Qfn package chip test tooling

Abstract

The application discloses a QFN package chip test tool, which comprises a bottom plate, a top plate and a directional telescopic element, the bottom plate is provided with a plurality of guide columns in the circumferential direction, the top of the bottom plate is provided with an IC base and a PCBA base in parallel, and is used for placing IC and PCBA to be tested; the top plate is located directly above the bottom plate and is provided with guide holes in sliding fit with the guide columns, the first metal spring probe and the second metal spring probe are provided in a penetrating mode on the top plate, the first metal spring probe is opposite to the IC base and is used for connecting the IC to be tested, the second metal spring probe is opposite to the PCBA base and is used for connecting the PCBA to be tested, and the top of the first metal spring probe is used for connecting the top of the second metal spring probe; the directional telescopic element is located above the top plate and is fixedly connected with the bottom plate through a back plate, the telescopic end of the directional telescopic element is fixedly connected with the top of the top plate and is used for driving the top plate to move directionally up and down, so that the functional test of the QFN package chip can be realized, and various problems caused by poor welding can be avoided.

Description

Technical Field

[0001] This utility model relates to the field of chip testing equipment technology, and in particular to QFN packaged chip testing fixtures. Background Technology

[0002] As a crucial part of the semiconductor testing process, chip testing fixtures play a bridging role in connecting chips and testing equipment, undertaking multiple key functions and being of great significance in ensuring the accuracy and reliability of testing.

[0003] From a physical connection perspective, chip test fixtures are responsible for ensuring a stable and precise connection between the chip under test (DUT) and the test equipment. Taking common integrated circuit (IC) chips as an example, chip test fixtures need to ensure that every pin on the chip can achieve a correct and stable connection with the corresponding channel of the test equipment. Different types of chips, such as those using BGA (Ball Grid Array), QFN (Quad Flat No-Leader), DFN (Double Flat No-Leader), QFP (Quad Flat Package), SOP (Small Outline Package), and LGA (Large Grid Array Package), have different pin layouts and spacings. This requires chip test fixtures to have a high degree of adaptability, accurately positioning and connecting chip pins, thus laying the foundation for the transmission of test signals.

[0004] In existing technologies, QFN is a leadless package, square or rectangular in shape, with a large exposed pad at the center of the bottom for heat conduction. Electrically connected conductive pads surround the large pad. It's important to note that QFN packaging is completely different from LCC packaging. LCC still has external leads, but these are bent to the bottom, while QFN packaging has no external leads at all. After PCB layout is complete, it needs to be soldered into a PCBA for functional testing. Because only a small number of samples are needed, and SMT reflow soldering is costly, manual soldering is generally performed. However, for QFN ICs without external leads, manual soldering with a hot air gun is difficult and can easily damage the chip. Furthermore, the QFN chip solder joints are located on the bottom of the chip, making it difficult to directly observe the solder joints and PCB pads during soldering, making it impossible to determine if there are cold solder joints, which can easily affect the functional testing of the PCBA. Utility Model Content

[0005] This application provides a QFN packaged chip testing fixture that can connect the chip to the PCBA without soldering, verifying whether the PCBA is functioning properly. This effectively avoids problems such as poor soldering caused by soldering QFN packaged chips, which prevents the PCBA from being functionally verified and makes it impossible to determine whether the functional abnormality is due to PCBA design or chip soldering.

[0006] This application provides a QFN packaged chip testing fixture, including a base plate, a top plate, and a directional telescopic element. The base plate is provided with multiple guide posts along the circumference, and the top of the base plate is provided with an IC base and a PCBA base in parallel, which are used to place the IC and PCBA to be tested, respectively. The top plate is located directly above the bottom plate and has a guide hole that slides with the guide post. The top plate has a first metal spring probe and a second metal spring probe that pass through it. The bottom of the first metal spring probe faces the IC base and is used to connect the IC to be tested. The bottom of the second metal spring probe faces the PCBA base and is used to connect the PCBA to be tested. The top of the first metal spring probe is used to connect the top of the second metal spring probe. The directional telescopic element is located above the top plate and is fixedly connected to the bottom plate via a back plate. The telescopic end of the directional telescopic element is fixedly connected to the top of the top plate and is used to drive the top plate to move directionally up and down.

[0007] In one possible implementation, the directional telescopic element is implemented as a quick clamp, the stroke of which is the same as the vertical movement of the top plate during the test.

[0008] In one possible implementation, the quick clamp is a flange-base type push-pull quick clamp, the quick clamp model is tcpf1, the quick clamp includes a flange base and a clamp body, the clamp body is connected to the back plate through the flange base, and the clamp body is provided with a pressing handle for driving the telescopic end to move up and down in a directional manner.

