A detection jig for large-size multi-point substrate

Abstract

The utility model discloses a kind of detection fixtures for large-size multi-point base plate, including mounting base, adjusting seat and jig unit;The mounting base is used to support multiple adjusting seats, adjusting seat is used to support jig unit, and it is installed one-to-one correspondence with jig unit;Multiple probes are equipped on each jig unit, and multiple jig units are spliced into a complete detection area;A plurality of first positioning holes are provided on the mounting base, a plurality of second positioning holes are provided on the adjusting seat, the adjusting seat can move relative to the mounting base, and after moving, there are positionally opposite first positioning holes and second positioning holes;The jig unit can be positionally fine-tuned by the adjusting seat.The utility model splices multiple small-size jig units into large-size detection fixture, with high precision and high performance, can perform O / S detection and 4W low resistance detection on high-density and small pads, and can be applied to inspect multiple specifications of substrates.

Description

Technical Field

[0001] This utility model relates to the field of circuit board testing technology, and in particular to a testing fixture for large-size multi-point circuit boards. Background Technology

[0002] In the electronics manufacturing industry, circuit boards (such as PCBs) are core components of electronic devices, and their electrical performance and structural reliability must be rigorously verified using testing fixtures. Traditional testing fixtures use probe arrays to contact pads or test points on the substrate to perform continuity, insulation, or signal integrity tests.

[0003] However, with the increasing complexity of electronic products and the expansion of substrate size, existing testing fixtures have many problems in terms of technical adaptability and large-scale testing capabilities:

[0004] With the increasing size of substrates (e.g., 550mm × 650mm and above) and the surge in the number of test points (e.g., 32,000 test points), traditional testing fixtures, limited by probe density and signal routing capabilities, struggle to cover all test points at once. Currently, the industry typically divides large-size substrates into multiple testing areas and tests them step-by-step. However, step-by-step testing requires frequent movement of the substrate or fixture, with each positioning and calibration taking considerable time, severely impacting testing efficiency and failing to meet the demands of mass production. Multiple positioning operations may introduce mechanical errors, especially under micron-level alignment requirements, where the cumulative error can lead to unreliable test results in subsequent areas. Furthermore, area division may disrupt test logic across signal paths, easily overlooking potential defects at area boundaries.

[0005] Although testing fixtures are specifically designed for certain types of circuit boards, in actual production, different batches of boards may experience dimensional deformation (i.e., "expansion and contraction") due to material properties (such as the hygroscopicity of the resin substrate and differences in the coefficient of thermal expansion) or process fluctuations (such as lamination temperature and etching accuracy deviations). This deformation typically manifests as micron-level shrinkage or expansion of the entire substrate or localized areas (e.g., dimensional deviations of ±0.1% to ±0.3%), leading to misalignment between the probes fixed on the fixture and the substrate pads. When the pad misalignment exceeds the probe's alignment tolerance, the probe cannot reliably contact the pad, causing test misjudgments (such as false open circuits or short circuits). The same fixture is difficult to accommodate deformation differences between different batches, requiring frequent adjustments or custom fixtures, increasing production costs and downtime. Existing solutions rely on high-precision probe processing or flexible probe structures, but their compensation capabilities are limited (typically covering only tens of micron deviations) and cannot dynamically adapt to the nonlinear characteristics of substrate deformation.

[0006] In summary, existing testing fixtures face multiple challenges in addressing the demands of substrate expansion and contraction, as well as high-density and large-size testing requirements, including insufficient technical adaptability, high costs, and low efficiency. Utility Model Content

[0007] To address the aforementioned problems, this invention provides a testing fixture for large-size, multi-point substrates.

[0008] Therefore, the technical solution of this utility model is: a detection fixture for large-size multi-point substrates, including a mounting base, an adjustment seat, and fixture units; the mounting base is used to support multiple adjustment seats, the adjustment seats are used to support fixture units, and are installed in a one-to-one correspondence with the fixture units; each fixture unit is provided with multiple probes, and multiple fixture units are combined to form a complete detection area.

