WO2018214393A1

WO2018214393A1 - Fast detection method for functional defect of pcb micro pad having minimum width of 1 millimeter

Info

Publication number: WO2018214393A1
Application number: PCT/CN2017/106652
Authority: WO
Inventors: 聂兴培; 李敬虹; 陈春; 樊廷慧; 吴世亮
Original assignee: 惠州市金百泽电路科技有限公司; 深圳市金百泽电子科技股份有限公司; 西安金百泽电路科技有限公司
Priority date: 2017-05-23
Filing date: 2017-10-18
Publication date: 2018-11-29
Also published as: CN107356857B; CN107356857A

Abstract

A fast detection method for a functional defect of a PCB micro pad having a minimum width of 1 millimeter. The method comprises the following steps: first generating, by means of automatic point determination of an engineering software, a test file, manually performing, according to a pad shape, local adjustment of a test position of a micro pad in the test file, and generating a test file; selecting a high-precision flying probe test machine having a screw shaft movement system to select an optimal flying probe test machine; performing replacement for a micro-scale testing tool and precision calibration, replacing a conventional blade-tipped testing probe on the flying probe test machine with a micro probe being a needle-tipped testing probe dedicated to micro pads; performing a micro pad alignment design, selecting a micro pad as an alignment point, and performing alignment by means of direct alignment with a center of the micro pad; and configuring an operation parameter of the flying probe test machine. A fast method for detecting a open- or short-circuit defect of a micro pad having a minimum width of 1 millimeter has various advantages, such as strong operability, low manufacturing difficulties, high efficiency, and guaranteed quality.

Description

Fast detection method for functional defects of PCB micro pads with a minimum width of 1 mil

Technical field

The invention relates to a printed circuit board pad width: lmil < PAD Size < 4 mil chip-level micro-sized pad in the field of circuit and short-circuit functional detection, specifically a micro pad with a pad width of l-4 mil A quick detection method for short-circuit defects.

Background technique

[0002] The physical contact between the test probe and the conductive pad of the printed circuit board to detect the conduction performance of the substrate line and the insulation performance (Isolation) are conventional solutions for verifying the electrical performance characteristics of the PCB substrate.

[0003] PCB substrate as a bridge for signal transmission. With the advent of 5G generation, smart device integrated chips led by mobile phone communication have entered the lOnm-class chip packaging technology from surface mount. The pad size of the BGA/IC area is also getting smaller due to the package space requirements (regular width requirement ≥61^1, minimum ≥4mil), and the current IC package has reached the limit of 1-4 mil. In order to ensure the short circuit electrical performance of the PCB substrate, the PCB factory must conduct electrical measurement on the network structure of all solder joints of the PCB substrate before shipment. The micro-pads of less than 4 mils are proposed for the technical capabilities and testing methods of the PCB factory testing equipment. higher requirement.

[0004] When PAD Size≥6mil day, use general or compound fixture test; When PAD Size≥4mil day size, small batch order adopts flying probe test, large batch order can only use one kind of special conductive material PCR (Pressure) Differential Conductive Rubber) and PTB (PitchTranslation Board) made of conductive rubber fixture test, some manufacturers also use CCD fully automatic micro-needle fixture production, but the latter two production models are quite expensive to test, small and medium PCB factory In particular, a variety of small-scale model companies can not afford; when PAD

8 < 41^1 and ≥111 11吋, the limit capability of the above test equipment has been exceeded. For such orders, PCB factories usually use AOI scanning lines + outer manual visual inspection methods, not only slow detection speed, low efficiency, and not suitable for mass production, because the human eye can not find potential functional defects between inner layers or holes. Therefore, there is a serious risk of a huge shortfall in the face of a short-circuit loss.

PCB boards are affected by various factors such as plate and film shrinkage and etching during the production process. The test device itself has a precision deviation of l-2 mil, resulting in a normal offset of the pad center test bit of 1-2 mils. Therefore, the flying probe machine is inefficient or unable to test when testing a micro-position pad of less than 4 mil. The following will study the electrical performance testing technology of the flying needle machine from the data production of the flying needle machine, equipment precision adjustment, test tool selection, alignment mode selection, test program optimization, etc., to eliminate the precision deviation, find the use of flying needle machine The movable feature test <4MIL's best solution for miniature pads.

