Detection jig and detection method for large-size multi-point substrate

Abstract

The invention discloses a detection jig and a detection method for a large-size multi-point substrate. The detection jig comprises a mounting base, an adjusting seat and a jig unit, the mounting base is used for supporting the plurality of adjusting seats, and the adjusting seats are used for supporting the jig units and are mounted in one-to-one correspondence with the jig units; each jig unit is provided with a plurality of probes, and the plurality of jig units are spliced to form a complete detection area; a plurality of first positioning holes are formed in the mounting base, a plurality of second positioning holes are formed in the adjusting seat, the adjusting seat can move relative to the mounting base, and after the adjusting seat moves, the first positioning holes and the second positioning holes which are opposite in position exist; and the position of the jig unit can be finely adjusted through the adjusting seat. According to the invention, a plurality of small-size jig units are spliced into a large-size detection jig, so that O / S detection and 4W low-resistance detection can be carried out on high-density and small pads by virtue of high precision and high performance, and the large-size detection jig can be suitable for checking substrates of various specifications.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit substrate detection, and in particular to a detection fixture and a detection method for a large-size multi-point substrate. Background Art

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

[0003] However, as the complexity of electronic products increases and the size of substrates expands, existing inspection fixtures have many problems in terms of technical adaptability and large-scale inspection capabilities: With the expansion of substrate size (such as 550mm×650mm and above) and the surge in the number of test points (such as 32,000 test points), traditional inspection fixtures are difficult to cover all test points at one time due to the limitations of probe density and signal routing capabilities. At present, the industry usually divides large-size substrates into multiple inspection areas and tests them in steps. However, step-by-step testing requires frequent movement of substrates or fixtures, and each positioning and calibration takes a long time, which seriously affects the inspection efficiency and is difficult to meet the needs of mass production. Multiple positioning may introduce mechanical errors, especially under micron-level alignment requirements. Error superposition will cause unreliable inspection results in subsequent areas. In addition, regional division may cause interruption of the test logic of cross-regional signal paths, which may easily miss potential defects at the junction of regions.

[0004] Although the inspection fixture is specially designed for a specific type of circuit substrate, in actual production, different batches of substrates may experience dimensional deformation (i.e., "expansion and contraction") due to material properties (such as hygroscopicity of the resin substrate, differences in thermal expansion coefficient) or process fluctuations (such as lamination temperature, etching accuracy deviation). This deformation usually manifests as micron-level contraction or expansion of the entire or local area of ​​the substrate (for example, dimensional deviation of ±0.1% to ±0.3%), resulting in misalignment between the probe fixed on the fixture and the substrate pad. When the pad offset exceeds the probe's alignment tolerance range, the probe cannot reliably contact the pad, causing test misjudgment (such as false open or short circuit). The same fixture is difficult to accommodate deformation differences between different batches, and the fixture needs to be frequently adjusted or customized, increasing production costs and downtime. Existing solutions rely on high-precision probe processing or elastic probe structures, but their compensation capabilities are limited (usually only covering deviations of tens of microns) and cannot dynamically adapt to the nonlinear characteristics of substrate deformation.

[0005] In summary, existing inspection fixtures face multiple challenges such as insufficient technical adaptability, high cost and low efficiency when dealing with substrate expansion and contraction and high-density, large-size inspection needs. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a detection fixture and a detection method for large-size multi-point substrates.

[0007] To this end, the technical solution of the present invention is: a detection fixture for large-size multi-point substrates, including 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 units, and are installed one by one with the fixture units; 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. The adjusting seat can move relative to the mounting base, and after the movement, there are first positioning holes and second positioning holes with relative positions, and the positioning is performed by positioning pins; the adjusting seat can drive the fixture unit to move and fine-tune the position of the fixture unit.

[0008] On the basis of the above scheme and as a preferred scheme of the above scheme: a plurality of groups of second positioning holes are provided at the edge of the adjustment seat, each group comprises a plurality of second positioning holes distributed in a rectangular array and a 45° diamond distribution, that is, the adjustment seat has 8 adjustment directions of up, down, left, right, upper left, lower left, upper right and lower right, distributed in a cross shape.

[0009] On the basis of the above scheme and as a preferred scheme of the above scheme: a plurality of groups of first positioning holes are provided at the edge of the mounting base, each group includes a plurality of first positioning holes distributed in a rectangular array and a 45° diamond distribution, and the first positioning holes are misaligned with the second positioning holes.

