Tube socket

Abstract

The present invention provides a tube socket. The tube socket of the present invention comprises: a tube socket body, which has a first surface placed on a flexible substrate and a second surface on the opposite side of the first surface, and is formed with a through hole penetrating the first surface and the second surface; a cylindrical body, which is mounted on the through hole of the tube socket body; and a pin, which is inserted through the cylindrical body and fixed to the cylindrical body by a fixing material, and one end of which protrudes from the first surface of the tube socket body, and the cylindrical body has a protruding portion of the outer peripheral surface that protrudes toward the flexible substrate side compared to the first surface of the tube socket body and surrounds the end of the pin. The tube socket of the present invention can suppress the resonance between the tube socket and the flexible substrate on which the tube socket is placed.

Description

Technical Field

[0001] The invention relates to a tube seat. Background Art

[0002] Conventionally, a stem that carries a semiconductor element such as an optical element is placed on a flexible printed circuit (FPC) and electrically connected to the FPC. That is, the stem and the FPC are electrically connected by soldering a lead protruding from the bottom surface of the stem to a land of a via formed on the FPC.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2005-286305 Summary of the invention

[0004] In addition, the FPC on which the tube socket is placed is formed of a flexible material, so it may be deformed into a curved shape due to the tension of the circuit pattern or solder resist on the surface and back of the FPC. Therefore, if the pins of the tube socket are welded to the welding ring of the FPC, an uneven gap is formed between the tube socket and the FPC. When a gap is formed between the tube socket and the FPC, the high-frequency signal propagating on the outer peripheral surface of the pin leaks into the gap between the tube socket and the FPC. As a result, the high-frequency signal may resonate in the gap between the tube socket and the FPC. The resonance generated in the gap between the tube socket and the FPC will cause the high-frequency characteristics to deteriorate, so it is not ideal.

[0005] The technology disclosed in the present invention is proposed in view of the above-mentioned problems, and its object is to provide a stem that can suppress resonance generated in a gap between the stem and a flexible substrate on which the stem is placed.

[0006] The tube seat disclosed in the present application, in one embodiment, includes: a tube seat body, which has a first surface placed on the flexible substrate and a second surface on the opposite side of the above-mentioned first surface, and is formed with a through hole penetrating the above-mentioned first surface and the above-mentioned second surface; a cylindrical body, which is installed in the through hole of the above-mentioned tube seat body; and a pin, which is inserted into the above-mentioned cylindrical body and fixed to the above-mentioned cylindrical body by a fixing material, and one end of the pin protrudes from the above-mentioned first surface of the above-mentioned tube seat body, and the above-mentioned cylindrical body has a protruding portion that protrudes toward the above-mentioned flexible substrate side compared with the above-mentioned first surface of the above-mentioned tube seat body and surrounds the outer peripheral surface of the above-mentioned end of the above-mentioned pin.

[0007] According to one embodiment of the stem disclosed in the present application, it is possible to obtain an effect of suppressing resonance generated in a gap between the stem and the flexible substrate on which the stem is placed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a perspective view when the stem according to the embodiment is viewed from above.

[0009] Figure 2 It is a perspective view when the stem according to the embodiment is viewed from the bottom.

[0010] Figure 3 It is a figure which shows the state which mounted|worn with the stem which concerns on Example.

[0011] Figure 4 It is a front view showing the structure of the surface of the FPC opposite to the ground pattern.

[0012] Figure 5 It is a side cross-sectional view showing the structure of the connection portion between the stem and the FPC.

[0013] Figure 6 This is a diagram showing an example of a simulation model for simulating changes in the transmission characteristics of a high-frequency signal of a stem.

[0014] Figure 7 This is a diagram showing an example of a simulation model for simulating changes in the transmission characteristics of a high-frequency signal of a stem.

[0015] Figure 8 To indicate the use Figure 6 Graph showing the results of changes in the transmission characteristic S21 of high-frequency signals at different frequencies obtained by the simulation model shown.

[0016] Fig. 9 To indicate the use Figure 7 Graph showing the results of changes in the transmission characteristic S21 of high-frequency signals at different frequencies obtained by the simulation model shown.

