Cable assembly and method for manufacturing cable assembly

Abstract

The present invention provides a cable assembly disposed between a first connector disposed at a position near an ASIC (Application Specific Integrated Circuit) on a substrate, and a second connector disposed at a position far away from the control device on the substrate, the first connector being disposed at a position near the ASIC on the substrate, and the second connector being disposed at a position far away from the control device on the substrate. The cable assembly is provided with: a cable array in which a plurality of twin-axis cables for transmitting differential signals are arranged side by side; and a blade card substrate provided with a signal electrode for electrically connecting the inner conductors of the plurality of twin-axis cables, and a ground electrode for electrically connecting the outer conductors of the plurality of twin-axis cables. And a hot melt material configured to cover at least the solder joint portion of the front end of the exposed portion of the inner conductor and the exposed portion of the inner conductor on the blade card substrate. According to the present invention, the occurrence of crosstalk can be prevented when high-speed signal transmission is performed between devices disposed at separate positions on a substrate.

Description

Technical Field

[0001] The present invention relates to high-speed signal transmission between an ASIC (application specific integrated circuit) and an optical transceiver, and in particular to a cable assembly and a high-speed transmission device formed by combining the cable assembly. Background Art

[0002] As documents related to this technology, there are Patent Documents 1 and 2. The high-speed interconnect cable assembly disclosed in Patent Document 1 is configured by configuring a twin-ax type bypass cable between an ASIC on a circuit substrate and a terminal component on its peripheral portion, connecting a connector component to the terminal component, and transmitting a signal to an external device via the connector component. The electrical device disclosed in Patent Document 2 is configured by setting the bypass cable on the circuit substrate as a communication cable, the communication cable including a differential pair of signal conductors, a shielding layer surrounding the signal conductors, and a cable sheath surrounding the shielding layer, and providing an access opening portion in the cable sheath of the communication cable to expose a portion of the shielding layer, so that the access opening portion is electrically connected to a ground contact on the substrate.

[0003] The signal transmission characteristics of this circuit board depend on the signal frequency and the signal transmission distance. The higher the signal frequency, the shorter the transmission distance. The reference values ​​of the transmission and reception signal speed and transmission distance in the case of signal transmission in the board are 50cm for 50Gbps, 25cm for 100Gbps, and 12.5cm for 200Gbps.

[0004] Prior art literature Patent Literature Patent Document 1: U.S. Patent Publication No. 9011177B2 Patent Document 2: U.S. Patent Publication No. 9203193B2 Summary of the invention Problems to be solved by the invention However, the inventors of this application have attempted to develop a technology for high-speed signal transmission of 112 Gbps or more between ASIC and optical transceiver. However, the technologies of Patent Documents 1 and 2 only use cables to connect the ASIC on the substrate to the device far away from it. Therefore, if high-speed signal transmission of 112 Gbps or more is performed, the generation of crosstalk can only be fully prevented unless the distance between the devices is brought close to about 25 cm. In addition, there are problems such as difficulty in adjusting impedance and inappropriate electrical characteristics.

[0005] The present invention has been made in view of such a problem, and an object of the present invention is to provide a technical means for suppressing the occurrence of crosstalk when high-speed signal transmission is performed between devices arranged at separate positions on a substrate, and for easily adjusting impedance and obtaining good electrical characteristics.

[0006] Means for solving problems As a preferred embodiment of the present invention, a cable assembly is arranged between a first connector and a second connector, the first connector is arranged at a position near a control device in a substrate, and the second connector is arranged at a position in the substrate away from the control device. The cable assembly is characterized in that it comprises: a cable array, the cable array is formed by arranging a plurality of cables that respectively transmit differential signals side by side; a paddle card substrate, the paddle card substrate is provided with a signal electrode for electrically connecting the internal conductors of the plurality of cables and a grounding electrode for electrically connecting the external conductors of the plurality of cables; and a hot-melt material, the hot-melt material is arranged to cover at least the welding joint at the front end of the exposed portion of the internal conductor and the exposed portion of the internal conductor on the paddle card substrate.

[0007] In this aspect, the thickness of the hot melt material at the solder joint portion at the tip of the exposed portion of the inner conductor may be thinner than the thickness of the hot melt material disposed at the exposed portion of the inner conductor.

[0008] Furthermore, a ground cover covering the internal conductor on the paddle card substrate may be provided, and the hot melt material may be arranged to cover at least an exposed portion of the internal conductor inside the ground cover on the paddle card substrate.

[0009] Furthermore, a ground cover covering the internal conductor on the paddle card substrate may be provided, and the hot melt material may be arranged on the paddle card substrate to cover at least the ground cover and at least the exposed portion of the internal conductor inside the ground cover.

[0010] In addition, it may also be that there is a grounding cover covering the above-mentioned internal conductor on the above-mentioned paddle card substrate, and the grounding cover is arranged in each channel and is staggered on the front and back sides of the above-mentioned paddle card substrate, and the above-mentioned hot-melt material is arranged to cover at least the exposed portion of the above-mentioned internal conductor on the inner side of the above-mentioned grounding cover on the above-mentioned paddle card substrate.

[0011] Furthermore, the hot melt material may be arranged on the paddle card substrate to cover at least the ground cover and at least an exposed portion of the internal conductor inside the ground cover.

