Flexible circuit board, package connection structure, package base and optical semiconductor device

Abstract

The embodiment of the present application provides a flexible circuit board, a package connection structure, a package base and an optical semiconductor device, wherein the flexible circuit board includes: a dielectric layer; a conductive circuit, which is arranged on the dielectric layer and has a first terminal thereon, and the first terminal is used to weld with the first pad of the conductive wiring to form a welding area; the conductive circuit has an outer buffer zone, the outer buffer zone is adjacent to the boundary of the welding area, and the outer buffer zone extends outside the welding area, wherein the line width of the outer buffer zone gradually increases toward the direction close to the boundary of the welding area. This effectively alleviates the sudden change of impedance at the boundary of the welding area, ensures the stability and continuity of impedance, is conducive to reducing the return loss, reduces the signal reflectivity, ensures the integrity of the high-frequency signal, and enables the signal to maintain a high transmission rate.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic packaging, and in particular to a flexible circuit board, a packaging connection structure, a packaging base and an optical semiconductor device. Background Art

[0002] In the optical module in the field of optical communication, the conversion between optical signals and electrical signals needs to be realized through the optical devices in the optical module, which usually include optical semiconductor elements and a packaging base for sealing the optical semiconductor elements. The optical signal is transmitted into the packaging base through the optical coupling component of the packaging base, and is converted into an electrical signal by the optical semiconductor element. The electrical signal is output through the wiring on the input and output terminals of the packaging base.

[0003] The electrical signal output by the optical device is usually transmitted by a flexible circuit board, so the flexible circuit board needs to be welded to the package base, that is, the terminals on the flexible circuit board are welded to the pads on the connecting components in the package base.

[0004] In the prior art, there is a welding area formed by welding the terminals on the flexible circuit board to the pads of the connecting components. Since the welding area forms an overlap of the welding terminals, the pads and the welding materials, there is an impedance mutation at the boundary of the welding area, which leads to a significant increase in return loss and deterioration of the integrity of the transmission signal. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a flexible circuit board, a packaging connection structure, a packaging base and an optical semiconductor device, which are used to solve the technical problem in the prior art that in the welding area formed by welding the terminals on the flexible circuit board to the pads of the connecting components, there is an impedance mutation at the boundary of the welding area due to the superposition of the welding terminals, pads and welding materials in the welding area, resulting in a significant increase in return loss.

[0006] To solve the above technical problems, the embodiments of the present invention adopt the following technical solutions:

[0007] An embodiment of the present application provides a flexible circuit board, the flexible circuit board comprising:

[0008] dielectric layer;

[0009] A conductive circuit is provided on the dielectric layer and has a first terminal thereon, wherein the first terminal is used to be welded with a first pad of the conductive wiring to form a welding area;

[0010] The conductive circuit has an outer buffer zone, the outer buffer zone is adjacent to the boundary of the welding area, and the outer buffer zone extends outside the welding area.

[0011] Wherein, the line width of the outer buffer area gradually increases toward the boundary of the welding area.

[0012] In some embodiments of the present application, the conductive circuit further has an inner buffer zone, the inner buffer zone is adjacent to the outer buffer zone, and the inner buffer zone extends within the welding area;

[0013] The line width of the inner buffer area gradually increases toward the outer buffer area.

[0014] In some embodiments of the present application, the absolute value of the slope of the tangent line at any point on the contour line of the outer buffer zone is ≤0.5.

[0015] In some embodiments of the present application, the slope of the tangent line on the contour line of the outer buffer zone changes continuously.

[0016] In some embodiments of the present application, the absolute value of the slope of the tangent line at any point on the contour line of the inner buffer zone is ≤0.5.

[0017] In some embodiments of the present application, the slope of a tangent line on a contour line of the inner buffer zone changes continuously.

[0018] In some embodiments of the present application, the conductive circuit includes:

[0019] Signal lines;

[0020] The first terminal comprises:

[0021] A signal terminal, the signal terminal is located on the signal line, and the signal terminal is used to be welded with the signal pad of the pad to form the welding area;

[0022] Wherein, the outer buffer and the inner buffer are both located on the signal line.

[0023] In some embodiments of the present application, the maximum width of the outer buffer area is equal to the line width of the signal line in the welding area.

[0024] In some embodiments of the present application, the maximum width of the inner buffer area is greater than the line width of the signal line in the welding area.

[0025] In some embodiments of the present application, the impedance value outside the welding area is R1, and the impedance value of the welding area is R2, wherein the absolute value of the difference between R1 and R2 is ΔR≤8Ω.

[0026] An embodiment of the present application further provides a package connection structure, the connection structure comprising:

[0027] A flexible circuit board as described above;

[0028] A connecting component, the connecting component comprising:

[0029] Insulation parts;

[0030] The conductive wiring is arranged on the insulating member and has a first pad thereon. The first pad is welded to the first terminal to form the welding area.

