Signal transfer board and signal transfer test device

Abstract

The present application provides a signal transfer board and a signal transfer test device for transferring transmission signals between a circuit board and a device under test. The signal transfer board includes at least one signal transfer area, and the signal transfer area includes: a carrier substrate, a signal routing layer and a ground layer. The signal routing layer is arranged on the carrier substrate. The signal routing layer includes at least one signal connection line and at least one signal test line. The signal connection line is used to electrically connect between the circuit board and the device under test; one end of the signal test line is electrically connected to the signal connection line, and the other end of the signal test line is used to electrically connect the detection equipment to transmit the signal in the signal connection line to the detection equipment; the ground layer is arranged on the carrier substrate and is arranged on a different layer from the signal routing layer. The ground layer has a hollow portion, and the hollow portion corresponds to at least part of the signal test line. The ground layer near the signal test line in the signal transfer board of the present application is provided with a corresponding hollow portion, which has better transmission characteristics.

Description

Technical Field

[0001] The present application relates to the field of signal transmission technology, and in particular to a signal adapter board and a signal adapter test device. Background Art

[0002] With the development of communication technology, it is becoming increasingly important to detect the working status of chips and devices under test. Generally, a signal adapter board is used to detect the transmission signal of the chip and devices under test in the working state. In this process, how to improve the transmission characteristics of the signal adapter board becomes a technical problem that needs to be solved. Summary of the Invention

[0003] The present application provides a signal transfer board and a signal transfer test device with better transmission characteristics.

[0004] In a first aspect, the present application provides a signal transfer board for transferring transmission signals between a circuit board and a device under test, wherein the signal transfer board includes at least one signal transfer area, and the signal transfer area includes:

[0005] a carrier substrate;

[0006] a signal routing layer, the signal routing layer being provided on the carrier substrate, the signal routing layer comprising at least one signal connection line and at least one signal test line, the signal connection line being used to electrically connect the circuit board and the device under test; one end of the signal test line being electrically connected to the signal connection line, and the other end of the signal test line being used to electrically connect to a detection device to transmit a signal in the signal connection line to the detection device; and

[0007] A ground layer is provided on the carrier substrate and is arranged in a different layer from the signal wiring layer. The ground layer has a hollow portion, and the hollow portion corresponds to at least a portion of the signal test line.

[0008] In the second aspect, the present application provides a transfer test device, including a circuit board, a device to be tested and the signal transfer board, wherein at least one electronic device is provided on the circuit board, and the circuit board, the signal transfer board and the device to be tested are arranged in sequence in the thickness direction of the signal transfer board, and the two ends of the signal connection line are electrically connected to the circuit board and the device to be tested respectively, and the device to be tested is electrically connected to the electronic device through the signal connection line and the circuit board.

[0009] In the signal adapter board provided by the present application, the signal routing layer and the ground layer are arranged in different layers on the carrier substrate. The signal routing layer includes at least one signal connection line for electrically connecting the circuit board and the device to be tested. The signal routing layer also includes at least one signal test line. One end of the signal test line is electrically connected to the signal connection line, and the other end of the signal test line is used to electrically connect the detection equipment and transmit the signal in the signal connection line to the detection equipment. At least part of the signal test line corresponds to the position of the hollow part of the ground layer, and the hollow part of the ground layer has better transmission characteristics of the signal adapter board. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0011] Figure 1 This is a schematic cross-sectional view of a signal transfer test device provided in an embodiment of the present application;

[0012] Figure 2 This is a schematic top view of the signal adapter board provided in the first embodiment of the present application;

[0013] Figure 3 This is a schematic diagram of the top view of the signal adapter board provided in the second embodiment of the present application. Figure 1 ;

[0014] Figure 4 This is a schematic cross-sectional structural diagram of a signal adapter board provided in the first embodiment of the present application;

[0015] Figure 5 2 is a schematic cross-sectional structural diagram of a signal adapter board provided in a second embodiment of the present application;

[0016] Figure 6 1 is a schematic top view of the signal adapter board provided in the third embodiment of the present application;

[0017] Figure 7 This is a schematic diagram of the top view of the signal adapter board provided in the second embodiment of the present application. Figure 2 ;

[0018] Figure 8 This is a schematic top view of the signal transfer area provided in the first embodiment of the present application;

[0019] Figure 9 This is a schematic top view of the signal transfer area provided in the second embodiment of the present application;