[0006] With the deepening of Internet+ and Industry 4.0, the order of dense and small PCB micro-pad substrates must be the main battlefield for future orders. The market urgently needs a kind of automatic detection of PCB substrate micro-pad defects. The method is to ensure the quality requirements of the manufacturers after accessing such orders in large quantities.

technical problem

[0007] In the production process, due to the combined influence of various factors such as plate and film expansion and etching, the test equipment itself has a precision deviation of l-2mil, resulting in a normal test position of the pad center of l-2mil. Offset. Therefore, the flying probe machine is inefficient or unable to test when testing micro-position pads of less than 4 mil.

Problem solution

Technical solution

[0008] A method for quickly detecting a short defect of a micro pad having a minimum width of 1 mil includes the following steps:

[0009] The first step, the production of the test file, firstly using the engineering software to automatically generate a test file, and then manually adjust the test position of the micro pad in the test file according to the shape of the pad and generate a test file;

[0010] The second step, the selection of the test machine, selects the high-precision flying probe tester with the screw motion system, and uses the test board to detect the CPK accuracy test value of the flying probe tester, and the detected CPK accuracy test value and The calculated CPK accuracy value is compared, the optimal flying probe test machine is selected, and then the system software is used to correct the screw precision of the flying probe test machine again, that is, the second test of the flying probe test machine is performed, so that the fly is made. The XY displacement accuracy of the needle testing machine reaches the optimal state;

[0011] The third step is to replace the micro test tool and perform the accuracy correction, and replace the conventional knife type test pin on the flying probe tester with a microneedle, which is a pin type test pin for the micro pad, and after replacement, utilize The calibration plate makes small corrections to the accuracy of the micro-needle tip on the flying probe tester, ensuring that the precision of the microneedle tip alignment after installation is optimal;

[0012] The fourth step, the micro pad alignment design, the selection of the micro pad as the opposite site, using the micro pad center straight The alignment method is used for alignment. The micro-pad alignment design adopts the method of direct alignment of the micro-pad center in the board to effectively reduce the influence of shrinkage and etching on the alignment accuracy, and improve the pair of physical plates and data coordinates. The bit precision, specifically, the matching of the microneedle with the tip diameter smaller than the pad width and the moving speed is preferred, thereby minimizing the influence of the pad precision variation on the test accuracy and efficiency due to the board, the film expansion and the manufacturing process deviation. , creating conditions for automated rapid mass production of chip-scale micro pads;

[0013] The fifth step, the test machine running parameter setting, setting the test machine operating parameters, adjusting the displacement accuracy, so that the front or rear two micro needles do not collide during the test.

[0014] The selection of a high-precision flying probe tester with a screw motion system in the rapid detection method of the mini-pad 幵 short-circuit defect with a minimum width of 1 mil in the present invention, the probe can be moved and tested using the flying probe tester Controllable features, optimized micro-needle, needle position and alignment scheme for tiny chip-scale micro-pads with a pad width of 1-4 mil, and matched with moving speed to minimize shrinkage and test efficiency And the influence of precision, to ensure that the micro-needle can effectively detect the electrical performance of tiny chip-level micro-position pads with a width of l-4mil, which can realize the rapid automatic mass production of the machine instead of the traditional AOI scanning + manual visual inspection. That is to improve the test efficiency and reduce the detection method of the micro pad product 幵 short circuit functional defect leakage. The detection method first uses the engineering software to automatically generate a test file, and then manually adjusts the test position of the micro-bit pad in the test file according to the shape of the pad to generate a test file, and then selects the high precision with the screw motion system. Flying probe tester, using the flying needle tester to move and test the speed controllable characteristics, combined with micro-needle and needle position and micro-position pad alignment design, the whole detection process realizes rapid automated mass production of flying probe tester. Instead of the traditional AOI scanning and manual visual inspection methods, it has high operability, low production difficulty, high efficiency and guaranteed quality.