[0031] In some embodiments of the present application, the conductive wiring has a transition area, the transition area is adjacent to the boundary of the welding area and is located outside the welding area.

[0032] Wherein, the line width of the transition zone gradually decreases in a direction away from the welding area.

[0033] In some embodiments of the present application, the conductive circuit includes:

[0034] Signal lines;

[0035] The first terminal comprises:

[0036] A signal terminal, wherein the signal terminal is located on the signal line;

[0037] Wherein, the external buffer is located on the signal line;

[0038] The conductive wiring comprises:

[0039] Signal wiring;

[0040] The first pad comprises:

[0041] A signal pad, the signal pad being located on the signal wiring;

[0042] The signal pad is welded to the signal terminal to form the welding area;

[0043] The transition region is located on the signal wiring.

[0044] In some embodiments of the present application, the conductive circuit further includes:

[0045] Grounding circuit;

[0046] The first terminal further comprises:

[0047] A grounding terminal, the grounding terminal being located on the grounding line;

[0048] The conductive wiring further comprises:

[0049] Ground wiring;

[0050] The first pad comprises:

[0051] A ground pad, the ground pad being located on the ground wiring;

[0052] The ground pad is welded to the ground terminal.

[0053] An embodiment of the present application further provides a packaging base, the packaging base comprising:

[0054] A substrate, wherein a first surface of the substrate is provided with a mounting portion, the mounting portion being used to mount an optical semiconductor element;

[0055] A housing, the housing being disposed on the first surface of the substrate, the housing having a mounting portion;

[0056] The loading portion is placed in the housing;

[0057] The package connection structure as described above;

[0058] The connecting component is arranged on the mounting portion.

[0059] In some embodiments of the present application, the mounting portion is a notch, and the insulating member is embedded and mounted on the notch to block the notch.

[0060] An embodiment of the present application further provides an optical semiconductor device, characterized in that the device comprises:

[0061] A packaging base as described above;

[0062] an optical semiconductor element mounted on the mounting portion;

[0063] Fiber optic components;

[0064] A through hole formed on a side surface of the shell;

[0065] an optical coupling component, the optical coupling component being inserted into the through hole and used for connecting the optical semiconductor element and the optical fiber component respectively;

[0066] Sealing ring;

[0067] A cover plate is covered on the upper surface of the shell through the sealing ring.

[0068] In some embodiments of the present application, the optical coupling component has sapphire, and the function of the sapphire is to polarize light, so as to cause slight refraction of the light path, thereby preventing the reflected light from returning along the straight line of the light path and weakening the intensity of the incident light; at the same time, the sapphire makes the packaging base airtight.

[0069] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0070] The embodiments of the present application provide a flexible circuit board, a packaging connection structure, a packaging base and an optical semiconductor device, wherein the flexible circuit board includes: a dielectric layer; a conductive circuit, which is arranged on the dielectric layer and has a first terminal thereon, and the first terminal is used to be welded to a first pad of the conductive wiring to form a welding area; the conductive circuit has an outer buffer area, the outer buffer area is adjacent to the boundary of the welding area, and the outer buffer area extends outside the welding area, wherein the line width of the outer buffer area gradually increases toward the direction approaching the boundary of the welding area.

[0071] In the flexible circuit board of the embodiment of the present application, the line width of the outer buffer zone on the flexible circuit board gradually increases toward the direction close to the boundary of the welding area, thereby effectively alleviating the drastic impedance mutation at the boundary of the welding area, ensuring the impedance stability and continuity, which is conducive to reducing the return loss, reducing the signal reflectivity, ensuring the integrity of the high-frequency signal, so that the signal can maintain a high transmission rate, and thus effectively solving the technical problem in the prior art that in the welding area formed by welding the terminals on the flexible circuit board to the pads of the connecting components, due to the superposition of the welding terminals, pads and welding materials formed in the welding area, there is an impedance mutation at the boundary of the welding area, resulting in a significant increase in return loss and deterioration of the integrity of the transmission signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0073] Figure 1 is a schematic structural diagram of a flexible circuit board provided by an embodiment of the present invention;

[0074] Figure 2 yes Figure 1 The enlarged view of the M in the middle;

[0075] Figure 3 is a structural schematic diagram of a packaging connection structure provided by an embodiment of the present invention;

[0076] Figure 4 It is a partial structural schematic diagram of a packaging connection structure provided by an embodiment of the present invention;

[0077] Figure 5 It is a structural schematic diagram of a conductive wiring and conductive circuit connection of a package connection structure provided by an embodiment of the present invention;

[0078] Figure 6It is a structural schematic diagram of the connection between an insulating member and a conductive wiring of a packaging connection structure provided by an embodiment of the present invention;

[0079] Figure 7 is a top view of the connection between an insulating member and a conductive wiring of a packaging connection structure provided by an embodiment of the present invention;

[0080] Figure 8 yes Figure 7 Sectional view of AA in the middle;

[0081] Fig. 9 yes Figure 8 The enlarged view of the N position in the middle;

[0082] Fig.10 is an exploded view of a packaging base provided by an embodiment of the present invention;

[0083] Fig.11 is a schematic structural diagram of an optical semiconductor device provided by an embodiment of the present invention;

[0084] Fig.12 is a structural schematic diagram of the A-type structure provided by an embodiment of the present invention;

[0085] Fig.13 This is a schematic diagram of the structure of the B-type structure provided by an embodiment of the present invention.

