JP3462080B2 - High frequency semiconductor element storage package - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package for accommodating high-frequency semiconductor devices such as a microwave band and a millimeter wave band.
More specifically, the present invention relates to a package for housing a high-frequency semiconductor element having excellent high-frequency signal input / output characteristics. 2. Description of the Related Art Hitherto, a high-frequency semiconductor element housing package for hermetically sealing and housing a high-frequency semiconductor element using a high-frequency signal in a microwave band or a millimeter wave band is called a flat package. There are types. This has a mounting portion for mounting a high-frequency semiconductor element on the upper surface, and a dielectric substrate on which a transmission line such as a microstrip line for transmitting a high-frequency signal as an input / output signal is formed, and on a dielectric substrate. A dielectric frame which is joined to surround the mounting portion and forms a feed-through portion with a part of the transmission line interposed between the dielectric frame and the dielectric substrate. Then, for electrical connection with an external electric circuit, a lead terminal is attached to a portion where the transmission line is drawn out of the dielectric frame via a feed-through portion, and the lead terminal is soldered or This is performed by wire bonding directly to the site. [0003] On the other hand, there is a surface mount type package as a type of package aimed at reducing the manufacturing cost. FIG. 4 shows an example of a conventional surface mount type high frequency semiconductor element storage package. FIG. 4A is an exploded perspective view, and FIG. 4B is a perspective view seen from the lower surface side of the dielectric substrate. In FIG. 4, reference numeral 1 denotes a dielectric substrate, 2 denotes a dielectric frame, and 3 denotes a high-frequency semiconductor element. Dielectric substrate 1
Has a mounting portion 1a for mounting the high-frequency semiconductor element 3 on the upper surface, and a line conductor 4 for transmitting a high-frequency signal and a grounding wiring conductor 5 are arranged from the vicinity of the mounting portion 1a to the outer periphery. I have. The line conductor 4 and the grounding wiring conductor 5 are connected to each other through a through conductor formed in the dielectric substrate 1 or a side conductor layer 6 called a castellation formed on the side surface and a ground side conductor layer 7. 1 is connected to the connection electrode 8 and the ground connection electrode 9 formed on the lower surface of the dielectric substrate 1. The dielectric frame 2 has a dielectric substrate 1
Is a frame-like member having a through-hole formed so as to surround the mounting portion 1a. The line conductor 4 and a part of the grounding wiring conductor 5 surround the mounting portion 1a and the dielectric substrate 1. It is attached to the upper surface of the dielectric substrate 1 so as to sandwich it. The high-frequency semiconductor element 3 mounted on the mounting portion 1a is electrically connected to the grounding wiring conductor 5 on the back surface, and the electrode on the front surface and the line conductor 4 are electrically connected via the bonding wire 10. They are connected and, if necessary, are hermetically accommodated inside by attaching a lid or sealing with a resin. Then, the package is surface-mounted on an external electric circuit, and the connection electrode 8 and the ground connection electrode 9 on the lower surface of the dielectric substrate 1 are connected via lead terminals attached to these electrodes 8.9, By being electrically connected to the wiring conductor of the external electric circuit in the form of an electronic circuit, the high-frequency semiconductor element 3 and the external electric circuit are connected to perform input and output of a high-frequency signal, thereby being used as a semiconductor device. Become. [0007] However, among the above-mentioned conventional high-frequency semiconductor element storage packages, the flat package type package has excellent transmission characteristics of high-frequency signals, but the package body is not suitable. It is necessary to attach lead terminals in advance, or wire bonding is required at the time of mounting to an external electric circuit, so it is difficult to reduce the size, and the mounting cost is high. There is a problem that it is difficult to do so. Further, in this flat package type, since the lead terminals are attached to the transmission line by brazing or the like, and the connection is performed by wire bonding at the time of mounting, the high frequency characteristics due to variations in the manufacturing process and the like are reduced. There is also a problem that the influence on the variation is large. On the other hand, in a surface mount type package,
Although the mounting cost can be reduced, the line conductor 4 is routed from the upper surface of the dielectric substrate 1 to the connection electrode 8 on the lower surface of the dielectric substrate 1 via the side conductor layer 6 or the through conductor. 4 has a bent shape (stepped shape) in the middle, so that when the high-frequency semiconductor element 3 is operated, transmission loss such as reflection loss in transmission of a high-frequency signal increases, and particularly, the frequency of the signal becomes high. There has been a problem that the high-frequency characteristics are remarkably deteriorated. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to be able to be surface-mounted on an external electric circuit so as to reduce its size, and to further reduce reflection loss in transmitting a high-frequency signal. An object of the present invention is to provide a high-frequency semiconductor element storage package having excellent high-frequency characteristics by reducing the frequency. The high-frequency semiconductor element housing package of the present invention has a mounting portion for mounting the high-frequency semiconductor element on an upper surface thereof, and a high-frequency signal transmission package from the vicinity of the mounting portion to the outer periphery. A dielectric substrate on which the line conductor is disposed, and a dielectric member mounted on the dielectric substrate, surrounding the mounting portion, and having a portion protruding from an outer periphery of the dielectric substrate in an extending direction of the line conductor. A body frame and a portion formed on the lower surface of the dielectric frame from the projecting portion to a portion facing the line conductor, abutting on the line conductor and a wiring conductor of an external electric circuit to form the line conductor. An input / output line conductor electrically connected to an external electric circuit, and the line width of the line conductor is reduced from near the mounting portion toward a contact portion with the input / output line conductor, Said entry and exit The line width of the force line conductor is narrower than the line width of the line conductor at a contact portion with the line conductor and widened toward the projecting portion. According to the high frequency semiconductor element storage package of the present invention, the input / output line conductor formed on the lower surface of the dielectric frame is connected to the line conductor for high frequency signal transmission disposed on the upper surface of the dielectric substrate. And the input / output line conductor is brought into contact with the wiring conductor of the external electric circuit to electrically connect the line conductor and the wiring conductor. Are arranged on the same plane, so that signal wiring for high-frequency signal transmission can be connected without bending or forming a step in the middle. , Etc., can be reduced, so that it has excellent high frequency characteristics. In the contact portion between the line conductor on the upper surface of the dielectric substrate and the input / output line conductor on the lower surface of the dielectric frame, the line width of the line conductor is reduced from near the mounting portion toward the contact portion.
Since the line width of the input / output line conductor is narrower than the line width of the line conductor at the abutting portion, and the dielectric frame is widened toward a portion protruding from the dielectric substrate, the line conductor and the input / output line conductor Can be connected while matching the characteristic impedance at the contact portion, and even if a slight displacement occurs in the contact portion due to a variation in the manufacturing process, a sharp step-like shape can be obtained. Since the line width hardly changes and transmission loss such as reflection loss of a high-frequency signal hardly occurs, a high-frequency semiconductor element housing package having excellent high-frequency characteristics is obtained. Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 shows an example of an embodiment of a package for storing a high-frequency semiconductor element according to the present invention.
FIG. 2 is an exploded perspective view, and FIG. 2B is a perspective view of the dielectric frame viewed from the lower surface side. In FIG. 1, 11 is a dielectric substrate, 12 is a dielectric frame, and 13 is a high-frequency semiconductor element. Dielectric substrate 11
Is a mounting part for mounting the high-frequency semiconductor element 13 on the upper surface
A line conductor 14 for high-frequency signal transmission and a grounding wiring conductor 15 are provided from the vicinity of the mounting portion 11a to the outer periphery. The dielectric frame 12 has a dielectric substrate 11
Is a frame-shaped member having a through hole formed so as to surround the mounting portion 11a.
A portion 12 protruding from the outer periphery of the dielectric substrate 11 in the extension direction of 14
a, and is attached to the upper surface of the dielectric substrate 11 so as to sandwich a part of the line conductor 14 and a part of the grounding wiring conductor 15 between the dielectric substrate 11 and the dielectric substrate 11. In the package for storing a high-frequency semiconductor element having such a configuration, the high-frequency semiconductor element 13 is, for example, a high-frequency FET or HEMT which is an individual semiconductor element.
Alternatively, there is a type in which a high-frequency integrated circuit or MMIC is mounted and accommodated. FIG. 1 shows an example in which the present invention is applied to a low-noise package in which a HEMT is mounted as the high-frequency semiconductor element 13. Here, on the lower surface of the dielectric frame 12, an input / output line conductor 16 is formed from a projecting portion 12a to a portion of the upper surface of the dielectric substrate 11 facing the line conductor 14.
The input / output line conductor 16 is formed by mounting the dielectric frame 12 on the dielectric substrate 11 so that the line conductor 14 and its opposing parts are in contact with each other and are electrically connected to each other.
The line conductor 14 is electrically connected to an external electric circuit by directly mounting the portion located at position a at the surface of an external electric circuit board (not shown) and abutting the wiring conductor. The line conductor 14 and the input / output line conductor 16
That is, the line width of the line conductor 14 is narrowed from the vicinity of the mounting portion 11a toward the contact portion 14a with the input / output line conductor 16, while the input / output line conductor 16 is in contact with the line conductor 14. The contact portion 16a is formed to be narrower than the line width of the line conductor 14 and widen toward the projecting portion 12a. By setting the line widths of the line conductor 14 and the input / output line conductor 16 in a predetermined relationship as described above, the contact portions 14a and 14a sandwiched between the dielectric substrate 11 and the dielectric frame 12 are formed.