[0017] Fig.10 To indicate the use Figure 6 1 is a diagram showing the results of changes in the reflection characteristic S11 of the high-frequency signal at each frequency obtained by the simulation model shown.

[0018] Fig.11 To indicate the use Figure 7 1 is a diagram showing the results of changes in the reflection characteristic S11 of the high-frequency signal at each frequency obtained by the simulation model shown.

[0019] Explanation of symbols

[0020] 1 socket; 10 socket body; 10a lower surface; 10b upper surface; 10c through hole; 20 cylindrical body; 21 protrusion; 25 fixing material; 26 air layer; 30 high-frequency signal pin; 31 lower end portion; 50 FPC; 51 ground pattern. DETAILED DESCRIPTION

[0021] Hereinafter, with reference to the accompanying drawings, an embodiment of the tube seat disclosed in the present application is described in detail. In addition, the disclosed technology is not limited to this embodiment. In addition, the same symbols are given to the structures having the same functions in the embodiments, and repeated descriptions are omitted.

[0022] The structure of the tube holder

[0023] Figure 1 It is a perspective view when the stem 1 according to the embodiment is viewed from the upper side. Figure 2 It is a perspective view when the stem 1 according to the embodiment is viewed from the bottom. Figure 3 FIG. 1 is a diagram showing a state where the stem 1 according to the embodiment is placed on the FPC 50. Figure 3 A side cross-sectional view of the stem 1 and the FPC 50 is shown. Figure 1 to Figure 3 The illustrated stem 1 is placed on an FPC 50 which is a flexible substrate and is electrically connected to the FPC 50. The stem 1 includes a stem body 10, a cylindrical body 20, high-frequency signal pins 30, various power supply pins 40, and a case ground pin 45.

[0024] The socket body 10 is formed of a metal material such as iron in consideration of heat dissipation and cost, and is a base for mounting various components constituting the socket 1. The socket body 10 is formed in a disk shape, and has a lower surface 10a placed on the FPC 50 and an upper surface 10b on the opposite side of the lower surface 10a. The upper surface 10b is a mounting surface for mounting semiconductor elements (not shown) such as optical elements. The socket body 10 is formed with a through hole 10c and a through hole 10d that penetrate the lower surface 10a and the upper surface 10b. In addition, a rising portion 11 is formed near the through hole 10c of the upper surface 10b. The side surface of the rising portion 11 located on the through hole 10c side is a mounting surface for mounting the substrate 13 through the spacer 12. The substrate 13 is electrically connected to the high-frequency signal pin 30 to transfer the electrical signal propagated from the high-frequency signal pin 30 to the semiconductor element mounted on the upper surface 10b.

[0025] The cylindrical body 20 is attached to the through hole 10c of the socket body 10. The cylindrical body 20 has, for example, an internal space into which the high-frequency signal pin 30 is inserted. As a material of the cylindrical body 20, for example, Kovar can be used.

[0026] The pin 30 for high-frequency signal is formed, for example, in a cylindrical shape and is used to transmit an electrical signal as a high-frequency signal. The pin 30 for high-frequency signal is inserted into the cylindrical body 20 and fixed to the cylindrical body 20 by a fixing material 25. The fixing material 25 covers and seals the outer peripheral surface of the pin 30 for high-frequency signal corresponding to the inner side surface of the cylindrical body 20. The fixing material 25 has a lower relative dielectric constant than the fixing material 15 used to fix various power supply pins 40 to the socket body 10. By using the fixing material 25 with a lower relative dielectric constant, the increase in the outer diameter of the fixing material 25 can be suppressed, thereby suppressing the increase in the inner diameter of the cylindrical body 20. As the fixing material 25, for example, hard glass can be used.

[0027] The lower end portion 31 of the high-frequency signal pin 30 protrudes from the lower surface 10a of the socket body 10. The lower end portion 31 penetrates a via hole 50a formed in the FPC 50 when the socket 1 is placed on the ground pattern 51 of the FPC 50.