[0086] Fig.14 is a structural schematic diagram of a C-type structure provided by an embodiment of the present invention;

[0087] Fig.15 is an impedance curve diagram provided by an embodiment of the present invention.

[0088] in:

[0089] 101, signal circuit; 102, ground circuit; 103, ground terminal; 104, signal terminal; 105, first terminal; 106, outer buffer; 107, inner buffer; 110, conductive circuit; 120, dielectric layer; 200, connecting component; 210, insulating component; 220, conductive wiring; 221, signal wiring; 222, transition zone; 223, first pad; 300, welding area; 400, shell; 410, accommodating space; 420, mounting portion; 430, through hole; 500, substrate; 501, loading portion; 600, optical coupling component; 700, sealing ring; 800, cover plate. DETAILED DESCRIPTION

[0090] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0091] In the description of the embodiments of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0092] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a replaceable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0093] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0094] Example 1

[0095] like Figure 1 As shown, Figure 1 A schematic diagram of the structure of a flexible circuit board provided by an embodiment of the present invention;

[0096] An embodiment of the present invention provides a flexible circuit board, the flexible circuit board comprising:

[0097] A dielectric layer 120;

[0098] The dielectric layer is usually a flexible substrate with an inherent dielectric constant, used as an insulating layer between conductive lines of different layers;

[0099] The conductive circuit 110 is disposed on the dielectric layer 120 and has a first terminal 105 thereon. The first terminal 105 is used to be welded with the first pad 223 of the conductive wiring 220 to form a welding area 300;

[0100] The conductive circuit 110 is disposed on the dielectric layer 120;

[0101] A portion of the conductive circuit 110 forms a first terminal 105, and in particular, the first terminal 105 is located at an end of the conductive circuit 110;

[0102] The conductive circuit 110 is a plurality of first conductive lines, and the first conductive lines are laid in parallel on the dielectric layer 120;

[0103] Furthermore, the conductive circuit, except for the area where electrical connection such as welding or wire bonding is required (such as the first terminal), is covered with a green oil layer to achieve solder resistance and prevent the conductive circuit from being oxidized.

[0104] The conductive wiring 220 is electrically connected to the optical semiconductor element, wherein a portion of the conductive wiring 220 forms a first soldering pad 223 , wherein the first soldering pad 223 may be soldered on the conductive wiring.

[0105] The first pad 223 and the first terminal 105 are soldered together to form the soldering area 300. The soldering area 300 includes the first pad 223, the first terminal 105 and the solder. Fig. 9 Shown in the dashed box.

[0106] The conductive circuit 110 has an outer buffer zone 106 , the outer buffer zone 106 is adjacent to the boundary of the welding area 300 , and the outer buffer zone 106 extends outside the welding area 300 ;

[0107] The line width of the outer buffer region 106 gradually increases toward the boundary of the welding region 300 .

[0108] The outer buffer zone 106 is a portion of the conductive circuit 110 , which is adjacent to the boundary of the welding area 300 , and the outer buffer zone 106 extends outside the welding area 300 .

[0109] The line width of the outer buffer zone 106 gradually increases toward the boundary of the welding area 300 ; the projection shape of the outer buffer zone 106 may be a semicircle or a trapezoid, etc., and the wider side thereof is arranged on the boundary of the welding area 300 .

[0110] Among them, in optical semiconductor devices, return loss refers to the standing wave ratio return loss parameter. The smaller the value, the lower the electrical signal reflectivity of the optical semiconductor device, the stronger the signal integrity, and the better the product performance.

[0111] In the flexible circuit board of the embodiment of the present application, the line width of the outer buffer zone 106 on the flexible circuit board gradually increases toward the boundary of the welding area 300, thereby effectively alleviating the drastic impedance mutation at the boundary of the welding area 300, ensuring the impedance stability and continuity, which is conducive to reducing the return loss, reducing the signal reflectivity, ensuring the integrity of the high-frequency signal, so that the signal can maintain a high transmission rate, and thus effectively solving the technical problem in the prior art that in the welding welding area 300 formed by welding the terminal on the flexible circuit board to the pad of the connecting component 200, due to the superposition of the welding terminal, the pad and the welding material formed in the welding area 300, there is an impedance mutation at the boundary of the welding area 300, resulting in a significant increase in return loss and deterioration of the integrity of the transmission signal.