By making the line width of the line conductor 14 and the input / output line conductor 16 in 16a narrower than the line width before and after the line conductor 16a, characteristic impedance can be matched to a high-frequency signal, and transmission loss can be reduced. Even if the line conductor 14 or the input / output line conductor 16 is misaligned at the contact portions 14a and 16a, the line width such as a step changes suddenly due to the misalignment as in the case of joining line conductors having the same line width. Since it is possible to prevent the occurrence of locations, it is possible to effectively prevent the occurrence of reflection loss of high-frequency signals, and as a result, a surface-mount type having a signal input / output unit having excellent high-frequency characteristics. This is a package for storing a high-frequency semiconductor element. Such a line conductor 14 and an input / output line conductor in the package for storing a high-frequency semiconductor element of the present invention.
The state of the contact portions 14a and 16a with the 16 will be described with reference to the plan view shown in FIG. FIGS. 2A to 2C show the line conductors 14 respectively.
FIG. 6 is a plan view of a main part showing contact portions 14a and 16a between the input and output line conductors 16; In each case, the dielectric substrate is from the dielectric frame 12 side
11 shows the vicinity of the contact portions 14a and 16a of the line conductor 14 and the input / output line conductor 16 when looking at the upper surface, and the left side in the figure is in the direction of the mounting portion 11a of the dielectric substrate 11, The right side corresponds to the direction of the protruding portion 12a of the dielectric frame 12. First, FIG. 2A shows a state in which the line conductor 14 and the input / output line conductor 16 are normally in contact with each other. As can be seen from this figure, the line width of the line conductor 14 is
The line width of the input / output line conductor 16 is smaller than the line width of the line conductor 14 at the contact portion 16a with the line conductor 14 from the vicinity of 11a toward the contact portion 14a with the input / output line conductor 16. It is formed to be narrower and wider toward the projecting portion 12a, and in this example, the line width of each line conductor 14, 16 is changed to a tapered shape toward the contact portion 14a, 16a so as to be narrower. . By bringing the line conductors 14 and 16 into contact with each other, it is possible to prevent a sudden change in the line width at the connection portion and prevent the occurrence of reflection loss of a high-frequency signal,
By appropriately adjusting the setting of the change in the line width according to the specification, it is possible to match the characteristic impedance in the connection between the line conductor 14 and the input / output line conductor 16 and to obtain a signal input / output unit having excellent high-frequency characteristics. Can be configured. Next, FIG. 2B shows a state where the input / output line conductor 16 is displaced upward in the figure in the line width direction with respect to the line conductor 14. FIG. 2C shows a line conductor.
14 shows a state in which the input / output line conductor 16 is shifted downward in the figure in the line width direction and rightward in the figure in the line length direction. As described above, in the high-frequency semiconductor element housing package of the present invention, no abrupt change in the line width occurs at the contact portions 14a and 16a between the line conductor 14 and the input / output line conductor 16, and the high-frequency signal It can be seen that it is possible to prevent the occurrence of reflection loss and the like. In the case where the line widths of the line conductor 14 and the input / output line conductor 16 are reduced toward the contact portions 14a and 16a, respectively, the shapes and dimensions are set in accordance with the high frequency due to the displacement of the contact portions 14a and 16a. Although it is not particularly limited as long as the characteristic variation is reduced, the line conductor
The characteristic impedance of each part of 14 and the input / output line conductor 16 has a line width that is generally matched, so that even if there is a manufacturing deviation, the line width does not suddenly fluctuate, The contact portions 14a and 16a are designed by adopting a tapered shape or the like. In the example shown in FIG. 1, similarly, for the grounding wiring conductor 15, external electric power extends from a portion 12 a protruding from the lower surface of the dielectric frame 12 to a portion facing the grounding wiring conductor 15. Although the ground connection wiring conductor 17 for connection with the circuit ground wiring conductor is formed, by adopting the same configuration as the line conductor 14 for the ground wiring conductor 15 in this way, When surface-mounted on an external electric circuit, the grounding wiring conductor 15 can also be connected without bending or step, and as a result, a high-frequency semiconductor element housing package having extremely good high-frequency characteristics can be obtained. Also, in this example, the shape of the ground connection wiring conductor 17 does not change