Board, terminal and RF test method

Abstract

The embodiments of the present application relate to the field of radio frequency technology, and provide a single board, a terminal and a radio frequency testing method. The single board includes a radio frequency front-end circuit, a first short-circuit pad, a second short-circuit pad, a radio frequency back-end circuit and a conductive adhesive. The radio frequency front-end circuit is used to generate a radio frequency signal. The first short-circuit pad is electrically connected to the radio frequency front-end circuit. The second short-circuit pad is spaced apart from the first short-circuit pad. The radio frequency back-end circuit is electrically connected to the second short-circuit pad. The conductive adhesive electrically connects the first short-circuit pad and the second short-circuit pad to transmit the radio frequency signal from the first short-circuit pad to the radio frequency back-end circuit via the second short-circuit pad. The single board can remove the traditional radio frequency switch test socket, saving the device cost of the single board and the layout area of ​​the single board.

Description

Technical Field

[0001] The present application relates to the field of radio frequency technology, and in particular to a single board, a terminal and a radio frequency testing method. Background Art

[0002] On a single board of a terminal (such as a mobile phone), an RF switch test socket is usually provided to be electrically connected to the RF test pin to implement the test of the RF signal. However, the RF switch test socket is specifically used for production testing. After the RF test is completed, the RF switch test socket has no other use for the terminal product and the user, but it is still retained on the single board. Therefore, the setting of the RF switch test socket not only increases the device cost of the single board but also occupies the layout area of ​​the single board.

[0003] In addition, in the RF field, the RF switch test socket is set on the single board by welding. That is, in the RF field, the transmission line of the RF signal is formed by welding. However, in order to realize the electrical connection between the RF switch test socket and the single board, the solder (such as solder) needs to be heated to a high temperature (such as 300°C to 400°C), and the process is complicated. Moreover, when the single board is reworked, the single board needs to go through steps such as high-temperature rework and cleaning of the pad. In addition, in the step of high-temperature rework of the single board, although the part of the single board is reheated to a high temperature, this step will still affect other devices around the device to be repaired, thereby affecting the reliability of the entire single board. Summary of the invention

[0004] The first aspect of the present application provides a single board. The single board includes:

[0005] A radio frequency front-end circuit for generating a radio frequency signal;

[0006] A first short-circuit pad, electrically connected to the RF front-end circuit;

[0007] A second short-circuit pad is spaced apart from the first short-circuit pad;

[0008] A radio frequency back-end circuit electrically connected to the second short-circuit pad; and

[0009] Conductive glue electrically connects the first short-circuit pad and the second short-circuit pad to transmit the radio frequency signal from the first short-circuit pad to the radio frequency back-end circuit via the second short-circuit pad.

[0010] In the single board of the first aspect of the present application, the first short-circuit pad is electrically connected to the RF front-end circuit. During the production and processing stage of the single board, the first short-circuit pad and the second short-circuit pad are not connected, and the first short-circuit pad and the second short-circuit pad are in a disconnected state. During the RF test, the first short-circuit pad can be used to electrically connect to the signal pin of the RF test pin, so that the RF signal generated by the RF front-end circuit is transmitted to the RF test instrument through the first short-circuit pad and the RF test pin for testing. In this way, the single board of the first aspect of the present application can realize the function of a traditional RF switch test socket by setting the first short-circuit pad and the second short-circuit pad. The single board of the first aspect of the present application can remove the traditional RF switch test socket, saving the device cost of the single board and the layout area of ​​the single board.

[0011] In addition, in the single board of the first aspect of the present application, conductive glue is used to form a part of the RF signal transmission line, that is, the conductive glue is used as a transmission line to transmit the RF signal. Compared with the traditional method of using welding to form a part of the RF signal transmission line, it has the following advantages.

[0012] First, the method of using welding to form a part of the transmission line of the RF signal requires heating the solder (such as solder) to a high temperature (such as 300°C to 400°C), which is a complicated process. However, the conductive glue is used as a transmission line to transmit the RF signal, and the conductive glue can be cured at room temperature. Even if the conductive glue needs to be cured at a high temperature, the high-temperature curing temperature of the conductive glue (generally below 150°C) is much lower than the welding method.

[0013] Second, when welding is used to form a part of the transmission line of the RF signal, the electronic assembly materials (such as solder) need to be repaired at high temperature and the pads need to be cleaned during the single board repair, which is a complicated process. However, when the conductive glue is used as a transmission line to transmit the RF signal, the conductive glue is easy to remove during the single board repair, and in some embodiments, it can even be directly removed by tweezers without high temperature.

[0014] Third, when welding is used to form part of the transmission line of the RF signal, high-temperature repair requires the use of a soldering iron to reheat to a high temperature (such as 300°C to 400°C). Although only a part of the single board is heated to a high temperature, it will still affect other devices around the device to be repaired, thereby affecting the reliability of the entire single board. However, when the conductive glue is used as a transmission line to transmit RF signals, the conductive glue is easy to remove during single board repair. In some embodiments, it can even be directly removed by tweezers without high temperature, and the operation of removing the conductive glue has little impact on other devices on the single board.

[0015] In some embodiments, the first short-circuit pad is used to electrically connect the signal pin of the radio frequency test pin during radio frequency testing. By reusing the function of the first short-circuit pad, the circuit design of the single board can be simplified and the layout area of ​​the single board can be saved.

[0016] In some embodiments, the single board further includes a ground test pad, and the ground test pad is used to be electrically connected to a ground pin of a radio frequency test pin. The ground pin of the radio frequency test pin serves as a reference point for radio frequency signal testing. The ground test pad is used to be electrically connected to the ground pin of the radio frequency test pin during radio frequency testing to reduce the false detection rate and improve the accuracy of radio frequency testing.

[0017] In some embodiments, the first short-circuit pad is used to electrically connect the signal pin of the RF test pin during RF testing, and the ground test pad, the first short-circuit pad, and the second short-circuit pad are all located on the same surface of the single board. When performing RF testing on the single board to be tested, the signal pin and the ground pin of the RF test pin can be electrically connected to the first short-circuit pad and the ground test pad, respectively. On the one hand, by reusing the function of the first short-circuit pad, the circuit design of the single board can be simplified and the layout area of ​​the single board can be saved. On the other hand, the ground test pad and the first short-circuit pad are arranged on the same layer, which can further simplify the circuit design of the single board.

[0018] In some embodiments, the single board further includes a signal test pad, the signal test pad being electrically connected to the RF front-end circuit so as to be used to electrically connect the signal pin of the RF test pin during RF testing. That is, the single board can be separately designed to be used for a test pad electrically connected to the RF test pin during RF testing, so that the test pad is not shared with the first short-circuit pad.

[0019] In some embodiments, the signal test pad, the ground test pad, the first short pad, and the second short pad are all located on the same surface of the single board. When performing radio frequency testing on the single board to be tested, the signal pin and the ground pin of the radio frequency test pin can be electrically connected to the signal test pad and the ground test pad, respectively. The ground test pad and the signal test pad are arranged on the same layer, which can further simplify the circuit design of the single board.

[0020] In some embodiments, the ground test pad and the signal test pad are located on the first surface of the single board, and the first short-circuit pad and the second short-circuit pad are located on the second surface of the single board, and the second surface is different from the first surface. The ground test pad and the signal test pad are located on the same surface of the single board, which is conducive to electrical connection with the RF test pin on the same side of the single board. The first short-circuit pad and the second short-circuit pad are located on the same surface of the single board, which is conducive to setting conductive glue on the same side of the single board.

[0021] In some embodiments, the single board further includes a via hole penetrating the first surface and the second surface, and the signal test pad is electrically connected to the first short-circuit pad through the via hole. In this way, when the RF test pin is a coaxial test pin, it can be avoided that the ground pin of the RF test pin contacts the transmission line connected to the RF front-end circuit by the first short-circuit pad and causes a short circuit.

[0022] In some embodiments, the ground test pad is a closed ring surrounding the signal test pad. When performing RF testing on the board to be tested, if the RF test needle is a coaxial test needle, the ground needle of the RF test needle is also a closed ring, so the ground needle of the RF test needle can be aligned 360° with the ground test pad without deliberately rotating the RF test needle for alignment, thereby simplifying the test steps.

[0023] In some embodiments, the conductive adhesive includes at least one of conductive silver adhesive, conductive silver paste, and conductive copper paste, but is not limited thereto.

[0024] A second aspect of the present application provides a terminal. The terminal includes:

[0025] a housing; and

[0026] The single board described in the first aspect of the present application is installed in the shell.

[0027] The terminal has at least the same advantages as the single board in the first aspect of the present application, which will not be described in detail here.

[0028] A third aspect of the present application provides a radio frequency testing method. The radio frequency testing method comprises:

[0029] Performing a radio frequency test on a radio frequency front-end circuit of a single board to be tested, wherein the single board to be tested includes the radio frequency front-end circuit for generating a radio frequency signal, a first short-circuit pad electrically connected to the radio frequency front-end circuit, a second short-circuit pad spaced apart from and insulated from the first short-circuit pad, and a radio frequency back-end circuit electrically connected to the second short-circuit pad; and

[0030] Conductive glue is provided on the single board to be tested to electrically connect the first short-circuit pad and the second short-circuit pad.

[0031] In the RF testing method of the third aspect of the present application, before the RF front-end circuit of the single board to be tested is subjected to RF testing, the first short-circuit pad and the second short-circuit pad are arranged to be spaced and insulated. When the RF front-end circuit of the single board to be tested is subjected to RF testing, the first short-circuit pad can be used to be electrically connected to the signal pin of the RF test pin, so that the RF signal generated by the RF front-end circuit is transmitted to the RF testing instrument via the first short-circuit pad and the RF test pin for testing. After the RF test of the RF front-end circuit of the single board to be tested is completed, the first short-circuit pad and the second short-circuit pad are electrically connected by conductive glue, so that the RF signal generated by the RF front-end circuit can be transmitted from the first short-circuit pad to the RF back-end circuit via the second short-circuit pad. In this way, in the RF testing method of the third aspect of the present application, the traditional RF switch test socket can be removed, saving the device cost of the single board and the layout area of ​​the single board.