[0012] As another preferred embodiment of the present invention, a cable assembly is arranged between a first connector and a second connector, wherein the first connector is arranged near a control device in a substrate, and the second connector is arranged in a position in the substrate away from the control device. The cable assembly is characterized in that it comprises: a cable array, wherein the cable array is formed by arranging a plurality of cables that transmit differential signals respectively; a paddle card substrate, wherein the paddle card substrate is provided with a signal electrode for electrically connecting the internal conductors of the plurality of cables and a grounding electrode for electrically connecting the external conductors of the plurality of cables; a plastic component, wherein the plastic component is arranged on the paddle card substrate and comprises an outer frame portion, and a plurality of inner frame portions that are arranged side by side with a small gap at an inner edge of the outer frame portion; a grounding shield, wherein the grounding shield is arranged to cover a part or all of the plurality of inner frame portions; and a packaging material, wherein the packaging material is arranged to cover at least the exposed portion of the internal conductor in the inner frame portion.

[0013] In this aspect, the ground shields may be arranged for each channel and arranged alternately on the front and back surfaces of the paddle card substrate.

[0014] As another preferred embodiment of the present invention, a cable assembly is arranged between a first connector and a second connector, wherein the first connector is arranged at a position near a control device in a substrate, and the second connector is arranged at a position in the substrate away from the control device. The cable assembly is characterized in that it comprises: a cable array formed by arranging a plurality of cables that transmit differential signals respectively in parallel; and a paddle card substrate, wherein the paddle card substrate has a signal electrode for electrically connecting the internal conductors of the plurality of cables, and a grounding electrode arranged at a position for installing an external conductor of the cable and at a position connected to a contact portion that contacts the first connector on both sides of the signal electrode, and the grounding electrode for installing the external conductor of the cable is arranged at a position on the substrate that is thinner than the thickness of the substrate where the signal electrode is located.

[0015] In this embodiment, the grounding electrode may include a cable-side contact portion that contacts the cable and a connector-side contact portion that contacts the first connector, and the cable-side contact portion and the connector-side contact portion may be connected via inner layer wiring of the paddle card substrate.

[0016] Furthermore, a solder joint portion disposed on the paddle card substrate so as to cover at least the front end of the exposed portion of the internal conductor and a hot melt material of the exposed portion of the internal conductor may be provided.

[0017] In addition, it may also be provided with: a hot-melt material, the hot-melt material being configured to cover at least the front end welding joint of the exposed portion of the internal conductor and the exposed portion of the internal conductor on the paddle card substrate; and a grounding cover, the grounding cover covers the internal conductor on the paddle card substrate and is configured for each channel, and is staggered on the front and back sides of the paddle card substrate.

[0018] Furthermore, the grounding electrode disposed at a position connected to a contact portion that contacts the first connector on both sides of the signal electrode may include a grounding cover disposed so as to cover the internal conductor.

[0019] Furthermore, a ground shield may be provided, the ground shield covering the internal conductor on the paddle card substrate and arranged for each channel and arranged alternately on the front and back surfaces of the paddle card substrate.

[0020] As another preferred embodiment of the present invention, a method for manufacturing a cable assembly is characterized in that a front end of an exposed portion of an internal conductor is welded on a paddle card substrate, a plastic component having an outer frame portion and a plurality of inner frame portions arranged side by side with a small gap at an inner edge of the outer frame portion is installed on the paddle card substrate, a grounding cover having a crimping terminal is configured to cover a part or all of the plurality of inner frame portions and is inserted into a hole installed on the paddle card substrate, and a packaging material is injected into the inner frame portion in a manner to cover the exposed portion of the internal conductor, and then cured.

[0021] Effects of the invention The cable assembly of the present invention is arranged between a first connector and a second connector, the first connector is arranged at a position near a control device in a substrate, and the second connector is arranged at a position in the substrate away from the control device, and the cable assembly comprises: a cable array formed by arranging a plurality of cables that transmit differential signals, respectively; a paddle card substrate, the paddle card substrate being provided with a signal electrode for electrically connecting the internal conductors of the plurality of cables and a ground electrode for electrically connecting the external conductors of the plurality of cables; and a hot melt material, the hot melt material being arranged to cover at least the welding joint at the front end of the exposed portion of the internal conductor and the exposed portion of the internal conductor on the paddle card substrate. Therefore, when high-speed signal transmission is performed between devices arranged at separate positions on the substrate, an increase in impedance can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a side view of the high-speed transmission device 1 including the ASIC 10 , the first connector 30 , the cable assembly 40 , and the second connector 80 according to the first embodiment of the present invention.

[0023] Figure 2 It is a perspective view of a cable assembly 40 as a first embodiment of the present invention.

[0024] Figure 3 This is a perspective view of the cable assembly 40 after the hot melt material 440 is removed.

[0025] Figure 4 Observed from the direction of arrow J Figure 2 The obtained picture.

[0026] Figure 5 4 is a diagram showing the impedance waveform of the cable assembly 40 and the impedance waveform after the hot melt material 440 is removed from the cable assembly 40 .

[0027] Figure 6 It is a figure which shows the cable assembly 40A which is the 2nd Embodiment of this invention.

[0028] Figure 7 Observed from the direction of arrow J Figure 6 The obtained picture.