[0009] The mounting base is provided with a plurality of first positioning holes, and the adjusting seat is provided with a plurality of second positioning holes, and there is a deviation in the size of the interval between the first positioning holes and the second positioning holes; the adjusting seat can move relative to the mounting base through the deviation between the first positioning holes and the second positioning holes, and after the movement, there are first positioning holes and second positioning holes in opposite positions, and positioning is achieved by positioning pins; the adjusting seat can drive the fixture unit to move and fine adjust the position of the fixture unit.

[0010] Based on the above scheme and as a preferred embodiment of the above scheme: the edge of the adjustment seat is provided with several sets of second positioning holes, each set containing multiple second positioning holes distributed in a rectangular array and a 45° rhomboid distribution, that is, the adjustment seat has 8 adjustment directions, which are distributed in a star shape.

[0011] Based on the above scheme and as a preferred embodiment of the above scheme: the edge of the mounting base is provided with several sets of first positioning holes, each set including multiple first positioning holes distributed in a rectangular array and a 45° rhomboid distribution, and the first positioning holes are misaligned with the second positioning holes.

[0012] Based on the above scheme and as a preferred embodiment of the above scheme: the adjustment range of the adjustment seat in all directions is 20um~80um.

[0013] Based on the above scheme and as a preferred embodiment of the above scheme: the number of fixture units is 2, 3, 4 or 6.

[0014] Based on the above scheme and as a preferred embodiment of the above scheme: the fixture unit is fixed to the adjusting seat by fasteners, and the second positioning hole is located at the edge of the adjusting seat, without interfering with the fixture unit.

[0015] Based on the above scheme and as a preferred embodiment of the above scheme: the adjusting seat is provided with an assembly hole, the mounting base is provided with a screw hole, and the fastening bolt passes through the assembly hole and is fixedly connected to the screw hole to lock the adjusting seat and the mounting base.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] By assembling multiple small fixture units into a large inspection fixture, this fixture boasts high precision and performance, enabling O / S and 4W low-resistance testing on highly dense, tiny pads. This inspection fixture is applicable to the inspection of substrates of various specifications, achieving rapid and accurate O / S and 4W testing with the support of high-precision equipment.

[0018] It adopts a split structure, which can arrange up to 6 fixture units, and can be adjusted according to the actual locking status of the substrate; it adopts an extra-large base, and the structure adopts an up-down, left-right or left-center-right arrangement structure, so as to double the number of points without increasing the line length, to meet different testing needs.

[0019] By mounting the fixture unit on the adjustment base, the fixture unit can be finely adjusted in eight directions: up, down, left, right, upper left, lower left, upper right, and lower right. This allows the probes of the fixture unit to be adjusted to match the substrates of different batches, effectively solving the test deviation problem caused by expansion and contraction and ensuring the accuracy of the test. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 This is a schematic diagram of the structure of the mounting base of this utility model;

[0022] Figure 3 This is a schematic diagram of the structure of the adjusting seat of this utility model;

[0023] Figure 4 This is a schematic diagram illustrating the principle of fine-tuning of the adjusting seat of this utility model;

[0024] Figures 5-7 This is a schematic diagram of the assembly of different numbers of fixture units of this utility model.

[0025] The components are marked as follows: mounting base 1, screw hole 11, first positioning hole 12, adjusting seat 2, assembly hole 21, second positioning hole 22, fixture unit 3, and positioning pin 4. Detailed Implementation

[0026] In the description of this utility model, it should be noted that the directional terms such as "center", "horizontal (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this utility model.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In the description of this utility model, "several" or "a number" means two or more, unless otherwise explicitly specified.

[0028] See the attached figures. The inspection fixture for large-size multi-point substrates described in this embodiment includes a mounting base 1, multiple adjustment seats 2, and multiple fixture units 3.