the line width unlike the input / output line conductor 16, but the ground connection is different from the width of the ground wiring conductor 15. There is no particular problem if the width of the ground connection wiring conductor 17 is set in consideration of the displacement. It goes without saying that the ground wiring conductor 15 and the ground connection wiring conductor 17 may have a configuration in which the line width is changed similarly to the line conductor 14 and the input / output line conductor 16. The high-frequency semiconductor element 13 mounted on the mounting portion 11a is electrically connected to, for example, the ground wiring conductor 15 on the back surface of the high-frequency semiconductor element housing package of the present invention having such a configuration. At the same time, the electrode on the surface and the line conductor 14 are electrically connected via a bonding wire 18 or a bonding ribbon, and if necessary, an Fe-Ni-Co or Fe-Ni42 alloy is formed on the upper surface of the dielectric frame 12. A lid made of Fe-Ni alloy, oxygen-free copper, aluminum, stainless steel, Cu-W alloy, Cu-Mo alloy, etc. is soldered, high melting point metal brazing such as AuSn brazing or AuGe brazing, seam welding, etc. And airtightly housed inside by resin sealing. Then, as shown in a perspective view in FIG. 3, for example, the dielectric substrate 11 of this high-frequency semiconductor element housing package formed in the external electric circuit 19 is dropped and the dielectric frame 12 is projected. The package is mounted on a mounting hole 20 designed so that the lower surface of the portion 12a to be brought into contact with the upper surface, the package is surface-mounted on the external electric circuit 19, and the lower surface of the projecting portion 12a of the dielectric frame 12 The input / output line conductor 16 and the ground connection wiring conductor 17 are respectively brought into contact with the high-frequency signal transmission wiring conductor 21 and the ground wiring conductor 22 of the external electric circuit 19 to be electrically connected to each other, thereby achieving high-frequency operation. The semiconductor element for use 13 and the external electric circuit 19 are electrically connected to perform input and output of a high-frequency signal, and are used as a high-frequency semiconductor device as a product. In the package for housing a high-frequency semiconductor element of the present invention, the dielectric substrate 11 and the dielectric frame 12 are made of a ceramic material such as alumina or mullite.
What is called glassacea (glass + ceramics) or resin-based materials such as Teflon (PTFE), glass epoxy, and polyimide are used. Although the same material as that of the dielectric substrate 11 may be used for the dielectric frame 12, a different material may be used to obtain desired high-frequency characteristics. For example, if the permittivity of the dielectric frame 12 is set to be smaller than the permittivity of the dielectric substrate 11, the dielectric loss of the contact portions 14a and 16a can be reduced. The line conductor 14, the input / output line conductor 16, the ground wiring conductor 15, and the ground connection wiring conductor 17 are made of a metal material for a high-frequency line conductor, for example, Cu or MoMn + Ni + A
u, W + Ni + Au, Cr + Cu, Cr + Cu + Ni +
Au, Ta ₂ N + NiCr + Au, Ti + Pd + Au,
It is formed by a thick film printing method, various thin film forming methods, a plating method, or the like using NiCr + Pd + Au or the like, and its thickness and width are set according to the frequency and characteristic impedance of the transmitted high-frequency signal. EXAMPLES Specific examples of the present invention will be described below. As the dielectric material, alumina of ε = 9 was used, and the thickness of the dielectric frame 12 was set to 0.
38 mm, the thickness of the dielectric substrate 11 is 0.25 mm, the dielectric frame 12
The line width of the input / output line conductor 16 formed at
The line width of the line conductor 14 formed on the dielectric substrate 11 is 0.25 m.
m, and the contact length between the input / output line conductor 16 and the line conductor 14 was set to be about 0.4 mm. The input / output line conductor 16 is connected at the contact portion 16a.
The taper is tapered from a width of 0.4 mm, while the line conductor 14 is formed with a straight width of 0.25 mm at the abutting portion 14a, so that these are designed to abut. These line conductors were designed so that the characteristic impedance was about 50Ω. When the package for accommodating the high-frequency semiconductor device of the present invention shown in FIG. 1 was produced in such a setting and the transmission characteristics of the high-frequency signal were evaluated, the conventional high-frequency semiconductor device having a bent portion in the line conductor was evaluated. The reflection loss of the high-frequency signal can be extremely reduced as compared with the storage package, and it was confirmed that the package had excellent high-frequency characteristics. It should be noted that the present invention is not limited to the following examples, and changes and improvements can be made without departing from the scope of the present invention. For example, in the example shown in FIG.