[0029] Figure 8 It is a figure which shows the cable assembly 40B which is the 3rd Embodiment of this invention.

[0030] Fig. 9 Observed from the direction of arrow J Figure 8 The obtained picture.

[0031] Fig.10 This is a diagram after the hot melt material 440B is removed from the cable assembly 40B.

[0032] Fig.11 yes Fig.10 Exploded diagram of .

[0033] Fig.12 Observed from the direction of arrow H Fig.10 The obtained picture.

[0034] Fig.13 It is a figure which shows the cable assembly 40C which is 4th Embodiment of this invention.

[0035] Fig.14 yes Fig.13 Exploded diagram of .

[0036] Fig.15 Observed from the direction of arrow J Fig.13 The obtained picture.

[0037] Fig.16 Observed from the direction of arrow H Fig.13 The obtained picture.

[0038] Fig.17 yes Fig.15 A partial cross-sectional view of .

[0039] Fig.18 This is a diagram showing a first stage of the manufacturing process of the cable assembly 40C.

[0040] Fig.19 This is a diagram showing the second stage of the manufacturing process of the cable assembly 40C.

[0041] Fig. 20 This is a diagram showing a third stage of the manufacturing process of the cable assembly 40C.

[0042] Fig.21 This is a diagram showing a fourth stage of the manufacturing process of the cable assembly 40C.

[0043] Fig. 22 It means in Fig. 20 FIG. 4 is a diagram comparing FEXT when the ground cover 240 is brought into close contact with the ground electrode 5 of the paddle card substrate 41 at the stage of 0.05 mm and when the ground cover 240 is lifted up by 0.05 mm.

[0044] Fig.23 4 is a diagram showing the impedance waveform of the cable assembly 40C and the impedance waveform after removing the sealing material 541 from the cable assembly 40C.

[0045] Fig.24 It is a top view of the paddle card base plate 41 according to the fifth embodiment of the present invention.

[0046] Fig.25 is from Fig.24 This is a cross-sectional view of the fifth embodiment as viewed along line AA'. DETAILED DESCRIPTION

[0047] <First embodiment> A high-speed transmission device 1 including a cable assembly 40, a first connector 30, and a second connector 80 as a first embodiment of the present invention is described. The high-speed transmission device 1 is mounted on a network switch or a server. The high-speed transmission device 1 includes a rectangular substrate 20, an ASIC 10 and an optical transceiver 90 disposed at a position separated by a predetermined distance (for example, 25 cm) on the substrate 20, a first connector 30 disposed between the ASIC 10 and the optical transceiver 90, a cable assembly 40, and a second connector 80, and a shell 95 covering the optical transceiver 90 and the second connector 80. The optical transceiver 90 is mounted on the second connector 80, and performs high-speed differential transmission of 112 Gbps or more based on PAM (Pulse Amplitude Modulation) with the ASIC 10. In this embodiment, 16 channels of differential signals can be transmitted between the ASIC 10 and the optical transceiver 90.

[0048] In the following description, the direction in which the ASIC 10 and the optical transceiver 90 on the substrate 20 are separated is appropriately referred to as the X direction, a direction orthogonal to the X direction is appropriately referred to as the Y direction, and a direction orthogonal to both the X direction and the Y direction is appropriately referred to as the Z direction. In addition, the side in the X direction where the ASIC 10 exists as viewed from the optical transceiver 90, that is, the -X side, is often referred to as the front side, and the +X side opposite thereto is often referred to as the rear side. In addition, the side in the Z direction where the ASIC 10 and the optical transceiver 90 exist as viewed from the substrate 20, that is, the +Z side, is often referred to as the upper side, and the -Z side opposite thereto is often referred to as the lower side. In addition, the +Y side is often referred to as the left side as viewed from the rear side in the X direction, and the -Y side is often referred to as the right side as viewed from the rear side.

[0049] exist Figure 1 In the embodiment, each pair of + and - terminals of differential signals corresponding to one channel and a ground terminal are exposed on the bottom surface of the ASIC 10. Each pair of + and - terminals and a ground terminal of the ASIC 10 are soldered to pads (not shown) of the substrate 20.

[0050] The first connector 30 is disposed near the rear side of the ASIC 10 on the substrate 20. The distance between the ASIC 10 and the first connector 30 is, for example, 5 cm.

[0051] The first connector 30 has a substantially rectangular parallelepiped insulator provided with a socket 35 penetrating the top and the bottom, and 25 fine grooves are provided on the front and rear wall surfaces in the socket 35, and contact pins are press-fitted into the 25 fine grooves.

[0052] Here, the contact pins at the left and right ends and the contact pins arranged every three between the 25 contact pins pressed into the front and rear walls of the socket 35 of the first connector 30 are grounding contact pins, and the contact pins sandwiched between the grounding contact pins are differential signaling contact pins. Hereinafter, the grounding contact pins are marked with a letter (G), and the differential signaling contact pins are marked with a letter (S) to distinguish between the two.

[0053] exist Figure 1 In the example, wiring is laid on the substrate 20 from fixed positions of the + and − terminals of the differential signal and the ground terminal of the ASIC 10 in the substrate 20 toward the rear, and the wiring is connected to the substrate-side contact portions of the contact pins (G) and (S) of the first connector 30 .

