A display module testing device, system, and method

Abstract

The application discloses a display module testing device, which comprises a probe module arranged on a testing circuit board and comprising a probe array for transmitting testing signals between a display module to be tested and the testing circuit board; the probe array comprises differential signal probes and ground signal probes; wherein the ground signal probes are uniformly and evenly arranged, and the interval distances between the differential signal probes and / or between the differential signal probes and the ground signal probes are different from the interval distance between the ground signal probes. The application can solve the problem that the existing display module testing device cannot realize high-speed signal transmission due to the impedance mismatch between differential signals caused by the uniform array distribution of each signal probe.

Description

Technical Field

[0001] This application relates to the field of display module testing technology, and in particular to a display module testing device, a display module testing system, and a display module testing method. Background Technology

[0002] In automated testing production lines, screen modules move along the assembly line. A robotic arm precisely picks up the modules and places them at the testing station. The electronic control system then connects the module interfaces to the test board. Finally, the CPU unit sends display image data to the display module via probes to inspect for defects. Conventional testing station designs often focus only on PCB-level signal design, neglecting the probes. However, as screen resolution increases, the transmitted image data signal rate also rises. Inappropriate conventional probe signal arrangement designs lead to serious signal integrity issues, causing problems such as image distortion and screen flickering.

[0003] In existing conventional designs, the probes on the probe module are arranged in an array, with high-speed differential signals (DP and DN signals) located on two adjacent probes, surrounded by a GND reference signal. Because the probes are relatively thick (e.g., 1.56 mm) and very close together (e.g., 2 mm), there is strong coupling between the differential signals DP and DN. Actual test results show... Figure 1 As shown, M1, M2, and M3 represent the impedance fluctuations of the transmission lines on the front probe test board, and M5 represents the impedance of the transmission lines on the back probe test board. The differential characteristic impedance of the above signal arrangement is 46.5Ω, while the ideal differential line characteristic impedance is 100Ω, which will lead to a serious impedance mismatch problem.

[0004] Combination Figure 2 As shown, the 3dB bandwidth of the current signal arrangement used by the probe is 2.3GHz; the maximum return loss within the 3dB bandwidth of the current signal arrangement used by the probe is -2.747dB. The current application arrangement of the probe can only be applied to low-speed signals below 2.3GHz, such as D-PHY (below 1.5GHz) or DP RBR (1.62GHz), and cannot be applied to high-speed signals above 10GHz. Summary of the Invention

[0005] In response to at least one defect or improvement requirement of the prior art, the present invention provides a display module testing device, system and method, which aims to solve the problem that the uniform array distribution of each signal probe in the existing display module testing device leads to impedance mismatch between differential signals, making it impossible to achieve high-speed signal transmission.

[0006] To achieve the above objectives, according to a first aspect of the present invention, a display module testing apparatus is provided, comprising: a probe module disposed on a test circuit board, including a probe array for transmitting test signals between the display module under test and the test circuit board; the probe array including differential signal probes and ground signal probes; wherein the ground signal probes are uniformly spaced apart, and the spacing between the differential signal probes and / or between the differential signal probes and the ground signal probes is different from the spacing between the ground signal probes, so as to reduce the difference between the characteristic impedance and the target impedance of the differential signal probes.

[0007] In one embodiment of the present invention, the probe module further includes: a fixing device having probe positioning holes evenly spaced, wherein the ground signal probe and the differential signal probe are pluggably fixed in the corresponding probe positioning holes.

[0008] In one embodiment of the present invention, the number of probe positioning holes between the differential signal probe and the ground signal probe is different from the number of probe positioning holes between the ground signal probes.

[0009] In one embodiment of the present invention, the number of probe positioning holes spaced between the differential signal probes is different from the number of probe positioning holes spaced between the ground signal probes.

[0010] In one embodiment of the present invention, the number of probe positioning holes between the differential signal probes and between the differential signal probe and the ground signal probe are different from the number of probe positioning holes between the ground signal probes.

[0011] In one embodiment of the present invention, the number of probe positioning holes between a portion of the ground signal probes and the differential signal probes is different from the number of probe positioning holes between the ground signal probes, while the number of probe positioning holes between another portion of the ground signal probes and the differential signal probes is the same as the number of probe positioning holes between the ground signal probes.

[0012] In one embodiment of the present invention, the number of probe positioning holes spaced between the ground signal probes is zero, and the number of probe positioning holes spaced between the differential signal probes and / or between the differential signal probe and the ground signal probe is greater than zero.

