JP5430451B2 - High frequency package - Google Patents

Description

  The present invention relates to a non-hermetic high-frequency package in which a substrate on which a high-frequency oscillation unit is mounted is sealed with a lid that is joined by solder, and more particularly to a high-frequency package in which a vent is formed in solder.

  Conventionally, by forming an annular pattern so as to surround the high-frequency oscillation unit on the substrate on which the high-frequency oscillation unit for transmitting radio waves is mounted, by joining the lid to the substrate with solder stacked on the annular pattern, A high-frequency package having a structure in which a high-frequency oscillation unit is sealed with a lid is known (for example, see Patent Document 1).

  In the high-frequency package having the above-described structure, the internal space in which the high-frequency oscillation unit is housed may be a non-airtight space without being airtight. When making a high-frequency package non-hermetic, it is necessary to provide minute ventilation holes that do not leak radio waves for the purpose of preventing condensation. Conventionally, a method has been proposed in which the vent hole is formed in solder for joining the substrate and the lid. According to this method, for example, one portion of the annular pattern is divided to form a void portion without a pattern locally. As a result, since no solder is placed in the gap, a minute air hole can be easily formed in a part of the solder that joins and seals the substrate and the lid.

JP 2009-010170 A

  However, in the method of forming a vent hole in the solder that joins the substrate and the lid, the solder fillet cannot be formed into an appropriate shape due to variations in the amount of solder applied, resulting in an increase in the size of the vent hole. there were. For this reason, conventionally, the amount of solder applied is strictly controlled so that the vent hole does not become large. However, due to manufacturing variations, there may be a case where the width of the vent hole inevitably increases. If the size of the vent hole is larger than a predetermined value, a high-frequency signal inside the high-frequency package leaks to the outside, and there is a problem that EMI characteristics deteriorate and system noise increases.

  The present invention has been made in view of the above, and an object of the present invention is to provide a high-frequency package that can reduce leakage of high-frequency signals as a result of leakage high-frequency signals canceling each other.

  In order to solve the above-described problems and achieve the object, a high-frequency package according to the present invention includes a substrate on which a high-frequency oscillation unit for transmitting radio waves is mounted on a first surface, and a high-frequency oscillation unit on a first surface of the substrate. An annular pattern formed so as to surround the substrate, solder stacked on the annular pattern, and a lid that is bonded to the first surface of the substrate by the solder and covers the high-frequency oscillation unit, and forms a vent hole in the solder For this reason, the annular pattern is intermittently divided into a plurality of parts, and the pitch of the gaps formed in each part is set to a pitch of λ / 2 with respect to the wavelength λ of the radio wave oscillated by the high frequency oscillation part. It is characterized by being.

  According to the present invention, since the plurality of air holes are formed at a pitch of λ / 2, a high-frequency signal leaks from each of the air holes with a phase difference of λ / 2. The high frequency signals having a phase difference of λ / 2 cancel each other. Since the leaked high-frequency signals cancel each other, the leakage of the high-frequency signals can be reduced as a result.

FIG. 1 is an exploded perspective view of a first embodiment of a high-frequency package according to the present invention. FIG. 2 is a cross-sectional view taken along plane A in FIG. FIG. 3 is a top view of an annular pattern in the vicinity of which the A plane of FIG. 1 intersects. 4 is a cross-sectional view corresponding to FIG. 2 of a second embodiment of the high-frequency package according to the present invention. FIG. 5 is a cross-sectional view of a conventional high-frequency package corresponding to FIG.

  Embodiments of a high-frequency package according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is an exploded perspective view of a first embodiment of a high-frequency package according to the present invention. FIG. 2 is a cross-sectional view taken along plane A in FIG. FIG. 3 is a top view of an annular pattern in the vicinity of which the A plane of FIG. 1 intersects. In FIG. 1, the solder stacked on the annular pattern is omitted.

  The high-frequency package 20 of the present embodiment includes a substrate 1, an annular pattern 2 formed on the first surface of the substrate 1, solder 4 (FIG. 2) stacked on the annular pattern 2, and the solder 4. 1 has a metal lid (lid body) 3 joined to the first surface. A transmission / reception circuit (not shown) as a high-frequency oscillation unit (including a high-frequency amplification unit that amplifies a high-frequency signal from the outside) is mounted at the center of the first surface of the substrate 1. A recess 3a is formed on the back surface of the metal lid 3 to avoid interference with the transmission / reception circuit. The annular pattern 2 is formed on the first surface of the substrate 1 at a position facing the outer peripheral edge of the metal lid 3 so as to surround the transmission / reception circuit. The annular pattern 2 is formed to deposit solder 4 for joining the metal lid 3.