[0020] Figure 10 2 is a schematic cross-sectional structural diagram of a signal adapter board provided in a third embodiment of the present application;

[0021] Figure 11 1 is a schematic top view of the signal transfer area provided in the third embodiment of the present application;

[0022] Figure 12a This is a transmission characteristic table of the signal adapter board under the transmission signal provided by the embodiment of the present application;

[0023] Figure 12b This is the transmission characteristics table of the traditional adapter board under the transmission signal;

[0024] Figure 13 This is a topological diagram provided by an embodiment of the present application;

[0025] Figure 14a is an eye diagram at the IOpad of the device under test in an embodiment of the present application;

[0026] Figure 14b This is the eye diagram of the test unit in the embodiment of the present application;

[0027] Figure 15a This is the eye diagram at the IOpad of the device under test when using a traditional adapter board;

[0028] Figure 15b This is the eye diagram of the test unit when using a traditional adapter board.

[0029] Explanation of the reference numerals: signal transfer test device-100, signal transfer board-1, signal transfer area-10, carrier substrate-11, signal routing layer-20, signal connection line-21, signal test line-22, first signal test line-221, second signal test line-222, third signal test line-223, test part-221, first plane-31, second plane-32, third plane-33, ground layer-40, hollow part-41, first hollow part-411, second hollow part-412, isolation ground-42, circuit board-2, device under test-3, electronic device-4. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] References herein to "embodiments" or "implementations" mean that a particular feature, structure, or characteristic described in connection with the embodiments or implementations may be included in at least one embodiment of the present application. The appearance of such phrases in various places in the specification does not necessarily refer to the same embodiment, nor do they constitute independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] It should be noted that the terms "first," "second," and so on in the specification, claims, and drawings of this application are used to distinguish different objects, rather than to describe a specific order. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0033] With the development of communication technology, how to improve the transmission quality of signals has attracted more and more attention from developers. If you want to improve the transmission quality of signals, you should first test the transmission quality of the current signals.

[0034] See also Figure 1 and Figure 2 , the present application provides a signal transfer test device 100 capable of improving transmission characteristics.

[0035] The signal transfer test device 100 includes a circuit board 2, a device under test 3 and a signal transfer board 1. The circuit board 2 is provided with at least one electronic device 4, and the circuit board 2, the signal transfer board 1 and the device under test 3 are arranged in sequence in the thickness direction of the signal transfer board 1. The thickness direction of the signal transfer board 1 is Figure 1 Optionally, the electronic device 4 includes but is not limited to a camera module and other devices. The device under test 3 includes but is not limited to a 3.5Gsps MIPI CPHY chip. The circuit board 2 and the device under test 3 mentioned later can refer to Figure 1 .

[0036] The switching test device 100 of the present application includes but is not limited to performing switching tests on high-frequency or other frequency signals.

[0037] Adapter boards are widely used in the process of testing the transmission quality of signals. Currently, the commonly used adapter boards lead out a test line, which is equivalent to a branch of a signal line. The characteristic impedance of the test line led out by the traditional adapter board is about 50Ω, which makes the transmission characteristics of the adapter board poor. The poor transmission characteristics of the adapter board cause a large difference in signal quality when the adapter board is added and when it is not added, such as large return loss and insertion loss. The signal measured after adding the adapter board cannot truly reflect the signal quality of the original channel, and thus cannot effectively reflect the working status of the device under test in the original channel. Among them, the original channel refers to the connection channel between the device under test and the circuit board in the state without the adapter board.

[0038] The present application provides a signal adapter board 1 capable of achieving better transmission characteristics. The signal adapter board 1 provided in the present application includes but is not limited to being used for measuring 3.5Gsps MIPI CPHY signals.

[0039] See also Figure 1 and Figure 2 The signal transfer board 1 includes at least one signal transfer area 10 .

[0040] The signal transfer board 1 may have a plurality of signal transfer areas 10. Each signal transfer area 10 can transfer the transmission signal between the circuit board 2 and the device under test 3 corresponding to its position.

[0041] See also Figure 3 In one embodiment, the signal transfer board 1 includes a signal transfer area 10. Optionally, the number of the circuit board 2 and the device under test 3 is one, and the signal transfer area 10 transfers the transmission signal of a corresponding area between the circuit board 2 and the device under test 3.