[0015] Further, in the above first step, the test file is produced, and the specific steps are as follows:

[0016] The test file is prepared according to the parameters of the flying probe tester, and the round or shaped pad test point is designed at the center position, the strip pads are staggered at both ends, and the chip-level micro-plate test file is indicated on the process card. Name

[0017] Further, the pin type test pin for the micro pad in the third step is a tapered needle shape, and includes a needle and a needle seat, wherein the needle is a thick and thin conical needle, the needle and the needle seat. Formed by injection molding and fixed at the end of the needle hub, the protruding length of the needle extending from the needle seat portion is 3 mm, the diameter of the needle tip of the needle is less than 2 mil, and the tail of the needle is connected by flying metal wire Needle test machine The signal wires of the test circuit are connected to form a passage, and the injection portion of the needle seat is provided with a fixing hole for mounting the needle seat on the flying probe tester, and the needle seat is mounted on the flying pin by the micro chip-level microneedle through the fixing hole. On the test machine. a micro-needle with a thick and thin conical shape, the needle protrudes from the needle portion by 3 mm, and the needle tip has a diameter of less than 2 mil. The needle and the needle holder are integrally formed by injection molding and fixed at the end of the needle holder, and the injection-molded sheet mechanism of the needle holder has The good elasticity ensures that the test pin does not hurt the test pad and protects the safety of the needle, so that the overall performance of the conical test pin is stable, and the test is more accurate.

[0018] Further, the large correction of the screw precision and the small correction of the microneedle tip in the second step and the third step constitute the accuracy correction of the flying probe tester, and the accuracy correction includes the screw XY axis of the flying probe tester. Displacement accuracy correction, and micro needle tip accuracy correction, the screw XY axis displacement accuracy is corrected to a large correction, and the accuracy correction plate and the calibration program provided by the flying needle tester manufacturer are corrected by the operator, and the micro needle tip precision is corrected. Corrected to a small correction, using the defect correction plate provided by the flying probe tester manufacturer, and then correcting the tip of the replaced microneedle in turn.

[0019] Further, the correction time of the large correction is about 20 minutes, and the correction time of the small correction is about 5 minutes.

[0020] Further, in the step of designing the mini-pad alignment in the fourth step, when each of the boards has a plurality of micro-pad regions 吋, the preferred apex angle corresponds to the apex of the unit micro-pad as the alignment point alignment; During the test, it was found that the board was flawed due to the shrinkage of the board, film, drilling, etc., and the test file was divided according to each shipping unit, and the bipolar alignment was performed according to the micro pad design in the fourth step above. .

[0021] Further, in the fifth step of the test machine operating parameter setting, the design of the detection moving speed is selected when the micro-bit pad width is greater than or equal to 3 mil 吋, and the medium speed is selected; when the micro-bit pad width is less than 3 mil 吋, select Low speed.

Advantageous effects of the invention

Beneficial effect

[0022] The operability is strong, the production difficulty is low, the efficiency is high, and the quality is guaranteed.

[0023] First, the test efficiency is high. The invention selects a high-precision flying needle test machine with a screw motion system, and utilizes the movable characteristics of the flying probe test machine to replace the traditional AOI with the rapid automated production technology of the mobile flying probe tester. Scan + manual visual inspection technology to meet the needs of large-scale production of enterprises, and effectively improve test efficiency;

[0024] Second, the quality is guaranteed, the invention replaces the traditional A with the rapid automated production technology of the mobile flying probe tester. 01 scanning + manual visual inspection technology, effectively avoiding the loss of printed boards with defective short-circuit functional defects to the client, resulting in manufacturers facing huge claims risk of more than 1:10, providing technical support for large-scale automated rapid production of enterprises ;

[0025] Third, the operability is strong, the production difficulty is low, and the fast detection method of the invention is compared with the traditional AOI scanning + manual visual inspection technical solution, which effectively reduces the production difficulty of the product, and the rapid detection method of the invention first utilizes The engineering software automatically generates test files for the seed, and then selects the high-precision flying probe tester with screw motion. After selecting the test machine, replace the conventional knife test pin with the special pin test pin for the micro pad, and then the micro-position. The pad is tested to set the position, and finally the operating parameters of the flying probe tester are set, and the operability is strong.