[0029] The fixture unit 3 is provided with multiple probes that contact the substrate, and the fixture unit 3 is fixed to the adjustment seat 2 by fasteners. The number of adjustment seats 2 and fixture units 3 is the same, and they are installed one-to-one. Multiple fixture units 3 are combined into a complete detection area, thereby realizing the combination of multiple small fixtures into a large fixture, which can perform electrical testing on a large substrate at one time without step-by-step testing.

[0030] The adjusting seat 2 has an assembly hole 21, and the mounting base 1 has a screw hole 11. Fastening bolts pass through the assembly hole 21 and are fixedly connected to the screw hole 11 to lock the adjusting seat 2 and the mounting base 1. The mounting base 1 has several sets of first positioning holes 12 along its edge, each set consisting of eight first positioning holes 12. Four of the eight first positioning holes 12 are arranged in a rectangular array, and four are arranged in a 45° rhombus. Similarly, the adjusting seat 2 has several sets of second positioning holes 22 along its edge, each set consisting of eight second positioning holes 22. Four of the eight second positioning holes 22 are arranged in a rectangular array, and four are arranged in a 45° rhombus. The spacing between the first positioning holes 12 and the second positioning holes 22 has a slight deviation, allowing the adjusting seat 2 to move relative to the mounting base 1 through this deviation. After movement, there are first positioning holes 12 and second positioning holes 22 in relative positions, which are positioned by positioning pins 4, but the remaining first positioning holes and second positioning holes are misaligned.

[0031] The fine-tuning principle of its adjusting seat 2 is as follows: Figure 4 As shown (the position, number, and size of the holes in the figure are only for illustrative purposes), the diameter of the adjustment hole 21 on the adjustment seat 2 is larger than the diameter of the screw hole 11 on the mounting base 1, so that the adjustment seat 2 remains within the installation range of the adjustment hole 21 after fine adjustment.

[0032] In the initial state, after the second positioning hole A1 on the adjusting seat 2 is aligned with the first positioning hole B1 on the mounting base 1, the other first positioning holes and second positioning holes are misaligned. At this time, the positioning pin 4 is inserted into the second positioning hole A1 and the first positioning hole B1, and then the fastening bolt is passed through the adjusting hole and locked with the screw hole to fix the adjusting seat on the mounting base.

[0033] When the adjusting seat 2 needs to be adjusted to the left, loosen the fastening bolt and pull out the positioning pin 4. Insert the positioning pin 4 into the second positioning hole A2. At this time, in order for the positioning pin 4 to continue to be inserted into the first positioning hole B2, the adjusting seat 2 needs to be adjusted to the left. The adjustment distance of the adjusting seat 2 can be controlled according to the hole position difference to achieve accurate adjustment. After adjustment, tighten the fastening bolt again.

[0034] When the adjusting seat 2 needs to be adjusted to the right, loosen the fastening bolt and pull out the positioning pin 4. Insert the positioning pin 4 into the second positioning hole A3. At this time, in order for the positioning pin 4 to continue to be inserted into the first positioning hole B3, the adjusting seat 2 needs to be adjusted to the right. The adjustment distance of the adjusting seat 2 can be controlled according to the hole position difference to achieve accurate adjustment. After adjustment, tighten the fastening bolt again.

[0035] In summary, the adjustment base 2 has eight adjustment directions: up, down, left, right, upper left, lower left, upper right, and lower right, arranged in a star-shaped pattern. Furthermore, the adjustment range of the adjustment base 2 in the horizontal, vertical, and 45° tilt directions is 20µm to 80µm, making it suitable for substrates with varying degrees of expansion and contraction.

[0036] The number of fixture units 3 can be 2, 3, 4, or 6, and can be designed according to the size of the substrate, such as... Figures 5-7 As shown.

