Chip short circuit detection and simple positioning method and device

Abstract

A chip short circuit detection device disclosed by the present invention comprises a PCB base plate and a chip test clamp, the chip test clamp and the PCB base plate are detachably assembled, the edge of the PCB base plate is provided with a pin header part, and the PCB base plate is internally provided with a circuit to enable the pin header and a probe of the chip test clamp to be correspondingly and electrically connected. And the pins of the chip extend to the pin header parts at the periphery of the PCB bottom plate in a one-to-one correspondence manner. Through the arrangement of the pin header part, a large number of pins in the chip can be uniformly connected and dispersed to the periphery of the PCB, a universal meter can be conveniently and accurately connected to the pins needing to be measured, and the pins of the chip are not directly contacted, so that the pins of the chip are not influenced; the pin header group and the jumper wire group can accurately find short-circuited pins from the whole to the local through different short-circuit modes. According to the scheme of the invention, the problems of high cost and long period of third-party detection are solved, the defect that a universal meter is directly contacted with a chip pin is overcome, and the coexistence of economy and high efficiency is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of chip short - circuit detection, and specifically refers to a method and device for chip short - circuit detection and simple positioning. Background Art

[0002] With the continuous development of chip manufacturing processes, the integration level is getting higher and higher, and the corresponding failure modes are also increasing. How to quickly and effectively test and analyze chip failures has become very important; chip manufacturers will conduct special electrical performance tests when the chips leave the factory to ensure their reliability; when problems occur during the use of the chips and they are returned to the factory for testing, it is often necessary to first rule out short - circuit problems. If the chip has a short - circuit phenomenon, during SLT, it may cause secondary damage to the chip and damage to the test board.

[0003] There are different methods for short - circuit detection, such as BGA testers, X - Ray non - destructive testing, multimeter measurement, etc.; the most commonly used and economical method is to directly measure the resistance value with a multimeter to quickly determine whether there is a short - circuit phenomenon in the chip. For example, in the prior art, the application number: CN201611196363.2 discloses a detection method for DRAM, which includes the following steps: Step 1, detect the DRAM through a test system to determine the short - circuit area; Step 2, perform short - circuit detection on the area described in Step 1 with a multimeter to determine the two short - circuited pins; Step 3, grind off the gold wires at the connection between the two pins described in Step 2 and the chip, and then use a multimeter to test the two pins. If there is still a short - circuit, it is an internal short - circuit of the substrate. If there is no short - circuit, it is an internal short - circuit of the chip. The two pins for short - circuit detection described in Step 2 are determined according to the solder ball position map.

[0004] Although this method can detect the specific short - circuited pins on the chip, it also has obvious disadvantages. One is that when the number of pins is large, and now BGA - packaged chips have hundreds or thousands of pins. If measured one by one with a multimeter, it will still greatly increase the workload of the detection personnel and the detection efficiency is low. The other is that the pitch of the solder balls themselves is also small, which increases the difficulty of probe contact and is prone to mis - contact, and there is also a possibility of damaging the solder balls of the pins.

[0005] Of course, other detection methods such as BGA testers and X - Ray detection can also be used for chip short - circuit detection. These detection methods generally require entrusting a third party for testing, resulting in a longer processing cycle and higher detection costs.

[0006] Therefore, it is urgent to study a method and device for chip short - circuit detection and simple positioning to solve the above - mentioned problems. Summary of the Invention

[0007] The purpose of the present invention is to solve the above - mentioned technical problems and provide a method and device for chip short - circuit detection and simple positioning.

[0008] To achieve the above object, the present invention adopts the following technical solutions: A chip short-circuit detection device includes a PCB bottom plate and a chip test fixture. The chip test fixture and the PCB bottom plate are detachably assembled. A pin portion is provided at the edge of the PCB bottom plate, and a circuit is provided inside the PCB bottom plate to electrically interconnect the pins with the probes of the chip test fixture, so that the pins of the chip are extended to the pin portion around the PCB bottom plate in a one-to-one correspondence manner.

[0009] Further, the pin portion includes a plurality of pin groups arranged in a sub-region along the edge of the PCB bottom plate.