  As shown in FIG. 2, the metal lid 3 is joined to the substrate 1 by solder 4 placed on the annular pattern 2 to form a generally closed space for accommodating the transmission / reception circuit inside the package. The solder 4 is provided with a minute ventilation hole 5 that does not leak radio waves for the purpose of preventing condensation.

  As shown in FIG. 3, in order to form the air holes 5 in the solder 4, the annular pattern 2 is intermittently divided into a plurality of portions, and a void portion 2 a having no pattern is formed at each divided portion. Yes. The plurality of gaps 2a are arranged at a pitch of λ / 2 with respect to the wavelength λ of the radio wave oscillated by the transmitting / receiving circuit. The size of each gap 2a (the length in the longitudinal direction of the annular pattern 2) is desirably as small (short) as possible within a range in which the air holes 5 can be reliably formed. Since the annular pattern 2 is intermittently divided into a plurality of portions and the vent holes 5 are formed at the respective divided portions, the pitch of the vent holes 5 is also λ / 2. A high frequency signal leaks outside the high frequency package 20 with a phase difference of λ / 2 from each vent hole. Since the high-frequency signals having a phase difference of λ / 2 cancel each other, leakage of the high-frequency signals can be reduced as a result.

Embodiment 2. FIG.
FIG. 4 is a cross-sectional view corresponding to FIG. 2 of the second embodiment of the high-frequency package according to the present invention. In the high-frequency package 30 according to the present embodiment, at the position facing the annular pattern 2 of the metal lid 3, the concave and convex portions 3a are formed at a pitch of λ / 2 so that the concave portions overlap the gap portions 2a corresponding to the gap portions 2a. Is formed. Since the top portion of the solder fillet is connected to the convex portion and has an appropriate shape, the vent hole 5 formed between the solder fillets also has an appropriate shape, and more accurately has a phase difference of λ / 2 from each vent hole. Since the high-frequency signal leaks in this state, the high-frequency signal is canceled more reliably, and the leakage of the high-frequency signal can be reduced.

  FIG. 5 is a cross-sectional view corresponding to FIG. 2 of a conventional high-frequency package shown for comparison. In the conventional high-frequency package 50, the conventional annular pattern 12 is formed with a gap 12a in which the pattern is divided at a predetermined position. For this reason, due to variations in the amount of solder applied, the solder fillet formed is reduced when the amount of solder in the vicinity of the gap 12a is reduced, and the vent hole 15 formed in this portion may be larger than expected. As a result, leakage of high-frequency signals increases, which has been a problem. According to the first and second embodiments, this problem can be solved as described above.

  As described above, the high-frequency package according to the present invention is useful when applied to a high-frequency package in which a substrate on which a high-frequency oscillation unit is mounted is sealed with a lid that is joined by solder. It is optimally applied to the non-hermetic type high frequency package to be formed.

DESCRIPTION OF SYMBOLS 1 Substrate 2 Ring pattern 2a Cavity 3 Metal lid (lid)
3a Concavity and convexity 4 Solder 5 Vent hole 20, 30 High frequency package

Claims (2)

A substrate on which a high-frequency oscillation unit for transmitting radio waves is mounted on a first surface;
An annular pattern formed on the first surface of the substrate so as to surround the high-frequency oscillating portion; and solder stacked on the annular pattern;
A lid that is bonded to the first surface of the substrate by the solder and covers the high-frequency oscillation unit, and the annular pattern is intermittently divided into a plurality of pieces to form a vent hole in the solder. The high frequency package is characterized in that the pitch of the gaps formed in each divided portion is λ / 2 with respect to the wavelength λ of the radio wave oscillated by the high frequency oscillation unit. The concave and convex portions are formed at a pitch of λ / 2 so that the concave portions overlap the gap portions 2a corresponding to the gap portions at positions facing the annular pattern of the lid. The high frequency package according to 1.

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