[0042] Please refer again Figure 1 and Figure 2 In another embodiment, the signal transfer board 1 includes a plurality of signal transfer areas 10. Optionally, the number of the circuit board 2 and the device under test 3 is one, and the signal transfer board 1 includes a plurality of signal transfer areas 10, each of which transfers transmission signals between a local area of ​​the circuit board 2 and a local area of ​​the device under test 3. The plurality of signal transfer areas 10 can transfer transmission signals from multiple different local areas of the device under test 3.

[0043] Optionally, there is one circuit board 2 and multiple devices under test 3 (the number of devices under test 3 is less than or equal to the number of signal transfer zones 10). Each signal transfer zone 10 transfers the transmission signal between a local area of ​​the circuit board 2 and one device under test 3. Multiple signal transfer zones 10 transfer the transmission signal between the circuit board 2 and multiple devices under test 3.

[0044] Optionally, there are multiple circuit boards 2 and multiple devices under test 3 (the number of circuit boards 2 and devices under test 3 is less than or equal to the number of signal transfer areas 10). Optionally, each signal transfer area 10 transfers the transmission signal between one circuit board 2 and one device under test 3. The signal transfer area 10 transfers the transmission signal between the circuit board 2 and multiple devices under test 3.

[0045] Please refer again Figure 1 The signal transfer area 10 includes a carrier substrate 11 and a signal routing layer 20. Optionally, the material of the carrier substrate 11 includes but is not limited to plastic or other materials. The thickness direction of the carrier substrate 11 is also the Z direction, and the thickness direction of the carrier substrate 11 mentioned below can refer to Figure 1 .

[0046] The signal routing layer 20 includes at least one signal connection line 21. The signal connection line 21 extends along the thickness direction of the carrier substrate 11 and is used to electrically connect the circuit board 2 and the device under test 3. The device under test 3 is electrically connected to the electronic device 4 through the signal connection line 21 and the circuit board 2.

[0047] Specifically, the carrier substrate 11 includes a first plane 31 and a second plane 32 that are arranged opposite to each other, and the first plane 31 and the second plane 32 are both perpendicular to the thickness direction of the carrier substrate 11. The first plane 31 is the side of the carrier substrate 11 facing the device under test 3, and the second plane 32 is the side of the carrier substrate 11 facing the circuit board 2. The first plane 31 and the second plane 32 are both provided with a welding portion connected to the signal connection line 21. The welding portion of the first plane 31 is used for welding to the device under test 3, and the welding portion of the second plane 32 is used for welding to the circuit board 2. It should be noted that the welding portion can also serve as a part of the signal connection line 21, and the way in which the welding portion is connected to the circuit board 2 includes but is not limited to welding.

[0048] Please refer again Figure 1The signal routing layer 20 further includes at least one signal test line 22. One end of the signal test line 22 is electrically connected to the signal connection line 21, and the other end of the signal test line 22 is used to electrically connect to a detection device (not shown) to transmit the signal in the signal connection line 21 to the detection device. The detection device includes but is not limited to a signal detector such as an oscilloscope. The detection device is used to detect the voltage signal of the signal test line 22.

[0049] Specifically, a test section 221 is further provided on the carrier substrate 11. The test section 221 is connected to the signal test line 22, and the test section 221 is used to be welded to the detection device. Optionally, the test section 221 includes but is not limited to the first plane 31, the second plane 32, or other planes located on the carrier substrate 11. It should be noted that the test section 221 can also serve as part of the signal test line 22, and the method for connecting the test section 221 to the detection device includes but is not limited to welding.

[0050] Please refer again Figure 1 and Figure 4 , the signal transfer board 1 also includes a grounding layer 40, and the grounding layer 40 is provided on the carrier substrate 11, and the grounding layer 40 is at least partially provided in a different layer from the signal routing layer 20. Optionally, the material of the grounding layer 40 includes but is not limited to metal (such as copper foil), conductive oxide, conductive polymer and other conductive materials. The functions of the grounding layer 40 include but are not limited to the following aspects: First, the grounding layer 40 provides a common reference zero potential for the entire circuit to ensure that the entire circuit can work stably; second, the grounding layer 40 can be used to prevent interference from external electromagnetic fields, and the grounding layer 40 can also be used for signal shielding to ensure the stability of the signal in the signal test line 22 and the signal connection line 21; third, to ensure that the circuit operates safely, to avoid damage to the signal transfer board 1, and to avoid leakage of the circuit board and electric shock accidents to the operator.