[0009] In one possible implementation, the bottom of the top plate is provided with a first fixing seat and a second fixing seat in a detachable manner. The first metal spring probe and the second metal spring probe are respectively disposed on the first fixing seat and the second fixing seat, and protrude from the first fixing seat and the second fixing seat respectively. The top plate is provided with a clearance hole at the position directly opposite the first metal spring probe and the second metal spring probe.

[0010] In one possible implementation, the top plate is connected to the first fixing seat and the second fixing seat by screws.

[0011] Beneficial effects: Compared with the prior art, the QFN packaged chip testing fixture provided in this application uses a directional telescopic element to drive the first and second metal spring probes to press down onto the IC base and PCBA base respectively to form a connection between them. At the same time, the tops of the first and second metal spring probes are connected. Then, the PCBA is powered on, and the output signal of the PCBA is received by a monitoring device to verify whether the PCBA is functioning normally. This can effectively avoid poor soldering caused by soldering QFN packaged chips, which would prevent the PCBA from being functionally verified and make it impossible to determine whether the functional abnormality is due to PCBA design or chip soldering. It does not require complex electrical and electronic connections, has a simple overall structure, is easy to manufacture and maintain, is easy to operate, and has low cost.

[0012] These and other objects, features and advantages of this utility model will be fully realized through the following detailed description. Attached Figure Description

[0013] Figure 1 A three-dimensional structural schematic diagram of the QFN packaged chip test fixture of this application is shown.

[0014] Figure 2 The diagram shows a bottom view of the test fixture for the QFN packaged chip of this application. Detailed Implementation

[0015] The following description is intended to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0016] Those skilled in the art should understand that, in the disclosure of this specification, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or 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. Therefore, the above terms should not be construed as limitations on this utility model.

[0017] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0018] refer to Figure 1 and Figure 2 This application provides a QFN packaged chip testing fixture, including a base plate 10, a top plate 20, and a directional telescopic element 30. The base plate 10 has multiple guide posts 11 arranged circumferentially. For example, on a square base plate 10, one guide post 11 is provided at each of the four corners, or an additional guide post 11 is provided at the center of the long side. Alternatively, on a circular base plate 10, three to five guide posts 11 are evenly arranged along the outer circumference. An IC base 12 and a PCBA base 13 are arranged side-by-side on the top of the base plate 10, for placing the IC and PCBA to be tested, respectively. The top plate 20 is located directly above the bottom plate 10 and has a guide hole 201 that slides with the guide post 11. This sliding engagement ensures stable directional up-and-down movement of the top plate 20. Furthermore, the top plate 20 has a first metal spring probe 21 and a second metal spring probe 22 that pass through it. The bottom of the first metal spring probe 21 faces the IC base 12 for connecting to the IC under test, while the bottom of the second metal spring probe 22 faces the PCBA base 13 for connecting to the PCBA under test. The top of the first metal spring probe 21 connects to the top of the second metal spring probe 22, for example, using a matching, industry-standard connector. Additionally, the directional telescopic element 30 is located above the top plate 20 and is fixedly connected to the bottom plate 10 via a back plate 31. The telescopic end 32 of the directional telescopic element 30 is fixedly connected to the top of the top plate 20, driving the top plate 20 to move directionally up and down, away from or towards the bottom plate 10.

[0019] In practice, when a QFN chip is present in a PCBA that requires functional verification, the connection between the chip and the PCBA can be achieved without direct soldering.

[0020] First, the IC base 12 and PCBA base 13 of the chip to be tested are fixed to the base plate 10 of the fixture with screws; Then, the first metal spring probe 21 and the second metal spring probe 22 are fixed to the top plate 20 of the tooling, and the metal spring probes on the left and right sides of the top are connected by connectors. Subsequently, the top plate 20 is driven downward by the directional telescopic element 30, causing the first metal spring probe 21 and the second metal spring probe 22 to connect to the IC on the IC base 12 and the PCBA on the PCBA base 13, respectively. After confirming that the connection is correct, the PCBA is powered on, and the output signal of the PCBA is received by the monitoring equipment to verify whether the PCBA is functioning normally, thereby completing the functional test of the QFN packaged chip. This fixture testing method can effectively avoid poor soldering caused by soldering QFN packaged chips, which would prevent the PCBA from being functionally verified and make it impossible to determine whether the functional abnormality is due to PCBA design or chip soldering issues. At the same time, the fixture does not require complex electrical and electronic connections, only simple mechanical fixation is required, the structure is simple, easy to operate, manufacture and maintain, and the cost is low.

[0021] During the monitoring and testing process, after confirming that the chip and PCBA are correctly connected, all ports of the PCBA are led out using wire harnesses. The power lines are connected to the power supply, and the output lines are connected to an oscilloscope or other monitoring equipment to observe whether the output signal is consistent with the design function.