[0054] The second connector 80 has a socket 85 penetrating the front and rear of an insulator having a shape obtained by cutting off a corner of a rectangular parallelepiped, 25 fine grooves are provided on the upper and lower walls of the socket 85, and contact pins (G) and (S) are press-fitted into the 25 fine grooves.

[0055] The contact pins (G) and (S) of the second connector 80 are connected to the rear end of the outer conductor 23 and the rear end of the inner conductor 21 of the twinax cable 2 respectively via the ground electrode and the signal electrode on the connector substrate. The plug of the optical transceiver 90 is fitted into the openings on one side and the opposite side of the twinax cable 2 in the second connector 80, and the electrodes of the plug of the optical transceiver 90 are electrically connected to the contact pins (G) and (S) of the second connector 80.

[0056] like Figure 2 , Figure 3 as well as Figure 4 As shown, the cable assembly 40 includes a cable row 42 in which eight twinax cables 2 are arranged side by side, a paddle card substrate 41 , and a hot melt material 440 .

[0057] The twinax cable 2 includes two inner conductors 21 , a dielectric 22 , an outer conductor 23 , and a sheath 24 . The two inner conductors 21 are arranged in parallel and each inner conductor 21 is covered by a dielectric 22 . The outer conductor 23 covers the periphery of the structure in which the two dielectrics 22 are bound together, and the sheath 24 covers the outer conductor 23 .

[0058] The paddle card substrate 41 has a rectangular plate shape having substantially the same width and thickness as the socket 35 of the first connector 30. The signal electrodes 4 and the ground electrode 5 are provided on the front and rear surface layers 410 of the paddle card substrate 41.

[0059] like Figure 3 As shown, for each of the 16 signal electrodes 4 in the front and rear surface layers 410, two electrodes form a pair. There are grounding electrodes 5 at positions connected to the contact portions that contact the first connector 30 on both sides of the signal electrodes 4 in the surface layer 410. The base of the grounding electrode 5 occupies substantially the entire surface of the upper side of the signal electrode 4 in the surface layer 410, and the two first extension portions 55 at the left and right ends and the seven second extension portions 56 therebetween extend downward from the base. On the inner side of the surface layer 410 sandwiched by the left and right first extension portions 55, the pairs of signal electrodes 4 and the second extension portions 56 are alternately arranged side by side with intervals therebetween.

[0060] The lower ends of the first extension portion 55 and the second extension portion 56 reach below the lower end of the signal electrode 4. The left-right widths of the first extension portion 55 and the second extension portion 56 become narrower halfway to the lower ends.

[0061] like Figure 2As shown, the hot-melt material 440 has a shape obtained by cutting off one corner of a rectangular parallelepiped, and the rectangular parallelepiped has a left-right width substantially the same as that of the paddle card substrate 41, and a top-bottom width slightly larger than the exposed portion of the inner conductor 21 of the twinax cable 2 on the surface layer 410 thereof. The cut portion of the hot-melt material 440 forms a step portion 411. The hot-melt material 440 contacts and covers the exposed portion of the inner conductor 21 of the signal electrode 4 and the solder joint portion 29 at the front end thereof on the surface layer 410. The hot-melt material 440 is formed by pouring a thermoplastic polymer into a mold disposed on the surface layer 410 of the paddle card substrate 41, cooling and solidifying it, and then removing the mold.

[0062] like Figure 4 As shown, the thickness of the step portion 411 of the hot melt material 440 is thinner than the thickness of the upper portion thereof. The upper thick portion of the step portion 411 of the hot melt material 440 is arranged at the exposed portion of the internal conductor 21 in the paddle card substrate 41, and the step portion 411 is arranged at the solder joint portion 29 at the front end of the exposed portion of the internal conductor 21.

[0063] When the paddle card substrate 41 is inserted into the socket 35 of the first connector 30 , the contact pins of the first connector 30 come into contact with the ground electrode 5 and the signal electrode 4 on the connector side.

[0064] The above is the details of the structure of this embodiment. The cable assembly 40 of this embodiment is arranged between the first connector 30 and the second connector 80. The first connector 30 is arranged near the control device, that is, the ASIC 10 in the substrate 20, and the second connector 80 is arranged in the substrate 20 away from the control device. The cable assembly 40 has: a cable array 42, which is formed by arranging a plurality of twinax cables 2 that transmit differential signals in parallel; a paddle card substrate 41, which is provided with a signal electrode 4 for electrically connecting the inner conductors 21 of the plurality of twinax cables 2 and a grounding electrode 5 for electrically connecting the outer conductors 23 of the plurality of twinax cables 2; and a hot melt material 440, which is arranged to cover at least the welding joint 29 at the front end of the exposed portion of the inner conductor 21 and the exposed portion of the inner conductor 21 on the paddle card substrate 41. Therefore, when high-speed signal transmission is performed between the ASIC 10 and the optical transceiver 90 disposed at separate positions on the substrate 20, the impedance increase can be suppressed. Generally, the impedance of the air layer region around the solder joint 29 and the exposed portion of the internal conductor 21 increases, but the structure of this embodiment can suppress the impedance increase, so that better signal transmission characteristics can be achieved.