[0013] In one embodiment of the present invention, the probe module further includes: a fixing device, which is provided with a dedicated hole for a ground signal probe and a dedicated hole for a differential signal probe, respectively used to fix the ground signal probe and the differential signal probe; wherein the dedicated holes for the ground signal probe are evenly spaced, and the spacing between the dedicated holes for the differential signal probe and the dedicated hole for the ground signal probe are different from the spacing between the ground signal probes.

[0014] According to a second aspect of the present invention, a display module testing system is also provided, comprising: a test circuit board; a display module testing device as described in any of the above embodiments, fixedly disposed on the test circuit board; the test circuit board being connected to the display module under test via the probe array.

[0015] According to a third aspect of the present invention, a display module testing method is also provided, applicable to the display module testing apparatus described in any of the above embodiments, comprising: mounting a probe module including differential signal probes and ground signal probes on a test circuit board; defining signal types on the test circuit board corresponding to the signal probes, and making the spacing between the differential signal probes and / or between the differential signal probes and the ground signal probes different from the spacing between the ground signal probes; and pressing the display module under test with the probe module to perform a screen test.

[0016] In one embodiment of the present invention, the step of making the spacing distance between the differential signal probes and / or between the differential signal probe and the ground signal probe different from the spacing distance between the ground signal probes includes: detachably fixing the differential signal probe and the ground signal probe in uniformly distributed probe positioning holes; and making the number of probe positioning holes between the differential signal probes and / or between the differential signal probe and the ground signal probe different from the number of probe positioning holes between the ground signal probes by inserting and removing the probes.

[0017] In one embodiment of the present invention, the step of making the spacing between the differential signal probes and / or between the differential signal probes and the ground signal probes different from the spacing between the ground signal probes includes: fixing the ground signal probes in uniformly distributed ground signal probe holes; fixing the differential signal probes in differential signal probe holes with different spacings between them and between them and the ground signal probe holes.

[0018] In general, compared with the prior art, the above-described technical solutions conceived by this invention can achieve at least the following beneficial effects:

[0019] 1) By changing the spacing between differential signal probes and / or between differential signal probes and ground signal probes to be different from the spacing between ground signal probes, the characteristic impedance of differential probes can be effectively optimized and the 3dB bandwidth of differential probes can be increased without changing the material and structure of the probes themselves, so that the probes can be applied to high-speed signal environments above 10GHz.

[0020] 2) The differential signal probe and the ground signal probe are pluggable and fixed in the evenly distributed probe positioning holes. By plugging and unplugging the probes, the differential signal probes and / or the differential signal probe and the ground signal probe are spaced apart by a preset number of probe positioning holes, thereby changing the spacing between the probes. This allows for quick and convenient optimization of the characteristic impedance of the differential probes.

[0021] 3) The fixing device of the probe module is equipped with a dedicated hole for fixing the ground signal probe and a dedicated hole for fixing the differential signal probe. The distance between the dedicated holes for differential signal probes and between the dedicated holes for differential signal probes and the dedicated hole for ground signal probes are customized according to the simulation results, which can meet the impedance matching requirements to a great extent. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 Signal integrity feature map of a probe module in the prior art;

[0024] Figure 2 The insertion loss and return loss curves of the probe module in the prior art are shown.

[0025] Figure 3 This is a simulation diagram of a probe module in the prior art;

[0026] Figure 4 A simulation diagram of a display module testing device provided in this application embodiment;

[0027] Figure 5 A simulation diagram of another display module testing device provided in the embodiments of this application;

[0028] Figure 6 A simulation diagram of another display module testing device provided in the embodiments of this application;

[0029] Figure 7A simulation diagram of another display module testing device provided in the embodiments of this application;

[0030] Figure 8 A simulation diagram of yet another display module testing device provided in this application embodiment;

[0031] Figure 9 A simulation diagram of yet another display module testing device provided in this application embodiment;

[0032] Figure 10 This application provides yet another signal integrity feature diagram of a display module testing device.

[0033] Figure 11 This application provides yet another display module testing device with insertion loss and return loss curves.

[0034] Figure 12 A simulation diagram of another display module testing device provided in the embodiments of this application;

[0035] Figure 13 Insertion loss curve of another display module testing device provided in the embodiments of this application;

[0036] Figure 14 The return loss curve of another display module testing device provided in the embodiments of this application. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0038] The terms "first," "second," "third," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0039] The first embodiment of the present invention provides a display module testing device, including, for example, a probe module disposed on a test circuit board. The probe module includes a probe array for transmitting test signals between the display module under test and the test circuit board.

[0040] The probe array includes differential signal probes and ground signal probes, wherein the spacing between the differential signal probes and / or between the differential signal probes and the ground signal probes is different from the spacing between the ground signal probes.