[0028] Figure 4 1 is a front view showing the structure of the surface opposite to the ground pattern 51 of the FPC 50. Figure 3 As shown in FIG. 1 , a receiving solder ring 50b surrounding the via hole 50a is formed on the surface of the FPC 50 on the ground pattern 51 side. Figure 4 As shown in FIG. 1 , a connection solder ring 50c surrounding the via hole 50a is formed on the surface of the FPC 50 opposite to the ground pattern 51. In addition, a circuit pattern 50d for transmitting an electrical signal is formed on the surface of the FPC 50 opposite to the ground pattern 51, and the circuit pattern 50d is connected to the connection solder ring 50c around the via hole 50a. The lower end 31 of the high-frequency signal pin 30 that passes through the via hole 50a is soldered to the connection solder ring 50c of the via hole 50a. Thus, the stem 1 is electrically connected to the FPC 50.

[0029] Back to Figure 1 to Figure 3 The various power supply pins 40 are formed, for example, in a cylindrical shape, and are pins for monitoring or controlling the state of the semiconductor element mounted on the upper surface 10b of the socket body 10. The various power supply pins 40 are inserted through the through hole 10d of the socket body 10 and fixed to the through hole 10d by the fixing material 15. The fixing material 15 covers and seals the outer peripheral surface of the various power supply pins 40 corresponding to the through hole 10d. As the fixing material 15, for example, soft glass can be used, which is suitable for sealing iron.

[0030] The case grounding pin 45 is formed in, for example, a cylindrical shape, and is a pin for grounding the socket body 10. The case grounding pin 45 is joined to the lower surface 10a of the socket body 10 by, for example, welding.

[0031] Connection between the socket and FPC

[0032] Next, refer to Figure 5 , the connection portion between the stem 1 and the FPC 50 is described in detail. Figure 5 1 is a side cross-sectional view showing the structure of the connection portion between the tube seat 1 and the FPC 50. As described above, the tube seat 1 is configured so that the cylindrical body 20 can be mounted in the through hole 10c of the tube seat body 10. The high-frequency signal pin 30 is fixed in the cylindrical body 20 by the fixing material 25, and the lower end portion 31 of the high-frequency signal pin 30 protrudes from the lower surface 10a of the tube seat body 10 and is welded to the connection welding ring 50c of the through hole 50a of the FPC 50.

[0033] The cylindrical body 20 has a protrusion 21 that protrudes toward the FPC 50 side by a predetermined length compared to the lower surface 10a of the socket body 10. The protrusion 21 surrounds the outer peripheral surface of the lower end 31 of the high-frequency signal pin 30. The protrusion 21 is placed on the ground pattern 51 of the FPC 50 (see Figure 3 ) state, it is joined to the ground pattern 51 of the FPC 50. A flange portion 21a protruding toward the radially outer side of the cylindrical body 20 is formed on the outer side surface of the protrusion 21. When the protrusion 21 is joined to the ground pattern 51 of the FPC 50, the flange portion 21a of the protrusion 21 is welded to the ground pattern 51 of the FPC 50. As a result, the protrusion 21 and the ground pattern 51 of the FPC 50 are more firmly joined.

[0034] In addition, the cylindrical body 20 has an air layer 26 not filled with a fixing material 25 between the protrusion 21 and the outer peripheral surface of the lower end 31 of the high-frequency signal pin 30. That is, a coaxial line (hereinafter referred to as "air coaxial line") formed by covering the lower end 31 of the high-frequency signal pin 30 with the air layer 26 is formed on the protrusion 21 of the cylindrical body 20. The connection welding ring 50c of the FPC50 used for welding the lower end 31 of the high-frequency signal pin 30 is usually wider than the circuit pattern 50d of the FPC50, so that the characteristic impedance related to the FPC50 is partially reduced. In contrast, when the protrusion 21 of the cylindrical body 20 is formed with an air coaxial line, the characteristic impedance above the connection welding ring 50c of the FPC50 can be increased by the air coaxial line. That is, the air layer 26 can compensate for the reduction of the characteristic impedance generated by the connection welding ring 50c of the FPC50.

[0035] In addition, the FPC 50 on which the stem 1 is placed is formed of a flexible material, and therefore may be deformed into a curved shape due to the tension of the circuit pattern or solder resist on the surface and back of the FPC 50. Therefore, if the lower end 31 of the high-frequency signal pin 30 of the stem 1 is welded to the connecting welding ring 50c of the via 50a of the FPC 50, an uneven gap is formed between the stem 1 and the FPC 50. When a gap is formed between the stem 1 and the FPC 50, a high-frequency signal (i.e., an electrical signal) propagating on the outer peripheral surface of the high-frequency signal pin 30 leaks into the gap between the stem 1 and the FPC 50. As a result, resonance of the high-frequency signal may occur in the gap between the stem 1 and the FPC 50.