Is formed in a quadrangular shape, and portions 12a protruding from the outer periphery of the dielectric substrate 11 are provided at the four corners, and one input / output line conductor 16 or one ground connection wiring conductor 17 is formed for each.
If necessary, the dielectric frame 12 may be formed in various other shapes to have more protruding portions 12a, or each protruding portion 12a
A plurality of input / output line conductors 16 or ground connection wiring conductors 17 may be formed. Further, a thin lead terminal may be attached to the protruding portion 12a according to a desired mounting form. According to the high frequency semiconductor element storage package of the present invention, the input / output line conductor formed on the lower surface of the dielectric frame is provided with the high frequency signal arranged on the upper surface of the dielectric substrate. Since the line conductor and the wiring conductor are electrically connected by contacting the transmission line conductor and the wiring conductor of the external electric circuit, the line conductor and the wiring conductor are arranged on substantially the same plane. As a result, signal wiring for high-frequency signal transmission can be connected without bending or forming a step, and transmission loss such as reflection loss can be reduced even for high-frequency signals. Therefore, a high-frequency semiconductor element housing package having excellent high-frequency characteristics can be obtained. Further, at the contact portion between the line conductor and the input / output line conductor, the line width of the line conductor is reduced from the vicinity of the mounting portion toward the contact portion, and the line width of the input / output line conductor is reduced. The width of the line conductor is narrower than the line width of the line conductor, and the width of the dielectric frame is widened toward the part protruding from the dielectric substrate. In addition, even if the contact part is slightly displaced due to variations in the manufacturing process, it is difficult to cause a sudden change in the line width such as a step-like shape, and the reflection of high-frequency signals Since a transmission loss such as a loss is unlikely to occur, a high-frequency semiconductor element housing package having excellent high-frequency characteristics is obtained. Moreover, according to the package for housing a high-frequency semiconductor element of the present invention, the wiring structure of the line conductor is simplified as compared with the conventional surface-mount type package, so that it is easy to manufacture and can be miniaturized. Therefore, a low-cost and inexpensive high-frequency semiconductor device can be realized. As described above, according to the present invention, it is possible to reduce the size of an external electric circuit by surface mounting and reduce reflection loss in transmitting a high-frequency signal, and to obtain a high-frequency signal having excellent high-frequency characteristics. A semiconductor device storage package can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is an exploded perspective view showing an example of an embodiment of a package for housing a high-frequency semiconductor element according to the present invention, and FIG.
FIG. 3 is a perspective view of the dielectric frame viewed from the lower surface side. FIGS. 2A to 2C are plan views of main parts showing contact portions between a line conductor and an input / output line conductor in the package for housing a high-frequency semiconductor element according to the present invention; FIG. 3 is a perspective view showing an example of surface mounting of the high-frequency semiconductor element housing package of the present invention to an external electric circuit. FIG. 4A is an exploded perspective view showing an example of a conventional package for housing a high-frequency semiconductor element, and FIG. 4B is a perspective view seen from the lower surface side of the dielectric substrate. [Description of Signs] 11 ... Dielectric substrate 11a ... Mounting part 12 ... Dielectric frame 12a ... Dielectric A portion 13 protruding from the outer periphery of the substrate 11 ... High frequency semiconductor element 14 ... Line conductor 14a ... Input / output line conductor 16 of line conductor 14 Contact portion 16 with input / output line conductor 14a Contact portion 19 of input / output line conductor 16 with line conductor 14・ External electric circuit 21 ・ ・ ・ ・ ・ ・ ・ ・ Wiring conductor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-82826 (JP, A) JP-A-5-335436 (JP, A) JP-A-6-29419 (JP, A) JP-A 64-64 84655 (JP, A) JP-A-3-167841 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 23/04

Claims (1)

(1) A dielectric having a mounting portion for mounting a high-frequency semiconductor element on an upper surface thereof, and a line conductor for transmitting a high-frequency signal disposed from the vicinity of the mounting portion to the outer periphery. A substrate, a dielectric frame attached to the dielectric substrate, surrounding the mounting portion, and having a portion protruding from an outer periphery of the dielectric substrate in an extending direction of the line conductor; and a dielectric frame. An input is formed on the lower surface of the device from the projecting portion to a portion facing the line conductor, and is in contact with the line conductor and a wiring conductor of an external electric circuit to electrically connect the line conductor to the external electric circuit. An output line conductor, the line width of the line conductor is reduced from the vicinity of the mounting portion toward the contact portion with the input / output line conductor, and the line width of the input / output line conductor is reduced. The line at the contact portion with the line conductor High-frequency semiconductor element storage package, characterized in that wider toward the site of the protruding with narrower than the line width of the conductor.