[0065] Here, the inventors of the present application performed the following verification to confirm the effect of the present invention. The inventors of the present application used a TDR simulator to calculate the TDR waveforms of the cable assembly 40 as the DUT and the TDR waveforms of the structure in which the hot melt material 440 was removed from the cable assembly 40 as the DUT. Figure 5 2 is a diagram showing the simulation results. Figure 5 The solid line is the TDR waveform of the cable assembly 40, and the dotted line is the TDR waveform of the structure in which the hot melt material 440 is removed from the cable assembly 40. In this waveform, the interval E1 corresponds to the propagation time of the signal of the substrate 20, the interval E2 corresponds to the propagation time of the signal of the first connector 30, the interval E3 corresponds to the propagation time of the signal of the welding joint 29, the interval E4 corresponds to the propagation time of the signal of the exposed portion of the internal conductor 21 of the twinax cable 2, and the interval E5 corresponds to the propagation time of the signal in the twinax cable 2.

[0066] If you refer to Figure 5 , in the TDR waveform of the structure in which the hot melt material 440 is removed from the cable assembly 40, the peak impedance in the interval E3 is 97Ω, and the peak impedance in the interval E4 is as high as 128Ω. In contrast, in the TDR waveform of the cable assembly 40, the impedance in the interval E3 is 87Ω, and the peak impedance in the interval E4 is as low as 108Ω. Figure 2 , Figure 4 As shown, in the cable assembly 40, the exposed portion of the inner conductor 21 of the twinax cable 2 and the welded joint 29 at the front end thereof are completely covered by the hot melt material 440, which is considered to contribute to reducing the peak impedance in the sections E3 and E4. In addition, by making the thickness of the step portion 411 of the hot melt material 440 disposed at the welded joint 29 thinner than the thickness of the portion above it, a significant reduction in the impedance in the section E3 is prevented.

[0067] <Second embodiment> Next, a second embodiment of the present invention will be described. Figure 6 It is a figure which shows the cable assembly 40A which is the 2nd Embodiment of this invention. Figure 7 Observed from the direction of arrow J Figure 6 In these drawings, the same elements as those of the first embodiment are denoted by the same reference numerals, and repeated description thereof is omitted.

[0068] In this embodiment, the hot melt material 440 of the first embodiment is replaced with a hot melt material 440A. The hot melt material 440A has a rectangular parallelepiped shape: it has a left-right width substantially the same as that of the paddle card substrate 41, and a top-bottom width slightly larger than the exposed portion of the inner conductor 21 of the twinax cable 2 on its surface layer 410. The hot melt material 440A contacts and covers the first extension portion 55 and the second extension portion 56 of the grounding electrode 5 on the surface layer 410, the welding joint 29, the inner conductor 21, the dielectric 22, and the outer conductor 23. The hot melt material 440A is formed by pouring a thermoplastic polymer into a mold disposed on the surface layer 410 of the paddle card substrate 41, cooling and solidifying it, and then removing the mold.

[0069] According to this embodiment, when the hot melt material 440A is removed, if the impedance of the solder joint 29 and the exposed portion of the internal conductor 21 are about the same, the same effects as those of the first embodiment can be obtained.

[0070] <Third embodiment> Next, a third embodiment of the present invention will be described. Figure 8 It is a figure which shows the cable assembly 40B which is the 3rd Embodiment of this invention. Fig. 9 Observed from the direction of arrow J Figure 8 The obtained picture. Fig.10 This is a diagram after the hot melt material 440B is removed from the cable assembly 40B. Fig.11 yes Fig.10 Exploded diagram of . Fig.12 Observed from the direction of arrow H Fig.10 In these drawings, the same elements as those of the first and second embodiments are denoted by the same reference numerals, and repeated descriptions thereof are omitted.

[0071] In this embodiment, the hot melt material 440 in the first embodiment is replaced with a hot melt material 440B and a ground cover 240 .

[0072] The grounding cover 240 is formed by bending a metal plate having a rectangular opening 245 with portions on both sides of the opening 245 as ridges. A crimping terminal 246 is provided at an end side of the bent front end of the grounding cover 240.

[0073] like Fig.12As shown, the ground shield 240 is arranged for each channel and is arranged alternately on the front and back surfaces of the blade card substrate 41. There are four ground shields 240 on the -X side and the +X side of the blade card substrate 41. The four ground shields 240 on the -X side cover the pairs of the inner conductors 21 and the solder joints 29 in the twinax cables 2 of the first, third, fifth, and seventh channels from the end of the -Y side of the -X side, and are fixed to the surface layer 410 on the -X side. The four ground shields 240 on the +X side cover the pairs of the inner conductors 21 and the solder joints 29 in the twinax cables 2 of the second, fourth, sixth, and eighth channels from the end of the -Y side of the +X side, and are fixed to the surface layer 410 on the +X side. The crimping terminals 246 of the ground shields 240 are inserted into the holes of the extensions 55 and 56 of the grounding electrode 5.

[0074] The hot melt material 440B contacts and covers the first extension portion 55 and the second extension portion 56 of the grounding electrode 5 on the surface layer 410, the welded joint portion 29, the exposed portion of the inner conductor 21 inside the grounding cover 240, the dielectric 22, the outer conductor 23, and the grounding cover 240. The hot melt material 440B is formed by pouring a thermoplastic polymer into a mold arranged on the surface layer 410 of the paddle card substrate 41, cooling and solidifying it, and then removing the mold.