BEST MODE FOR CARRYING OUT THE INVENTION

[0026] A method for quickly detecting a short circuit defect of a PCB micro-pad with a minimum width of 1 mil includes the following steps: [0027] The first step, the production of the test file, firstly using the engineering software to automatically generate a test file, and then according to the welding The shape of the disc manually adjusts the test position of the micro-bit pad in the test file and generates a test file. Specifically, the test file is prepared according to the parameters of the flying probe tester, and the round or shaped pad test point is designed at the center position. The strip pads are staggered at both ends, and the name of the micro pad test file and the width of the micro pad are indicated on the process card;

[0028] The second step, the selection of the test machine, selects the high-precision flying probe tester with the screw motion system, and uses the test board to detect the CPK accuracy test value of the flying probe tester, and the detected CPK accuracy test value and The calculated CPK accuracy value is compared, the optimal flying probe test machine is selected, and then the system software is used to correct the screw precision of the flying probe test machine again, that is, the second test of the flying probe test machine is performed, so that the fly is made. The XY displacement accuracy of the needle testing machine motion system reaches the optimal state;

[0029] The third step, replacing the micro test tool and performing the accuracy correction, replacing the conventional knife type test pin on the flying probe tester with a microneedle, the microneedle is a pin type test pin for the micro pad, and after the replacement, the use The calibration plate makes small corrections to the accuracy of the micro-needle tip on the flying probe tester, ensuring that the precision of the microneedle tip alignment after installation is optimal;

[0030] The fourth step, the micro pad alignment design, the micro pad is selected as the opposite site, and the micro pad center is directly aligned, and the micro pad alignment design adopts the in-board micro pad center directly. Counterpoint approach Alignment, effectively reducing the influence of shrinkage and etching on the alignment accuracy, improving the alignment accuracy of the physical plate and the data coordinates, specifically, preferably matching the microneedle with a tip diameter smaller than the pad width to the moving speed, maximally reducing The influence of pad precision variation on test accuracy and efficiency due to board and film shrinkage and manufacturing process deviations creates conditions for automated rapid mass production of micro chip-level micro pads.

[0031] The fifth step, the test machine operating parameter setting, the test machine operating parameters are set, the displacement accuracy is adjusted, so that the front or rear two micro needles do not collide during the test, and the test machine is adjusted. In the parameter setting, the design of the detection moving speed is selected. When the micro-bit pad width is greater than or equal to 3 mil 吋, select the medium speed; when the micro-bit pad width is less than 3 mil 吋, select the low speed, and delay the nip between the pins to reduce the false幵

[0032] The invention relates to the selection of a high-precision flying probe tester with a screw motion system in a rapid detection method for a micro-pad 幵 short-circuit defect with a minimum width of 1 mil, which can be moved and tested by a flying probe tester. Controlled features, optimized micro-needle, needle position and alignment scheme for tiny chip-scale micro-pads with a pad width of 1-4 mil, and matched with the moving speed to minimize shrinkage and test efficiency The influence of precision ensures that the micro-needle can effectively detect the electrical performance of micro-chip-level micro-pads with a width of l-4mil, which can realize the rapid automated mass production of the machine instead of the traditional AOI scanning + manual visual inspection. Improve the test efficiency and reduce the detection method of micro-board 幵 short circuit functional defect leakage. The detection method first uses the engineering software to automatically generate a test file, and then manually adjusts the test position of the micro-bit pad in the test file according to the shape of the pad to generate a test file, and then selects the high precision with the screw motion system. Flying probe tester, using the flying needle tester to move and test the speed controllable characteristics, combined with the micro-needle and needle position and micro-pad alignment design, the whole detection process realizes the rapid automatic mass production of the flying probe test machine, instead of The traditional AOI scanning and manual visual inspection methods have strong operability, low production difficulty, high efficiency and guaranteed quality.

