Ultra-wideband transition transmission structure loaded with open-circuit branches

Abstract

The invention discloses an ultra-wideband transition transmission structure loaded with open-circuit branches. The ultra-wideband transition transmission structure comprises a signal conversion plate transition structure and a film probe card transition structure, the signal conversion plate transition structure comprises a first dielectric layer, a coaxial cable, a first signal line, a first upper metal layer arranged on one side of the first dielectric layer and a first lower metal layer arranged on the other side of the first dielectric layer, and the first dielectric layer is provided with a plurality of first metal via holes used for connecting the first upper metal layer and the first lower metal layer. The coaxial cable is arranged on the first dielectric layer, an outer conductor of the coaxial cable is connected with the first upper metal layer, the first signal line is arranged on the first dielectric layer and connected with an inner conductor of the coaxial cable, the first lower metal layer comprises a first metal sheet and a second metal sheet, and the first metal sheet and the second metal sheet define a first groove. The first groove coincides with the central axis of the first signal line. The film probe card transition structure is connected with the first signal line and the first upper metal layer. According to the scheme, the bandwidth is improved, and the performance requirement of low loss is met.

Description

Technical Field

[0001] The invention relates to the technical field of thin film probe card testing systems, in particular to an ultra-wideband transition transmission structure loaded with open-circuit branches. Background Art

[0002] With the development of communication technology, optical communication technology and chips with higher transmission rate and bandwidth have been widely used, which has prompted the thin film probe card chip test system to develop in the direction of low loss, high frequency and ultra-wideband. The thin film probe card test system is roughly composed of a signal conversion board and a probe card. The grid ground coplanar waveguide (MGCPW) is used as the high-frequency transmission line of the thin film probe card. The signal transition transmission quality between it and the signal conversion board directly affects the overall performance of the thin film probe card test system. At present, the design of such transition transmission structure is still an important challenge.

[0003] The traditional transition transmission technology between the signal conversion board and the thin film probe card mainly adopts the transition between microstrips and microstrips, the transition between coplanar waveguide and microstrip, etc. However, the above technical solutions have the problems of narrow bandwidth and large loss. In order to further improve the bandwidth and reduce the loss, the industry has proposed a coplanar waveguide heterogeneous transition structure. Although this design has improved the bandwidth, with the development of communication technology, this type of design still needs to be further improved in bandwidth.

[0004] In summary, it is necessary to propose a new type of ultra-wideband transition transmission structure loaded with open branches to further improve the bandwidth while meeting the low-loss performance requirements. Summary of the invention

[0005] In order to overcome the defects in the prior art, an embodiment of the present invention provides an ultra-wideband transition transmission structure loaded with an open-circuit branch, which realizes ultra-wideband signal transition transmission from a signal conversion plate to a thin film probe card with a compact structure while having low-loss performance.

[0006] The embodiment of the present application discloses: an ultra-wideband transition transmission structure loaded with open branches, including: a signal conversion board transition structure and a thin film probe card transition structure; the signal conversion board transition structure includes a first dielectric layer, a coaxial cable, a first signal line, a first upper metal layer arranged on one side of the first dielectric layer and a first lower metal layer arranged on the other side of the first dielectric layer, the first dielectric layer is provided with a plurality of first metal vias for connecting the first upper metal layer and the first lower metal layer, the coaxial cable is arranged on the first dielectric layer and the outer conductor of the coaxial cable is connected to the first upper metal layer, the first signal line is arranged on the first dielectric layer and is connected to the inner conductor of the coaxial cable, the first lower metal layer includes a first metal sheet and a second metal sheet arranged oppositely, the first metal sheet and the second metal sheet surround a first groove, and the central axis of the first groove coincides with the central axis of the first signal line; the thin film probe card transition structure is connected to the first signal line and the first upper metal layer.

[0007] Specifically, the first groove includes a first rectangular groove and a second rectangular groove that are connected, the first rectangular groove is located at one end of the second rectangular groove close to the coaxial cable, and the width of the first rectangular groove is smaller than the width of the second rectangular groove.

[0008] Specifically, the first upper metal layer includes a third metal sheet and a fourth metal sheet arranged opposite to each other, the third metal sheet and the fourth metal sheet form a second slot, the coaxial cable and the first signal line are both located in the second slot, and the central axis of the second slot coincides with the central axis of the first signal line.