[0032] In some embodiments, performing a radio frequency test on the radio frequency front-end circuit of the single board to be tested includes: electrically connecting the signal pin of the radio frequency test pin to the first short-circuit pad, so that the radio frequency signal of the radio frequency front-end circuit is transmitted to the radio frequency test pin via the first short-circuit pad. By reusing the function of the first short-circuit pad, the circuit design of the single board can be simplified and the layout area of ​​the single board can be saved.

[0033] In some embodiments, electrically connecting the signal pin of the RF test pin to the first short-circuit pad includes: making the signal pin of the RF test pin directly contact and electrically connect to the first short-circuit pad; and / or making the signal pin of the RF test pin electrically connect to the first short-circuit pad through an RF switch test socket. In this way, the setting of the first short-circuit pad is compatible with the solution of the traditional RF switch test socket. In the debugging stage of the single board, by welding the RF switch test socket to the single board and using the corresponding RF test pin, the early debugging of the RF indicators of the single board can be facilitated.

[0034] In some embodiments, the single board to be tested further includes a signal test pad, and the signal test pad is electrically connected to the RF front-end circuit; performing a radio frequency test on the RF front-end circuit of the single board to be tested includes electrically connecting the signal pin of the RF test pin to the signal test pad, so that the RF signal of the RF front-end circuit is transmitted to the RF test pin via the signal test pad. That is, the single board to be tested can be separately designed to electrically connect the test pad of the RF test pin during the RF test, so that the test pad is not shared with the first short-circuit pad.

[0035] In some embodiments, electrically connecting the signal pin of the RF test pin to the signal test pad includes: making the signal pin of the RF test pin directly contact and electrically connect to the signal test pad; and / or making the signal pin of the RF test pin electrically connect to the signal test pad through an RF switch test socket. In this way, the setting of the signal test pad is compatible with the solution of the traditional RF switch test socket. In the debugging stage of the single board, by welding the RF switch test socket to the single board and using the corresponding RF test pin, the early debugging of the RF indicators of the single board can be facilitated.

[0036] In some embodiments, the single board to be tested further includes a ground test pad; performing a radio frequency test on the radio frequency front-end circuit of the single board to be tested further includes electrically connecting a ground pin of the radio frequency test pin to the ground test pad. The ground pin of the radio frequency test pin serves as a reference point for radio frequency signal testing to reduce the false detection rate and improve the accuracy of radio frequency testing.

[0037] In some embodiments, electrically connecting the ground pin of the RF test pin to the ground test pad includes: making the ground pin of the RF test pin directly contact and electrically connect to the ground test pad; and / or making the ground pin of the RF test pin electrically connect to the ground test pad through an RF switch test socket. In this way, the setting of the ground test pad is compatible with the solution of the traditional RF switch test socket. In the debugging stage of the single board, by welding the RF switch test socket to the single board and using the corresponding RF test pin, the early debugging of the RF indicators of the single board can be facilitated.

[0038] In some embodiments, when the signal pin of the RF test pin is electrically connected to the first short-circuit pad via the RF switch test socket, when the signal pin of the RF test pin is electrically connected to the signal test pad via the RF switch test socket, and when the ground pin of the RF test pin is electrically connected to the ground test pad via the RF switch test socket, the RF test method further includes removing the RF switch test socket from the single board to be tested after the RF test is completed and before the conductive adhesive is set. In this way, the layout area of ​​the single board is saved.

[0039] In some embodiments, the conductive adhesive is provided by dispensing or transferring. In the dispensing or transferring method, the conductive adhesive can be cured at room temperature. Even if the conductive adhesive needs to be cured at high temperature, the high temperature curing temperature of the conductive adhesive (generally below 150° C.) is much lower than that of the welding method.

[0040] In some embodiments, before performing RF testing on the RF front-end circuit of the single board to be tested, it also includes providing a single board, the single board including the RF front-end circuit, the first short-circuit pad electrically connected to the RF front-end circuit, the second short-circuit pad spaced apart from the first short-circuit pad, another conductive glue, and the RF back-end circuit electrically connected to the second short-circuit pad, the first short-circuit pad and the second short-circuit pad being electrically connected through the another conductive glue; and removing the another conductive glue so that the first short-circuit pad and the second short-circuit pad are insulated. That is, the single board to be tested is a single board in the repair stage. Since the first short-circuit pad and the second short-circuit pad are electrically connected through another conductive glue in the single board in the repair stage, the another conductive glue is easy to remove. In some embodiments, it can even be directly removed by tweezers without high temperature. The operation of removing the another conductive glue has little effect on other devices on the single board. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the structure of a traditional RF test system.

[0042] Figure 2 for Figure 1 Schematic diagram of the working principle of the RF switch test socket.

[0043] Figure 3 for Figure 1 Schematic diagram of the RF switch test socket in the working state (non-RF test state).

[0044] Figure 4 for Figure 1 Schematic diagram of the RF switch test socket in the RF test state.

[0045] Figure 5 This is a flow chart of a radio frequency testing method according to an embodiment of the present application.

[0046] Figure 6 Schematic diagram of the structure of a board to be tested according to the first embodiment of the present application.

[0047] Figure 7 For Figure 6 The schematic diagram of the RF test of the board under test is shown.

[0048] Figure 8 It is a schematic diagram of performing a radio frequency test on a board to be tested according to the second embodiment of the present application.

[0049] Fig. 9 It is a schematic diagram of performing a radio frequency test on a board to be tested according to the third embodiment of the present application.

[0050] Fig. 10A It is a top view of a single board to be tested according to the fourth embodiment of the present application.

[0051] Fig. 10B for Fig. 10A The bottom view of the board to be tested is shown.

[0052] Fig. 10C for Fig. 10B The cross-sectional view of the board to be tested along line AA is shown.

[0053] Fig. 10D It is a schematic diagram of performing a radio frequency test on a board to be tested according to the fourth embodiment of the present application.

[0054] Fig.11 This is a schematic diagram of the structure of a board to be tested according to the fifth embodiment of the present application.

[0055] Fig.12 It is a schematic diagram of performing a radio frequency test on a board to be tested according to the sixth embodiment of the present application.

[0056] Fig.13 It is a schematic diagram of performing radio frequency testing on the board to be tested according to the seventh embodiment of the present application.

[0057] Fig.14 for Fig.13 A three-dimensional image of the RF switch test socket at one viewing angle.

[0058] Fig.15 for Fig.13 A three-dimensional image of the RF switch test socket from another perspective.

[0059] Fig.16 It is a schematic diagram of performing radio frequency testing on the board to be tested according to the eighth embodiment of the present application.

[0060] Fig.17 This is a schematic diagram of setting the conductive glue by dispensing.

[0061] Fig.18 A schematic diagram of a single board according to an embodiment of the present application.

[0062] Fig.19 Schematic diagram of setting conductive glue by transfer printing.

[0063] Fig. 20 This is a schematic diagram of loss simulation results of a single board according to an embodiment of the present application.

[0064] Fig.21 This is a schematic diagram of loss simulation results of a single board according to another embodiment of the present application.

[0065] Fig. 22 A schematic diagram of the structure of a terminal according to an embodiment of the present application.

[0066] Description of main component symbols:

[0067] RF test system 1'

[0068] Boards to be tested 10', 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h

[0069] RF front-end circuit 11', 11

[0070] RF back-end circuit 12', 12

[0071] The first transmission lines 131 ′, 131

[0072] The second transmission lines 132 ′, 132

[0073] The third transmission line 133

[0074] First short-circuit pads 141a, 141b, 141c, 141d, 141e, 141f, 141g, 141h

[0075] Second short-circuit pads 142a, 142b, 142c, 142d, 142e, 142f, 142g, 142h Signal test pads 151a, 151b, 151c, 151d, 151e, 151f, 151g, 151h Ground test pads 152a, 152b, 152c, 152d, 152e, 152f, 152g, 152h Dielectric layer 16

[0076] First surface 161

[0077] Second surface 162

[0078] Via H

[0079] Gap G

[0080] RF switch test socket 20', 20

[0081] The first signal terminals 21 ′, 21

[0082] The second signal terminals 22', 22

[0083] Connecting spring pieces 23', 23

[0084] Base 24', 24

[0085] The first ground terminal 25

[0086] The second ground terminal 26

[0087] Conductive shell 27

[0088] Opening O

[0089] RF test pins 30', 30a, 30b, 30c, 30d, 30f

[0090] Signal pins 31a, 31b, 31c, 31d, 31f

[0091] Ground pins 32a, 32b, 32c, 32d, 32f

[0092] RF cable 40', 40

[0093] RF test equipment 50', 50

[0094] Dispensing needle 60

[0095] Conductive glue 70a

[0096] Conductive adhesive 70

[0097] Screen 80

[0098] Groove R

[0099] Dispensing head 90

[0100] Single board 100

[0101] Housing 200

[0102] Terminal 1000

[0103] Steps S1, S2, S3 DETAILED DESCRIPTION

[0104] An RF switch test socket (also called a connector or RF connector) is usually placed on the single board of a wireless terminal product (such as a mobile phone) to facilitate connecting the RF front-end circuit of the single board to the RF test instrument during the production and processing stage of the single board. The RF test instrument can be electrically connected to the RF switch test socket through the RF test pin to conduction calibration and test the RF indicators of the single board.

[0105] For the convenience of description, the boards to be tested are referred to as boards to be tested below, that is, boards to be tested may include boards that need to be tested during the production and processing stage, and may also include boards that need to be tested again during the repair stage.