[0033] Further, the pin type test pin for the micro pad in the third step is a tapered needle shape, and includes a needle and a needle seat, wherein the needle is a thick and thin conical needle, the needle and the needle seat. Formed by injection molding and fixed at the end of the needle hub, the protruding length of the needle extending from the needle seat portion is 3 mm, the diameter of the needle tip of the needle is less than 2 mil, and the tail of the needle is connected by flying metal wire The signal wires of the needle tester test circuit are connected to form a passage, and the injection portion of the needle seat is provided with a fixing hole for mounting the needle seat on the flying probe tester, and the needle seat mounts the micro needle seat on the fly through the fixing hole Needle tester On. The needle of the conventional knife type test needle is in the shape of a flaky knife. In order to ensure the stability of the blade during the movement, the width of the blade is generally designed to be 2 mm to 3 mm, the length is about 5 mm, and the thickness of the new knife is greater than 4 mil. Testing the edge of the pad that is smaller than its diameter will contact the surrounding solder mask, and the test with the pad under test fails. As the number of tests increases, the tip size also increases, so only pads over 4 mils can be tested. In the present invention, a thick and thin conical test needle is used as a microneedle, and a microneedle having a thick and a thin conical shape, the needle protrudes from the needle seat portion by 3 mm, and the tip diameter is less than 2 mil, and the needle and the needle hub are injection molded. And fixed at the end of the needle holder as a unitary structure, the injection part of the needle seat is set according to the type of the flying needle machine, the fixing hole of different positions is set, and the special test pin of the micro pad is mounted on the flying needle testing machine through the fixing hole, and the needle is guaranteed to be a needle type The micro test pin has good contact with the PCB pad, and the injection molded sheet mechanism of the needle seat has good elasticity, which ensures that the test pin does not damage the test pad and protects the safety of the needle, and the thick and thin cone on the same side. The type of test pin effectively ensures the stability of the test pin during the test, that is, the overall performance of the conical test pin is stable. Selecting a special test pin for the micro-pad that is smaller than the width of the micro-pad can increase the safe distance between the edge of the test pin and the surrounding solder resist, improve the problem of floating with the pad under test, and make the tip and the pad firmly and tightly contact. Make sure the test passes. Specifically, the needle type is selected using 吋, the size of the needle tip is first measured and classified according to the size. According to the width of the pad on the flow card, a microneedle having a needle tip diameter of less than 2 mil is preferred, and the diameter of the needle tip of the microneedle is greater than or equal to 4 mil 吋, can only be used to produce conventional boards, or to produce micro-boards after passing the sanding.

[0034] Further, the large correction of the screw precision and the small correction of the microneedle tip in the second step and the third step constitute the accuracy correction of the flying probe tester, and the accuracy correction includes the screw XY axis of the flying probe tester. Displacement accuracy correction, and micro needle tip accuracy correction, the screw XY axis displacement accuracy is corrected to a large correction, and the accuracy correction plate and the calibration program provided by the flying needle tester manufacturer are corrected by the operator, and the micro needle tip precision is corrected. Corrected to a small correction, using a defect correction plate provided by a flying probe tester manufacturer, and sequentially performing tip correction on the replaced microneedle, the correction time of the large correction is about 20 minutes, and the correction of the small correction is about It is 5 minutes.

[0035] Further, in the step of designing the mini-pad alignment in the fourth step, a plurality of micro-pad regions 出现 appear in each of the boards, and the apex of the preferred board angle corresponding to the unit micro-pad is aligned as a counter point; During the test, it was found that the board was flawed due to the shrinkage of the board, film, drilling, etc., and the test file was divided according to each shipping unit, and the micro-pad alignment design in the fourth step above was divided. Counterpoint. Conventional flying probe tester It is to select the hole or pad of the diagonal corner of the board as the alignment point between the data pattern and the physical board to facilitate the operation of the staff, but since the conventional alignment pad is much larger than the micro pad, the production hole or pad is produced. The effect of the expansion and contraction is naturally larger than that of the micro-pad, resulting in a decrease in the alignment accuracy of the physical board and the test data. In order to ensure the absolute alignment accuracy of the micro pad, the micro pad product selects the solution in the fourth step of the invention, selects the micro pad as the counter point, and adopts the method of direct alignment of the micro pad center to reduce the position. The effect of shrinking and etching on the alignment accuracy can quickly and effectively improve the alignment accuracy of the physical plate and the data coordinates. Embodiments of the invention

[0036] A method for quickly detecting a short circuit defect of a PCB micro-pad with a minimum width of 1 mil includes the following steps:

[0037] The first step, the production of the test file, firstly using the engineering software to automatically generate a test file, and then manually adjust the test position of the micro-bit pad in the test file according to the shape of the pad and generate a test file, specifically Ground, according to the parameters of the flying probe tester to make test files, the round or shaped pad test points are designed at the center position, the strip pads are staggered at both ends, and the name of the micro pad test file is indicated on the process card. The width of the micro pad;

[0038] The second step, the selection of the test machine, selects the high-precision flying probe tester with the screw motion system, and uses the test board to detect the CPK accuracy test value of the flying probe tester, and the detected CPK accuracy test value and The calculated CPK accuracy value is compared, the optimal flying probe test machine is selected, and then the system software is used to correct the screw precision of the flying probe test machine again, that is, the second test of the flying probe test machine is performed, so that the fly is made. The XY displacement accuracy of the needle testing machine motion system reaches the optimal state;

[0039] The third step is to replace the micro test tool and perform the accuracy correction, and replace the conventional knife type test pin on the flying probe tester with a microneedle, which is a special pin type test pin for the micro pad, and after replacement, utilize The calibration plate makes small corrections to the accuracy of the micro-needle tip on the flying probe tester, ensuring that the precision of the microneedle tip alignment after installation is optimal;

[0040] The fourth step, the micro pad alignment design, the micro pad is selected as the opposite site, and the micro pad center is directly aligned, and the micro pad alignment design adopts the in-board micro pad center directly. The alignment of the alignment method effectively reduces the influence of the expansion and contraction and the etching on the alignment accuracy, and improves the alignment accuracy of the physical plate and the data coordinates. Specifically, it is preferable to match the microneedle having a needle tip diameter smaller than the pad width and the moving speed. Maximizes the accuracy of the pad due to plate, film expansion, and manufacturing process variations. And the impact of efficiency, creating conditions for automated, rapid mass production of tiny chip-scale micro-pads;

[0041] The fifth step, the test machine operating parameter setting, the test machine operating parameters are set, the displacement accuracy is adjusted, so that the front or rear two micro needles do not collide during the test, and the test machine is adjusted. In the parameter setting, the design of the detection moving speed is selected. When the micro-bit pad width is greater than or equal to 3 mil 吋, select the medium speed; when the micro-bit pad width is less than 3 mil 吋, select the low speed, and delay the nip between the pins to reduce the false幵

[0042] The invention has the minimum width of 1 mil micro-pad 幵 short-circuit defect rapid detection method in the selection of a high-precision flying probe test machine with a screw motion system, the flying probe tester can be moved, the test speed can be Controlled features, optimized micro-needle, needle position and alignment scheme for tiny chip-scale micro-pads with a pad width of 1-4 mil, and matched with the moving speed to minimize shrinkage and test efficiency The influence of precision ensures that the micro-needle can effectively detect the electrical performance of micro-chip-level micro-pads with a width of l-4mil, which can realize the rapid automated mass production of the machine instead of the traditional AOI scanning + manual visual inspection. Improve the test efficiency and reduce the detection method of micro-board 幵 short circuit functional defect leakage. The detection method first uses the engineering software to automatically generate a test file, and then manually adjusts the test position of the micro-bit pad in the test file according to the shape of the pad to generate a test file, and then selects the high precision with the screw motion system. Flying probe tester, using the flying needle tester to move and test the speed controllable characteristics, combined with the micro-needle and needle position and micro-pad alignment design, the whole detection process realizes the rapid automatic mass production of the flying probe test machine, instead of The traditional AOI scanning and manual visual inspection methods have strong operability, low production difficulty, high efficiency and guaranteed quality.