[0009] Specifically, the second slot includes a third rectangular slot and a fourth rectangular slot that are connected, the coaxial cable is located in the third rectangular slot, and the first signal line is located in the fourth rectangular slot.

[0010] Specifically, the thin film probe card transition structure includes a second dielectric layer, a second signal line, a second upper metal layer and a second lower metal layer, the second upper metal layer is arranged on one side of the second dielectric layer, the second lower metal layer is arranged on the other side of the second dielectric layer, the second dielectric layer is provided with a plurality of second metal vias for connecting the second upper metal layer and the second lower metal layer, the second lower metal layer includes a fifth metal sheet and a sixth metal sheet arranged opposite to each other, the fifth metal sheet and the sixth metal sheet form a third groove, and the second signal line is arranged on the second dielectric layer and is located in the third groove.

[0011] Specifically, the second signal line includes a first portion and a second portion connected to each other, and a width of the first portion is smaller than a width of the second portion.

[0012] Specifically, the connection part between the first part and the second part is trapezoidal in shape.

[0013] Specifically, a first probe base is provided on the second signal line, and a plurality of first probes for connecting to the first signal line are provided on the first probe base.

[0014] Specifically, the central axes of the first probe base and the first probes coincide with the central axis of the first signal line respectively.

[0015] Specifically, second probe bases are respectively provided on the fifth metal sheet and the sixth metal sheet, and a plurality of second probes for connecting to the first upper metal layer are respectively provided on the second probe bases.

[0016] The present invention has at least the following beneficial effects:

[0017] 1. By constructing an open-circuit stub loaded with a first slot on one side of the coaxial cable, an ultra-wideband signal transition transmission from the signal conversion board to the thin-film probe card is realized with a compact structure, and at the same time, it has the performance of low loss.

[0018] 2. The first rectangular slot is loaded on the side close to the coaxial cable, which can adjust the parasitic inductance mutation during the installation of the coaxial cable, so that the TEM mode in the coaxial cable is better converted into the quasi-TEM mode in the open-circuit stub.

[0019] 3. The second signal line adopts the structure of a tapered signal line, is connected to the first signal line through the first probe base and the first probes, and by controlling the relative position of the connection point to the open end of the open-circuit stub, the coupling electric field can be controlled. At the same time, the impedance is adjusted by matching with the second rectangular slot on the first lower metal layer, so that the overall transmission transition structure can operate in an ultra-wide frequency band.

[0020] To make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given, and in conjunction with the accompanying drawings, the detailed description is as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 is a schematic structural diagram of an ultra-wideband transition transmission structure with an open-circuit stub loaded in an embodiment of the present invention;

[0023] Figure 2 is a schematic structural diagram of a signal conversion board transition structure in an embodiment of the present invention;

[0024] Figure 3 is a schematic structural diagram of a thin film probe card transition structure according to an embodiment of the present invention;

[0025] Figure 4 3 is a frequency response diagram of an ultra-wideband transition transmission structure loaded with an open-circuit branch in an embodiment of the present invention.

[0026] The figure marks of the above drawings are: 1. first dielectric layer; 11. first metal via; 2. coaxial cable; 3. first signal line; 4. first upper metal layer; 41. third metal sheet; 42. fourth metal sheet; 5. first lower metal layer; 51. first metal sheet; 52. second metal sheet; 531. first rectangular groove; 532. second rectangular groove; 6. second dielectric layer; 61. second metal via; 7. second signal line; 71. first part; 72. second part; 73. first probe seat; 74. first probe; 8. second upper metal layer; 9. second lower metal layer; 91. fifth metal sheet; 92. sixth metal sheet; 10. signal conversion board transition structure; 20. thin film probe card transition structure. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "fixed", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or 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 this application can be understood by specific circumstances.

[0029] In the present invention, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may include the first feature and the second feature being in direct contact, or may include the first feature and the second feature being in contact not directly but through another feature between them. Moreover, a first feature being “above”, “below”, and “above” a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature includes the first feature being below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0030] In the description of this embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing 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 scope of protection of the present application.