[0106] Figure 1 Figure 1 is a schematic diagram of the structure of a traditional RF test system. Figure 1 As shown, the RF test system 1' includes a single board to be tested 10', a RF switch test socket 20', a RF test needle 30', a RF cable 40' and a RF test instrument 50'. The RF switch test socket 20' is located on the single board to be tested 10'. During the RF test process of the single board to be tested 10', the RF test needle 30' is electrically connected to the RF switch test socket 20' on the single board to be tested 10'. The RF signal on the single board to be tested 10' is transmitted to the RF test instrument 50' through the RF switch test socket 20', the RF test needle 30' and the RF cable 40' to perform RF index testing.

[0107] Figure 2 for Figure 1 The working principle diagram of the RF switch test socket is shown in the figure. Figure 2 As shown in Figure (a), the RF switch test socket 20' includes a first signal terminal 21', a second signal terminal 22', a connecting spring 23' and an insulating base 24'. Under normal circumstances (referring to the RF switch test socket 20' in a working state or in a state where no RF test is being performed), the first signal terminal 21' and the second signal terminal 22' are in a connected conductive state (i.e., the switch is normally closed) through the connecting spring 23'. Figure 2 As shown in FIG. 5( b ), when the RF switch test socket 20 ′ is in the RF test state, the RF test needle 30 ′ presses down and opens the connecting spring 23 ′, so that the first signal terminal 21 ′ and the second signal terminal 22 ′ are in the disconnected state.

[0108] Figure 3 for Figure 1 The schematic diagram of the RF switch test socket in the working state (non-RF test state). Figure 3 As shown, the single board 10' to be tested includes a radio frequency front-end circuit 11', a radio frequency back-end circuit 12', a first transmission line 131' and a second transmission line 132'. The radio frequency front-end circuit 11' is used to generate a radio frequency signal. The radio frequency front-end circuit 11' is electrically connected to the first signal terminal 21' of the radio frequency switch test socket 20' through the first transmission line 131'. The radio frequency back-end circuit 12' is electrically connected to the second signal terminal 22' of the radio frequency switch test socket 20' through the second transmission line 132'. When the radio frequency switch test socket 20' is not in a state of performing radio frequency testing, the radio frequency test needle 30' is not pressed down, the first signal terminal 21' and the second signal terminal 22' are connected and conducted through the connecting spring 23', and the radio frequency signal generated by the radio frequency front-end circuit 11' is transmitted to the radio frequency back-end circuit 12' via the first transmission line 131', the first signal terminal 21', the connecting spring 23', the second signal terminal 22', and the second transmission line 132'. That is, the RF front-end circuit 11 ′ is electrically connected to the RF back-end circuit 12 ′ through the RF switch test socket 20 ′, and the single board 10 ′ to be tested is in a normal connection state.

[0109] Figure 4 for Figure 1 The schematic diagram of the RF switch test socket in the RF test state. Figure 4 As shown, when the single board 10' to be tested needs to be tested for RF, the RF test needle 30' is pressed down to push open the connecting spring 23' in the RF switch test socket 20', so that the RF switch test socket 20' disconnects the RF front-end circuit 11' and the RF back-end circuit 12'. The RF signal generated by the RF front-end circuit 11' is transmitted to the RF test needle 30' through the first transmission line 131', the first signal terminal 21', the connecting spring 23', and then to the RF test instrument 50' (shown in FIG. Figure 1 for RF indicator testing.

[0110] However, in traditional RF testing methods, the RF switch test socket is specifically used for RF testing of single boards during the production and processing stage. After the RF test is completed, the RF switch test socket has no other use for terminal products and users, but it still remains on the single board. Therefore, the setting of the RF switch test socket not only increases the device cost but also occupies the layout area of ​​the single board.

[0111] In this regard, the first aspect of the present application provides a single board. The single board includes a radio frequency front-end circuit, a first short-circuit pad, a second short-circuit pad, a radio frequency back-end circuit, and a conductive adhesive. The radio frequency front-end circuit is used to generate a radio frequency signal. The first short-circuit pad is electrically connected to the radio frequency front-end circuit. The second short-circuit pad is spaced apart from the first short-circuit pad. The radio frequency back-end circuit is electrically connected to the second short-circuit pad. The conductive adhesive electrically connects the first short-circuit pad and the second short-circuit pad to transmit the radio frequency signal from the first short-circuit pad to the radio frequency back-end circuit via the second short-circuit pad.

[0112] In the single board of the first aspect of the present application, the first short-circuit pad is electrically connected to the RF front-end circuit. During the production and processing stage of the single board, the first short-circuit pad and the second short-circuit pad are not connected, and the first short-circuit pad and the second short-circuit pad are in a disconnected state. During RF testing, the first short-circuit pad can be used to electrically connect to the signal pin of the RF test pin, so that the RF signal generated by the RF front-end circuit is transmitted to the RF test instrument through the first short-circuit pad and the RF test pin for testing.

[0113] Thus, the single board of the first aspect of the present application can realize the function of the traditional RF switch test socket by setting the first short-circuit pad and the second short-circuit pad. The single board of the first aspect of the present application can remove the traditional RF switch test socket, saving the component cost and layout area of ​​the single board.

[0114] In addition, in the single board of the first aspect of the present application, the conductive adhesive forms a part of the radio frequency signal transmission line, that is, the conductive adhesive is used as a transmission line to transmit the radio frequency signal.

[0115] Specifically, electromagnetic waves with frequencies below 100kHz will be absorbed by the ground and cannot be effectively transmitted. However, electromagnetic waves with frequencies above 100kHz can propagate in the air and be reflected by the ionosphere at the outer edge of the atmosphere, thus having the ability to transmit over long distances. Such high-frequency electromagnetic waves with the ability to transmit over long distances are usually called radio frequency signals.

[0116] Transmission lines are specialized cables or other structures used in electronic engineering to carry alternating current at radio frequencies, that is, when the frequency of the current is high enough, the wave nature of the current must be considered. Ordinary cables are sufficient to carry low-frequency alternating current such as household electricity (changing direction 100 to 120 times per second). However, ordinary cables cannot be used to carry current in the radio frequency range or higher frequencies. Currents of this frequency change direction millions of times per second, and energy tends to radiate from the cable in the form of electromagnetic waves, resulting in energy loss. RF signals also tend to be reflected back to the source at the connection point of the cable. These reflections prevent the signal power from reaching its destination.

[0117] Transmission lines use special structures and impedance matching methods to transmit electromagnetic signals with minimal reflection and power loss. The most notable feature of most transmission lines is that they have uniform cross-sectional dimensions along their length, which gives the transmission line a consistent impedance, called characteristic impedance, which prevents reflections from occurring. Characteristic impedance refers to the magnitude of the resistance that a line has to the RF energy transmitted on it. Currently, 50 ohm characteristic impedance is used in RF systems. Transmission lines come in many forms, such as parallel lines (ladder lines, twisted pairs), coaxial cables, strip lines, and microstrip lines. The frequency of electromagnetic waves is inversely proportional to the wavelength. When the length of the cable is equivalent to the wavelength of the transmitted signal, a transmission line must be used. For example, if an ordinary cable transmits a low-frequency signal such as a DC signal, the impedance of the line is a few tenths of an ohm, but when the frequency reaches 3GHz, 4GHz, or 5GHz, the impedance may be hundreds of ohms, which does not meet the special requirements for the impedance of the transmission line in RF signals.

[0118] It can be seen that RF signals are high-frequency electromagnetic waves. The application scenarios of conductive adhesives for transmitting non-RF signals (such as ground signals) and for transmitting RF signals are completely different. Therefore, the performance requirements of conductive adhesives for transmitting non-RF signals and for transmitting RF signals are completely different. Moreover, the method of using conductive adhesives as transmission lines to transmit RF signals is a significant improvement over the method of using welding to form a part of the transmission line of RF signals. The following is a detailed description.

[0119] First, the method of using welding to form a part of the transmission line of the RF signal requires heating the solder (such as solder) to a high temperature (such as 300°C to 400°C), which is a complicated process. However, the conductive glue is used as a transmission line to transmit the RF signal, and the conductive glue can be cured at room temperature. Even if the conductive glue needs to be cured at a high temperature, the high-temperature curing temperature of the conductive glue (generally below 150°C) is much lower than the welding method.

[0120] Second, when welding is used to form a part of the transmission line of the RF signal, the electronic assembly materials (such as solder) need to be repaired at high temperature and the pads need to be cleaned during the single board repair, which is a complicated process. However, when the conductive glue is used as a transmission line to transmit the RF signal, the conductive glue is easy to remove during the single board repair, and in some embodiments, it can even be directly removed by tweezers without high temperature.

[0121] Third, when welding is used to form part of the transmission line of the RF signal, high-temperature repair requires the use of a soldering iron to reheat to a high temperature (such as 300°C to 400°C). Although only a part of the single board is heated to a high temperature, it will still affect other devices around the device to be repaired, thereby affecting the reliability of the entire single board. However, when the conductive glue is used as a transmission line to transmit RF signals, the conductive glue is easy to remove during single board repair. In some embodiments, it can even be directly removed by tweezers without high temperature, and the operation of removing the conductive glue has little impact on other devices on the single board.

[0122] The second aspect of the present application provides a terminal. The terminal includes a housing and a single board of the first aspect of the present application installed in the housing. The terminal has at least the same advantages as the single board of the first aspect of the present application, which will not be repeated here.

[0123] The third aspect of the present application provides a radio frequency testing method. The radio frequency testing method includes performing a radio frequency test on a radio frequency front-end circuit of a single board to be tested, wherein the single board to be tested includes a radio frequency front-end circuit for generating a radio frequency signal, a first short-circuit pad electrically connected to the radio frequency front-end circuit, a second short-circuit pad spaced and insulated from the first short-circuit pad, and a radio frequency back-end circuit electrically connected to the second short-circuit pad; and providing a conductive adhesive on the single board to be tested to electrically connect the first short-circuit pad of the single board to be tested and the second short-circuit pad of the single board to be tested.