[0051] See also Figure 1 、 Figure 2 and Figure 4 The ground layer 40 has a hollow portion 41, which corresponds to at least a portion of the signal test line 22. It should be emphasized that the hollow portion 41 is a spatial channel hollowed out in the ground layer 40. The shape of the hollow portion 41 includes but is not limited to a rectangular channel, a cylindrical channel, or an irregularly shaped channel.

[0052] For details, please refer to Figure 1 、 Figure 2 and Figure 4 , Figure 41 is a top view of a portion of the signal transfer area 10. As viewed from the top, at least partial correspondence between the hollow portion 41 and the signal test line 22 means that the position of the hollow portion 41 at least partially overlaps with the position of the signal test line 22. For example, as viewed from the top, the position of the hollow portion 41 may partially overlap with the position of the signal test line 22, or may completely overlap with the position of the hollow portion 41.

[0053] See also Figures 1 to 4 In the signal adapter board 1 provided in the present application, the signal routing layer 20 and the ground layer 40 are arranged in different layers on the carrier substrate 11, and the signal routing layer 20 includes at least one signal connection line 21 for electrically connecting the circuit board 2 and the device under test 3. The signal routing layer 20 also includes at least one signal test line 22, one end of the signal test line 22 is electrically connected to the signal connection line 21, and the other end of the signal test line 22 is used to electrically connect the detection equipment and transmit the signal in the signal connection line 21 to the detection equipment, and at least part of the signal test line 22 corresponds to the position of the hollow portion 41 of the ground layer 40.

[0054] The grounding layer 40 near the signal test line 22 in the signal adapter board 1 of the present application is provided with the corresponding hollow portion 41. The hollow portion 41 reduces the mutual capacitance between the signal test line 22 and the grounding layer 40, so as to increase the characteristic impedance of the signal test line 22 itself, thereby increasing the input impedance from the end of the signal test line 22 connected to the signal connection line 21 to the test section 221, and thereby increasing the input impedance from the end of the signal test line 22 connected to the signal connection line 21 to the test section 221, thereby promoting the signal test line 22 to form a high characteristic impedance line, thereby improving the transmission characteristics of the signal adapter board 1.

[0055] Compared with the technical solution of the adapter board in which the signal test line 22 directly contacts the ground layer 40, the signal adapter board 1 of the present application has less impact on the signal under the main channel (the connection channel between the circuit board 2 and the device under test 3), has better transmission characteristics, and can be used to transfer the transmission signal between the circuit board 2 and the device under test 3.

[0056] There are two ground layers 40, and the two ground layers 40 are respectively disposed on opposite sides of the signal test line 22 in the thickness direction of the carrier substrate 11. It should be emphasized that at least one of the ground layers 40 has the hollow portion 41, and either one of the ground layers 40 or both of the ground layers 40 may have the hollow portion 41.

[0057] Optionally, when both ground layers 40 have the hollow portions 41, the hollow portions 41 of the two ground layers 40 may or may not correspond to each other in the thickness direction of the carrier substrate 11. For example, when the hollow portions 41 of the two ground layers 40 correspond to each other in the thickness direction of the carrier substrate 11, the hollow portions 41 may be formed above and below at least one of the signal test lines 22.

[0058] The grounding layer 40 is provided on both opposite sides of the signal test line 22, so that the signal test line 22 has corresponding grounding layers 40 on both the upper and lower sides. The two grounding layers 40 can further ensure the stable operation of the entire circuit, and further strengthen the signal shielding function of the signal adapter board 1, thereby improving the stability of the signal transfer of the signal adapter board 1. In addition, the two grounding layers 40 can be provided with the hollow portion 41, so that the signal test line 22 has corresponding hollow portions 41 on both the upper and lower sides, further reducing the mutual capacitance between the signal test line 22 and the grounding layer 40, thereby increasing the characteristic impedance of the signal test line 22 itself, and further improving the transmission characteristics of the signal adapter board 1 itself.

[0059] It should be emphasized that the description or examples of the hollow portion 41 in the following text in this embodiment are all descriptions or examples of the hollow portion 41 set on the ground layer 40, and the shape, position and other features of the hollow portion 41 set on the corresponding ground layer 40 may be the same or different.