[0037] The testing process includes the following steps:

[0038] S1. Install the assembled testing fixture onto the testing device;

[0039] S2. Place the substrate to be tested in the testing area and cover the substrate with a blue film;

[0040] S3. Drive the testing fixture toward the substrate so that the probe leaves an indentation on the blue film;

[0041] S4. Send the substrate with the blue film into the imaging device. The imaging device can be a microscope or a 3D image detection device, which can magnify the image of the solder joint and the indentation, so as to facilitate observation of whether there is a misalignment between the solder joint of the substrate and the indentation left by the probe on the blue film. If there is a misalignment, proceed to step S5; if there is no misalignment, proceed to step S6.

[0042] S5. Obtain the offset direction and offset distance, and adjust the position of each fixture unit according to the offset direction and offset distance so that the probe corresponds to the solder joint on the substrate. When adjusting, first loosen the fastening bolt and remove the positioning pin on the adjustment seat. According to the offset direction and offset distance, insert the positioning pin into the second positioning hole at the appropriate position. When the positioning pin continues to be inserted into the first positioning hole below, it will drive the adjustment seat to move, thus completing the fine adjustment of the fixture unit.

[0043] S6. Place the substrate with the blue film removed back into the testing area for electrical testing. At this time, the probe can make precise contact with the solder joints on the substrate.

[0044] This embodiment develops a large-size, multi-point inspection fixture. With its high precision and high performance, it can perform O / S inspection and 4W low-resistance inspection on highly dense, tiny pads. This inspection fixture is applicable to various specifications of substrates within 550*650mm (previously within 400mm), thickness 1~6mm (previously within 2mm), and maximum single-mode point count within 32768 (previously within 16384). With the support of high-precision equipment, it achieves fast and accurate O / S and 4W inspection.

[0045] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A testing fixture for large-size multi-point substrates, characterized in that: It includes a mounting base, an adjustment seat, and a fixture unit; the mounting base is used to support multiple adjustment seats, the adjustment seats are used to support the fixture unit, and are installed in a one-to-one correspondence with the fixture unit; each fixture unit is provided with multiple probes, and multiple fixture units are assembled into a complete detection area. The mounting base is provided with a plurality of first positioning holes, and the adjusting seat is provided with a plurality of second positioning holes, and there is a deviation in the size of the interval between the first positioning holes and the second positioning holes; the adjusting seat can move relative to the mounting base through the deviation between the first positioning holes and the second positioning holes, and after the movement, there are first positioning holes and second positioning holes in opposite positions, and positioning is achieved by positioning pins; the adjusting seat can drive the fixture unit to move and fine adjust the position of the fixture unit.

2. The inspection fixture for large-size multi-point substrates as described in claim 1, characterized in that: The adjustment seat has several sets of second positioning holes along its edge. Each set contains multiple second positioning holes arranged in a rectangular array and a 45° rhomboid pattern. In other words, the adjustment seat has eight adjustment directions, arranged in a star-shaped pattern.

3. The inspection fixture for large-size multi-point substrates as described in claim 2, characterized in that: The mounting base has several sets of first positioning holes along its edge. Each set includes multiple first positioning holes arranged in a rectangular array and a 45° rhomboid pattern, and the first positioning holes are misaligned with the second positioning holes.

4. The inspection fixture for large-size multi-point substrates as described in claim 2, characterized in that: The adjustment range of the adjustment seat in all directions is 20um~80um.

5. The inspection fixture for large-size multi-point substrates as described in claim 1, characterized in that: The number of fixture units is 2, 3, 4 or 6.

6. The inspection fixture for large-size multi-point substrates as described in claim 1, characterized in that: The fixture unit is fixed to the adjusting seat by fasteners, and the second positioning hole is located at the edge of the adjusting seat and does not interfere with the fixture unit.

7. The inspection fixture for large-size multi-point substrates as described in claim 1, characterized in that: The adjusting seat is provided with an assembly hole, and the mounting base is provided with a screw hole. The fastening bolt passes through the assembly hole and is fixedly connected to the screw hole to lock the adjusting seat and the mounting base.

Images