[0112] Especially during 5G high-frequency transmission, signals are more sensitive to impedance mutations. Impedance mutations at the boundaries cause a significant increase in signal return loss and reflectivity, ultimately leading to a significant reduction in signal integrity.

[0113] The flexible circuit board in this embodiment can effectively solve the technical problem that during 5G high-frequency transmission, the signal is more sensitive to impedance mutation, the impedance mutation at the boundary causes a significant increase in signal return loss and an increase in reflectivity, which ultimately leads to a significant reduction in signal integrity.

[0114] For example, the impedance of the conductive line 110 of a general flexible circuit board is 55Ω before entering the welding area 300, and then the impedance suddenly changes to 45Ω after entering the welding area 300; in the flexible circuit board of this embodiment, since the conductive line 110 has an outer buffer area 106 with a gradually increasing line width before entering the welding area 300, the impedance gradually decreases in the buffer area, thereby suppressing the severity of the impedance sudden change;

[0115] The factors that affect the characteristic impedance of the line mainly include line width, line spacing, line thickness, dielectric constant and thickness of the upper and lower layers of the line medium. The wider the line width, the smaller the impedance; the smaller the line spacing (i.e., the larger the line width), the smaller the impedance; the thicker the line thickness, the smaller the impedance; the larger the dielectric constant of the medium, the smaller the impedance; the smaller the dielectric thickness, the smaller the impedance; when the line spacing, line thickness, dielectric constant and thickness of the upper and lower layers of the line medium are fixed, the external buffer area 106 can gradually reduce the impedance in the buffer area, thereby suppressing the severity of impedance mutation.

[0116] In some embodiments of the present application, the conductive circuit 110 further has an inner buffer zone 107 , the inner buffer zone 107 is adjacent to the outer buffer zone 106 , and the inner buffer zone 107 extends into the welding area 300 ;

[0117] The line width of the inner buffer area 107 gradually increases toward the outer buffer area 106 .

[0118] The inner and outer buffers are combined as follows Fig. 9 As shown in the solid line box;

[0119] The inner buffer zone 107 is a part of the conductive circuit 110;

[0120] The projection shape of the inner buffer area 107 may be a semicircle or a trapezoid, etc., and the wider side thereof is disposed on the boundary of the welding area 300 or exceeds the boundary of the welding area 300 .

[0121] The inner buffer zone 107 and the outer buffer zone 106 are interconnected and integrated, and are both part of the conductive circuit 110. They can be divided according to the boundary of the welding area 300. The part located inside the welding area 300 or inside the first terminal 105 is the inner buffer zone 107, and the part located outside the welding area 300 or outside the first terminal 105 is the outer buffer zone 106. Of course, in other embodiments, when there is only a separate inner buffer zone 107 or an outer buffer zone 106, the two can be divided according to actual conditions.

[0122] The impedance value of the signal line 101 outside the welding area 300 is R1, and the impedance value of the welding area 300 is R2, wherein the absolute value of the difference between R1 and R2 is ΔR≤8Ω.

[0123] The impedance value R2 of the welding area 300 includes the impedance value of the entire welding area, that is, includes the impedance value after the signal terminal-solder-signal pad are connected.

[0124] When the value of ΔR is relatively large, the internal buffer zone 107 causes the impedance change rate near the boundary of the welding area 300 to increase from small to large and then decrease, thereby avoiding the problem of increasing impedance change rate, drastic impedance change and deterioration of return loss performance caused by a large ΔR.

[0125] In some embodiments of the present application, the absolute value of the slope of the tangent line at any point on the contour line of the outer buffer zone 106 is ≤0.5.

[0126] If the absolute value of the slope of the tangent at any point on the contour line of the outer buffer zone 106 exceeds 0.5, the morphology of the conductive line 110 of the outer buffer zone 106 is not easy to process, and an excessively large slope can easily cause the outer buffer zone 106 to fail, resulting in impedance discontinuity.

[0127] In some embodiments of the present application, the slope of the tangent line on the contour line of the outer buffer zone 106 changes continuously.

[0128] The continuous change in the slope of the tangent line on the contour line of the outer buffer zone 106 allows the impedance to change smoothly, thereby avoiding the phenomenon that the return loss performance deteriorates due to a sudden change in impedance.

[0129] In some embodiments of the present application, the absolute value of the slope of the tangent line at any point on the contour line of the inner buffer zone 107 is ≤0.5;

[0130] Similarly, when the absolute value of the slope of the tangent at any point on the contour line of the inner buffer zone 107 exceeds 0.5, the morphology of the conductive circuit 110 of the inner buffer zone 107 is not easy to process, and an excessively large slope can easily cause the inner buffer zone 107 to fail, resulting in impedance discontinuity.