[0031] In addition, the terms "first", "second", etc. are only used to distinguish in description and have no special meaning.

[0032] Combination Figures 1 to 3 As shown, the ultra-wideband transition transmission structure loaded with open branches in this embodiment includes a signal conversion plate transition structure 10 and a thin film probe card transition structure 20 that are connected to each other, and the two are fixedly connected to form an electrical connection.

[0033] like Figure 2As shown, the signal conversion board transition structure 10 of this embodiment includes a first dielectric layer 1, a coaxial cable 2, a first upper metal layer 4 and a first lower metal layer 5. Among them, the first dielectric layer 1 includes a first surface and a second surface arranged oppositely, the first upper metal layer 4 is arranged on the first surface of the first dielectric layer 1, and the second metal layer is arranged on the second surface of the first dielectric layer 1. The first dielectric layer 1 is provided with a plurality of first metal vias 11, and the first metal vias 11 are used to achieve conduction between the first metal layer and the second metal layer. The coaxial cable 2 includes an inner conductor and an outer conductor arranged coaxially, and an insulator is also arranged between the inner conductor and the outer conductor. The cross section of the inner conductor is circular, and the cross sections of the outer conductor and the insulator are both annular. The coaxial cable 2 is fixed on the first dielectric layer 1, and the outer conductor of the coaxial cable 2 is electrically connected to the first upper metal layer 4, and the inner conductor of the coaxial cable 2 is electrically connected to the first signal line 3 arranged on the first dielectric layer 1. The first lower metal layer 5 includes a first metal sheet 51 and a second metal sheet 52 which are arranged on the second surface of the first dielectric layer 1. The first metal sheet 51 and the second metal sheet 52 are not connected to each other and they surround a first groove, and the central axis of the first groove coincides with the central axis of the first signal line 3. The thin film probe card transition structure 20 is electrically connected to the first signal line 3 and the first upper metal layer 4.

[0034] The first upper metal layer 4, the first dielectric layer 1, the first lower metal layer 5 with the first groove and the first signal line 3 together form a grounded coplanar waveguide (GCPW)-shaped open-circuit branch. The ultra-wideband transition transmission structure loaded with the open-circuit branch of this embodiment can realize ultra-wideband signal transmission between the signal conversion board and the thin film probe card by constructing an open-circuit branch loaded with the first groove on one side of the coaxial cable 2. The structure is very compact and the loss is low.

[0035] Preferably, the central axis of the first signal line 3 coincides with the axis of the coaxial cable 2 .

[0036] like Figure 2 As shown, the first slot of this embodiment includes a first rectangular slot 531 and a second rectangular slot 532 that are interconnected, and the first rectangular slot 531 is located at one end of the second rectangular slot 532 close to the coaxial cable 2. The width of the first rectangular slot 531 is smaller than the width of the second rectangular slot 532. The first rectangular slot 531 can change the impedance mutation introduced by the installation of the coaxial cable 2, so that the TEM mode in the coaxial cable 2 is converted to the quasi-TEM mode in the open branch.

[0037] Continue to refer to Figure 2 The first upper metal layer 4 of this embodiment includes a third metal sheet 41 and a fourth metal sheet 42 which are relatively arranged on the first surface of the first dielectric layer 1. The third metal sheet 41 and the fourth metal sheet 42 are not connected to each other, and the two surround a second groove. The coaxial cable 2 and the first signal line 3 are both located in the second groove, and the central axis of the second groove coincides with the central axis of the first signal line 3.

[0038] Furthermore, the second slot includes a third rectangular slot and a fourth rectangular slot that are interconnected, and the width of the third rectangular slot is greater than the width of the fourth rectangular slot. The coaxial cable 2 is located in the third rectangular slot and is electrically connected to the third metal sheet 41 and the fourth metal sheet 42 on both sides of the third rectangular slot, and the first signal line 3 is located in the fourth rectangular slot.

