
Accordingly, an object of the present invention is to obtain an electromagnetic device and a method for manufacturing the same in which excess or deficiency of a bonding material such as solder does not adversely affect the electrical characteristics of the device.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, an electromagnetic device according to the present invention is an electromagnetic device including a substrate on which an electronic component is mounted, which is bonded to a carrier member having a carrier member opening that can be connected to a waveguide. A bonding material layer bonded onto the carrier member within a range including a carrier member opening; and the bonding material layer and the bonding pad bonded to the substrate between the bonding material layer and the substrate; The bonding material layer includes a connection opening that communicates with the carrier member opening and electromagnetically connects the carrier member opening and the substrate, and the bonding pad includes a bonding material storage cavity that communicates with the connection opening. This is an electromagnetic device.
[0008]
In addition, a method of manufacturing an electromagnetic device for joining a carrier member having a carrier member opening that can be connected to a waveguide and a substrate on which an electronic component is mounted is provided on the substrate at a position corresponding to the carrier member opening. A bonding pad having a bonding pad opening with a slit is provided, a bonding material layer is provided on the bonding pad, and the carrier member is connected to the bonding material at a position where the carrier member opening communicates with the bonding pad opening. Arranged on a layer, heating and cooling the bonding material layer to bond the substrate and the carrier member, and communicating with the carrier member opening by the bonding pad and the bonding material layer, the carrier member opening A method for manufacturing an electromagnetic device is characterized in that a connection opening for electromagnetically connecting the substrate and the substrate is formed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
1 and 2 schematically show an embodiment of the electromagnetic device of the present invention in a side sectional view and a bottom view. The electromagnetic device includes a pair of waveguides 3 that are provided at both ends of a metal casing 1 and each have a waveguide coupling hole 2. A rectangular plate-shaped carrier member 5 is provided on the upper surface of the waveguide 3, and the carrier member opening 6 of the carrier member 5 is soldered or conductive resin adhesive into the waveguide coupling hole 2 of the waveguide 3. Etc. are joined together. A bonding material layer 7 such as a solder or a conductive resin adhesive is provided on the upper surface of the carrier member 5, and an alumina ceramic substrate 9 having a bonding pad 8 is bonded thereon. An electronic component 10 that is a semiconductor element is mounted on the ceramic substrate 9.
[0010]
A carrier member opening 6 provided in the carrier member 5 is an opening constituting a part of the waveguide that electromagnetically couples between the waveguide 3 and the substrate 9, and is provided in the bonding material layer 7. Similarly, the bonding material layer opening 11 is an opening that constitutes a part of the waveguide that electromagnetically couples between the waveguide 3 and the substrate 9. These openings 6 and 11 communicate with each other and are connected to a bonding pad opening 12 provided in the bonding pad 8 on the substrate 9 to expose the surface of the substrate 9 from the bonding pad opening 12. Thus, the carrier member opening 6 of the carrier member 5 is electromagnetically connected to the exposed substrate 9, and in this sense, the bonding material layer opening 11 and the bonding pad opening 12 are connection openings 13. And the carrier member opening 6 connect the waveguide 4 to the substrate 9. Of course, the bonding material layer 7 is provided between the carrier member 5 and the bonding pad 8 in a range including at least the connection opening 13 so that the connection opening 13 can be formed. is necessary.
[0011]
3 and 4 show a rectangular plate-shaped alumina ceramic substrate 9 having bonding pads 8 in a schematic side sectional view and a bottom view. For example, the substrate 9 has a width of 7.5 mm, a length of 15 mm, and a thickness of 1.0 mm, and a bonding pad 8 having a width of, for example, 6.9 mm and a length of 14.4 mm is formed on the bottom surface thereof by metallization. . The bonding pad 8 is, for example, tungsten or silver. Further, a bonding pad opening 12 is provided at a position corresponding to the carrier member opening 6 (FIG. 2) of the bonding pad 8 so that the alumina ceramic on the surface of the substrate is exposed therefrom, and the inner layer of the inner layer is exposed. Electromagnetic waves are input / output from / to a waveguide (not shown). In the illustrated example, the bonding pad opening 12 is a rectangular opening having a width of 1.5 mm and a length of 5 mm. The carrier member 5 is made of, for example, Kovar (registered trademark) having a width of 9 mm, a length of 20 mm, and a thickness of 1.0 mm. As a metallization for soldering, for example, a nickel layer having a thickness of 5 μm and a thickness of 0.5 μm are formed on the entire surface. A gold layer is formed.