[0124] In the RF testing method of the third aspect of the present application, before the RF front-end circuit of the single board to be tested is subjected to RF testing, the first short-circuit pad and the second short-circuit pad are arranged to be spaced and insulated. When the RF front-end circuit of the single board to be tested is subjected to RF testing, the first short-circuit pad can be used to be electrically connected to the signal pin of the RF test pin, so that the RF signal generated by the RF front-end circuit is transmitted to the RF testing instrument via the first short-circuit pad and the RF test pin for testing. After the RF test of the RF front-end circuit of the single board to be tested is completed, the first short-circuit pad and the second short-circuit pad are electrically connected by conductive glue, so that the RF signal generated by the RF front-end circuit can be transmitted from the first short-circuit pad to the RF back-end circuit via the second short-circuit pad. In this way, in the RF testing method of the third aspect of the present application, the traditional RF switch test socket can be removed, saving the device cost of the single board and the layout area of ​​the single board.

[0125] In addition, in the traditional RF test method, the RF switch test socket is welded on the single board by heating the solder (such as solder) to a high temperature (such as 300°C to 400°C), which is a complicated process. In the RF test method of the third aspect of the present application, the first short-circuit pad and the second short-circuit pad are electrically connected by a conductive adhesive, and the curing temperature of the conductive adhesive is low (generally below 150°C), which is much lower than the welding method. In some embodiments, the conductive adhesive can even be cured at room temperature, and the process is simple.

[0126] Moreover, in the traditional RF testing method, when a single board is repaired, it is necessary to use a soldering iron to reheat the area of ​​the single board where the RF switch test socket is welded to a high temperature (such as 300°C to 400°C) to melt the solder and remove the RF switch test socket. In addition, the traditional RF testing method also requires steps such as cleaning the pads of the RF switch test socket, which is a complicated process. In the RF testing method of the third aspect of the present application, the first short-circuit pad and the second short-circuit pad are electrically connected by conductive glue. When the single board is repaired, the conductive glue can even be removed by tweezers. It does not require high temperature and has no residue, and the process is simple.

[0127] Furthermore, in the conventional RF testing method, the step of reheating the single board locally to a high temperature will affect other devices around the high temperature area, thereby affecting the reliability of the entire single board. In the RF testing method of the third aspect of the present application, when the single board is repaired, the conductive glue can even be directly removed by tweezers without high temperature, and the impact on other devices on the single board is small.

[0128] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0129] Figure 5 This is a flow chart of a radio frequency testing method according to an embodiment of the present application. According to different requirements, the order of steps of the radio frequency testing method can be changed, and some steps can be omitted, split or combined.

[0130] like Figure 5 As shown, the radio frequency testing method includes the following steps S1 and S2.

[0131] Step S1: Performing a radio frequency test on the radio frequency front-end circuit of the board to be tested.

[0132] Step S2: Disposing a conductive adhesive on the single board to be tested to electrically connect the first short-circuit pad of the single board to be tested and the second short-circuit pad of the single board to be tested.

[0133] Specifically, step S1 includes step S11 and step S12.

[0134] Step S11: providing a board to be tested.

[0135] Specifically, the board to be tested includes a RF front-end circuit for generating a RF signal, a first short-circuit pad electrically connected to the RF front-end circuit, a second short-circuit pad spaced and insulated from the first short-circuit pad, and a RF back-end circuit electrically connected to the second short-circuit pad.

[0136] In some embodiments, step S11 is in the production and processing stage of the single board. The first short-circuit pad and the second short-circuit pad on the single board to be tested provided in step S11 are directly spaced and insulated.

[0137] In some other embodiments, step S11 is in the stage of repairing the single board. Step S11 includes the steps of providing the single board to be repaired and processing the single board to be repaired.

[0138] Specifically, the single board to be repaired includes a radio frequency front-end circuit, a first short-circuit pad electrically connected to the radio frequency front-end circuit, a second short-circuit pad spaced apart from the first short-circuit pad, a conductive adhesive, and a radio frequency back-end circuit electrically connected to the second short-circuit pad. The first short-circuit pad and the second short-circuit pad are electrically connected through the conductive adhesive. Processing the single board to be repaired includes removing the conductive adhesive so that the first short-circuit pad and the second short-circuit pad are insulated.

[0139] It can be seen that the RF testing method of the above-mentioned embodiment of the present application can realize RF testing of single boards at different stages.

[0140] Step S12: performing a radio frequency test on the radio frequency front-end circuit of the board to be tested.

[0141] In some embodiments, the first short-circuit pad of the board to be tested is used as a signal test pad. In step S12, performing an RF test on the RF front-end circuit of the board to be tested includes electrically connecting the signal pin of the RF test pin to the first short-circuit pad so that the RF signal of the RF front-end circuit is transmitted to the RF test pin via the first short-circuit pad.

[0142] In some other embodiments, the first short-circuit pad of the board to be tested is not used as a signal test pad, but the board to be tested includes an additional signal test pad, which is electrically connected to the first short-circuit pad and the RF front-end circuit. In step S12, performing RF testing on the RF front-end circuit of the board to be tested includes electrically connecting the signal pin of the RF test pin to the additional signal test pad so that the RF signal of the RF front-end circuit is transmitted to the RF test pin via the signal test pad.

[0143] In some embodiments, the board to be tested includes a ground test pad, and performing a radio frequency test on the radio frequency front-end circuit of the board to be tested in step S12 may include electrically connecting a ground pin of the radio frequency test pin to the ground test pad.

[0144] In some other embodiments, the board to be tested does not include a ground test pad, and step S12 does not include a step of electrically connecting the ground pin of the RF test pin to the ground test pad.

[0145] In addition, when the first short-circuit pad of the single board to be tested is reused as a signal test pad, electrically connecting the signal pin of the RF test pin to the first short-circuit pad includes: making the signal pin of the RF test pin directly contact and electrically connect to the first short-circuit pad; and / or, making the signal pin of the RF test pin electrically connect to the first short-circuit pad through an RF switch test socket.

[0146] Similarly, electrically connecting the signal pin of the RF test pin with the additional signal test pad includes: making the signal pin of the RF test pin directly contact and electrically connect with the additional signal test pad; and / or, making the signal pin of the RF test pin electrically connect with the additional signal test pad through the RF switch test socket.

[0147] Similarly, electrically connecting the ground pin of the RF test pin to the ground test pad includes: making the ground pin of the RF test pin directly contact and electrically connect to the ground test pad; and / or making the ground pin of the RF test pin electrically connect to the ground test pad through an RF switch test socket.

[0148] In this way, the first short-circuit pad, and / or the signal test pad, and / or the ground test pad are compatible with the solution of the traditional RF switch test socket. During the debugging stage of the single board, by welding the RF switch test socket to the single board and using the corresponding RF test needle, the early debugging of the RF indicators of the single board can be facilitated. After the RF test is completed, the RF switch test socket can be removed from the single board, and then the first short-circuit pad and the second short-circuit pad can be electrically connected.

[0149] The following is combined with Figures 6 to 15 Step S1 will be described in detail.

[0150] Figure 6 FIG. 1 is a schematic diagram of the structure of a single board to be tested according to the first embodiment of the present application. Figure 6 As shown, the board to be tested 10a includes a RF front-end circuit 11, a first transmission line 131, a first short-circuit pad 141a, a second short-circuit pad 142a, a second transmission line 132, a RF back-end circuit 12 and a ground test pad 152a.

[0151] The RF front-end circuit 11 is used to generate RF signals. The RF front-end circuit 11 includes but is not limited to filters, power amplifiers, low noise amplifiers, and some RF connections and matching circuits. The filter is used to filter out signals of a specific frequency, obtain a power signal of a specific frequency, or eliminate a power signal after a specific frequency. The power amplifier is used to amplify the RF signal. The low noise amplifier is used to amplify the signal in the receiving channel.

[0152] The first short pad 141a is electrically connected to the RF front-end circuit 11 through the first transmission line 131. The first transmission line 131 includes but is not limited to a microstrip line.

[0153] The first short-circuit pad 141a is used to electrically connect the signal pin of the RF test pin during the RF test, so that the RF signal of the RF front-end circuit 11 is transmitted to the RF test pin through the first short-circuit pad 141a. If the RF signal of the RF front-end circuit 11 is normal during the RF test (such as the RF signal of the RF front-end circuit 11 is stronger than the preset value), after the RF test is completed, the first short-circuit pad 141a is also used to electrically connect with the second short-circuit pad 142a, so that the RF signal of the RF front-end circuit 11 is transmitted to the RF back-end circuit 12 through the first short-circuit pad 141a and the second short-circuit pad 142a. That is, in the single board 10a to be tested, the first short-circuit pad 141a is used as a pad for short-circuiting with the second short-circuit pad 142a after the RF test is completed, and is also used as a signal test pad 151a electrically connected to the RF test pin during the RF test. By reusing the function of the first short-circuit pad 141a, the circuit design of the single board can be simplified and the layout area of ​​the single board can be saved.

[0154] The second short-circuit pad 142a is spaced apart from and insulated from the first short-circuit pad 141a, that is, before the radio frequency test, the second short-circuit pad 142a and the first short-circuit pad 141a are disconnected.

[0155] The RF back-end circuit 12 is electrically connected to the second short-circuit pad 142a via the second transmission line 132. The second transmission line 132 includes but is not limited to a microstrip line. The RF back-end circuit 12 includes but is not limited to an antenna matching circuit.

[0156] The ground test pad 152a, the first short-circuit pad 141a, and the second short-circuit pad 142a are all located on the same surface of the single board 10a to be tested, and the ground test pad 152a is spaced and insulated from the first short-circuit pad 141a and the second short-circuit pad 142a. The ground test pad 152a is used to electrically connect to the ground pin of the RF test pin during the RF test to improve the performance of the RF test. In the single board 10a to be tested, the pads for electrically connecting to the RF test pin (i.e., the ground test pad 152a and the first short-circuit pad 141a) are arranged on the same layer, which can further simplify the circuit design of the single board.