[0060] See also Figure 4 and Figure 5 , the dimension D1 of the hollow portion 41 in the first direction is greater than or equal to the dimension D2 of the signal connection line 21 in the first direction. The first direction is the X direction, and the dimension D2 of the signal connection line 21 in the first direction is the width of the signal connection line 21. In this embodiment, the width of the signal connection line 21 is designed to accommodate the minimum line width for signal transmission between the circuit board 2 and the device under test 3. In other embodiments, the width of the signal connection line 21 can be varied. In this embodiment, the length of the signal connection line 21 is designed to be the minimum length to facilitate the detection of the transmission signal between the device under test 3 and the circuit board 2 by the detection equipment.

[0061] In this embodiment, the width of the signal connection line 21 is designed to be the minimum line width. According to the formula: characteristic impedance = RF voltage / RF current, when the RF voltage is the same, the smaller the width of the signal test line 22, the smaller the RF current, and thus the larger the characteristic impedance. When the width of the signal test line 22 is minimized, the characteristic impedance of the signal test line 22 can be increased to a certain extent, further reducing the impact of the signal test line 22 on the transmission characteristics of the signal adapter board 1.

[0062] In this embodiment, the length of the signal connection line 21 is designed to be the shortest line length. According to the formula: characteristic impedance = RF voltage / RF current, when the RF voltage is the same, the shorter the length of the signal test line 22, the smaller the RF current, and thus the greater the characteristic impedance. When the length of the signal test line 22 is minimized, the characteristic impedance of the signal test line 22 can be increased to a certain extent, further reducing the impact of the signal test line 22 on the transmission characteristics of the signal adapter board 1.

[0063] Optionally, the number of the hollow portions 41 includes but is not limited to 1, 2, 3, etc.

[0064] See also Figure 6 In one embodiment, there is one hollow portion 41, which corresponds to a distance from one end of the signal test line 22 to the other end of the signal test line 22. That is, without considering the intermediate dielectric layer, the hollow portion 41 completely exposes the signal test line 22 to the ground layer 40.

[0065] The signal test line 22 has the hollow portion 41 above and below the carrier substrate 11 in the thickness direction, further allowing more of the signal test line 22 to be separated from the ground layer 40 (see FIG. Figure 1 ) there is a certain distance between them, thereby increasing the characteristic impedance of the signal test line 22 to improve the transmission characteristics of the signal adapter board 1.

[0066] The number of the hollow portion 41 can be multiple, see Figure 7 In another embodiment, the number of the hollow portions 41 is two, one of the hollow portions 41 corresponds to one end of the signal test line 22, and the other hollow portion 41 corresponds to the other end of the signal test line 22. The ground layer 40 between the two hollow portions 41 covers the portion between the two ends of the signal test line 22. The hollow portions 41 are provided in the local portion of the signal test line 22, so that the ground layer 40 can partially prevent the local portion of the signal test line 22 from being interfered with by external signals, and can also increase the characteristic impedance of the signal test line 22, thereby improving the transmission characteristics of the signal adapter board 1.

[0067] For another example, it is difficult to hollow out some special positions of the signal adapter board 1 to set the hollow parts 41. The hollow parts 41 are hollowed out at the opposite ends of the signal test line 22 respectively, so that the structure of the signal adapter board 1 itself is more stable and the durability of the signal adapter board 1 is enhanced.

[0068] Optionally, there are multiple signal test lines 22, and there is at least one hollow portion 41, and each hollow portion 41 corresponds to at least one signal test line 22. Specifically, when viewed from above, the position of the hollow portion 41 may partially overlap with the position of at least one signal test line 22.

[0069] Optionally, the number of the signal test lines 22 includes but is not limited to 1, 2, 3, 4, etc., see Figure 8 and Figure 9 , Figure 8 The number of the signal test line 22 is one, that is, one hollow portion 41 corresponds to one signal test line 22 . Figure 9 The number of the signal test lines 22 is four, that is, one hollow portion 41 corresponds to four signal test lines 22 .

[0070] The number of the signal test lines 22 of the signal adapter board 1 described in the present application can be designed and produced according to the number of specific connection channels between the circuit board 2 and the device under test 3, thereby improving the scope of application of the signal adapter board 1 and facilitating the signal adapter board 1 to perform adapter testing on the quality of signal transmission between circuit boards 2 of more specifications and the device under test 3.