[0075] The above is the details of the configuration of this embodiment. According to this embodiment, the same effects as those of the first and second embodiments can be obtained. In addition, the occurrence of crosstalk can be prevented, and good electrical characteristics can be ensured.

[0076] <Fourth embodiment> Next, a fourth embodiment of the present invention will be described. Fig.13 It is a figure which shows the cable assembly 40C which is 4th Embodiment of this invention. Fig.14 yes Fig.13 Exploded diagram of . Fig.15 Observed from the direction of arrow J Fig.13 The obtained picture. Fig.16 Observed from the direction of arrow H Fig.13 The obtained picture. Fig.17 yes Fig.15 In these drawings, the same elements as those of the first to third embodiments are denoted by the same reference numerals, and repeated description thereof is omitted.

[0077] In this embodiment, the hot melt material 440 in the first embodiment is replaced with a plastic member 140 , a ground cover 240 , and a sealing material 541 .

[0078] like Fig.14As shown, the plastic component 140 includes an outer frame portion 141 and eight inner frame portions 142 arranged side by side with a small gap 146 at the inner edge of the outer frame portion 141. The left-right width of the outer frame portion 141 is substantially the same as the left-right width of the paddle card substrate 41. The upper-lower width of the outer frame portion 141 is substantially the same as the upper-lower width from the front end of the welding joint portion 29 of the inner conductor 21 of the twinax cable 2 in the surface layer 410 of the paddle card substrate 41 to a part of the outer conductor 23.

[0079] The inner frame portion 142 includes two left and right wall portions 143 extending vertically, and a wall portion 144 connecting the middle portions of the two wall portions 143 in the vertical direction.

[0080] The surface on the -Z side of the outer frame portion 141 and the surface on the +Z side of the wall portion 144 are separated by a distance approximately equal to the upper and lower widths of the exposed portion of the internal conductor 21 of the dual-strand axial cable 2 and the exposed portion of the dielectric portion 22, forming a rectangular opening 145 surrounded by the outer frame portion 141 and the left and right walls 143 and 144 of the inner frame portion 142.

[0081] In this embodiment, the four ground covers 240 on the -X side cover the first inner frame 142, the third inner frame 142, the fifth inner frame 142, and the seventh inner frame 142 from the end of the plastic component 140 on the -X side, and are fixed to the surface layer 410 on the -X side. The four ground covers 240 on the +X side cover the second inner frame 142, the fourth inner frame 142, the sixth inner frame 142, and the eighth inner frame 142 from the end of the plastic component 140 on the +X side, and are fixed to the surface layer 410 on the +X side. The crimping terminals 246 of the ground covers 240 are inserted into the holes of the extensions 55 and 56 of the grounding electrode 5.

[0082] The sealing material 541 is formed by pouring epoxy resin into each inner frame portion 142 of the plastic member 140 and curing the epoxy resin. As the material of the sealing material 541, a polyurethane resin or a silicone resin may be used instead of the epoxy resin.

[0083] The packaging material 541 is in contact with the internal conductor 21 , the dielectric 22 , and the plastic component 140 on the surface layer 410 , and covers the internal conductor 21 .

[0084] The cable assembly 40C is manufactured through the following stages. Fig.18 As shown, in the first stage, after the outer conductor 23 is welded to the grounding electrode 5 on the surface of the paddle card substrate 41, the exposed portion of the inner conductor 21 of the double-stranded axial cable 2 is welded to the signal electrode 4 on the surface 410 of the paddle card substrate 41 to form a welded joint 29.

[0085] like Fig.19As shown, in the second stage, the plastic component 140 is positioned so that the end surface on the −Z side is substantially flush with the end surface on the −Z side of the welded joint 29 , and is fixed to the surface layer 410 .

[0086] like Fig. 20 As shown, in the third stage, the ground cover 240 is inserted into the holes of the extension portions 55 and 56 of the ground electrode 5 from the gap 146 between the adjacent inner frame portions 142 in the plastic component 140 on the surface layer 410 of the paddle card substrate 41, and the crimping terminal 246 is inserted into the hole of the substrate.

[0087] like Fig.21 As shown, in the fourth stage, the sealing material 541 is injected from the openings 145 of each inner frame portion 142 in the plastic component 140 and then cured.

[0088] The above is the details of the configuration of this embodiment. According to this embodiment, the same effects as those of the first to third embodiments described above can be obtained.

[0089] Here, the inventors of the present application conducted the following verifications in order to confirm the effects of the present invention. First, the inventors of the present application used electromagnetic field analysis software to Fig. 20 The cable assembly 40C of the stage Figure 1 In the device connected with the first connector 30 shown, FEXT was calculated in two cases: a case where the ground shield 240 of the cable assembly 40C was in close contact with the ground electrode 5 of the paddle card substrate 41 and a case where the ground shield 240 was lifted by 0.05 mm. Fig. 22 2 is a diagram showing the simulation results. Fig. 22 The solid line represents the FEXT when the ground cover 240 and the ground electrode 5 of the paddle card substrate 41 are in close contact with each other. Fig. 22 The dotted line represents the FEXT when the ground cover 240 is floated 0.05 mm from the ground electrode 5 of the paddle card substrate 41 .