[0010] On the basis of the above solution and as a preferred solution of the above solution: the adjustment range of the adjustment seat in each direction is 20um~80um.

[0011] On the basis of the above scheme and as a preferred scheme of the above scheme: the number of the fixture units is 2, 3, 4 or 6.

[0012] On the basis of the above scheme and as a preferred scheme of the above scheme: the fixture unit is fixed on the adjustment seat by a fastener, and the second positioning hole is located at the edge of the adjustment seat without interfering with the fixture unit.

[0013] On the basis of the above scheme and as a preferred scheme of the above scheme: the adjustment seat is provided with an assembly hole, the mounting base is provided with a screw hole, the fastening bolt passes through the assembly hole and is fixedly connected with the screw hole, and is used to lock the adjustment seat and the mounting base.

[0014] Another technical solution of the present invention is: a detection method for a large-size multi-point substrate, comprising the following steps: S1. Install the assembled detection fixture on the test device; S2, placing the substrate to be tested in the testing area and covering the substrate with a layer of blue film; S3, driving the detection fixture to move toward the substrate so that the probe leaves an indentation on the blue film; S4, sending the substrate with the blue film into the imaging device to observe whether there is an offset between the solder joint of the substrate and the indentation left by the probe on the blue film. If there is an offset, execute step S5; if there is no offset, execute step S6; S5, obtaining an offset direction and an offset spacing, and adjusting the position of each fixture unit according to the offset direction and the offset spacing so that the probe corresponds to the solder joint on the substrate; S6. Put the substrate after the blue film is torn off back into the testing area for electrical testing.

[0015] On the basis of the above scheme and as a preferred scheme of the above scheme: the imaging device in step S4 is a microscope or a 3D image detection device.

[0016] On the basis of the above scheme and as a preferred scheme of the above scheme: in the step S5, loosen the fastening bolt and take out the positioning pin on the adjustment seat; according to the offset direction and the offset spacing, insert the positioning pin into the second positioning hole at the appropriate position, and when the positioning pin continues to be inserted into the first positioning hole below, it will drive the adjustment seat to move, thereby completing the fine adjustment of the fixture unit.

[0017] Compared with the prior art, the present invention has the following beneficial effects: Multiple small-sized fixture units are assembled into a large-sized inspection fixture. With high precision and high performance, O / S inspection and 4W low-resistance inspection can be performed on high-density and tiny pads. This inspection fixture can be applied to various specifications of substrates for inspection. With the support of high-precision equipment, fast and accurate O / S and 4W inspection can be achieved.

[0018] The split structure can accommodate up to 6 fixture units, which can be adjusted according to the actual locking status of the substrate. The oversized base is used, and the structure is arranged up and down, left and right, or left, middle and right. The number of points is increased to twice the original without increasing the line length, meeting different test requirements.

[0019] By installing the fixture unit on the adjustment seat, the fixture unit can be fine-tuned in 8 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 substrates from different batches, effectively solving the test deviation problem caused by expansion and contraction and ensuring the accuracy of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a structural schematic diagram of the mounting base of the present invention; Figure 3 It is a structural schematic diagram of the adjustment seat of the present invention; Figure 4 It is a schematic diagram of the principle of fine adjustment of the adjustment seat of the present invention; Figure 5 It is a schematic diagram of assembling two fixture units of the present invention; Figure 6 It is a schematic diagram of assembling three fixture units of the present invention; Figure 7 This is a schematic diagram of assembling six fixture units of the present invention.

[0021] Marked in the figure are: mounting base 1, screw hole 11, first positioning hole 12, adjustment seat 2, assembly hole 21, second positioning hole 22, fixture unit 3, positioning pin 4. DETAILED DESCRIPTION

[0022] In the description of the present invention, it should be noted that directional words, such as the terms "center", "lateral (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of narrating the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific scope of protection of the present invention.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. Therefore, the definition of "first" and "second" features can explicitly or implicitly include one or more of the features. In the description of the present invention, "several" and "a number" mean two or more, unless otherwise clearly and specifically defined.

[0024] See the attached drawings. The inspection fixture for large-size multi-point substrates described in this embodiment includes a mounting base 1 , a plurality of adjustment seats 2 and a plurality of fixture units 3 .