[0039] like Figure 3 As shown, the thin film probe card transition structure 20 of the present embodiment includes a second dielectric layer 6, a second signal line 7, a second upper metal layer 8 and a second lower metal layer 9. The second dielectric layer 6 includes a first surface and a second surface which are arranged oppositely, the second upper metal layer 8 is arranged on the first surface of the second dielectric layer 6, the second lower metal layer 9 is arranged on the second surface of the second dielectric layer 6, and the second dielectric layer 6 is provided with a plurality of second metal vias 61, and the second metal vias 61 are used to realize the electrical connection between the second upper metal layer 8 and the second lower metal layer 9. The second lower metal layer 9 includes a fifth metal sheet 91 and a sixth metal sheet 92 which are arranged oppositely on the second dielectric layer 6, the fifth metal sheet 91 and the sixth metal sheet 92 together surround a third groove, the second signal line 7 is arranged on the second surface of the second dielectric layer 6 and is located in the third groove, the second signal line 7 is not connected to the second lower metal layer 9, and the central axis of the third groove and the central axis of the second signal line 7 are both coincident with the central axis of the first signal line 3.

[0040] The second signal line 7 includes a first portion 71 and a second portion 72 connected to each other. The first portion 71 and the second portion 72 are rectangular in shape, and the width of the first portion 71 is smaller than the width of the second portion 72. When the film probe card transition structure 20 is connected to the signal conversion board transition structure 10, the second portion 72 is located at one end of the first portion 71 facing the coaxial cable 2.

[0041] Preferably, the connection between the first portion 71 and the second portion 72 of the second signal line 7 is in a trapezoidal shape, and is an isosceles trapezoidal shape, the end of the first portion 71 is the upper base of the trapezoid, and the end of the second portion 72 is the lower base of the trapezoid. In other words, the width of the second signal line 7 gradually increases from the first portion 71 to the second portion 72, that is, the second signal line 7 is a signal line with a gradually changing width. Correspondingly, the width of the portion corresponding to the third groove and the first portion 71 is also smaller than the width of the portion corresponding to the third groove and the second portion 72, and the portion corresponding to the connection between the third groove and the first portion 71 and the second portion 72 is also in a trapezoidal shape.

[0042] like Figure 3As shown, the second signal line 7 of this embodiment is also provided with a first probe seat 73, and a plurality of first probes 74 are provided on the first probe seat 73. The second signal line 7 is electrically connected to the first signal line 3 through the plurality of first probes 74, and the second rectangular groove 532 is matched to provide a transmission channel for the overall structure. The central axis of the first probe seat 73 and the central axis of the first probe 74 coincide with the central axis of the first signal line 3 respectively. By changing the relative position of the connection between the first probe 74 and the first signal line 3, the coupling electric field can be adjusted, so that the overall transmission transition structure can work in an ultra-wide frequency band.

[0043] In this embodiment, the fifth metal sheet 91 and the sixth metal sheet 92 of the second lower metal layer 9 are respectively provided with second probe seats, and the second probe seats are respectively provided with a plurality of second probes. The second lower metal layer 9 is electrically connected to the first upper metal layer 4 via the plurality of second probes.

[0044] Figure 4 The frequency response of a design case of the present invention is shown. The parameters of this design case are as follows: the total length of the overall link of the thin film probe card test system (signal conversion card and thin film probe card connection) is 93mm, of which the coaxial cable 2 is 80mm long, the open branch is 1mm, and the thin film probe card is 12mm; the thin film probe card uses polyimide as a substrate, with a dielectric constant of 3.71, a loss angle of 0.02, and a thickness of 50μm; the first dielectric layer of the open branch is made of copper clad M6 material, and the insulator of the coaxial cable 2 is made of PTFE material. Figure 4 As shown in the figure, the matching of the above design case in the 0-110GHz passband is better than -13dB and the insertion loss is better than 14dB.

[0045] The working process of the ultra-wideband transition transmission structure loaded with open branches in this embodiment is as follows: the first part of the second signal line contacts the wafer to be tested, and the test signal is transmitted to the coaxial cable through the first signal line, and then transmitted to the test machine.

[0046] In summary, the ultra-wideband transition transmission structure loaded with open branches in this embodiment has the following advantages:

[0047] 1. By constructing an open-circuit branch loaded with a first slot on one side of the coaxial cable 2, ultra-wideband signal transition transmission from the signal conversion board to the thin film probe card is achieved with a compact structure while having low-loss performance.