[0010] Further, the pin groups are sequentially divided into eight regions A1, A2, A3, A4, A5, A6, A7, and A8, and two of them are provided on each of the four edges of the PCB bottom plate.

[0011] Further, the pin portion further includes a jumper group, and the jumper group is arranged between two adjacent pin groups.

[0012] Further, two pins are provided in the jumper group, and the two pins are respectively short-circuited to an adjacent pin group through a shorting plate.

[0013] Further, the adjacent two pin groups are electrically connected through a jumper cap between the two pins.

[0014] Further, ground network test points T1, T2, T3, and T4 are provided on the PCB bottom plate.

[0015] Further, test fixture mounting holes H1, H2, H3, and H4 are provided on the PCB bottom plate.

[0016] Further, a chip mounting position is provided at the center of the four mounting holes.

[0017] A method for chip short-circuit detection and simple positioning includes the following steps:

[0018] Step 1: Fix the chip test fixture on the PCB bottom plate through the mounting holes, and electrically connect the probes on the chip test fixture to the respective probes of the pin group.

[0019] Step 2: Place the chip to be tested into the chip test fixture. The chip test fixture fixes each pin of the chip and electrically conducts the pin to the probe, so as to realize the one-to-one connection between the pins of the chip and the pins in the pin group.

[0020] Step 3: Use a shorting plate and a jumper cap to short-circuit each pin group to the jumper group, and select any one pin to measure its resistance to the ground with a multimeter to judge whether there is a short-circuit situation in the whole.

[0021] Step 4: If there is a short circuit in the whole, remove the jumper caps on all jumper groups, and then test the resistance to ground of each row of pins in turn to find out the short-circuited row of pins; if there is no short circuit in the whole, there is no short-circuited pin in the chip.

[0022] Step 5: Remove the shorting plate on the short-circuited row of pins, and then test the resistance to ground of each row of pins in the row of pins in turn to find out the specific short-circuited pin.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: through the arrangement of the row of pins part, the present invention can evenly connect and disperse a large number of pins in the chip to the four sides of the PCB board, which is convenient for accurately connecting to the pins to be measured with a multimeter, and does not directly contact the chip pins, so it will not affect the chip pins; the arranged row of pins group and jumper group can find the short-circuited pins accurately from the whole to the part and finally through different shorting methods. The solution of the present invention not only solves the problems of high cost and long cycle of third-party detection, but also solves some drawbacks of directly contacting the chip pin solder balls with a multimeter, realizing the coexistence of economy and high efficiency. Description of the Drawings

[0024] Figure 1 is the planar layout diagram of the PCB bottom board in the present invention;

[0025] Figure 2 is the measurement flow chart of a method for chip short-circuit detection and simple positioning in the present invention;

[0026] In the figure: 1. PCB bottom board; 2. Row of pins part; 3. Row of pins group; 4. Jumper group; 5. Ground network test point; 6. Test fixture mounting hole; 7. Chip mounting position. Detailed Embodiment

[0027] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0028] A chip short-circuit detection device, such as Figure 1As shown in the figure, it includes a PCB bottom plate 1 and a chip test fixture. The chip test fixture is detachably assembled with the PCB bottom plate 1. The chip test fixture is a transfer fixture slot matching the chip to be tested. Probes corresponding to the pins of the chip are provided inside the chip test fixture. After the chip is installed on the chip test fixture, the pins of the chip are electrically connected to the probes one by one. The chip test fixture can adopt a structural form disclosed in a prior art patent application number: CN202023009775.5, a test fixture for CCGA packaged chips, or a patent application number: CN201120282990.4, a manual chip test fixture. Using the above chip test fixture, each pin of the chip can be led out to the pin header part 2 while maintaining good electrical contact.