[0131] In some embodiments of the present application, the slope of the tangent line on the contour line of the inner buffer zone 107 changes continuously.

[0132] Similarly, the continuous change in the slope of the tangent line on the contour line of the inner buffer zone 107 allows the impedance to change smoothly, thereby avoiding the phenomenon that the return loss performance is deteriorated due to a sudden change in impedance.

[0133] In some embodiments of the present application, the conductive circuit 110 includes:

[0134] Signal line 101;

[0135] The signal lines 101 include a plurality of lines, which are respectively arranged on the dielectric layer 120;

[0136] The first terminal 105 comprises:

[0137] A signal terminal 104, the signal terminal 104 is located on the signal line 101, and the signal terminal 104 is used to be welded with the signal pad of the pad to form the welding area 300;

[0138] As can be seen from the above, the signal terminal 104 is a part of the signal circuit 101;

[0139] The outer buffer 106 and the inner buffer 107 are both located on the signal line 101 .

[0140] As can be seen from the above, the signal terminal is a part of the signal line 101, and in particular, the inner ring buffer is a part of the signal terminal 104;

[0141] In some embodiments of the present application, the maximum width of the outer buffer zone 106 is equal to the line width of the signal line 101 in the welding area 300 .

[0142] In some embodiments of the present application, the maximum width of the inner buffer area 107 is greater than the line width of the signal line 101 in the welding area 300 .

[0143] Example 2

[0144] An embodiment of the present application further provides a packaging connection structure, the connection structure comprising:

[0145] A flexible circuit board as described above;

[0146] The connecting component 200 includes:

[0147] Insulating member 210; the material of the insulating member 210 is selected from any one or more dielectric materials of aluminum oxide, aluminum nitride, and mullite;

[0148] The conductive wiring 220 is disposed on the insulating member 210 and has a first pad 223 thereon. The first pad 223 is welded to the first terminal 105 to form the welding area 300 .

[0149] The conductive wiring 220 is a plurality of groups of second conductive wires, and the second conductive wires are installed and arranged on the insulating member 210;

[0150] The first pad 223 is a portion of the conductive wiring 220, and in particular, a portion of the end portion of the conductive wiring 220;

[0151] As described in Embodiment 1, the first pad 223 and the first terminal 105 are welded together by solder to form the welding area 300;

[0152] In the packaging connection architecture of the embodiment of the present application, the line width of the outer buffer zone 106 on the packaging connection structure gradually increases toward the boundary of the welding area 300, thereby effectively alleviating the drastic impedance mutation at the boundary of the welding area 300, ensuring the impedance stability and continuity, which is conducive to reducing the return loss, reducing the signal reflectivity, ensuring the integrity of the high-frequency signal, and allowing the signal to maintain a high transmission rate, thereby effectively solving the technical problem in the prior art that in the welding welding area 300 formed by welding the terminal on the flexible circuit board to the pad of the connecting component 200, due to the superposition of the welding terminal, the pad and the welding material formed in the welding area 300, there is an impedance mutation at the boundary of the welding area 300, resulting in a significant increase in return loss and deterioration of the integrity of the transmission signal.

[0153] In some embodiments of the present application, the impedance value outside the welding area 300 is R1, and the impedance value of the welding area 300 is R2, wherein the absolute value of the difference between R1 and R2 is ΔR ≤ 8Ω.

[0154] If ΔR is greater than 8Ω, the impedance changes more drastically under the outer buffer 106 of the same structure, and the return loss performance deteriorates. Therefore, the ΔR≤8Ω can effectively solve the problem that when ΔR is greater than 8Ω, the impedance changes more drastically under the outer buffer 106, and the return loss performance deteriorates.

[0155] In some embodiments of the present application, the conductive wiring 220 has a transition area 222, and the transition area 222 is adjacent to the boundary of the welding area 300 and is located outside the welding area 300.

[0156] The line width of the transition zone 222 gradually decreases in a direction away from the welding area 300 .

[0157] Since the first pad 223 is used to solder the first terminal 105 of the flexible circuit board, in order to ensure the welding strength, the width of the first pad 223 is greater than the width of the conductive wiring 220 outside the welding area 300. As a result, the width of the conductive wiring 220 is different inside the welding area 300 and outside the welding area 300. The position where the line width changes is likely to cause a sudden impedance change, resulting in poor return loss performance. The transition zone 222 can effectively reduce the severity of the impedance transformation and suppress the deterioration of the return loss performance.

[0158] In some embodiments of the present application, the conductive circuit 110 includes:

[0159] Signal line 101;

[0160] The first terminal 105 comprises:

[0161] A signal terminal 104, wherein the signal terminal 104 is located on the signal line 101;

[0162] The signal terminal 104 is a part of the signal line 101;

[0163] Wherein, the external buffer 106 is located on the signal line 101;

[0164] The conductive wiring 220 includes:

[0165] Signal wiring 221;

[0166] The first pad 223 includes:

[0167] A signal pad, the signal pad is located on the signal wiring 221;

[0168] The signal pad is a portion of the signal pad;

[0169] The signal pad is welded to the signal terminal 104 to form the welding area 300;

[0170] The transition region 222 is located on the signal wiring 221 .