[0048] 2. The first rectangular groove 531 is loaded on the side close to the coaxial cable 2, which can adjust the parasitic inductance mutation when the coaxial cable 2 is installed, so that the TEM mode in the coaxial cable 2 is better converted to the quasi-TEM mode in the open branch.

[0049] 3. The second signal line 7 adopts a gradient signal line structure, and is connected to the first signal line 3 through a first probe seat 73 and a first probe 74. The coupling electric field can be controlled by controlling the relative position of the connection point to the open end of the open branch. At the same time, the impedance is adjusted by combining with the second rectangular groove 532 on the first lower metal layer 5, so that the overall transmission transition structure can operate in an ultra-wide frequency band.

[0050] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An ultra-wideband transition transmission structure loaded with open branches, characterized in that: include: A signal conversion board transition structure and a thin film probe card transition structure; the signal conversion board transition structure includes a first dielectric layer, a coaxial cable, a first signal line, a first upper metal layer arranged on one side of the first dielectric layer, and a first lower metal layer arranged on the other side of the first dielectric layer, the first dielectric layer is provided with a plurality of first metal vias for connecting the first upper metal layer and the first lower metal layer, the coaxial cable is arranged on the first dielectric layer and the outer conductor of the coaxial cable is connected to the first upper metal layer, the first signal line is arranged on the first dielectric layer and is connected to the inner conductor of the coaxial cable, the first lower metal layer includes a first metal sheet and a second metal sheet arranged oppositely, the first metal sheet and the second metal sheet surround a first groove, and the central axis of the first groove coincides with the central axis of the first signal line; the thin film probe card transition structure is connected to the first signal line and the first upper metal layer.

2. The ultra-wideband transition transmission structure loaded with open branches according to claim 1, characterized in that: The first groove includes a first rectangular groove and a second rectangular groove that are connected. The first rectangular groove is located at one end of the second rectangular groove close to the coaxial cable. The width of the first rectangular groove is smaller than the width of the second rectangular groove.

3. The ultra-wideband transition transmission structure loaded with open branches according to claim 1, characterized in that: The first upper metal layer includes a third metal sheet and a fourth metal sheet arranged opposite to each other, the third metal sheet and the fourth metal sheet surround a second slot, the coaxial cable and the first signal line are both located in the second slot, and the central axis of the second slot coincides with the central axis of the first signal line.

4. The ultra-wideband transition transmission structure loaded with open branches according to claim 3, characterized in that: The second slot includes a third rectangular slot and a fourth rectangular slot that are connected. The coaxial cable is located in the third rectangular slot, and the first signal line is located in the fourth rectangular slot.

5. The ultra-wideband transition transmission structure loaded with open branches according to claim 1, characterized in that: The thin film probe card transition structure includes a second dielectric layer, a second signal line, a second upper metal layer and a second lower metal layer, the second upper metal layer is arranged on one side of the second dielectric layer, the second lower metal layer is arranged on the other side of the second dielectric layer, the second dielectric layer is provided with a plurality of second metal vias for connecting the second upper metal layer and the second lower metal layer, the second lower metal layer includes a fifth metal sheet and a sixth metal sheet arranged opposite to each other, the fifth metal sheet and the sixth metal sheet form a third groove, and the second signal line is arranged on the second dielectric layer and located in the third groove.

6. The ultra-wideband transition transmission structure loaded with open branches according to claim 5, characterized in that: The second signal line includes a first portion and a second portion connected to each other, and a width of the first portion is smaller than a width of the second portion.

7. The ultra-wideband transition transmission structure loaded with open branches according to claim 6, characterized in that: A connection between the first portion and the second portion is in a trapezoidal shape.

8. The ultra-wideband transition transmission structure loaded with open branches according to claim 5, characterized in that: A first probe seat is disposed on the second signal line, and a plurality of first probes for connecting with the first signal line are disposed on the first probe seat.

9. The ultra-wideband transition transmission structure loaded with open branches according to claim 8, characterized in that: Central axes of the first probe seat and the first probe respectively coincide with central axes of the first signal line.

10. The ultra-wideband transition transmission structure loaded with open branches according to claim 5, characterized in that: The fifth metal sheet and the sixth metal sheet are respectively provided with a second probe seat, and the second probe seat is respectively provided with a plurality of second probes for connecting with the first upper metal layer.

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