[0036] Therefore, if Figure 5 As shown, in the stem 1 of the present embodiment, the cylindrical body 20 to which the high-frequency signal pin 30 is fixed is installed in the through hole 10c of the stem body 10, and the protrusion 21 surrounding the outer peripheral surface of the lower end portion 31 of the high-frequency signal pin 30 is formed on the cylindrical body 20. As a result, when the stem 1 is placed on the ground pattern 51 of the FPC 50, the protrusion 21 can be joined to the ground pattern 51 of the FPC 50. Therefore, the gap of width g1 between the stem 1 and the FPC 50 and the outer peripheral surface of the lower end portion 31 of the high-frequency signal pin 30 are blocked by the protrusion 21 of the cylindrical body 20, so that the high-frequency signal propagating on the outer peripheral surface of the high-frequency signal pin 30 can be prevented from leaking to the gap of width g1 between the stem 1 and the FPC 50. As a result, the resonance generated in the gap of width g1 between the stem 1 and the FPC 50 can be suppressed.

[0037] Simulation of changes in high-frequency signal transmission characteristics caused by protrusions

[0038] Here, a description will be given of changes in the transmission characteristics (transmission characteristics S21 and reflection characteristics S11 ) of high-frequency signals of stem 1 caused by forming protrusion 21 on cylindrical body 20 . Figure 6 and Figure 7 FIG. 1 is a diagram showing an example of a simulation model for simulating changes in the transmission characteristics of a high-frequency signal of the stem 1. Figure 6 and Figure 7 As shown, the stem body 10 of the stem 1 is formed with a through hole 10c, and a cylindrical body 20 is installed in the through hole 10c. A high-frequency signal pin 30 is fixed to the cylindrical body 20 by a fixing material 25, and a lower end portion 31 of the high-frequency signal pin 30 protrudes downward from the lower surface 10a of the stem body 10 and is connected to a connecting solder ring 50c of a via hole 50a of the FPC 50 by solder S. In addition, the width g2 of the gap between the stem 1 and the FPC 50 changes due to the warping or deformation of the FPC 50. Figure 6 The state in which the cylindrical body 20 does not have the protrusion 21 is shown. Figure 721. Figure 7 In the simulation model shown, when the length of the protrusion 21 changes, the width g3 of the gap between the stem 1 and the FPC 50 also changes.

[0039] Figure 8 To indicate the use Figure 6 Graph showing the results of changes in the transmission characteristic S21 of high-frequency signals at different frequencies obtained by the simulation model shown. Fig. 9 To indicate the use Figure 7 The results of the changes in the transmission characteristics S21 of the high-frequency signal at each frequency obtained by the simulation model shown in FIG. Figure 8 represents the change of the transmission characteristic S21 when the cylindrical body 20 does not have the protrusion 21, Fig. 9 FIG. 2 shows a change in the transmission characteristic S21 when the cylindrical body 20 has the protrusion 21 . Figure 8 and Fig. 9 , respectively, for different widths g2 and g3 of the gap between the stem 1 and the FPC 50, the change in the transmission characteristic S21 with respect to the frequency of the high-frequency signal. Figure 8 As shown, when the cylindrical body 20 does not have the protrusion 21, the higher the frequency of the high-frequency signal, the greater the change in the transmission characteristic S21. That is, it can be confirmed that when the cylindrical body 20 does not have the protrusion 21, resonance occurs in the gap between the stem 1 and the FPC 50.

[0040] On the other hand, when the cylindrical body 20 has the protrusion 21, the leakage of the high-frequency signal from the outer peripheral surface of the high-frequency signal pin 30 can be suppressed by the protrusion 21. Fig. 9 As shown, the transmission characteristic S21 does not deteriorate significantly around 17 GHz and in the frequency band of 36 to 50 GHz. That is, it can be confirmed that when the cylindrical body 20 has the protrusion 21, the resonance generated in the gap between the stem 1 and the FPC 50 can be suppressed.