[0071] Please refer again Figure 4 There are multiple hollow parts 41, and the part of the ground layer 40 between two adjacent hollow parts 41 is an isolation ground 42. The isolation ground 42 can be used for signal shielding and isolation.

[0072] In this embodiment, the position of each hollow portion 41 along the thickness direction of the carrier substrate 11 corresponds to the position of a signal test line 22 along the thickness direction of the carrier substrate 11, and the isolation ground 42 is used to prevent signal crosstalk between each two adjacent signal test lines 22.

[0073] In other implementations, see Figure 10The hollow portion 41 is divided into a first hollow portion 411 and a second hollow portion 412, with the isolation ground 42 located between the first hollow portion 411 and the second hollow portion 412. From a top view, the first hollow portion 411 overlaps with the three signal test lines 22, while the second hollow portion 412 overlaps with the two signal test lines 22. The isolation ground 42 can be used to prevent signal crosstalk between the three signal test lines 22 and the two signal test lines 22.

[0074] One hollow portion 41 corresponds to a plurality of the signal test lines 22 , and at least two of the plurality of the signal test lines 22 form a differential pair, that is, the signals transmitted by at least two of the plurality of the signal test lines 22 are used for differential detection.

[0075] For example, in this embodiment, see Figure 11 One hollow portion 41 corresponds to three signal test lines 22. The signal test lines 22 include a first signal test line 221, a second signal test line 222, and a third signal test line 223. The first signal test line 221, the second signal test line 222, and the third signal test line 223 form differential pairs and perform differential detection.

[0076] Specifically, the first signal test line 221 and the second signal test line 222 form a differential pair and perform differential detection, the second signal test line 222 and the third signal test line 223 form a differential pair and perform differential detection, and the first signal test line 221 and the third signal test line 223 also form a differential pair and perform differential detection.

[0077] It should be noted that differential detection means that the detection device calculates and detects the signal difference between every two signal test lines 22. That is, the difference between the signal of the first signal test line 221 and the signal of the second signal test line 222 is a first difference, the difference between the signal of the second signal test line 222 and the signal of the third signal test line 223 is a second difference, and the difference between the signal of the first signal test line 221 and the signal of the third signal test line 223 is a third difference. The detection device calculates and tests the transmission signal quality between the circuit board 2 and the device under test through the first difference, the second difference, and the third difference.

[0078] By forming differential pairs of the plurality of signal test lines 22 and performing differential detection, electromagnetic interference generated by the signal test lines 22 can be reduced or eliminated, and crosstalk between adjacent signal test lines 22 can be avoided. Optionally, the lengths of the signal test lines 22 forming a differential pair can be equal or unequal.

[0079] By forming differential pairs of the plurality of signal test lines 22 and performing differential detection, the signal adapter board 1 does not need to be provided with the isolation ground 42, making the processing of the signal adapter board 1 simpler and requiring less consumables, which is beneficial to the mass production of the signal adapter board 1.

[0080] The signal adapter board 1 also includes an adjustment device (not shown), which is connected in series to one end of the signal test line 22 close to the signal connection line 21. The adjustment device is used to reduce the difference between the signal transmitted by the signal connection line 21 and the signal received by the detection device through the signal test line 22.

[0081] Optionally, the regulating device is provided in the form of a buried resistor at one end of the signal test line 22 close to the signal connection line 21. The regulating device can further reduce the influence of the signal test line 22 on the signal of the main channel (the connection channel between the circuit board 2 and the device under test 3).

[0082] Under normal circumstances, the detection device includes a test probe. The test probe has a relatively high resistance so as not to interfere with the signal in the signal test line 22 when electrically connected to the signal test line 22. When the signal frequency in the signal test line 22 is relatively high, the test probe exhibits capacitance. At the same time, the signal test line 22 exhibits inductance, and there is an LC resonance between the test probe and the signal test line 22. This resonance causes a large difference between the voltage of the signal transmitted by the signal connection line 21 and the voltage of the signal received by the detection device via the signal test line 22. By connecting the adjustment device in series, the LC resonance between the signal test line 22 and the test probe can be effectively suppressed, reducing the difference between the voltage of the signal test line 22 near the test portion 221 and the voltage at the other end.

[0083] The regulating device itself has a certain resistance. After the regulating device is connected in series to the end of the signal test line 22 close to the signal connection line 21, the input impedance from the end where the signal test line 22 is connected to the signal connection line 21 to the test part 221 is further increased, thereby reducing the influence of the signal test line 22 on the main channel (the connection channel between the circuit board 2 and the device under test 3) signal.