[0043] Further, the pin type test pin for the micro pad in the third step is a tapered needle shape, and includes a needle and a needle seat, wherein the needle is a thick and thin conical needle, the needle and the needle seat. Formed by injection molding and fixed at the end of the needle hub, the protruding length of the needle extending from the needle seat portion is 3 mm, the diameter of the needle tip of the needle is less than 2 mil, and the tail of the needle is connected by flying metal wire The signal wires of the needle tester test circuit are connected to form a passage, and the injection portion of the needle seat is provided with a fixing hole for mounting the needle seat on the flying probe tester, and the needle seat mounts the micro needle seat on the fly through the fixing hole Needle test machine. The needle of the conventional knife type test needle is in the shape of a flaky knife. In order to ensure the stability of the blade during the movement, the width of the blade is generally designed to be 2 mm to 3 mm, the length is about 5 mm, and the thickness of the new knife is greater than 4 mil. Testing the edge of the pad which is smaller than its diameter will contact the surrounding solder mask and form a contact with the measured pad. The dangling state test failed. As the number of tests increases, the tip size also increases, so only pads over 4 mils can be tested. In the present invention, a thick and thin conical test needle is used as a microneedle, and a microneedle having a thick and a thin conical shape, the needle protrudes from the needle seat portion by 3 mm, and the tip diameter is less than 2 mil, and the needle and the needle hub are injection molded. And fixed at the end of the needle holder as a unitary structure, the injection part of the needle seat is set according to the type of the flying needle machine, the fixing hole of different positions is set, and the special test pin of the micro pad is mounted on the flying needle testing machine through the fixing hole, and the needle is guaranteed to be a needle type The micro test pin has good contact with the PCB pad, and the injection molded sheet mechanism of the needle seat has good elasticity, which ensures that the test pin does not damage the test pad and protects the safety of the needle, and the thick and thin cone on the same side. The type of test pin effectively ensures the stability of the test pin during the test, that is, the overall performance of the conical test pin is stable. Selecting a special test pin for the micro-pad that is smaller than the width of the micro-pad can increase the safe distance between the edge of the test pin and the surrounding solder resist, improve the problem of floating with the pad under test, and make the tip and the pad firmly and tightly contact. Make sure the test passes. Specifically, the needle type is selected using 吋, the size of the needle tip is first measured and classified according to the size. According to the width of the pad on the flow card, a microneedle having a needle tip diameter of less than 2 mil is preferred, and the diameter of the needle tip of the microneedle is greater than or equal to 4 mil 吋, can only be used to produce conventional boards, or to produce micro-boards after passing the sanding.

[0044] Further, the large correction of the screw precision and the small correction of the microneedle tip in the second step and the third step constitute the accuracy correction of the flying probe tester, and the accuracy correction includes the screw XY axis of the flying probe tester. Displacement accuracy correction, and micro needle tip accuracy correction, the screw XY axis displacement accuracy is corrected to a large correction, and the accuracy correction plate and the calibration program provided by the flying needle tester manufacturer are corrected by the operator, and the micro needle tip precision is corrected. Corrected to a small correction, using a defect correction plate provided by a flying probe tester manufacturer, and sequentially performing tip correction on the replaced microneedle, the correction time of the large correction is about 20 minutes, and the correction of the small correction is about It is 5 minutes.

[0045] Further, in the step of designing the mini-pad alignment in the fourth step, a plurality of micro-pad regions 出现 appear in each of the boards, and the apex of the preferred board angle corresponding to the unit micro-pad is aligned as a counter point; During the test, it was found that the board was flawed due to the shrinkage of the board, film, drilling, etc., and the test file was divided according to each shipping unit, and the micro-pad alignment design in the fourth step above was divided. Counterpoint. The conventional flying probe tester selects the hole or pad of the diagonal corner of the plate as the alignment point between the data pattern and the physical plate to facilitate the operation of the staff, but since the conventional alignment pad is much larger than the micro pad, the production The effect of the expansion or contraction of the mesopores or pads is naturally larger than that of the micro-pads, resulting in a decrease in the alignment accuracy of the physical board and the test data. In order to guarantee micro Absolute alignment accuracy of the pad, the micro pad product selects the solution in the fourth step of the invention, selects the micro pad as the counter point, and adopts the method of direct alignment of the micro pad center to reduce the shrinkage and The influence of etching on the alignment accuracy can quickly and effectively improve the alignment accuracy of the physical plate and the data coordinates.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention; those skilled in the art can smoothly follow the description of the drawings and the above. The present invention is embodied by the skilled person in the art, and equivalent changes of the modifications, modifications and evolutions made by the above-disclosed technical contents are all within the scope of the technical scope of the present invention. Equivalent embodiment; the same, the modification, modification and evolution of any equivalent changes made to the above embodiments according to the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

[0047] The present invention has a minimum width of 1 mil micro-pad 幵 short-circuit defect rapid detection method, operability is strong

It is difficult to produce, high in efficiency and quality guaranteed, and can be mass-produced.