[0025] The fixture unit 3 is provided with a plurality of probes in contact with the substrate, and the fixture unit 3 is fixed to the adjustment seat 2 by fasteners. The adjustment seat 2 has the same number as the fixture units 3 and is installed one by one. The plurality of fixture units 3 are assembled into a complete detection area, thereby realizing the assembly of a plurality of small-sized fixtures into a large-sized fixture, and electrical detection of a large-sized substrate can be performed at one time without the need for step-by-step testing.

[0026] The adjustment seat 2 is provided with an assembly hole 21, and the mounting base 1 is provided with a screw hole 11. The fastening bolt passes through the assembly hole 21 and is fixedly connected with the screw hole 11, which is used to lock the adjustment seat 2 and the mounting base 1. The edge of the mounting base 1 is provided with a plurality of groups of first positioning holes 12, each group is composed of 8 first positioning holes 12, and among the 8 first positioning holes 12, four are distributed in a rectangular array and four are distributed in a 45° rhombus. Similarly, the edge of the adjustment seat 2 is provided with a plurality of groups of second positioning holes 22, each group is composed of 8 second positioning holes 22, and among the 8 second positioning holes 22, four are distributed in a rectangular array and four are distributed in a 45° rhombus. There is a slight deviation between the spacing size of the first positioning holes 12 and the spacing size of the second positioning holes 22, so that the adjustment seat 2 can move relative to the mounting base 1 through the deviation of the positioning holes, and after the movement, there are first positioning holes 12 and second positioning holes 22 that are relatively positioned, and are positioned by the positioning pin 4, but the remaining first positioning holes and second positioning holes are misaligned.

[0027] The fine-tuning principle of the adjustment seat 2 is as follows: Figure 4 As shown in the figure (the position, number and size of the holes in the figure are only set for the convenience of description), 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 is still within the installation range of the adjustment hole 21 after fine-tuning. For the convenience of description, three second positioning holes are set on the adjustment seat 2, which are the left second positioning hole A1, the middle second positioning hole A2 and the right second positioning hole A3 from left to right; three first positioning holes are set on the mounting base 1, which are the left first positioning hole B1, the middle first positioning hole B2 and the right first positioning hole B3 from left to right.

[0028] In the initial state, after the left second positioning hole A1 on the adjustment seat 2 is aligned with the left first positioning hole B1 on the mounting base 1, the remaining first positioning holes and second positioning holes are misaligned. At this time, insert the positioning pin 4 into the left second positioning hole A1 and the left first positioning hole B1, and then pass the fastening bolt through the adjustment hole and lock it with the screw hole to fix the adjustment seat on the mounting base.

[0029] When the adjustment seat 2 needs to be adjusted to the left, loosen the fastening bolt, pull out the positioning pin 4, and insert the positioning pin 4 into the middle second positioning hole A2. At this time, in order to allow the positioning pin 4 to continue to be inserted into the middle first positioning hole B2, the adjustment seat 2 needs to be adjusted to the left, and the adjustment distance of the adjustment seat 2 can be controlled according to the hole position gap to achieve accurate adjustment; after adjustment, retighten the fastening bolt.

[0030] When the adjustment seat 2 needs to be adjusted to the right, loosen the fastening bolt, pull out the positioning pin 4, and insert the positioning pin 4 into the second positioning hole A3 on the right. At this time, in order to allow the positioning pin 4 to continue to be inserted into the first positioning hole B3 on the right, the adjustment seat 2 needs to be adjusted to the right, and the adjustment distance of the adjustment seat 2 can be controlled according to the hole position gap to achieve accurate adjustment; after adjustment, retighten the fastening bolt.

[0031] In summary, the adjustment seat 2 has 8 adjustment directions, namely, up, down, left, right, upper left, lower left, upper right, and lower right, which are arranged in a cross-shaped pattern. The adjustment range of the adjustment seat 2 in the horizontal, vertical, and 45° directions is 20um~80um, which can adapt to substrates with various degrees of expansion and contraction.

[0032] The number of the fixture units 3 is 2, 3, 4 or 6, which can be designed according to the size of the substrate. Figures 5 to 7 shown.