[0084] Optionally, the regulating device includes, but is not limited to, a resistor having a resistance range of 25Ω-100Ω. If the resistance of the resistor is too large, the test probe will be divided (greater than 100Ω), resulting in a large difference between the voltage of the test section 221 and the voltage at the connection between the signal test line 22 and the signal connection line 21, making the signal test result inaccurate. If the resistance of the resistor is too small (less than 100Ω), the effect of reducing the influence of the signal test line 22 on the main channel signal is low.

[0085] Therefore, the resistance within the range of 25Ω-100Ω does not divide the voltage of the test probe and can minimize the impact of the signal test line 22 on the signal of the test line main channel (the connection channel between the circuit board 2 and the device under test 3). Optionally, the resistance of the adjustment device can be 50Ω.

[0086] The signal adapter board 1 provided in the present application has better transmission characteristics compared with traditional adapter boards, and the transmission characteristics include the insertion loss and return loss of the signal transmitted by the signal adapter board 1.

[0087] For details, please refer to Figure 12a and Figure 12b , Figure 12a Schematic diagram of the insertion loss and return loss of the signal transmitted by the signal adapter board 1 provided in this embodiment, Figure 12b Schematic diagram of the insertion loss and return loss of signals transmitted by a traditional adapter board. The first curve shows the insertion loss of the signal transmitted by the signal adapter board 1, the second curve shows the return loss of the signal transmitted by the signal adapter board 1, the third curve shows the insertion loss of the signal transmitted by a traditional adapter board, and the fourth curve shows the return loss of the signal transmitted by a traditional adapter board.

[0088] according to Figure 12a and Figure 12b It can be seen that when the frequency is 5 GHz, the point corresponding to the first curve moves upward by a certain distance relative to the point corresponding to the third curve, and the vertical coordinate corresponding to the moving distance is 0.94 dB, that is, when the frequency is 5 GHz, the insertion loss of the signal transmitted by the signal adapter board 1 is improved by 0.94 dB compared with the insertion loss of the signal transmitted by the traditional adapter board.

[0089] Similarly, according to Figure 12a and Figure 12bIt can be seen that when the frequency is 5 GHz, the point corresponding to the second curve moves upward by a certain distance relative to the point corresponding to the fourth curve, and the vertical coordinate corresponding to the moving distance is 8.28 dB, that is, when the frequency is 5 GHz, the return loss of the signal transmitted by the signal adapter board 1 is improved by 8.28 dB compared with the return loss of the signal transmitted by the traditional adapter board.

[0090] It should be noted that, from Figure 12a and Figure 12b It can be seen that when the frequency is higher than 5 GHz, the first curve as a whole has a greater upward shift relative to the third curve, and the second curve as a whole has a greater upward shift relative to the fourth curve. This shows that the signal adapter board 1 has a greater improvement effect on the transmission and switching of high-speed signals. The signal adapter board 1 can better improve the signal insertion loss and return loss when transmitting high-speed signals.

[0091] At the same time, when the frequency is lower than 5 GHz, the first curve as a whole also moves upward to a certain extent relative to the third curve, and the second curve as a whole also moves upward to a certain extent relative to the fourth curve. It can be seen that the signal main key panel also has a certain improvement effect on the transmission and conversion of lower-speed signals, and can also improve the insertion loss and return loss generated when the low-speed signal is transmitted in the signal conversion board 1.

[0092] The signal transfer board 1 of the present application can be used for various fields of equipment. For example, see Figure 13 , Figure 13 The signal adapter board 1 of this application is used for signal transfer and testing between a camera module and a 3.5Gsps MIPI CPHY chip.

[0093] See also Figure 13 、 Figure 14a 、 Figure 14b 、 Figure 15a and Figure 15b , Figure 14a is the eye diagram at the IOpad (input or output pin) of the device under test 3 when the signal adapter board 1 is used for signal transfer, Figure 14b is the eye diagram of the test unit 221 on the signal adapter board 1, Figure 15a The eye diagram at the IOpad (input or output pin) of the device under test 3 when using a traditional adapter board for signal transfer is shown in FIG. Figure 15b This is the eye diagram of the test part on the traditional adapter board.