[0090] If you refer to Fig. 22 It is known that when the ground cover 240 is in close contact with the ground electrode 5 of the paddle card substrate 41, the FEXT is reduced by approximately 5 dB in the frequency bands of 40 to 55 GHz and 68 to 76 GHz compared to the case where the ground cover 240 is raised 0.05 mm from the surface layer 410 of the paddle card substrate 41.

[0091] Second, the inventors of the present application calculated the TDR waveform using a TDR simulator when the cable assembly 40C was used as a DUT and the TDR waveform when the structure in which the sealing material 541 was removed from the cable assembly 40C was used as a DUT. Fig.23 2 is a diagram showing the simulation results. Fig.23The solid line is the TDR waveform of the cable assembly 40C, and the dotted line is the TDR waveform of the structure in which the sealing material 541 is removed from the cable assembly 40C. In this waveform, the interval E1 corresponds to the propagation time of the signal of the substrate 20, the interval E2 corresponds to the propagation time of the signal of the first connector 30, the interval E3 corresponds to the propagation time of the signal of the welding joint 29, the interval E4 corresponds to the propagation time of the signal of the exposed portion of the inner conductor 21 of the twinax cable 2, and the interval E5 corresponds to the propagation time of the signal in the twinax cable 2.

[0092] If you refer to Fig.23 , in the TDR waveform of the structure in which the sealing material 541 is removed from the cable assembly 40C, the peak impedance in the interval E4 is as high as 123Ω, whereas in the TDR waveform of the cable assembly 40C, the peak impedance in the interval E4 is as low as 97Ω. Fig.23 As shown, in the cable assembly 40C, the exposed portion of the inner conductor 21 of the twinax cable 2 is completely covered by the sealing material 541, which is considered to contribute to reducing the peak impedance in the section E4. When the sealing material 541 is injected from the opening 145 of each inner frame portion 142 of the plastic component 140, the wall of the plastic component is used to stop the flow, and the sealing material can be applied to a constant range. In addition, before injecting the sealing material 541, the ground cover 240 is installed, thereby closely contacting with the ground electrode, so that good electrical characteristics can be ensured.

[0093] <Fifth embodiment> Next, a fifth embodiment of the present embodiment will be described. Fig.24 It is a top view of the paddle card base plate 41 according to the fifth embodiment of the present invention. Fig.25 is from Fig.24 In these drawings, the same elements as those of the first to fourth embodiments are denoted by the same reference numerals, and repeated description thereof is omitted.

[0094] like Fig.25 As shown, the present embodiment is characterized in that the paddle card substrate 41 has a step difference.

[0095] A step 412 having a depth of about the radius of the twinax cable 2 is formed in the middle of the cable-side contact portion 587 from the signal electrode 4 to the ground electrode 5 in the surface layer 410 of the paddle card substrate 41. The thickness of the upper portion of the step 412 in the paddle card substrate 41 is thinner than that of the lower portion of the step 412.

[0096] The twinax cable 2 is positioned so that the dielectric 22 is contained in the step 412 and is arranged on the surface 410. The protruding portion of the inner conductor 21 of the twinax cable 2 is welded to the signal electrode 4 of the paddle card substrate 41. The outer conductor 23 of the twinax cable 2 is welded to the cable-side contact portion 587 of the ground electrode 5 of the paddle card substrate 41. The surface 410 of the paddle card substrate 41 on the left side of the step is welded to the signal electrode 4 of the paddle card substrate 41. Figure 3 The exposed portion of the inner conductor 21 of the twinax cable 2 ( Fig.17 The grounding electrode 588 on the surface of the paddle card substrate 41 is connected to the cable side contact portion 587 of the grounding electrode 5 via the inner layer wiring (inner layer through holes 413, 414 and wiring layer 415) of the paddle card substrate 41.

[0097] The above is the details of the structure of this embodiment. According to this embodiment, the inner conductor 21 of the twinax cable 2 does not need to be bent, and can be welded to the signal electrode 4 of the paddle card substrate 41 in a straight state. This simplifies the assembly process, and since the inner conductor exposed from the cable and the signal electrode 4 of the paddle card substrate 41 are at approximately the same position, the same Figure 3 The air layer around the exposed portion of the inner conductor 21 can be made extremely narrow, and the impedance increase can be suppressed. According to this structure, it is not necessary to coat the inner conductor 21 with a resin material such as a hot melt material or a sealing material. Therefore, productivity can be improved at low cost and in a short delivery time.

[0098] The following modifications may be made to this embodiment. A grounding cover 240 may be arranged on the grounding electrode 5 so as to cover the internal conductor 21. The grounding electrode 5 is arranged at a position of the paddle card substrate 41 connected to the contact portion that contacts the first connector 30 on both sides of the signal electrode 4. With this structure, the crimping terminal 246 of the grounding cover 240 is pressed into the hole of the grounding electrode 5, thereby making it possible to reliably and tightly contact the grounding electrode 5 with the grounding cover 240.

[0099] Alternatively, the ground shield 240 covering the inner conductor 21 on the paddle card substrate 41 may be disposed for each channel and alternately disposed on the front and back surfaces of the paddle card substrate 41. With this structure, crosstalk suppression can be achieved more effectively.