[0157] In the single board 10a to be tested, the number of the grounding test pad 152a is one, but not limited thereto. In the single board 10a to be tested, the grounding test pad 152a, the first shorting pad 141a, and the second shorting pad 142a are all circular, but not limited thereto.

[0158] Since the ground test pad and the first short-circuit pad are respectively used to electrically connect to the ground pin and the signal pin of the RF test pin during RF testing, the number, shape and size of the ground test pad and the first short-circuit pad can be designed according to the type of the RF test pin.

[0159] Figure 7 For Figure 6 The schematic diagram of the RF test of the board under test is shown in FIG. Figure 7 As shown, the radio frequency test needle 30a is a two-prong needle among non-coaxial test needles. The radio frequency test needle 30a includes a signal needle 31a and a ground needle 32a.

[0160] Figure 7 In the illustrated embodiment, when the single board 10a to be tested is subjected to RF testing, the signal pin 31a is in direct contact and electrical connection with the first short-circuit pad 141a (i.e., the signal test pad 151a), the ground pin 32a is in direct contact and electrical connection with the ground test pad 152a, and the second short-circuit pad 142a is in a disconnected and disconnected state with the first short-circuit pad 141a. That is, the second short-circuit pad 142a is neither directly electrically connected to the first short-circuit pad 141a nor electrically connected through other intermediate structures. The RF signal generated by the RF front-end circuit 11 is transmitted to the RF test instrument 50 via the signal pin 31a of the RF test pin 30a via the RF cable 40. The ground pin 32a serves as a reference point for the RF signal test. The interference signal generated by the RF test instrument 50 when analyzing the RF signal of the RF front-end circuit 11 can be derived via the ground test pad 152a and the ground pin 32a of the RF test pin 30a, thereby reducing the false detection rate and improving the accuracy of the RF test.

[0161] Figure 8 FIG. 1 is a schematic diagram of performing a radio frequency test on a single board to be tested according to the second embodiment of the present application. Figure 8 As shown, the single board 10b to be tested includes an RF front-end circuit 11, a first transmission line 131, a first short-circuit pad 141b, a second short-circuit pad 142a, a second transmission line 132, an RF back-end circuit 12, and a ground test pad 152b. The first short-circuit pad 141b is electrically connected to the RF front-end circuit 11 through the first transmission line 131. The second short-circuit pad 142b is spaced and insulated from the first short-circuit pad 141b. The RF back-end circuit 12 is electrically connected to the second short-circuit pad 142b through the second transmission line 132. The first short-circuit pad 141b is used as a pad for short-circuiting with the second short-circuit pad 142b after the RF test is completed, and is also used as a signal test pad 151b electrically connected to the RF test pin during the RF test. The ground test pad 152b is used to be electrically connected to the ground pin 32b of the RF test pin during the RF test.

[0162] Please refer to Figure 7 and Figure 8 The difference between the single board 10b to be tested in the second embodiment and the single board 10a to be tested in the first embodiment is that in the single board 10b to be tested, the ground test pad 152b, the first short pad 141b and the second short pad 142b are all rectangular. Correspondingly, when the single board 10b to be tested is subjected to RF testing, the RF test pin 30b includes a signal pin 31b and a ground pin 32b.

[0163] Figure 8 In the illustrated embodiment, when the single board 10b to be tested is subjected to RF testing, the second short-circuit pad 142b and the first short-circuit pad 141b are disconnected and disconnected, the signal pin 31b is in direct contact and electrically connected to the first short-circuit pad 141b, and the RF signal generated by the RF front-end circuit 11 is transmitted to the RF test instrument via the signal pin 31b of the RF test pin 30b via the RF cable. The ground pin 32b is used as a reference point for the RF signal test, and the ground pin 32b is in direct contact and electrically connected to the ground test pad 152b to reduce the false detection rate and improve the accuracy of the RF test.

[0164] Fig. 9 FIG. 1 is a schematic diagram of performing a radio frequency test on a single board to be tested in the third embodiment of the present application. Fig. 9 As shown, the single board 10c to be tested includes an RF front-end circuit 11, a first transmission line 131, a first short-circuit pad 141c, a second short-circuit pad 142c, a second transmission line 132, an RF back-end circuit 12, and a ground test pad 152c. The first short-circuit pad 141c is electrically connected to the RF front-end circuit 11 through the first transmission line 131. The second short-circuit pad 142c is spaced and insulated from the first short-circuit pad 141c. The RF back-end circuit 12 is electrically connected to the second short-circuit pad 142c through the second transmission line 132. The first short-circuit pad 141c is used as a pad for short-circuiting with the second short-circuit pad 142c after the RF test is completed, and is also used as a signal test pad 151c electrically connected to the RF test pin during the RF test.

[0165] Please refer to Figure 7 and Fig. 9 The difference between the single board 10c to be tested in the third embodiment and the single board 10a to be tested in the first embodiment is that the single board 10c to be tested includes two ground test pads 152c. The two ground test pads 152c are respectively located on opposite sides of the signal test pad 151c. The two ground test pads 152c and the signal test pad 151c are arranged in a row, and the two ground test pads 152c are roughly symmetrical about the signal test pad 151c.

[0166] Correspondingly, when the RF test is performed on the board 10c to be tested, the RF test pin 30c includes a signal pin 31c and two ground pins 32c. The two ground pins 32c are respectively located on opposite sides of the signal pin 31c and correspond to the relative positions of the two ground test pads 152c.

[0167] Fig. 9In the illustrated embodiment, when the single board 10c to be tested is subjected to RF testing, the second short-circuit pad 142c and the first short-circuit pad 141c are in a disconnected and disconnected state, the signal pin 31c is in direct contact with and electrically connected to the first short-circuit pad 141c, and the two ground pins 32c are respectively in direct contact with and electrically connected to a corresponding ground test pad 152c, and the RF signal generated by the RF front-end circuit 11 is transmitted to the RF test instrument via the signal pin 31b of the RF test pin 30b via the RF cable. The interference signal generated by the RF test instrument when analyzing the RF signal of the RF front-end circuit 11 can be derived via the ground test pad 152c and the ground pin 32c of the RF test pin 30c, thereby reducing the false detection rate and improving the accuracy of the RF test.

[0168] Fig. 10A FIG. 1 is a top view of a single board to be tested according to the fourth embodiment of the present application. In order to facilitate a clearer presentation, Fig. 10A Other circuits and components of the board to be tested are omitted, and only the signal test pad and the ground test pad are shown. Fig. 10A As shown, the single board 10d to be tested includes a signal test pad 151d and a ground test pad 152d. The signal test pad 151d is circular, and the ground test pad 152d is a closed ring surrounding the signal test pad 151d.

[0169] Fig. 10B for Fig. 10A The bottom view of the board to be tested is shown in FIG. Fig. 10B As shown, the single board to be tested 10d also includes a radio frequency front-end circuit 11, a first transmission line 131, a first short-circuit pad 141d, a second short-circuit pad 142d, a second transmission line 132, and a radio frequency back-end circuit 12. The first short-circuit pad 141d is electrically connected to the radio frequency front-end circuit 11 through the first transmission line 131. The second short-circuit pad 142d is spaced apart from the first short-circuit pad 141d and is insulated. The radio frequency back-end circuit 12 is electrically connected to the second short-circuit pad 142d through the second transmission line 132.

[0170] Fig. 10C for Fig. 10B The cross-sectional view of the board to be tested along line AA is shown in FIG. Fig. 10C As shown, the single board to be tested 10d also includes a dielectric layer 16. The dielectric layer 16 includes a first surface 161 and a second surface 162 opposite to each other. The signal test pad 151d and the ground test pad 152d are both located on the first surface 161. The RF front-end circuit 11, the first transmission line 131, the first short-circuit pad 141d, the second short-circuit pad 142d, the second transmission line 132, and the RF back-end circuit 12 are all located on the second surface 162.

[0171] The signal test pad 151d and the ground test pad 152d are located on the same surface of the single board 10d to be tested, which is conducive to electrically connecting with the RF test pin on the same side of the single board 10d to be tested. The first short-circuit pad 141d and the second short-circuit pad 142d are located on the same surface of the single board 10d to be tested, which is conducive to setting conductive glue on the same side of the single board 10d to be tested in the subsequent step S2.

[0172] The single board to be tested 10d also includes a via H that penetrates the first surface 161 and the second surface 162. The signal test pad 151d and the first short-circuit pad 141d are respectively located at opposite ends of the via H and are electrically connected through the via H. In this way, the signal test pad 151d is electrically connected to the RF front-end circuit 11 through the via H and the first short-circuit pad 141d. The material of the signal test pad 151d, the first short-circuit pad 141d and the via H is, for example, copper, but is not limited thereto.

[0173] The side where the first surface 161 is located is the side where the RF test pin is located when the RF test is performed on the single board 10d to be tested. The signal test pad 151d is used to electrically connect with the signal pin of the RF test pin during the RF test. The ground test pad 152d is used to electrically connect with the ground pin of the RF test pin during the RF test.

[0174] The first short-circuit pad 141d is used to be a pad for short-circuiting with the second short-circuit pad 142d after the RF test is completed, and is not used for electrical connection with the signal pin of the RF test pin during the RF test; in other words, a pad for electrically connecting to the signal pin of the RF test pin is separately provided in the single board 10d to be tested, and the pad electrically connected to the signal pin of the RF test pin during the RF test in the single board 10d to be tested and the pad short-circuited with the second short-circuit pad after the RF test is completed are not shared.