[0094] See also Figure 14a and Figure 14b, at the IOpad point, the eye width of the eye diagram is 181ps when using the signal adapter board 1, and the eye width of the eye diagram is 165ps when using the traditional adapter board. The eye width of the eye diagram of the signal adapter board 1 is increased by 16ps relative to the eye width of the eye diagram when using the traditional adapter board. The eye height of the eye diagram when using the signal adapter board 1 is 91.3ms, and the eye height of the eye diagram when using the traditional adapter board is 81.6ms. The eye height of the eye diagram of the signal adapter board 1 is increased by 7.7ms relative to the eye height of the eye diagram when using the traditional adapter board, indicating that after using the signal adapter board 1 of the present application, the signal in the device under test 3 is more stable than the signal in the device under test 3 after using the traditional adapter board, and the transmission characteristics of the signal adapter board 1 are better.

[0095] See also Figure 15a and Figure 15b In the test section, the eye height of the eye diagram is 76.3ms when the signal adapter board 1 is used, and the eye height of the eye diagram is 56.1ms when the traditional adapter board is used. The eye height of the eye diagram of the signal adapter board 1 is increased by 20.2ms relative to the eye height of the eye diagram when the traditional adapter board is used, indicating that the signal of the test section 221 is more stable after using the signal adapter board 1 of the present application than the signal of the test section after using the traditional adapter board, and the transmission characteristics of the signal adapter board 1 are better.

[0096] The above is part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications are also considered to be within the scope of protection of the present application.

Claims

1. A signal transfer board for transferring transmission signals between a circuit board and a device under test, characterized in that: The signal transfer board includes at least one signal transfer area, and the signal transfer area includes: a carrier substrate; a signal routing layer, the signal routing layer being provided on the carrier substrate, the signal routing layer comprising at least one signal connection line and at least one signal test line, the signal connection line being used to electrically connect the circuit board and the device under test; one end of the signal test line being electrically connected to the signal connection line, and the other end of the signal test line being used to electrically connect to a detection device to transmit a signal in the signal connection line to the detection device; and A ground layer is provided on the carrier substrate, the ground layer is at least partially provided in a different layer from the signal wiring layer, and the ground layer has a hollow portion, and the hollow portion corresponds to at least a portion of the signal test line.

2. The signal adapter board according to claim 1, wherein: A size of the hollow portion in the first direction is greater than or equal to a size of the signal connection line in the first direction.

3. The signal adapter board according to claim 1, wherein: The number of the hollow portion is one, and the hollow portion corresponds to one end of the signal test line to the other end of the signal test line; or, There are multiple hollow portions, one of which corresponds to one end of the signal test line, and another of which corresponds to the other end of the signal test line.

4. The signal adapter board according to claim 1, wherein: There are a plurality of signal test lines, there is at least one hollow portion, and each hollow portion corresponds to at least one signal test line.

5. The signal adapter board according to claim 4, characterized in that: There are multiple hollow parts, and a portion of the ground layer between two adjacent hollow parts is an isolation ground, which is used to prevent signal crosstalk between two adjacent signal test lines.

6. The signal adapter board according to claim 4, characterized in that: One hollow portion corresponds to a plurality of the signal test lines, and signals transmitted by at least two of the plurality of the signal test lines are used for differential detection.

7. The signal adapter board according to claim 1, wherein: The signal adapter board also includes an adjustment device, which is connected in series to one end of the signal test line close to the signal connection line. The adjustment device is used to reduce the difference between the signal transmitted by the signal connection line and the signal received by the detection device through the signal test line.

8. The signal adapter board according to claim 7, wherein: The regulating device is a resistor, and the resistance range of the resistor is 25Ω-100Ω.

9. The signal adapter board according to any one of claims 1 to 8, characterized in that: The number of the grounding layers is two, and the two grounding layers are respectively arranged on two opposite sides of the signal test line in the thickness direction of the carrier substrate.

10. A signal transfer test device, characterized in that: It includes a circuit board, a device to be tested and a signal adapter board as described in any one of claims 1 to 9, wherein at least one electronic device is provided on the circuit board, the circuit board, the signal adapter board and the device to be tested are arranged in sequence in the thickness direction of the signal adapter board, the two ends of the signal connection line are electrically connected to the circuit board and the device to be tested respectively, and the device to be tested is electrically connected to the electronic device through the signal connection line and the circuit board.

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