[0041] Fig.10 To indicate the use Figure 6 1 is a diagram showing the results of changes in the reflection characteristic S11 of the high-frequency signal at each frequency obtained by the simulation model shown. Fig.11 To indicate the use Figure 7 The graph is a graph showing the result of the change of the reflection characteristic S11 of the high-frequency signal at each frequency obtained by the simulation model shown. That is, Fig.10 2 shows the change of the reflection characteristic S11 when the cylindrical body 20 does not have the protrusion 21. Fig.11 FIG. 2 shows a change in the reflection characteristic S11 when the cylindrical body 20 has the protrusion 21 . Fig.10 and Fig.111 and 2 show the change of the reflection characteristic S11 with respect to the frequency of the high-frequency signal for different widths g2 and g3 of the gap between the tube seat 1 and the FPC 50. When the cylindrical body 20 does not have the protrusion 21, resonance occurs in the gap between the tube seat 1 and the FPC 50. Fig.10 As shown, the reflection characteristic S11 increases as the frequency of the high-frequency signal increases.

[0042] On the other hand, when the cylindrical body 20 has the protrusion 21, it is possible to suppress the resonance generated in the gap between the stem 1 and the FPC 50. Fig.11 As shown, the increase in the reflection characteristic S11 can be suppressed.

[0043] In summary, the stem 1 involved in this embodiment has a stem body 10, a cylindrical body 20, and a pin 30 for high-frequency signals. The stem body 10 has a lower surface 10a placed on the FPC 50 and an upper surface 10b on the opposite side of the lower surface 10a, and is formed with a through hole 10c that penetrates the lower surface 10a and the upper surface 10b. The cylindrical body 20 is mounted on the through hole 10c of the stem body 10. The pin 30 for high-frequency signals is inserted through the cylindrical body 20 and fixed to the cylindrical body 20 by a fixing material 25, and its lower end 31 protrudes from the lower surface 10a of the stem body 10. The cylindrical body 20 protrudes toward the FPC 50 side compared to the lower surface 10a of the stem body 10, and has a protruding portion 21 surrounding the outer peripheral surface of the lower end 31 of the pin 30 for high-frequency signals. As a result, it is possible to suppress the resonance generated in the gap between the stem 1 and the FPC 50 on which the stem 1 is placed, thereby improving the transmission characteristics.

[0044] Furthermore, in the stem 1 according to the present embodiment, the protrusion 21 is bonded to the ground pattern 51 of the FPC 50. Therefore, the protrusion 21 of the ground potential can suppress leakage of high-frequency signals from the outer peripheral surface of the high-frequency signal pin 30, and as a result, the resonance generated in the gap between the stem 1 and the FPC 50 can be suppressed more stably.

[0045] In the stem 1 according to the present embodiment, the cylindrical body 20 has an air layer 26 not filled with the fixing material 25 between the protrusion 21 and the outer peripheral surface of the lower end portion 31 of the high-frequency signal pin 30. Therefore, the air layer 26 can compensate for the decrease in characteristic impedance generated in the connection solder ring 50c of the FPC 50.

Claims

1. A tube socket, characterized in that: include: A socket body having a first surface placed on the flexible substrate and a second surface opposite to the first surface, and having a through hole penetrating the first surface and the second surface; a cylindrical body mounted in the through hole of the tube seat body; and a pin inserted through the cylindrical body and fixed to the cylindrical body by a fixing material, one end of which protrudes from the first surface of the socket body, The cylindrical body has a protruding portion that protrudes toward the flexible substrate side from the first surface of the socket body and surrounds the outer peripheral surface of the end portion of the lead. The protrusion is joined to a ground pattern of the flexible substrate, A flange portion protruding outward is formed on the side surface of the protruding portion. The flange portion is joined to a ground pattern of the flexible substrate.

2. The tube base according to claim 1, characterized in that: The cylindrical body has an air layer not filled with the fixing material between the protruding portion and the outer peripheral surface of the end portion of the pin.

3. The tube base according to claim 1 or 2, characterized in that: The pin is used to transmit high-frequency signals. The fixing material has a lower relative dielectric constant than other fixing materials used to fix other pins other than the pin.

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