[0175] Fig. 10D FIG. 4 is a schematic diagram of performing a radio frequency test on a single board to be tested according to the fourth embodiment of the present application. Fig. 10D As shown, the RF test pin 30d used for the RF test of the single board 10d to be tested is a coaxial test pin. The RF test pin 30d includes a signal pin 31d and a ground pin 32d. The signal pin 31d and the ground pin 32d are coaxially arranged. The signal pin 31d corresponds to the signal test pad 151d, and the ground pin 32d corresponds to the ground test pad 152d. The signal pin 31d is roughly cylindrical, and the ground pin 32d is roughly annular surrounding the signal pin 31d.

[0176] When the single board 10d to be tested is subjected to RF testing, the signal pin 31d is in direct contact and electrical connection with the signal test pad 151d, the ground pin 32d is in direct contact and electrical connection with the ground test pad 152d, and the second short-circuit pad 142d is in a disconnected and disconnected state with the first short-circuit pad 141d. That is, the second short-circuit pad 142d is neither directly electrically connected to the first short-circuit pad 141d nor electrically connected through other intermediate structures. The RF signal generated by the RF front-end circuit 11 is transmitted to the RF test instrument via the signal pin 31d of the RF test pin 30d via the RF cable. The interference signal generated by the RF test instrument when analyzing the RF signal of the RF front-end circuit 11 can be derived via the ground test pad 152d and the ground pin 32d of the RF test pin 30d, thereby reducing the false detection rate and improving the accuracy of the RF test.

[0177] Specifically, the signal pin 31d and the ground pin 32d are arranged in a non-planar manner, and the surface of the ground pin 32d directly contacting the ground test pad 152d is serrated, so as to avoid the problem of poor contact caused by the uneven surface of the single board 10d to be tested.

[0178] Please refer to FIG. 10A to FIG. 10D , along the thickness direction of the single board 10d to be tested, the projection of the ground test pad 152d on the dielectric layer 16 at least overlaps with the first transmission line 131; the signal test pad 151d and the first short pad 141d are electrically connected through the via H, rather than being arranged on the same surface (such as the second surface 162) of the dielectric layer 16. In this way, the ground pin 32d of the RF test pin 30d can be prevented from contacting the first transmission line 131 and causing a short circuit.

[0179] Fig.11 FIG. 5 is a schematic diagram of a single board to be tested according to the fifth embodiment of the present application. Fig.11 As shown, the single board 10e to be tested includes an RF front-end circuit 11, a first transmission line 131, a first short-circuit pad 141e, a second short-circuit pad 142e, a second transmission line 132, an RF back-end circuit 12, and two ground test pads 152e. The first short-circuit pad 141e is electrically connected to the RF front-end circuit 11 through the first transmission line 131. The second short-circuit pad 142e is spaced and insulated from the first short-circuit pad 141e. The RF back-end circuit 12 is electrically connected to the second short-circuit pad 142e through the second transmission line 132. The first short-circuit pad 141e is used as a pad for short-circuiting with the second short-circuit pad 142e after the RF test is completed, and is also used as a signal test pad 151e electrically connected to the RF test pin during the RF test. The two ground test pads 152e are respectively located on opposite sides of the signal test pad 151e.

[0180] Please refer to Fig. 9 and Fig.11, the difference between the single board to be tested 10e of the fifth embodiment and the single board to be tested 10c of the third embodiment mainly lies in the shape of the ground test pad 152e. In the single board to be tested 10e, each ground test pad 152e is in the shape of an arc that half surrounds the signal test pad 151e. The two ground test pads 152e are arranged roughly symmetrically. The two ground test pads 152e avoid the first transmission line 131 and the second short-circuit pad 142e, and the two ground test pads 152e are provided with gaps G at the positions corresponding to the first transmission line 131 and the second short-circuit pad 142e to avoid short-circuiting with the first transmission line 131 and the second short-circuit pad.

[0181] The center of the first short pad 141e is the same as the center of each ground test pad 152e.

[0182] Correspondingly, the RF test needle used for the RF test of the single board 10e to be tested is a coaxial test needle. The coaxial test needle includes a signal needle and two ground needles. The shapes and relative positional relationship of the signal needle and the two ground needles correspond to the shapes and relative positional relationship of the signal test pad 151e and the two ground test pads 152e, respectively. That is, each ground needle is in an arc shape that half surrounds the signal needle. The two ground needles are arranged roughly symmetrically. There is also a gap between the two ground needles.

[0183] When the RF test is performed on the single board 10e to be tested, the second short-circuit pad 142e and the first short-circuit pad 141e are in a disconnected state, the signal pin of the RF test needle is in direct contact with and electrically connected to the first short-circuit pad 141e, and the two ground pins of the RF test needle are in direct contact with and electrically connected to a corresponding ground test pad 152e respectively, and the RF signal generated by the RF front-end circuit 11 is transmitted to the RF test instrument via the RF cable through the signal pin of the RF test needle. The interference signal generated by the RF test instrument when analyzing the RF signal of the RF front-end circuit 11 can be derived through the ground test pad 152e and the ground pin of the RF test needle, thereby reducing the false detection rate and improving the accuracy of the RF test.

[0184] Since there is a gap G between the two grounding test pads 152e in the single board 10e to be tested, when performing RF testing on the single board 10e to be tested, the RF test needle needs to be rotated so that the gap between the two grounding pins of the RF test needle is aligned with the gap G between the two grounding test pads 152e. FIG. 10A to FIG. 10D In the single board 10d to be tested shown, the ground test pad 152d is a closed ring (such as a circular ring). When the single board 10d to be tested is subjected to an RF test, the ground pin 32d of the RF test pin 30d is also a closed ring (such as a circular ring). Therefore, the ground pin 32d can be 360° aligned with the ground test pad 152d without deliberately rotating the RF test pin 30d for alignment, thereby simplifying the test steps.

[0185] Fig.12 FIG. 1 is a schematic diagram of performing a radio frequency test on a single board to be tested in the sixth embodiment of the present application. Fig.12 As shown, the single board 10f to be tested includes a RF front-end circuit 11, a first transmission line 131, a first short-circuit pad 141f, a second short-circuit pad 142f, a second transmission line 132, a RF back-end circuit 12, a signal test pad 151f, a third transmission line 133 and a ground test pad 152f.

[0186] The signal test pad 151f is located between the RF front-end circuit 11 and the first short-circuit pad 141f. The signal test pad 151f is electrically connected to the RF front-end circuit 11 through the first transmission line 131. The signal test pad 151f is electrically connected to the first short-circuit pad 141f through the third transmission line 133. The second short-circuit pad 142f is spaced apart from the first short-circuit pad 141f and is insulated. The second short-circuit pad 142f is electrically connected to the RF back-end circuit 12 through the second transmission line 132.

[0187] The first short-circuit pad 141f is used to be a pad for short-circuiting with the second short-circuit pad 142f after the RF test is completed, and is not used for electrical connection with the signal pin of the RF test pin during the RF test; in other words, a pad for electrically connecting to the signal pin of the RF test pin is separately provided in the single board 10f to be tested, and the pad electrically connected to the signal pin of the RF test pin during the RF test in the single board 10f to be tested and the pad short-circuited with the second short-circuit pad after the RF test is completed are not shared.

[0188] The two ground test pads 152f are respectively located on opposite sides of the signal test pad 151f. The two ground test pads 152f and the signal test pad 151f are arranged in a row, and the two ground test pads 152f are roughly symmetrical about the signal test pad 151f. The signal test pad 151f is used to electrically connect with the signal pin of the RF test pin during RF testing. The ground test pad 152f is used to electrically connect with the ground pin of the RF test pin during RF testing.

[0189] Correspondingly, when performing RF testing on the board 10f to be tested, the RF test pin 30f includes a signal pin 31f and two ground pins 32f. The two ground pins 32f are respectively located on opposite sides of the signal pin 31f and correspond to the relative positions of the two ground test pads 152f.

[0190] Fig.12In the illustrated embodiment, when the single board 10f to be tested is subjected to RF testing, the second short-circuit pad 142f and the first short-circuit pad 141f are in a disconnected and disconnected state, the signal pin 31f is in direct contact with and electrically connected to the first short-circuit pad 141f, and the two ground pins 32f are respectively in direct contact with and electrically connected to a corresponding ground test pad 152f, and the RF signal generated by the RF front-end circuit 11 is transmitted to the RF test instrument via the signal pin 31f of the RF test pin 30f through the RF cable. The interference signal generated by the RF test instrument when analyzing the RF signal of the RF front-end circuit 11 can be derived through the ground test pad 152f and the ground pin 32f of the RF test pin 30f, thereby reducing the false detection rate and improving the accuracy of the RF test.

[0191] Fig.13 FIG. 1 is a schematic diagram of performing a radio frequency test on a single board to be tested according to the seventh embodiment of the present application. Fig.13 As shown, the single board 10g to be tested includes a RF front-end circuit 11, a first transmission line 131, a first short-circuit pad 141g, a second short-circuit pad 142g, a second transmission line 132, a RF back-end circuit 12, a signal test pad 151g, a third transmission line 133 and a ground test pad 152g.

[0192] The signal test pad 151g is located between the RF front-end circuit 11 and the first short-circuit pad 141g. The signal test pad 151g is electrically connected to the RF front-end circuit 11 through the first transmission line 131. The signal test pad 151g is electrically connected to the first short-circuit pad 141g through the third transmission line 133. The second short-circuit pad 142g is spaced and insulated from the first short-circuit pad 141g. The second short-circuit pad 142g is electrically connected to the RF back-end circuit 12 through the second transmission line 132. The third transmission line 133 includes but is not limited to a microstrip line.

[0193] The first short-circuit pad 141g is used to be a pad for short-circuiting with the second short-circuit pad 142g after the RF test is completed, and is not used for electrical connection with the signal pin of the RF test pin during the RF test; in other words, a pad for electrically connecting to the signal pin of the RF test pin is separately provided in the single board 10g to be tested, and the pad electrically connected to the signal pin of the RF test pin during the RF test in the single board 10g to be tested and the pad short-circuited with the second short-circuit pad after the RF test is completed are not shared.