[0029] As Figure 1 shown, a pin header part 2 is provided at the edge of the PCB bottom plate 1, and circuits are provided inside the board layer of the PCB bottom plate 1. The pins in the pin header part 2 are electrically interconnected with the probes of the chip test fixture by using the circuits, so that the pins of the chip are extended to the pin header part 2 around the four sides of the PCB bottom plate 1 in a one-to-one correspondence. The pins scattered around the PCB can lead out the pins of the chip to a distance and be dispersed, so that the chip pins do not need to be directly contacted during the subsequent measurement process, thus effectively protecting the chip pins and being beneficial to accurately connecting to each pin with a multimeter to detect the chip pins.

[0030] Specifically, the pin header part 2 includes a plurality of pin groups 3 arranged in sub-regions along the edge of the PCB bottom plate 1; two rows of pins are provided at the edge of the PCB bottom plate 1, and the two rows of pins are divided into a plurality of pin groups 3. Specifically, the pin groups 3 are sequentially divided into eight regions A1, A2, A3, A4, A5, A6, A7, and A8, and two of these eight regions are provided on each of the four edges of the PCB bottom plate 1.

[0031] The pin header part 2 further includes a jumper group 4, and the jumper group 4 is arranged between two adjacent pin groups 3. Two pins are provided inside the jumper group 4, and the two pins are independently arranged. When the pins in a pin group 3 are short-circuited with the pins in a certain jumper group 4 through a shorting plate, then the pins are short-circuited with the corresponding pin group 3, that is, the two pins are respectively short-circuited with an adjacent pin group 3 through the shorting plate. Then, a jumper cap is used to short-circuit the two pins in the jumper group 4, so that two adjacent pin groups 3 can be electrically connected.

[0032] Furthermore, ground network test points 5 are provided on the PCB bottom plate 1, and the ground network test points 5 are T1, T2, T3, and T4.

[0033] In some embodiments, test fixture mounting holes 6 are provided on the PCB base board 1. The test fixture mounting holes 6 include H1, H2, H3, and H4. Specifically, the chip test fixture is fixed on the PCB base board 1 through the mounting holes. In this way, the chip can be quickly installed and disassembled on the PCB base board 1. In some other embodiments, a chip mounting position 7 is provided at the center of the four mounting holes. It is also possible to connect the chip to the PCB board by directly soldering the chip. Figure 1 In, at U1 is the pad of the chip, and the chip can be connected at the chip mounting position 7.

[0034] A method for chip short-circuit detection and simple positioning, as Figure 2 shown, includes the following steps:

[0035] Step 1: Fix the chip test fixture on the PCB base board 1 through the mounting holes, so that the probes on the chip test fixture are electrically connected to the respective probes of the pin header group 3. During measurement, first install the chip test fixture on the base board through the mounting holes H1 - H4. The chip test fixture is a detachable installation. After installation, the probes on the chip test fixture maintain good electrical connection with the respective probes of the pin header group 3.

[0036] Step 2: Place the chip to be tested into the chip test fixture. The chip test fixture fixes each pin of the chip and makes the pins electrically conduct with the probes, realizing one-to-one connection between the pins of the chip and the pin headers in the pin header group 3. Put the chip into the chip test fixture, and through the probes in the chip test fixture, electrical interconnection between the chip pins and the pads on the PCB base board 1 is achieved, so as to lead out the chip pins to the respective pin headers.

[0037] Step 3: Use a shorting board and jumper caps to short-circuit each pin header group 3 and the jumper group 4. The shorting board and jumper caps can short-circuit all the pin headers, that is, short-circuit each pin of the chip. During measurement, any one pin header can be selected, and use a multimeter to measure its resistance to ground to judge whether there is a short-circuit situation as a whole. When the resistance is less than a few dozen ohms, there is a shorted pin on the chip, otherwise there is no short-circuit situation.

[0038] Step 4: If there is a short circuit as a whole, remove the jumper caps on all the jumper groups 4, and sequentially perform resistance-to-ground tests on each pin header group 3 to identify the shorted pin header group 3. If there is no short-circuit situation as a whole, there are no shorted pins in the chip. When there is a short circuit in the chip pins, disconnect J1 - J8, and sequentially measure the eight regions A1 - A8 to locate which pin header group 3 regions the short circuit is in.