Claims

Claim

[Claim 1] A method for quickly detecting a short defect of a micro pad having a minimum width of 1 mil, characterized in that

, including the following steps:

The first step, the production of test files, first use the engineering software to automatically generate test files.

And manually adjusting the test position of the micro pad in the test file according to the shape of the pad and generating a test file;

The second step, the selection of the test machine, select the high-precision flying probe test machine with the screw motion system, use the test board to test the CPK accuracy test value of the flying probe test machine, and calculate the CPK accuracy test value and calculation. Comparing the CPK accuracy values, selecting the optimal flying probe tester; the third step, replacing the micro test tool and performing the accuracy correction, replacing the conventional knife type test pin on the flying probe tester with a microneedle, which is a miniature The special needle type test pin for the pad is used, and after the replacement, the precision of the alignment accuracy of the center position of the tip and the micro pad is corrected for the replaced micro needle;

The fourth step is to design the micro pad alignment, select the micro pad as the opposite point, and use the micro pad center to directly align the position;

The fifth step, test machine running parameter setting, set the test machine operating parameters, adjust the displacement accuracy, so that the front or rear 2 micro needles will not collide during the test.

2 . The method for detecting a short defect of a micro pad of a minimum width of 1 mil according to claim 1 , wherein: the method for preparing the test file in the first step is as follows:

Test files are prepared according to the parameters of the flying needle machine. The round or shaped pad test points are designed at the center position, the strip pads are staggered at both ends, and the micro pad test file name and micro pad are indicated on the process card. The width.

3 . The method for rapidly detecting a micro pad 幵 short defect of a minimum width of 1 mil according to claim 1 , wherein: after the second step of selecting the flying probe tester, the system software is used to measure the wire of the flying probe tester. The rod accuracy is corrected a second time.

4 . The method for rapidly detecting a micro pad 幵 short defect of a minimum width of 1 mil according to claim 3 , wherein: the pin type test pin for the micro pad in the third step is The shape of the tapered needle includes a needle and a needle seat. The needle and the needle seat are integrally formed by injection molding and fixed at the end of the needle seat, and the tail of the needle passes the welding metal wire and the signal of the test circuit of the flying probe tester. The wires are connected to form a passage, and the injection portion of the needle holder is provided with a fixing hole for mounting the needle seat on the flying probe tester, and the needle seat is mounted on the flying probe tester through the fixing hole.

The method for rapidly detecting a micro pad 幵 short defect of a minimum width of 1 mil according to any one of claims 1 to 4, wherein: the protruding length of the needle extending from the hub portion is 3 mm .

The method of claim 5, wherein the tip of the needle has a tip diameter of less than 2 mils.

7 . The fast detection method for a micro pad 幵 short defect of a minimum width of 1 mil according to claim 6 , wherein: the accuracy correction in the third step comprises: correcting the XY axis displacement accuracy of the screw of the flying probe tester. And the micro needle tip precision correction, the screw rod XY axis displacement accuracy is corrected to a large correction, and the accuracy correction board and the calibration program provided by the flying needle tester manufacturer are corrected by the operator, and the micro needle tip precision is corrected to a small correction. , using the defect correction board provided by the flying probe tester manufacturer, and sequentially correcting the replaced micro needle

8 . The method of claim 7 , wherein the correction of the large correction is about 20 minutes, and the correction of the small correction is performed. It is about 5 minutes.

9 . The method of claim 8 , wherein the micro pad aligning design step in the fourth step is performed in each of the plurality of slabs. In the micro pad area 吋, the preferred plate angle corresponds to the apex of the micro-position pad of the unit as the alignment of the opposite position; during the test, it is found that the plate, the film, the drilling, etc. are caused by the expansion and contraction, and the shipment is delayed. The unit divides the test file and performs the split alignment according to the micro pad alignment design in the fourth step above.

10 . The method of claim 1 , wherein the method for detecting a short circuit defect of a micro pad having a minimum width of 1 mil is characterized by: The design of the moving speed is measured. When the width of the micro pad is greater than or equal to 3 mil 吋, select the medium speed; when the width of the micro pad is less than 3 mil 吋, select the low speed.