[0194] The ground test pad 152g is located on one side of the first short-circuit pad 141g and is roughly aligned with the first short-circuit pad 141g, so that the relative positions of the ground test pad 152g and the first short-circuit pad 141g are adapted to the relative positions of the ground pin and the signal pin of the RF test. The signal test pad 151g is used to be electrically connected to the signal pin of the RF test pin during RF testing. The ground test pad 152g is used to be electrically connected to the ground pin of the RF test pin during RF testing.

[0195] Specifically, when the single board 10g to be tested is subjected to a radio frequency test, the single board 10g to be tested can be electrically connected to the radio frequency test pin via the radio frequency switch test socket 20 . Fig.14 for Fig.13 A three-dimensional image of the RF switch test socket at one viewing angle. Fig.15 for Fig.13 A three-dimensional picture of the RF switch test socket in another perspective. Please refer to Fig.14 and Fig.15 The RF switch test socket 20 includes a first signal terminal 21 , a second signal terminal 22 , a connecting spring 23 , a base 24 , a first ground terminal 25 , a second ground terminal 26 and a conductive shell 27 .

[0196] The base 24 is insulated and defines an opening O. The connecting spring 23 is exposed from the opening O. The conductive shell 27 is annular and surrounds the connecting spring 23. The conductive shell 27 and the connecting spring 23 are insulated and spaced apart. The first signal terminal 21, the second signal terminal 22, the first ground terminal 25, and the second ground terminal 26 extend from the bottom of the base 24 in different directions. The first signal terminal 21 and the second signal terminal 22 are opposite to each other. The first ground terminal 25 and the second ground terminal 26 are opposite to each other.

[0197] The first signal terminal 21 and the connecting spring 23 can be integrally formed of the same first conductive material (such as metal), but is not limited thereto.

[0198] The second signal terminal 22, the first ground terminal 25 and the second ground terminal 26 may extend outward from the bottom of the conductive shell 27. That is, the conductive shell 27, the second signal terminal 22, the first ground terminal 25 and the second ground terminal 26 may be integrally formed of the same second conductive material (such as metal), but not limited thereto. The second conductive material may be the same as the first conductive material (such as copper), but not limited thereto.

[0199] The base 24 is made of insulating material, such as plastic, and can be formed by injection molding to fix the first signal terminal 21 and the connecting spring 23 integrally formed from the first conductive material, and the conductive shell 27, the second signal terminal 22, the first ground terminal 25 and the second ground terminal 26 integrally formed from the second conductive material.

[0200] Before using the RF switch test socket 20 for RF testing, please refer to Fig.13 The first signal terminal 21, the second signal terminal 22, and the first ground terminal 25 of the RF switch test socket 20 are electrically connected to the signal test pad 151g, the second short-circuit pad 142g, and the ground test pad 152g of the single board 10g to be tested. The first short-circuit pad 141f and the second short-circuit pad 142f are connected through the connecting spring 23, and the RF signal of the RF front-end circuit 11 is transmitted to the RF back-end circuit 12 through the RF switch test socket 20.

[0201] When using the RF switch test socket 20 for RF testing, one end of the RF test needle is electrically connected to the RF test instrument through the RF cable, and the other end of the RF test needle extends into the opening O and presses down the connecting spring 23, so that the second short-circuit pad 142f is disconnected from the first short-circuit pad 141f. The signal needle of the RF test needle is in direct contact with and electrically connected to the connecting spring 23, so that the RF signal generated by the RF front-end circuit 11 is transmitted to the RF test instrument through the signal test pad 151g, the connecting spring 23, the signal needle of the RF test needle, and the RF cable, thereby realizing the RF test of the single board 10g to be tested using the RF switch test socket 20. In addition, the interference signal generated by the RF test instrument when analyzing the RF signal of the RF front-end circuit 11 can be derived through the ground test pad 152g, the first ground terminal 25 and the second ground terminal 26 of the RF switch test socket 20, and the ground pin of the RF test needle, thereby reducing the false detection rate and improving the accuracy of the RF test.

[0202] Fig.16 FIG. 8 is a schematic diagram of performing a radio frequency test on a single board to be tested according to the eighth embodiment of the present application. Fig.16 As shown, the single board 10h to be tested includes a RF front-end circuit 11, a first transmission line 131, a first short-circuit pad 141h, a second short-circuit pad 142h, a second transmission line 132, a RF back-end circuit 12, a signal test pad 151h, a third transmission line 133 and a ground test pad 152h.

[0203] Please refer to Fig.16 and Fig.13 , the difference between the single board to be tested 10h of the eighth embodiment and the single board to be tested 10g of the seventh embodiment mainly lies in the number of ground test pads. The single board to be tested 10h includes two ground test pads 152h. The ground test pads 152h are used to be electrically connected to the ground pin of the RF test pin during RF testing. The two ground test pads 152h are respectively located on opposite sides of the first short-circuit pad 141h, and are roughly aligned with the first short-circuit pad 141h, so that the relative positions of the two ground test pads 152h and the first short-circuit pad 141h are adapted to the relative positions of the ground pin and the signal pin of the RF test.

[0204] When the RF switch test socket 20 is used to perform RF testing on the single board 10h to be tested, the first signal terminal 21 and the second signal terminal 22 of the RF switch test socket 20 are electrically connected to the signal test pad 151h and the second short-circuit pad 142h of the single board 10g to be tested in a one-to-one correspondence. The first ground terminal 25 of the RF switch test socket 20 is electrically connected to one of the two ground test pads 152h, and the second ground terminal 26 of the RF switch test socket 20 is electrically connected to the other of the two ground test pads 152h.

[0205] It is understandable that when performing RF testing on the single board to be tested in the above-mentioned first to sixth embodiments, the first short-circuit pad, and / or signal test pad, and / or ground test pad of the single board to be tested can also be electrically connected to the RF test pin through the RF switch test socket.

[0206] It should be noted that, when the board to be tested is electrically connected to the RF test pin via the RF switch test socket, in step S2, before setting the conductive adhesive on the board to be tested, the RF switch test socket needs to be removed from the board to be tested.

[0207] In addition, in the above embodiments, the RF test needle is a two-claw needle or a three-claw needle for illustration. In other embodiments, the number of signal test pads of the single board to be tested is one, and the number of ground test pads is more than two (such as three); correspondingly, the RF test needle can be a multi-claw needle with more than three claws, that is, the RF test needle includes a signal needle and more than two (such as three) ground pins. For the single board to be tested that completes the RF test in step S1 and has a normal RF signal, execute step S2. That is, a conductive glue is set on the single board to be tested to electrically connect the first short-circuit pad of the single board to be tested and the second short-circuit pad of the single board to be tested.

[0208] In some embodiments, step S2 is to dispose conductive glue on the board to be tested by dispensing, and step S2 includes the following steps S21 and S22.

[0209] Step S21: dispensing conductive glue on the board to be tested, wherein the conductive glue is formed on the first short-circuit pad and the second short-circuit pad and between the first short-circuit pad and the second short-circuit pad.

[0210] like Fig.17 As shown, the conductive glue 70a is applied on the first short-circuit pad 141a and the second short-circuit pad 142a and between the first short-circuit pad 141a and the second short-circuit pad 142a by the glue dispensing needle 60 of the automatic glue dispensing machine (not shown). The conductive glue includes at least one of conductive silver glue, conductive silver paste and conductive copper paste, but is not limited thereto. The conductive glue may also include other glues with good conductive properties.

[0211] Among them, conductive silver glue is a conductive adhesive, which is mainly formed by adding silver powder to resin, then fully mixing the silver powder and resin, and then heating and curing at different temperatures. Conductive silver paste is a viscous paste composed of a mechanical mixture of high-purity (such as 99.9%) metallic silver particles, adhesives, solvents, and additives. Generally, the conductivity of conductive silver paste is better than that of conductive silver glue.

[0212] The conductive adhesive can be epoxy resin conductive adhesive and silicone conductive adhesive. Epoxy resin conductive adhesive has reliable connection and stable fixation. Silicone conductive adhesive can be dispensed at room temperature, with a simple process, and silicone conductive adhesive is easy to remove, such as directly removing it with tweezers, without the need for high temperature and without residue.

[0213] In other embodiments, the conductive glue may be applied on the first short-circuit pad and the second short-circuit pad and between the first short-circuit pad and the second short-circuit pad through other equipment or tools.

[0214] Step S22: solidify the conductive glue into conductive adhesive, and the conductive adhesive electrically connects the first short-circuit pad and the second short-circuit pad.

[0215] like Fig.18 As shown, after the curing process, the conductive glue 70a forms the conductive glue 70, and the conductive glue 70 covers the first short-circuit pad 141a and the second short-circuit pad 142a, and electrically connects the first short-circuit pad 141a and the second short-circuit pad 142a. In this way, the RF front-end circuit 11 and the RF back-end circuit 12 are electrically connected to obtain the single board 100.

[0216] Specifically, the curing process can be high temperature curing or room temperature curing. The temperature of high temperature curing is generally lower than 150°C, but is not limited thereto. In addition, the conductive adhesive 70 obtained after curing still has a certain elasticity, and the conductive adhesive 70 is in direct contact with the first short-circuit pad 141a and the second short-circuit pad 142a, and also fills the gap between the first short-circuit pad 141a and the second short-circuit pad 142a.

[0217] In some other embodiments, step S2 is to arrange the conductive adhesive on the single board to be tested by transfer printing, and step S2 includes the following steps S21 ′ to S23 ′.

[0218] Step S21 ′: printing the conductive glue into the grooves of the screen.

[0219] Fig.19 Figure (a) is a top view of printing conductive glue into the grooves of the screen. Fig.19 Figure (b) is Fig.19 Figure (a) shows the cross-section along line BB. Fig.19 As shown in (a) and (b) of FIG. 80 , the screen 80 is provided with a groove R for accommodating the conductive glue 70 a. The shape, size and depth of the groove R are determined by the contact area required for short-circuiting the first short-circuit pad and the second short-circuit pad, the conductive resistance index, etc.