[0022] In one embodiment, the directional telescopic element 30 is implemented as a quick clamp. The stroke of the quick clamp is the same as the vertical movement stroke of the top plate 20 during the test. This allows the vertical movement stroke of the top plate 20 to be limited by the stroke of the quick clamp itself, thus preventing the top plate 20 from descending excessively and damaging the probes, ICs, or PCBAs.

[0023] Regarding the inspection and maintenance of tooling, after a period of storage, it is necessary to check whether the sliding parts and rotating components of the quick-clamp move smoothly. Foreign objects or rust in the mechanism can cause difficulties in the clamping mechanism's movement or even jamming, making testing impossible. Therefore, when storing tooling, rust spots should be ground and polished with a grinder, and professional anti-rust oil should be sprayed on. Then, the tooling should be stored in a dry, cool, and dust-free place. Metal spring probes also need to be checked for elastic fatigue. If the elasticity decreases, it will cause poor contact between the probe and the chip IC and PCBA, affecting the results of functional tests.

[0024] In one embodiment, the quick clamp is a flange-base type push-pull quick clamp. The quick clamp is model tcpf1. The quick clamp includes a flange base 33 and a clamp body 34, wherein the clamp body 34 is connected to the back plate 31 through the flange base 33, and the clamp body 34 is provided with a pressing handle 35 for driving the telescopic end 32 to move directionally up and down.

[0025] In one embodiment, the bottom of the top plate 20 is provided with a first fixing seat 23 and a second fixing seat 24 in a detachable manner, wherein the two can be connected by screws. The first metal spring probe 21 and the second metal spring probe 22 are respectively disposed on the first fixing seat 23 and the second fixing seat 24, and protrude vertically from the first fixing seat 23 and the second fixing seat 24 respectively. Simultaneously, the top plate 20 has a clearance hole 202 directly opposite the first metal spring probe 21 and the second metal spring probe 22, allowing the tops of the first metal spring probe 21 and the second metal spring probe 22 to connect. The first metal spring probe 21 and the second metal spring probe 22 can protrude from the clearance hole 202 or be located inside the clearance hole 202, as long as it does not affect the connection between the tops. In this way, the fixture can easily test different models of products, such as common QFN chip package specifications such as QFN-16, QFN-20, QFN-24, QFN-32, QFN-48, etc. If it is necessary to verify different specifications of ICs and PCBAs, it is only necessary to replace the IC base 12, PCBA base 13, first fixing seat 23 and second fixing seat 24, which can maximize the adaptability to the testing needs of different products.

[0026] It should be noted that the terms "first" and "second" used in this application are for descriptive purposes only and do not indicate any order. They should not be construed as indicating or implying relative importance, and can be interpreted as names.

[0027] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The advantages of the present invention have been fully and effectively realized. The functions and structural principles of the present invention have been shown and explained in the embodiments, and any modifications or variations may be made to the implementation of the present invention without departing from the stated principles.

Claims

1. A QFN packaged chip testing fixture, characterized in that, It includes a base plate, a top plate, and directional telescopic elements, wherein the base plate is provided with multiple guide posts along the circumference, and the top of the base plate is provided with an IC base and a PCBA base in parallel, which are used to place the IC and PCBA to be tested, respectively. The top plate is located directly above the bottom plate and has a guide hole that slides with the guide post. The top plate has a first metal spring probe and a second metal spring probe that pass through it. The bottom of the first metal spring probe faces the IC base and is used to connect the IC to be tested. The bottom of the second metal spring probe faces the PCBA base and is used to connect the PCBA to be tested. The top of the first metal spring probe is used to connect the top of the second metal spring probe. The directional telescopic element is located above the top plate and is fixedly connected to the bottom plate via a back plate. The telescopic end of the directional telescopic element is fixedly connected to the top of the top plate and is used to drive the top plate to move directionally up and down.

2. The QFN packaged chip testing fixture as described in claim 1, characterized in that, The directional telescopic element is implemented as a quick clamp, the stroke of which is the same as the vertical movement stroke of the top plate during the test.

3. The QFN packaged chip testing fixture as described in claim 2, characterized in that, The quick clamp is a flange-base type push-pull quick clamp. The quick clamp includes a flange base and a clamp body. The clamp body is connected to the back plate through the flange base. The clamp body is provided with a pressing handle for driving the telescopic end to move up and down in a directional manner.

4. The QFN packaged chip testing fixture as described in claim 1, characterized in that, The bottom of the top plate is provided with a first fixing seat and a second fixing seat in a detachable manner. The first metal spring probe and the second metal spring probe are respectively provided on the first fixing seat and the second fixing seat, and protrude from the first fixing seat and the second fixing seat respectively. The top plate is provided with a clearance hole at the position directly opposite the first metal spring probe and the second metal spring probe.

5. The QFN packaged chip testing fixture as described in claim 4, characterized in that, The top plate is connected to the first fixing seat and the second fixing seat by screws.

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