[0033] The detection method for a large-size multi-point substrate described in this embodiment includes the following steps: S1. Install the assembled detection fixture on the test device; S2, placing the substrate to be tested in the testing area and covering the substrate with a layer of blue film; S3, driving the detection fixture to move toward the substrate so that the probe leaves an indentation on the blue film; S4, sending the substrate with the blue film to an imaging device, which can be a microscope or a 3D image detection device, to magnify the image of the solder joint and the indentation, so as to observe whether there is an offset between the solder joint of the substrate and the indentation left by the probe on the blue film. If there is an offset, execute step S5; if there is no offset, execute step S6; S5. Obtain the offset direction and offset spacing, and adjust the position of each fixture unit according to the offset direction and offset spacing, so that the probe corresponds to the solder joint on the substrate; when adjusting, first loosen the fastening bolts and take out the positioning pins on the adjustment seat; according to the offset direction and offset spacing, insert the positioning pins into the second positioning holes at the appropriate positions, and when the positioning pins continue to be inserted into the first positioning holes below, the adjustment seat will be driven to move, and the fine adjustment of the fixture unit will be completed; S6. Put the substrate with the blue film removed back into the test area for electrical testing. At this time, the probe can accurately contact the solder joints on the substrate.

[0034] This embodiment develops a large-size, multi-point detection fixture. With high precision and high performance, it can perform O / S detection and 4W low-resistance detection on high-density, tiny pads. The detection fixture can be applied to substrates of various specifications within 550*650mm (previously within 400mm), 1~6mm thick (previously within 2mm thick), and within 32768 single-mode maximum points (previously within 16384 single-mode points). With the support of high-precision equipment, fast and accurate O / S and 4W detection can be achieved.

[0035] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A detection fixture for large-size multi-point substrates, characterized by: It includes a mounting base, an adjustment base and a fixture unit; the mounting base is used to support a plurality of adjustment bases, the adjustment base is used to support the fixture units, and is installed one by one with the fixture units; each fixture unit is provided with a plurality of probes, and the plurality of 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. The adjusting seat can move relative to the mounting base, and after the movement, there are first positioning holes and second positioning holes with relative positions, and the positioning is performed by positioning pins; the adjusting seat can drive the fixture unit to move and fine-tune the position of the fixture unit.

2. The inspection fixture for large-size multi-point substrates according to claim 1, characterized in that: Several groups of second positioning holes are provided at the edge of the adjustment seat, each group includes multiple second positioning holes distributed in a rectangular array and a 45° diamond distribution, that is, the adjustment seat has 8 adjustment directions of up, down, left, right, upper left, lower left, upper right and lower right, distributed in a cross shape.

3. The detection fixture for large-size multi-point substrates according to claim 2, characterized in that: A plurality of groups of first positioning holes are arranged at the edge of the mounting base, each group comprising a plurality of first positioning holes distributed in a rectangular array and a 45° rhombus, and the first positioning holes are misaligned with the second positioning holes.

4. The detection fixture for large-size multi-point substrates according to claim 2, characterized in that: The adjustment range of the adjustment seat in each direction is 20um~80um.

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

6. The inspection fixture for large-size multi-point substrates according to claim 1, characterized in that: The fixture unit is fixed on the adjustment seat by a fastener, and the second positioning hole is located at the edge of the adjustment seat without interfering with the fixture unit.

7. The inspection fixture for large-size multi-point substrates according to claim 1, characterized in that: 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 with the screw hole to lock the adjusting seat and the mounting base.

8. A method for detecting a large-size multi-point substrate, using the detection fixture according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Install the assembled detection fixture on the test device; S2, placing the substrate to be tested in the testing area and covering the substrate with a layer of blue film; S3, driving the detection fixture to move toward the substrate so that the probe leaves an indentation on the blue film; S4, sending the substrate with the blue film into the imaging device to observe whether there is an offset between the solder joint of the substrate and the indentation left by the probe on the blue film. If there is an offset, execute step S5; If there is no offset, execute step S6; S5, obtaining an offset direction and an offset spacing, and adjusting the position of each fixture unit according to the offset direction and the offset spacing so that the probe corresponds to the solder joint on the substrate; S6. Put the substrate after the blue film is torn off back into the testing area for electrical testing.

9. A method for detecting a large-size multi-point substrate as claimed in claim 8, characterized in that: The imaging device in step S4 is a microscope or a 3D image detection device.

10. The detection method for a large-size multi-point substrate according to claim 8, characterized in that: In step S5, the fastening bolts are loosened and the positioning pins on the adjustment seat are taken out; the positioning pins are inserted into the second positioning holes at the appropriate positions according to the offset direction and offset spacing, and when the positioning pins continue to be inserted into the first positioning holes below, the adjustment seat is driven to move, thereby completing the fine adjustment of the fixture unit.

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