[0041] Specifically, the impedance formula for a single-ended microstrip line is: (0.1 < W / H and 1 < Er < 15). The impedance formula for a differential microstrip line is: Based on the impedance formula above, the logical relationship between the characteristic impedance of each signal probe and other parameters can be verified as follows:

[0042] As the dielectric constant Er increases, the impedance Z0 decreases;

[0043] As the distance H from the signal to the reference plane increases, the impedance Z0 increases.

[0044] As the linewidth W increases, the impedance Z0 decreases;

[0045] As the copper thickness T increases, the impedance Z0 decreases.

[0046] As the spacing between adjacent lines (for differential signal lines) S increases, the impedance Z0 increases.

[0047] However, since the material and structural dimensions of the signal probes are fixed and cannot be modified, the characteristic impedance can only be changed by altering the distance H between the probe and the reference plane or the distance S between the differential probes. In this way, compared to a scheme where each signal probe is distributed in a uniform array, the characteristic impedance of the differential probes can be effectively optimized, reducing the difference between the characteristic impedance of the high-speed differential signal probes and the target impedance.

[0048] Furthermore, the probe module also includes a fixing device with uniformly distributed probe positioning holes. The ground signal probe and the differential signal probe are pluggably fixed in the corresponding probe positioning holes. That is, by plugging and unplugging the signal probes, the number of probe positioning holes between the differential signal probes and / or between the differential signal probe and the ground signal probe can be made different from the number of probe positioning holes between the ground signal probes, thereby changing the spacing between the signal probes.

[0049] Preferably, the number of probe positioning holes between ground signal probes is zero, while the number of probe positioning holes between differential signal probes and / or between differential signal probes and ground signal probes is greater than zero. This allows for the transmission of more signals in a minimal volume through a tightly arranged probe array, and facilitates the free definition of various signal types.

[0050] The specific implementation methods of this application will be described in detail below with reference to existing technologies:

[0051] like Figure 3 The diagram shows a simulation of an existing probe module. The distance H between the differential signal probe (marked S) and the ground signal probe (marked G) is 2mm, and the distance S between the two differential signal probes is 2mm. The simulation shows the original probe impedance to be 45.6Ω, with an error of only 0.9Ω compared to the measured value (46.5Ω). However, the target PCB board and screen module are designed with a signal link impedance of 100Ω, therefore this solution will lead to a severe impedance mismatch problem.

[0052] In one embodiment of this application, such as Figure 4 As shown, there are no probe positioning holes between the ground signal probes, and the distance between them is 2mm; there are also no probe positioning holes between the two differential signal probes, and the distance S is 2mm; the ground signal probe and the differential signal probe are separated by one probe positioning hole, that is, the distance H between the differential signal probe and the reference plane is 4mm. The simulation results show that the impedance of the differential signal probe is 60.89Ω, which is better than the existing design, but still less than the required value (100Ω).

[0053] Of course, in other embodiments, multiple probe positioning holes may be spaced apart between the ground signal probe and the differential signal probe, and this application is not limited thereto. Figure 5 As shown, the ground signal probe and the differential signal probe are spaced apart by, for example, two probe positioning holes, with a distance H of 6 mm. The simulation results show that the impedance of the differential signal probe is 62.72 Ω. It can be seen that simply increasing the distance between the ground signal probe and the differential signal probe has little effect on the impedance gain and has limited effect on the impedance matching.

[0054] In one embodiment of this application, such as Figure 6 As shown, there are no probe positioning holes between the ground signal probes, and the distance between them is 2mm; there are also no probe positioning holes between the ground signal probe and the differential signal probe, that is, the distance H between the differential signal probe and the reference plane is 2mm; there is one probe positioning hole between two differential signal probes, and the distance S is 4mm. The simulation results show that the impedance of the differential signal probe is 68.27Ω, which is better than the existing design, but still less than the required value (100Ω).

[0055] Of course, in other embodiments, multiple probe positioning holes may be spaced apart between the two differential signal probes, and this application is not limited thereto. Figure 7 As shown, if two differential signal probes are spaced apart by two probe positioning holes and the distance S is 4mm, the impedance of the differential signal probe is 71.63Ω according to the simulation. It can be seen that simply increasing the distance between the two differential signal probes has little effect on the impedance gain and has limited effect on the impedance matching.

[0056] In one embodiment of this application, such as Figure 8 As shown, there are no probe positioning holes between the ground signal probes, and the distance between them is 2mm; there is one probe positioning hole between the two differential signal probes, and the distance S is 4mm; there is one probe positioning hole between the differential signal probe and the ground signal probe, that is, the distance H between the differential signal probe and the reference plane is 4mm. The simulation results show that the impedance of the differential signal probe is 123.6Ω, which is better than the existing design, but still slightly larger than the required value (100Ω).