[0171] In some embodiments of the present application, the conductive circuit 110 further includes:

[0172] Ground circuit 102; that is, the conductive circuit 110 includes a signal circuit 101 and a ground circuit 102;

[0173] The first terminal 105 further includes:

[0174] A grounding terminal 103, wherein the grounding terminal 103 is located on the grounding line 102;

[0175] The ground terminal 103 is a part of the ground line 102;

[0176] The conductive wiring 220 further includes:

[0177] Ground wiring; that is, the conductive wiring 220 includes a signal wiring 221 and a ground wiring;

[0178] The first pad 223 includes:

[0179] A ground pad, the ground pad being located on the ground wiring;

[0180] The ground pad is a part of the ground wiring;

[0181] The ground pad is welded to the ground terminal 103. Specifically, the ground pad is welded to the ground terminal 103 through solder.

[0182] The preparation process of the connecting component 200 is as follows:

[0183] preparing a dielectric material into a ceramic slurry;

[0184] The ceramic slurry is tape-cast to obtain a ceramic green body; the ceramic green body is punched / punched;

[0185] Printing a conductive wiring 220 pattern on the ceramic green body by screen printing;

[0186] Laminating a plurality of ceramic green sheets having the pattern of the conductive wiring 220 to obtain a laminated green sheet;

[0187] Cutting the laminated green body to obtain a green body of the connecting component 200;

[0188] Printing a metal layer on the side of the green body of the connecting component 200 to obtain a green body of the connecting component 200 with a metal layer on the side;

[0189] The green body of the connecting component 200 is sintered into porcelain to obtain the connecting component 200;

[0190] Then, the conductive wiring 220 of the connecting component 200 is nickel plated;

[0191] Example 3

[0192] An embodiment of the present invention further provides a packaging base, the packaging base comprising:

[0193] A substrate 500, wherein a first surface of the substrate 500 is provided with a mounting portion 501, wherein the mounting portion 501 is used to mount an optical semiconductor element;

[0194] The substrate 500 can be made of alloy (iron-cobalt-nickel alloy) or copper-tungsten alloy, etc. The optical semiconductor element is not shown in the figure, wherein the optical semiconductor element is electrically connected to the conductive wiring 220;

[0195] The shell 400 is arranged on the first surface of the substrate 500, and the shell 400 has a mounting portion 420 and a receiving space 410; the interior of the shell 400 is the receiving space 410, and the receiving space 410 is open at the top and bottom; the material of the shell 400 is an alloy (iron-cobalt-nickel alloy) or a copper-tungsten alloy, etc.

[0196] The loading portion 501 is located in the accommodating space 410;

[0197] The loading portion 501 is located in the accommodating space 410, so that the optical semiconductor element can be installed in the housing 400. The outer side of the optical semiconductor element is surrounded and protected by the housing 400, and the bottom is protected by the substrate 500.

[0198] The package connection structure as described above;

[0199] The connecting component is disposed on the mounting portion 420 .

[0200] The first surface of the substrate is welded to the lower surface of the housing 400, and the housing surrounds the mounting portion;

[0201] The mounting portion 420 is connected to the accommodating space 410. Specifically, the mounting portion 420 is a notch, which is a notch located on the side of the housing 400.

[0202] Specifically, the insulating member 210 is embedded and installed in the notch to block the notch; thereby, the optical semiconductor element can be surrounded and protected by the housing 400 , the insulating member 210 and the base.

[0203] Example 4

[0204] The present invention also includes an optical semiconductor device, characterized in that the device includes:

[0205] The packaging base as described above;

[0206] an optical semiconductor element, the optical semiconductor element being mounted on the mounting portion 501 and being electrically connected to the conductive wiring 220;

[0207] Optical fiber component; the optical fiber component may be an optical fiber cable;

[0208] A through hole 430 , wherein the through hole 430 is formed on a side surface of the housing 400 ; the through hole 430 is connected to the accommodating space 410 ;

[0209] An optical coupling component 600, wherein the optical coupling component 600 is inserted into the through hole 430, and the optical coupling component 600 is used to connect the optical semiconductor element and the optical fiber component respectively;

[0210] Sealing ring 700; the sealing ring 700 is an alloy (iron-cobalt-nickel alloy) or a copper-tungsten alloy, etc.;

[0211] The cover plate 800 is covered on the upper surface of the housing 400 through the sealing ring 700. Specifically, the cover plate 800 is covered on the upper surface of the sealing ring 700 in a manner of sealing the semiconductor element accommodating space 410;

[0212] The sealing ring 700 serves to buffer thermal stress when the housing 400 and the cover plate 800 are welded.