[0012]
According to the present invention, two slits 14 are formed on the two long sides of the rectangular bonding pad opening 12 and one on each of the two short sides. ing. In this example, the slit 14 has a width of 0.2 mm and a length of 2 mm. As will be described later, the slit 14 is desired to open at least in the connection opening 13 when the bonding material layer 7 is bonded, and the bonding that absorbs the influence of excess or deficiency of the bonding material such as molten solder or conductive resin. It acts as a material storage cavity. Therefore, the shape, volume, and arrangement of the slits 14 are set so as to be able to cope with an excessive or insufficient bonding material. On the other hand, at least the width of the opening of the slit 14 is ¼ or less of the wavelength of the electromagnetic wave passing through the connection opening 13 so as not to affect the electromagnetic wave passing through the connection opening 13 which is a waveguide. An example of the electromagnetic wave used here has a frequency of 75 GHz and a wavelength of 4 mm.
[0013]
In order to join the substrate 9 on which the electronic component 10 is mounted and the carrier member 5 having the carrier member opening 6 that can be joined to the waveguide 4, when solder is used as the joining material, first, the surface of the alumina ceramic substrate 9 is applied. The bonding pad 8 having good wettability with respect to the solder is formed. At this time, a bonding pad opening 12 is formed in the bonding pad 8 at a position corresponding to the carrier member opening 6 to expose the surface of the substrate 9. Further, the slit 14 described above is formed in the bonding pad opening 12. This state is shown in FIG. 3 and FIG.
[0014]
Next, Sn—Pb eutectic solder is supplied onto the carrier member 5 by printing a solder paste, and the bonding pads 8 of the substrate 9 shown in FIGS. 3 and 4 are placed in contact with the solder bonding material layer. . At this time, the solder bonding material does not partially cover the bonding pad opening 12, but may cover the slit 14 as long as it does not enter the slit 14. Further, the substrate 9 is disposed at a position where the carrier member opening 6 is aligned with and communicates with the bonding pad opening 12.
[0015]
Next, when the carrier member 5 and the substrate 9 sandwiching the bonding material are heated to about 220 ° C. with a hot plate, the bonding material is heated and melted, and cooled and solidified, as shown in FIG. The substrate 9 and the carrier member 5 are bonded by the bonding material layer 7, and a bonded structure is obtained in which the substrate 9 and the carrier member 5 are electromagnetically bonded by the connection opening 13 including the bonding material layer opening 11 and the bonding pad opening 12.
[0016]
FIG. 5 shows details of this joining structure. In this joining structure, when the joining material is heated and melted, the joining material enters only a part of the slit 14 to fill the filling portion 14a, and does not enter the vicinity of the opening of the slit 14 but leaves the space portion 14b. ing. Due to unevenness in the amount of bonding material around the connection opening 13 during heating and melting, or because the substrate 9 or the carrier member 5 is inclined, a shortage or excess portion of the bonding material occurs around the connection opening 13. There is. However, according to the bonding structure of the present invention, the change in the amount of the bonding material appears as an increase or decrease in the amount of the bonding material in the slit 14, and the space portion 14 b in the slit 14 increases in the insufficient portion of the bonding material, and the excess portion. Then, it is only reduced, and unevenness is not generated on the peripheral wall surface of the connection opening 13. In this sense, the slit 14 is a bonding material storage cavity, not only the shape of the slit as shown in the figure, but also a cavity that does not affect electromagnetic waves and can absorb the excess or deficiency of the bonding material such as melting or conductive adhesive. Various shapes can be used.