Claims

1. A cable assembly, arranged between a first connector and a second connector, wherein the first connector is arranged at a position near a control device in a substrate, and the second connector is arranged at a position away from the control device in the substrate, The cable assembly is characterized by comprising: A cable array, wherein the cable array is formed by arranging a plurality of cables that transmit differential signals respectively in parallel; a paddle card substrate provided with a signal electrode to which the inner conductors of the plurality of cables are electrically connected and a ground electrode to which the outer conductors of the plurality of cables are electrically connected; and A hot melt material is configured to cover at least the solder joint portion at the front end of the exposed portion of the inner conductor and the exposed portion of the inner conductor on the paddle card substrate.

2. The cable assembly according to claim 1, characterized in that: The thickness of the hot melt material at the solder joint portion at the front end of the exposed portion of the inner conductor is thinner than the thickness of the hot melt material arranged at the exposed portion of the inner conductor.

3. The cable assembly according to claim 1, characterized in that: A ground shield covering the inner conductor on the paddle card substrate is provided, The hot melt material is configured to cover at least an exposed portion of the inner conductor on the inner side of the ground shield on the paddle card substrate.

4. The cable assembly according to claim 3, characterized in that: A ground shield covering the inner conductor on the paddle card substrate is provided, The hot melt material is configured to cover at least the ground shield and at least the exposed portion of the inner conductor on the inner side of the ground shield on the paddle card substrate.

5. The cable assembly according to claim 3, characterized in that: A grounding cover is provided to cover the internal conductor on the paddle card substrate, wherein the grounding cover is arranged for each channel and is arranged alternately on the front and back surfaces of the paddle card substrate. The hot melt material is configured to cover at least an exposed portion of the inner conductor on the inner side of the ground shield on the paddle card substrate.

6. The cable assembly according to claim 5, characterized in that: The hot melt material is configured to cover at least the ground shield and at least the exposed portion of the inner conductor on the inner side of the ground shield on the paddle card substrate.

7. A cable assembly, arranged between a first connector and a second connector, wherein the first connector is arranged at a position near a control device in a substrate, and the second connector is arranged at a position away from the control device in the substrate, The cable assembly is characterized by comprising: A cable array, wherein the cable array is formed by arranging a plurality of cables that transmit differential signals respectively in parallel; a paddle card substrate, the paddle card substrate being provided with a signal electrode to which the inner conductors of the plurality of cables are electrically connected and a ground electrode to which the outer conductors of the plurality of cables are electrically connected; A plastic component, the plastic component is arranged on the paddle card substrate and has an outer frame portion and a plurality of inner frame portions arranged side by side with a small gap at an inner edge of the outer frame portion; a grounding cover configured to cover a part or all of the plurality of inner frame portions; as well as A sealing material is configured to cover at least an exposed portion of the internal conductor in the inner frame portion.

8. The cable assembly according to claim 7, characterized in that: The ground shield is arranged in each channel and is staggered on the front and back surfaces of the paddle card substrate.

9. A cable assembly, arranged between a first connector and a second connector, wherein the first connector is arranged at a position near a control device in a substrate, and the second connector is arranged at a position away from the control device in the substrate, The cable assembly is characterized by comprising: a cable array formed by arranging a plurality of cables that transmit differential signals respectively; and a paddle card substrate, the paddle card substrate having a signal electrode to which the internal conductors of the plurality of cables are electrically connected, and a grounding electrode disposed at a position where the external conductors of the cables are mounted and at a position connected to a contact portion contacting the first connector on both sides of the signal electrode, The ground electrode to which the outer conductor of the cable is attached is arranged at a position of the substrate thinner than the thickness of the substrate where the signal electrode is located.

10. The cable assembly according to claim 9, characterized in that: The ground electrode has a cable-side contact portion that contacts the cable and a connector-side contact portion that contacts the first connector, and the cable-side contact portion and the connector-side contact portion are connected via inner-layer wiring of the paddle card substrate.

11. The cable assembly according to claim 9, characterized in that: A hot melt material is provided, and the hot melt material is arranged on the paddle card substrate to cover at least the solder joint portion at the front end of the exposed portion of the internal conductor and the exposed portion of the internal conductor.

12. The cable assembly according to claim 9, characterized in that: The invention comprises: a hot-melt material, wherein the hot-melt material is configured to cover at least the front end welding joint of the exposed portion of the internal conductor and the exposed portion of the internal conductor on the paddle card substrate; and a grounding cover, wherein the grounding cover covers the internal conductor on the paddle card substrate and is configured in each channel and is staggered on the front and back surfaces of the paddle card substrate.

13. The cable assembly according to claim 9, characterized in that: The grounding electrode disposed at a position connected to the contact portion that contacts the first connector on both sides of the signal electrode includes a grounding cover disposed so as to cover the inner conductor.

14. The cable assembly according to claim 13, characterized in that: A ground cover is provided, the ground cover covers the internal conductor on the paddle card substrate, is arranged for each channel, and is arranged alternately on the front and back surfaces of the paddle card substrate.

15. A method for manufacturing a cable assembly, characterized in that: Solder the tip of the exposed part of the inner conductor to the paddle card substrate. A plastic component having an outer frame and a plurality of inner frame portions arranged side by side with a small gap at the inner edge of the outer frame portion is mounted on a paddle card substrate. A ground cover having a crimping terminal is arranged to cover a part or all of the plurality of inner frame portions and is inserted into a hole mounted on a paddle card substrate. A sealing material is injected into the inner frame portion so as to cover the exposed portion of the inner conductor, and then cured.

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