[0039] Step 5: Remove the shorting board on the shorted pin header group 3, and sequentially perform resistance-to-ground tests on each pin header in the pin header group 3 to identify the specific shorted pin, and then the shorted pin header and its corresponding chip pin can be found. The measurement flow chart is as Figure 2As shown

[0040] The PCB bottom board 1 is as Figure 1 shown. The two rows of circles on the edge are pin headers, which are connected to the non-ground pins of the chip. Through J1 - J8, it is divided into eight regions A1 - A8, and all the pin headers in the region can be short-circuited through a shorting board; J1 - J8 are used to connect the pin headers of adjacent regions and are short-circuited through a jumper cap; T1 - T4 are test points for the ground network, H1 - H4 are mounting holes for the chip test fixture, and U1 is the pad for the chip. The principle used is: resistors in parallel, and the parallel resistance is smaller than the resistance value of any one resistor, that is, all the non-ground pins of the chip are paralleled. If there is a shorted pin, the measurement result will surely show a short circuit, so as to quickly detect whether the chip is short-circuited.

[0041] As mentioned above, it is only the preferred specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A chip short - circuit detection device, characterized in that, It includes a PCB base plate (1) and a chip test fixture. The chip test fixture is detachably assembled with the PCB base plate (1). A pin header part (2) is provided at the edge of the PCB base plate (1). A circuit is provided inside the PCB base plate (1) to electrically interconnect the pins and the probes of the chip test fixture, so that the pins of the chip are extended to the pin header part (2) around the PCB base plate (1) in a one-to-one correspondence manner.

2. The chip short - circuit detection device according to claim 1, characterized in that, The pin header part (2) includes a plurality of pin header groups (3) arranged in sub-regions along the edge of the PCB base plate (1).

3. The chip short - circuit detection device according to claim 2, characterized in that, The pin header groups (3) are sequentially divided into eight regions A1, A2, A3, A4, A5, A6, A7, and A8, and two of them are provided on each of the four edges of the PCB base plate (1).

4. The chip short - circuit detection device according to claim 2 or 3, characterized in that, The pin header part (2) further includes a jumper group (4), and the jumper group (4) is arranged between two adjacent pin header groups (3).

5. The chip short - circuit detection device according to claim 4, characterized in that, Two pins are provided in the jumper group (4), and the two pins are short-circuited to an adjacent pin header group (3) respectively through a shorting plate.

6. The chip short - circuit detection device according to claim 5, characterized in that, The adjacent two pin header groups (3) are electrically connected through a jumper cap between the two pins.

7. The chip short - circuit detection device according to claim 1, characterized in that, Ground network test points (5) are provided on the PCB base plate (1), and the ground network test points (5) are T1, T2, T3, and T4.

8. The chip short - circuit detection device according to claim 1, characterized in that, Test fixture mounting holes (6) are provided on the PCB base plate (1), and the test fixture mounting holes (6) include H1, H2, H3, and H4.

9. The chip short - circuit detection device according to claim 8, characterized in that, A chip mounting position (7) is provided at the center of the four mounting holes.

10. A method for chip short - circuit detection and simple positioning, characterized in that, It includes the following steps: Step 1: Fix the chip test fixture on the PCB base plate (1) through the mounting holes, and electrically connect the probes on the chip test fixture to each probe of the pin header group (3). Step 2: Place the chip to be tested into the chip test fixture. The chip test fixture fixes each pin of the chip and makes the pins electrically conduct with the probes, so as to realize the one-to-one connection between the pins of the chip and the pins in the pin header group (3). Step 3: Use a shorting plate and a jumper cap to short-circuit each pin header group (3) and the jumper group (4). Select any one pin and use a multimeter to measure its resistance to the ground to judge whether there is a short circuit in the whole. Step 4: If there is a short circuit in the whole, remove the jumper caps on all the jumper groups (4), and then measure the resistance to the ground of each pin header group (3) in turn to find out the short-circuited pin header group (3); if there is no short circuit in the whole, then there are no short-circuited pins in the chip. Step 5: Remove the shorting plate on the short-circuited pin header group (3), and then measure the resistance to the ground of each pin in the pin header group (3) in turn to find out the specific short-circuited pin.

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