[0017]
As described above, in the electromagnetic device according to the present invention, when the connection opening 13 is provided between the substrate 9 and the carrier member 5 by the bonding material and the bonding is performed, the amount of the bonding material varies depending on the location and is not uniform. Even if this occurs, the space 14b in the slit 14 increases in the insufficient portion where the bonding material is insufficient, and the filling portion 14a in the slit 14 increases in the excessive portion where the bonding material is excessive. Is absorbed. Therefore, there is no deformation of the cavity that affects the electromagnetic wave or the protruding portion of the bonding material in the connection opening 13, and no leakage or reflection of the electromagnetic wave due to such deformation occurs, which adversely affects the electrical characteristics. There is nothing. Therefore, the work for repairing the bonding material after the end of the joining work, which was necessary in the past, becomes unnecessary.
[0018]
Embodiment 2. FIG.
FIG. 6 shows a substrate 9 having another bonding pad 15 that can be used in the electromagnetic device of the present invention. In this bonding pad 15, a grid-like slit 16 is formed over the entire surface of the bonding pad 15, and passes through the bonding pad opening 17 constituting the above-described connection opening 13. A bonding material storage cavity communicating with the opening 13 is formed. Other configurations are the same as those shown in FIGS. If the slit 16 having such a shape is used, the excess / deficiency absorption capability of the molten bonding material can be increased. Moreover, since it is not necessary to manage the length of the slit, the manufacturing process is not complicated.
[0019]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent the excess or deficiency of the bonding material from adversely affecting the electrical characteristics of the apparatus.
[Brief description of the drawings]
FIG. 1 is a schematic side sectional view showing an electromagnetic device of the present invention.
FIG. 2 is a schematic plan sectional view of the electromagnetic device of FIG.
FIG. 3 is a schematic side view showing a substrate having the bonding pads of FIGS. 1 and 2;
4 is a schematic plan view of the substrate of FIG. 3. FIG.
FIG. 5 is a side cross-sectional view along a line passing through a slit showing details of a joining structure of the electromagnetic device according to the present invention.
FIG. 6 is a schematic plan view showing another example of a substrate having a bonding pad.
[Explanation of symbols]
5 Carrier member, 6 opening, 7 bonding material layer, 8 bonding pad, 9 substrate, 10 electronic component, 12 bonding pad opening, 13 connection opening, 14 bonding material storage cavity (slit).

Claims (5)

In an electromagnetic device including a substrate on which an electronic component is mounted and bonded to a carrier member having a carrier member opening that can be connected to a waveguide.
A bonding material layer bonded on the carrier member in a range including the carrier member opening;
A bonding pad bonded to the bonding material layer and the substrate between the bonding material layer and the substrate;
The bonding pad and the bonding material layer include a connection opening that communicates with the carrier member opening and electromagnetically connects the carrier member opening and the substrate, and the bonding pad stores the bonding pad in communication with the connection opening. An electromagnetic device comprising a cavity. 2. The electromagnetic wave according to claim 1, wherein the bonding material storage cavity is a slit provided in the bonding pad, and the width of the opening of the slit is ¼ or less of the wavelength of the electromagnetic wave passing through the connection opening. apparatus. The electromagnetic device according to claim 1, wherein the bonding material storage cavity is a dead end slit extending a predetermined distance from the connection opening. 3. The electromagnetic device according to claim 1, wherein the bonding material storage cavity is a lattice-shaped slit provided over the entire bonding pad. In a method of manufacturing an electromagnetic device for joining a carrier member having a carrier member opening that can be connected to a waveguide and a substrate on which an electronic component is mounted,
Exposing the substrate surface at a position corresponding to the carrier member opening on the substrate, providing a bonding pad having a bonding pad opening having a slit;
A bonding material layer is provided on the bonding pad,
In the position where the carrier member opening communicates with the bonding pad opening, the carrier member is disposed on the bonding material layer,
The bonding material layer is heated and cooled to bond the substrate and the carrier member, and the carrier pad opening and the substrate are electromagnetically communicated with the carrier member opening by the bonding pad and the bonding material layer. A method for manufacturing an electromagnetic device, characterized in that a connection opening for connection is formed.

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