[0057] In particular, in one embodiment of this application, such as Figure 9 As shown, there are no probe positioning holes between ground signal probes, and the distance between them is 2mm; there is one probe positioning hole between two differential signal probes, and the distance S is 4mm; some ground signal probes and differential signal probes are not separated by probe positioning holes, and the distance between them is 2mm, while in other parts, there is one probe positioning hole between ground signal probes and differential signal probes, and the distance between them is 4mm. Simulation results show that the impedance of the differential signal probe is 83.32Ω, which is significantly better than the existing design, but still slightly less than the required value (100Ω).

[0058] like Figure 10 As shown, the differential characteristic impedance (M4) obtained through actual measurement for the above design is 80.979Ω. Figure 11 As shown, the 3dB bandwidth of the probe signal arrangement is 11.29 GHz, and the maximum return loss within the 3dB bandwidth is -12.112 dB. The table below compares the high-speed electrical characteristics of the probe in the improved design and the existing design:

[0059]

[0060] The improved probe signal arrangement can be applied to signals up to 11.29 GHz, and it can be seen that the improved signal arrangement is significantly better than the existing design.

[0061] Based on the simulation results above, the advantage of the display module testing device provided in this application is that by inserting and removing the probes and moving the probe positions to change the spacing between the probes, the characteristic impedance of the differential probes can be quickly and conveniently optimized without changing the material and structure of the probes themselves, thereby improving the 3dB bandwidth of the differential probes and enabling the probes to be applied to high-speed signal environments above 10GHz.

[0062] Furthermore, the fixing device of the display module testing apparatus can be customized. Specifically, the fixing device is provided with dedicated holes for fixing the ground signal probe and dedicated holes for fixing the differential signal probe. The dedicated holes for the ground signal probe are evenly distributed at a first interval, and the distance between two dedicated holes for the differential probe and the distance between the dedicated holes for the differential probe and the probe positioning hole are customized based on simulation results, for example, to more accurately meet the expected design requirements.

[0063] For example, such as Figure 12 As stated above, when the distance S between the two differential signal probes is 3.5 mm, and the distance H between the differential signal probe and the ground signal probe is 3.5 mm, the characteristic impedance (M1) of the differential signal probe is found to be 100.19 Ω through simulation, which can largely meet the impedance matching requirements. Figure 13 As shown, in the 0-20GHz frequency band, the maximum insertion loss IL is -1.64dB@18.1GHz; Figure 14 As shown, the maximum return loss RL in the 0-20GHz frequency band is -9.27dB at 18.1GHz. The table below compares the high-speed electrical characteristics of the probe in the improved design and the existing design:

[0064]

[0065] The improved probe signal arrangement can be applied to signals up to 20G, and it can be seen that the improved signal arrangement is significantly better than the existing design.

[0066] In summary, the display module testing device proposed in the first embodiment of this application, by changing the spacing between differential signal probes and / or between differential signal probes and ground signal probes to be different from the spacing between ground signal probes, can effectively optimize the characteristic impedance of differential probes and improve the 3dB bandwidth of differential probes without changing the material and structure of the probes themselves, enabling the probes to be applied to high-speed signal environments above 10GHz. The differential signal probes and ground signal probes are pluggably fixed in uniformly distributed probe positioning holes. By plugging and unplugging the probes to create a preset number of probe positioning holes between differential signal probes and / or between differential signal probes and ground signal probes, the spacing between probes can be changed, enabling rapid and convenient optimization of the characteristic impedance of differential probes. The fixing device of the probe module is provided with dedicated holes for ground signal probes and dedicated holes for differential signal probes. The distances between the dedicated holes for differential signal probes and between the dedicated holes for differential signal probes and ground signal probes are customized based on simulation results, which can greatly meet the impedance matching requirements.

[0067] Furthermore, a second embodiment of the present invention provides a display module testing system, which includes, for example, a test circuit board and the display module testing device described in the first embodiment. The display module testing device is fixedly mounted on the test circuit board, and the display module under test is connected to the test circuit board through the probe array.

[0068] The structure and functions of the display module testing device can be referred to the content described in the first embodiment, and will not be described in detail here. Moreover, the beneficial effects of this embodiment are the same as those of the first embodiment, and will not be repeated here for the sake of brevity.