[0213] The substrate 500 and the housing, the through hole 430 and the optical coupling component 600, the connecting component 200 and the through portion, and the sealing ring 700 and the frame are all joined by brazing.

[0214] The surfaces of the substrate 500 , the housing 400 , the conductive wiring 220 , the optical coupling component 600 , and the sealing ring 700 are sequentially formed with nickel and gold metal layers.

[0215] In some embodiments of the present application, the optical coupling component 600 has sapphire, which has the function of polarizing light, and is used to slightly refract the light path, so as to prevent the reflected light from returning along the straight line of the light path and weakening the intensity of the incident light; at the same time, the sapphire makes the packaging base airtight. The sapphire can be accurately refracted into the housing 400.

[0216] The preparation process of the optical semiconductor device comprises:

[0217] The substrate 500, the housing, the optical coupling component 600, the connecting component 200, and the sealing ring 700 are assembled and joined by solder, and then the components are welded by brazing;

[0218] After the welding of each component is completed, the package base is plated with nickel and gold in sequence;

[0219] The optical semiconductor element is placed in the mounting portion 501, and the optical semiconductor element is electrically connected to the conductive wiring 220 on the connecting component 200 by means of wire connection, welding, etc.;

[0220] The cover plate 800 is soldered to the upper surface of the sealing ring 700 to seal the accommodating space 410 for carrying the semiconductor element; the flexible circuit board is soldered to the connecting component 200, that is, the first terminal 105 of the flexible circuit board is soldered to the first pad 223 of the connecting component 200 located outside the shell 400.

[0221] The optical semiconductor device was tested as follows:

[0222] 1) Performance indicators:

[0223] The value range that meets the requirements is return loss RL≤-15dB@0~40GHz;

[0224] The return loss RL that does not meet the required value range is greater than -15dB@0~40GHz;

[0225] 2) Test method:

[0226] (1) Return loss test method and process:

[0227] The test was performed using a network analyzer, specifically: one end of the adapter board (replacing the optical semiconductor element in actual application) was connected to the (internal) conductive wiring 220 of the package base through a gold wire, and the other end was connected to the network analyzer through a probe station; the non-welding area 300 end of the flexible circuit board was connected to the network analyzer through a probe station; and the product return loss performance was tested using the network analyzer.

[0228] (2) Impedance curve test method and process:

[0229] The test is carried out using a network analyzer, using the return loss test method. The difference lies in the different functional modules of the network analyzer selected.

[0230] 3) The corresponding performance data of the test examples and the comparative examples are compared in the following table:

[0231]

[0232]

[0233] In Experimental Examples 1-3 and Comparative Example 1, on the flexible circuit board, the width of the signal line 101 in the non-welding area 300 is 105um; the width of the signal line 101 (i.e., the signal terminal 104) in the welding area 300 is 210um; and the maximum width of the outer buffer area 106 is equal to the width of the line of the signal terminal 104 (210um).

[0234] In Experimental Examples 4-6 and Comparative Examples 2-3, on the flexible circuit board, the width of the signal line 101 in the non-welding area 300 is 105um; the width of the signal line 101 (i.e., the signal terminal 104) in the welding area 300 is 210um; and the maximum width of the outer buffer 106 and the inner buffer 107 is 240um.

[0235] In the test examples and comparative examples, ΔR=8, which is a relatively large case.

[0236] It can be seen from the test examples and comparative examples in the above table that:

[0237] 1. According to Experimental Examples 1-3 and Comparative Example 1, it is proved that the flatter the contour of the outer buffer 106 is, the less drastic the impedance change is and the smaller the return loss is; otherwise, the return loss is large.

[0238] 2. According to Experimental Examples 4-6 and Comparative Example 2, it is proved that the flatter the contour of the inner buffer 107 is, the less drastic the impedance change is and the smaller the return loss is; otherwise, the return loss is large.

[0239] 3. Comparison between Experimental Example 2 and Experimental Example 4 shows that when ΔR is large, the impedance variation of the solution with both the external buffer 106 and the internal buffer 107 is less drastic and the return loss is smaller than that of the solution with the external buffer 106 alone.

[0240] 4. The comparison between comparative examples 1 and 3 shows that the existence of the internal buffer 107 can suppress the aggravation of impedance change, thereby reducing return loss.