[0220] Fig.19 In FIG. 1 , the groove R is a rounded rectangle to match the shapes of the first short-circuit pad and the second short-circuit pad. In other embodiments, the shape of the groove is not limited thereto.

[0221] The conductive glue includes at least one of conductive silver glue, conductive silver paste and conductive copper paste, but is not limited thereto. The conductive glue may also include other glues with good conductive properties.

[0222] Step S22 ′: solidify the conductive glue into conductive adhesive.

[0223] The curing process may be high temperature curing or room temperature curing. The temperature of high temperature curing is generally lower than 150° C., but is not limited thereto.

[0224] Step S23 ′: transferring the conductive adhesive onto the first shorting pad and the second shorting pad and between the first shorting pad and the second shorting pad, so that the conductive adhesive electrically connects the first shorting pad and the second shorting pad.

[0225] like Fig.19 As shown in Figures (c) and (d) of FIG. 2 , after the curing process, the conductive glue 70a is formed into the conductive glue 70. In step S23', the conductive glue 70 can be adhered by the dispensing head 90, and the conductive glue 70 can be transferred to the first short-circuit pad 141a and the second short-circuit pad 142a and between the first short-circuit pad 141a and the second short-circuit pad 142a to achieve electrical connection between the first short-circuit pad 141a and the second short-circuit pad 142a. In this way, the RF front-end circuit 11 is electrically connected to the RF back-end circuit 12 to obtain the single board 100.

[0226] In step S22', the cured conductive adhesive 70 still has a certain elasticity. In step S23', the conductive adhesive 70 directly contacts the first short pad 141a and the second short pad 142a and fills the gap between the first short pad 141a and the second short pad 142a.

[0227] In the above step S2, the single board to be tested that has completed the RF test and has a normal RF signal is the single board to be tested 10a of the first embodiment as an example for explanation, and the single board to be tested in step S2 may also be the single board to be tested of the second embodiment to the seventh embodiment and the single board to be tested of the modified examples thereof. Accordingly, after step S2, the structure of the single board obtained is not limited to the structure of the single board 100.

[0228] Fig. 20 This is a schematic diagram of loss simulation results of a single board according to an embodiment of the present application. Fig. 20 The specific test conditions for the single board are as follows: the conductive glue material is conductive silver glue, the first short-circuit pad and the second short-circuit pad are both 0.5mm×0.5mm rectangular pads, the spacing between the first short-circuit pad and the second short-circuit pad is 0.2mm, and the height of the conductive glue above the first short-circuit pad or the second short-circuit pad is 0.3mm. Fig. 20As shown, within the frequency of 6 GHz, the loss is less than 0.3 dB. It can be understood that the specific data is the simulation result of this embodiment, and the real index shall be subject to the actual test result.

[0229] Fig.21 This is a schematic diagram of the loss simulation results of a single board of another embodiment of the present application. The specific test conditions of the single board in Figure 10 are: the material of the conductive glue is conductive silver glue, the first short-circuit pad and the second short-circuit pad are both 0.5mm×0.3mm rectangular pads, the spacing between the first short-circuit pad and the second short-circuit pad is 0.2mm, and the height of the conductive glue above the first short-circuit pad or the second short-circuit pad is 0.3mm. Fig.21 As shown, within the frequency of 6 GHz, the loss is less than 0.2 dB. It can be understood that the specific data is the simulation result of this embodiment, and the real index is subject to the actual test result.

[0230] The size and shape of the first short-circuit pad or the second short-circuit pad mainly affect the shape and volume of the conductive glue, and thus affect the size of the loss. Since high-frequency RF signals have a skin effect, the current is conducted on the surface of the conductive glue. Therefore, the size of the first short-circuit pad or the second short-circuit pad and the amount of conductive glue dispensed need to be designed to meet the loss requirements.

[0231] Fig. 20 and Fig.21 In the embodiment shown, the simulation is performed with the radio frequency signal within 6 GHz as an example, but it is not limited thereto. It is understandable that when the frequency of the radio frequency signal is 8 GHz, 9 GHz or higher, the loss of the radio frequency signal is greater, and the performance (such as conductivity) of the conductive adhesive is required to be higher.

[0232] Specifically, Fig. 20 and Fig.21 In the embodiment shown, the resistivity of the conductive adhesive is less than 10 -3 Ohms, but not limited to this. For example, for terminal products with low requirements for RF signals (such as home routers), a loss greater than 0.3dB (such as 1dB) can also meet the requirements, and the resistivity of the conductive glue can be greater than 10 -3 For example, for high RF signal requirements (such as mobile phones), although the loss is greater than 0.3dB (such as 1dB), if it can be compensated by other front-end devices (such as power amplifiers), the resistivity of the conductive glue can also be greater than 10 -3 ohm.

[0233] Fig. 22 FIG. 1 is a schematic diagram of the structure of a terminal according to an embodiment of the present application. Fig. 22As shown, the terminal 1000 includes a single board 100 and a housing 200. The single board 100 is mounted on the housing 200. The terminal 1000 can be a wireless terminal such as a mobile phone, a laptop computer, a tablet computer, a smart watch, a smart speaker, etc.

[0234] The above implementation modes are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred implementation modes, a person skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A single board, characterized in that: include: A radio frequency front-end circuit for generating a radio frequency signal; A first short-circuit pad, electrically connected to the RF front-end circuit; A second short-circuit pad is spaced apart from the first short-circuit pad; A radio frequency back-end circuit electrically connected to the second short-circuit pad; and Conductive glue, electrically connecting the first short-circuit pad and the second short-circuit pad, so as to transmit the radio frequency signal from the first short-circuit pad to the radio frequency back-end circuit via the second short-circuit pad; The single board also includes a signal test pad, which is electrically connected to the RF front-end circuit so as to be used to electrically connect the signal pin of the RF test pin during RF testing. The signal test pad is located on the first surface of the single board, and the first short-circuit pad and the second short-circuit pad are located on the second surface of the single board, and the second surface is different from the first surface.

2. The single board according to claim 1, characterized in that The single board also includes a ground test pad, and the ground test pad is used to be electrically connected to a ground pin of a radio frequency test pin.

3. The single board according to claim 2, characterized in that In the case that the single board further includes the signal test pad, the ground test pad is located on the first surface.

4. The single board according to claim 3, characterized in that The single board further includes a via hole penetrating the first surface and the second surface, and the signal test pad is electrically connected to the first short pad through the via hole.

5. The single board according to claim 4, characterized in that: The ground test pad is a closed ring surrounding the signal test pad.

6. The single board according to any one of claims 1 to 5, characterized in that: The conductive adhesive includes at least one of conductive silver adhesive, conductive silver paste and conductive copper paste.

7. A terminal, characterized in that: include: case; as well as The single board according to any one of claims 1 to 6 is installed in the housing.

8. A radio frequency testing method, characterized in that: include: Performing a radio frequency test on a radio frequency front-end circuit of a single board to be tested, wherein the single board to be tested includes the radio frequency front-end circuit for generating a radio frequency signal, a first short-circuit pad electrically connected to the radio frequency front-end circuit, a second short-circuit pad spaced apart from and insulated from the first short-circuit pad, and a radio frequency back-end circuit electrically connected to the second short-circuit pad; and Disposing a conductive adhesive on the single board to be tested to electrically connect the first short-circuit pad and the second short-circuit pad; The single board to be tested also includes a signal test pad, which is electrically connected to the RF front-end circuit. The signal test pad is located on the first surface of the single board, and the first short-circuit pad and the second short-circuit pad are located on the second surface of the single board, and the second surface is different from the first surface. Performing a RF test on the RF front-end circuit of the single board to be tested includes: electrically connecting the signal pin of the RF test pin to the signal test pad, so that the RF signal of the RF front-end circuit is transmitted to the RF test pin via the first short-circuit pad and the signal test pad.

9. The radio frequency testing method according to claim 8, characterized in that: Electrically connecting the signal pin of the radio frequency test pin to the signal test pad comprises: The signal pin of the radio frequency test pin is directly contacted with and electrically connected to the signal test pad; and / or, The signal pin of the radio frequency test pin is electrically connected to the signal test pad through a radio frequency switch test socket.

10. The radio frequency testing method according to claim 9, characterized in that: The single board to be tested also includes a ground test pad; Performing the radio frequency test also includes electrically connecting a ground pin of the radio frequency test pin to the ground test pad.

11. The radio frequency testing method according to claim 10, characterized in that: Electrically connecting the ground pin of the radio frequency test pin to the ground test pad comprises: The ground pin of the radio frequency test pin is directly in contact with and electrically connected to the ground test pad; and / or, The ground pin of the radio frequency test pin is electrically connected to the ground test pad through a radio frequency switch test socket.

12. The radio frequency testing method according to claim 11, characterized in that: When the signal pin of the RF test pin is electrically connected to the signal test pad via the RF switch test socket, and When the ground pin of the RF test pin is electrically connected to the ground test pad through the RF switch test socket, The radio frequency testing method further includes removing the radio frequency switch test socket from the single board to be tested after the radio frequency test is completed and before the conductive adhesive is set.

13. The radio frequency testing method according to claim 8, characterized in that: The conductive glue is disposed by dispensing or transferring.

14. The radio frequency testing method according to any one of claims 8 to 13, characterized in that: Before performing RF testing on the RF front-end circuit of the board to be tested, the following steps are also included: Providing a single board, the single board comprising the RF front-end circuit, the first short-circuit pad electrically connected to the RF front-end circuit, the second short-circuit pad spaced apart from the first short-circuit pad, another conductive adhesive, and the RF back-end circuit electrically connected to the second short-circuit pad, the first short-circuit pad and the second short-circuit pad being electrically connected via the another conductive adhesive; and The other conductive adhesive is removed to insulate the first short-circuit pad from the second short-circuit pad.

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