[0069] The third embodiment of the present invention also proposes a display module testing method, which includes, for example: mounting a probe module including differential signal probes and ground signal probes on a test circuit board; defining the signal type on the test circuit board corresponding to the signal probes, and making the spacing between the differential signal probes and / or between the differential signal probes and the ground signal probes different from the spacing between the ground signal probes; pressing the display module under test with the probe module to perform a screen test.

[0070] In one embodiment, the step of making the spacing between the differential signal probes and / or between the differential signal probe and the ground signal probe different from the spacing between the ground signal probes includes: detachably fixing the differential signal probe and the ground signal probe in uniformly distributed probe positioning holes; and making the number of probe positioning holes between the differential signal probes and / or between the differential signal probe and the ground signal probe different from the number of probe positioning holes between the ground signal probes by inserting and removing the probes.

[0071] In one embodiment, the step of making the spacing between the differential signal probes and / or between the differential signal probes and the ground signal probes different from the spacing between the ground signal probes includes: fixing the ground signal probes in uniformly distributed ground signal probe holes; fixing the differential signal probes in differential signal probe holes with different spacings between them and between them and the ground signal probe holes.

[0072] It is worth mentioning that the display module testing method proposed in this embodiment is applicable to the display module testing device described in the first embodiment. The specific structure and functions of the display module testing device can be referred to the content described in the first embodiment, which will not be described in detail here. Moreover, the beneficial effects of this embodiment are the same as those of the first embodiment, and will not be repeated here for the sake of brevity.

[0073] The foregoing description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of embodiments of this disclosure upon considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described herein. The specification and embodiments are to be considered exemplary only, and the scope and spirit of this disclosure are defined by the claims.

[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A display module testing device, characterized in that, include: A probe module, mounted on a test circuit board, includes a probe array and a fixing device, and is used to transmit test signals between the display module under test and the test circuit board. The probe array includes differential signal probes and ground signal probes; The fixing device is provided with probe positioning holes that are evenly spaced. The ground signal probe and the differential signal probe are pluggably fixed in the corresponding probe positioning holes, and there are no probe positioning holes between each ground signal probe. Alternatively, the fixing device is provided with a dedicated hole for the ground signal probe and a dedicated hole for the differential signal probe, respectively used to fix the ground signal probe and the differential signal probe; the dedicated holes for the ground signal probe are evenly spaced, and there are no gaps between the dedicated holes for the ground signal probes; The ground signal probes are evenly spaced apart, and the spacing between the differential signal probes and / or between the differential signal probes and the ground signal probes is different from the spacing between the ground signal probes, so as to reduce the difference between the characteristic impedance and the target impedance of the differential signal probes; the spacing between the differential signal probes refers to the spacing between two adjacent differential signal probes that constitute a pair of DP and DN signals; the pair of differential signals is surrounded by ground signals.

2. The display module testing device according to claim 1, characterized in that, The number of probe positioning holes between the differential signal probe and the ground signal probe is different from the number of probe positioning holes between the ground signal probes.

3. The display module testing device according to claim 1, characterized in that, The number of probe positioning holes spaced between the differential signal probes is different from the number of probe positioning holes spaced between the ground signal probes.

4. The display module testing device according to claim 1, characterized in that, The number of probe positioning holes between the differential signal probes and between the differential signal probe and the ground signal probe are different from the number of probe positioning holes between the ground signal probes.

5. The display module testing device according to claim 1, characterized in that, In one group, the number of probe positioning holes between the ground signal probe and the differential signal probe is different from the number of probe positioning holes between the ground signal probes; in another group, the number of probe positioning holes between the ground signal probe and the differential signal probe is the same as the number of probe positioning holes between the ground signal probes.

6. The display module testing device according to any one of claims 2-5, characterized in that, The number of probe positioning holes between the ground signal probes is zero, while the number of probe positioning holes between the differential signal probes and / or between the differential signal probe and the ground signal probe is greater than zero.

7. The display module testing device according to claim 1, characterized in that, The spacing between the differential signal probe holes and between the differential signal probe holes and the ground signal probe holes are different from the spacing between the ground signal probes.

8. A display module testing system, characterized in that, include: Test circuit board; The display module testing device according to any one of claims 1-7 is fixedly mounted on the test circuit board; The test circuit board is connected to the display module under test via the probe array.

9. A display module testing method, applicable to the display module testing apparatus as described in any one of claims 1-7, characterized in that, include: The probe module, which includes a differential signal probe and a ground signal probe, is mounted on the test circuit board. Define the signal type on the test circuit board corresponding to the signal probe, and make the spacing between the differential signal probes and / or between the differential signal probe and the ground signal probe different from the spacing between the ground signal probes; The display module under test is pressed together with the probe module to perform a screen test.

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