[0241] 4) Impedance curves under different buffer structures:

[0242] (1) Figure 12-14 In the three structural cases shown:

[0243] Fig.12 A vertical structure, i.e., without the inner buffer zone 107 and the outer buffer zone 106, wherein the dimensions and parameters are in accordance with Experimental Example 2;

[0244] Fig.13 The structure B has an outer buffer zone 106 but no inner buffer zone 107, wherein the dimensions and parameters are in accordance with Experimental Example 2;

[0245] Fig.14 C is a structure having both an outer buffer 106 and an inner buffer 107, wherein the dimensions and parameters are in accordance with Experimental Example 5;

[0246] (2) Impedance curves under the above three structural conditions:

[0247] Among them, the horizontal axis is time and the vertical axis is impedance;

[0248] Fig.15 2 is an impedance curve diagram. During the signal transmission process, the impedance changes of the impedance curves B and C of the signal line 101 structure with the external buffer 106 are more gradual; while the impedance change of the impedance curve A of the signal line 101 structure without the external buffer 106 is more drastic.

[0249] Compared with the case where there is only the outer buffer 106 , the signal line 101 structure having the inner buffer 107 and the outer buffer 106 has a smoother impedance change.

[0250] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A packaging connection structure, characterized in that: Including connecting parts and flexible circuit boards, The flexible circuit board comprises: dielectric layer; A conductive circuit is provided on the dielectric layer and has a first terminal thereon, wherein the first terminal is used to be welded with a first pad of the conductive wiring to form a welding area; The conductive circuit has an outer buffer zone, the outer buffer zone is adjacent to the boundary of the welding area, and the outer buffer zone extends outside the welding area; Wherein, the line width of the outer buffer area gradually increases toward the boundary of the welding area; The connection structure comprises: A connecting component, the connecting component comprising: Insulation parts; A conductive wiring is disposed on the insulating member and has a first pad thereon, wherein the first pad is welded to the first terminal to form the welding area; The impedance value of the signal line outside the welding area is R1, and the impedance value of the welding area is R2, wherein the absolute value of the difference between R1 and R2 is ΔR≤8Ω; The conductive wiring has a transition area, the transition area is adjacent to the boundary of the welding area and is located outside the welding area. Wherein, the line width of the transition zone gradually decreases in a direction away from the welding area.

2. The packaging connection structure according to claim 1, characterized in that: The conductive circuit further has an inner buffer area, the inner buffer area is adjacent to the outer buffer area, and the inner buffer area extends within the welding area; The line width of the inner buffer area gradually increases toward the outer buffer area.

3. The packaging connection structure according to claim 1 or 2, characterized in that: The absolute value of the slope of the tangent line at any point on the contour line of the outer buffer zone is ≤0.5; The slope of the tangent line on the contour line of the outer buffer zone changes continuously.

4. The packaging connection structure according to claim 2, characterized in that: The absolute value of the slope of the tangent line at any point on the contour line of the inner buffer zone is ≤0.5; The slope of the tangent line on the contour line of the inner buffer zone changes continuously.

5. The packaging connection structure according to claim 2, characterized in that: The conductive circuit comprises: Signal lines; The first terminal comprises: A signal terminal, the signal terminal is located on the signal line, and the signal terminal is used to be welded with the signal pad of the pad to form the welding area; Wherein, the outer buffer and the inner buffer are both located on the signal line.

6. The packaging connection structure according to claim 5, characterized in that: The maximum width of the outer buffer area is equal to the line width of the signal line in the welding area.

7. The packaging connection structure according to claim 6, characterized in that: The maximum width of the inner buffer area is greater than the line width of the signal line in the welding area.

8. The packaging connection structure according to claim 1, characterized in that: The conductive circuit comprises: Signal lines; The first terminal comprises: A signal terminal, wherein the signal terminal is located on the signal line; Wherein, the external buffer is located on the signal line; The conductive wiring comprises: Signal wiring; The first pad comprises: A signal pad, the signal pad being located on the signal wiring; The signal pad is welded to the signal terminal to form the welding area; The transition region is located on the signal wiring; Grounding circuit; The first terminal further comprises: A grounding terminal, the grounding terminal being located on the grounding line; The conductive wiring further comprises: Ground wiring; The first pad comprises: A ground pad, the ground pad being located on the ground wiring; The ground pad is welded to the ground terminal.

9. A packaging base, characterized in that: The packaging base comprises: A substrate, wherein a first surface of the substrate is provided with a mounting portion, the mounting portion being used to mount an optical semiconductor element; A housing, the housing being disposed on the first surface of the substrate, the housing having a mounting portion and an accommodating space; The loading portion is located in the accommodating space; The packaging connection structure as described in any one of claims 1 to 8; The connecting component is arranged on the mounting portion; The installation portion is a notch, and the insulating member is embedded and installed on the notch to block the notch.

10. An optical semiconductor device, characterized in that: The device comprises: The packaging base as claimed in claim 9; an optical semiconductor element, the optical semiconductor element being mounted on the mounting portion and being electrically connected to the conductive wiring; Fiber optic components; A through hole formed on a side surface of the shell; an optical coupling component, the optical coupling component being inserted into the through hole and used for connecting the optical semiconductor element and the optical fiber component respectively; Sealing ring; A cover plate is covered on the upper surface of the shell through the sealing ring.

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