Electrified vibration test clamp for surface-mounted integrated circuit with pins

Abstract

The invention relates to an electrified vibration test clamp for a pin-containing surface-mounted integrated circuit, belonging to the technical field of integrated circuit test. Comprising a road board part and a structural member part, and the structural member part comprises a limiting base, a fixing buckle and a silica gel sheet for pressing the fixing buckle. The test circuit and peripheral elements thereof are arranged on one side of the circuit board, and the package of the device to be tested is independently arranged on the other side of the circuit board. The limiting base is used for being installed and fixed on a functional circuit board, a positioning groove for containing a device is formed in the limiting base, the position of a notch is just consistent with the packaging layout position of the device on the circuit board, and after the device is placed in the notch, pins can be matched with bonding pads in a one-to-one correspondence mode. The fixing buckle is installed and fixed on the notch of the limiting base for placing the device and reliably presses the pin of the device. The problems that the reliability of surface pressing type and pin locking type testing technologies is poor and a testing device is easily damaged during an electrified vibration test of an existing pin-mounted surface-mounted integrated circuit are solved. The device can be widely applied to electrified vibration and related environment tests of surface-mounted integrated circuits with pins.

Description

Technical Field

[0001] This invention belongs to the field of integrated circuit testing technology, and more specifically relates to the field of surface mount integrated circuit testing with pins. In particular, it relates to a test fixture for electrically charged vibration of surface mount integrated circuits with pins. Background Technology

[0002] Vibration testing is a crucial method for ensuring the reliability of integrated circuits (hereinafter referred to as "devices"). It effectively eliminates conductive impurities and structural defects introduced during the packaging process. Surface-mount integrated circuits with leads include SOP, SOC, QFP, and SOT packages. These devices are characterized by their small size, short lead lengths, and small lead spacing, making clamping and fixing during testing very difficult and prone to damaging the device's appearance and shape. Currently, the industry commonly uses surface-pressing and lead-locking test fixtures. Surface-pressing fixtures are prone to poor contact during vibration testing. Furthermore, the pressing stress can easily damage the device's appearance and cause lead deformation. Therefore, surface-pressing fixtures cannot meet the requirements of vibration testing. While lead-locking fixtures avoid damage to the device's surface appearance and lead condition, their elastic locking mechanism also makes them prone to poor contact during vibration testing. Therefore, lead-locking fixtures also cannot meet the requirements of vibration testing.

[0003] For the reasons mentioned above, the reliability of live vibration testing technology for surface-mount integrated circuits with pins has become a key focus of research in the integrated circuit testing industry.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The technical problem to be solved by this invention is to address the issues of poor reliability and easy damage to the test device caused by existing surface-mount integrated circuits (hereinafter referred to as devices) during live vibration testing.

[0006] The inventive concept of this invention is as follows: Since metal materials easily scratch the surface of devices, and metal shavings generated during testing can easily cause short circuits, non-metallic materials should be selected for the structure. Testing has verified that acrylic material is brittle and prone to breakage during disassembly and testing, therefore its use is not recommended. ABS material, balancing strength and toughness, is a more suitable material. When designing the structure, the size and depth of the positioning slot of the limiting base are first determined based on the device volume, pin arrangement, and pin lead length. The slot size should be determined according to the machining accuracy. If the size is too large, it can easily increase the alignment error between the device pins and the printed circuit board package pads, affecting contact reliability; if the size is too small, the device cannot be placed in the positioning slot. Actual testing has verified that a positioning slot with dimensions approximately 0.1mm larger than the device is more reliable, and the height should be flush with the device for easy placement and retrieval. In addition, fixing holes are provided between each positioning slot to fix it to the printed circuit board, improving the contact reliability of the device pins. After the positioning base design is completed, the fixing buckles are designed according to the dimensions of the positioning slots. The fixing buckles adopt a "bridge-shaped" design to avoid direct contact with the device surface and thus prevent damage to the device appearance. The "bridge piers" are designed as thin horizontal strips to press the device pins. Silicone sheets of equal length are attached to the horizontal strips to increase the reliability of contact between the device pins and the printed circuit board pads. Each positioning slot is equipped with an independent fixing buckle to further increase contact reliability. For circuit board assembly, the printed circuit board layout is based on the dimensions of the positioning base, ensuring that the device package is perfectly aligned with the positioning slot, so that when the device is placed, the device pins correspond one-to-one with their pads.

[0007] Therefore, the present invention provides a surface-mount integrated circuit electrical vibration test fixture with pins, such as... Figure 1-7 As shown. Includes: Limiting base 1, fixing buckle 2, silicone sheet 3, circuit board 4, limiting base plastic fixing screw 5, fixing buckle plastic fixing screw 6, limiting base plastic fixing nut 7, device under test 8.

[0008] The bottom surface of the circuit board 4 is equipped with test circuit electronic components, and the top surface is provided with test electrode disks. The shape, position and size of the electrode disks correspond one-to-one with the pins of the chip integrated circuit.

[0009] The limiting base 1 is located on the top surface of the circuit board 4. A mounting cavity (i.e., positioning groove) for the integrated circuit is formed on the limiting base, penetrating through the limiting base. The shape and size of the mounting cavity are consistent with the shape and size of the integrated circuit, facilitating the placement and removal of the integrated circuit. The layout and position of the mounting cavity correspond one-to-one with the test electrode pads of the integrated circuit on the circuit board. Fixing holes are formed on the limiting base at both ends of the mounting cavity.

[0010] The limiting base 1 is connected to the circuit board 4 by screws through the limiting base fixing hole, the limiting base plastic fixing screw 5, and the limiting base plastic fixing nut 7.

[0011] The fixing buckle 2 is a bridge-type fixing buckle, with thin horizontal bridge piers on both sides of the center of the fixing buckle, forming a bridge-and-pier structure. This bridge-type fixing buckle is used to press and fix the pins of the chip integrated circuit. When pressing the chip integrated circuit, the fixing buckle bridge does not contact the chip integrated circuit, ensuring that the chip integrated circuit is not damaged. Each positioning slot is equipped with an independent fixing buckle to increase contact reliability.

[0012] The fixing buckle 2 is connected by screws through the fixing buckle plastic fixing screw 6, the fixing holes of the two fixing buckles, and the corresponding fixing holes on the limiting base.

[0013] The silicone sheet 3 is fixed to the bottom end of the bridge pier, and the shape and size of the silicone sheet are consistent with the shape and size of the bottom end of the bridge pier. Due to the softness of silicone, it ensures that the device is firmly pressed without loosening or displacement. This increases the reliability of the contact between the chip integrated circuit pins and the printed circuit board electrode test pads, preventing mechanical damage when the chip integrated circuit pins are pressed and fixed to the printed circuit board electrode test pads.

[0014] The limiting base is made of insulating material.

[0015] This invention provides a live vibration test fixture with a simple structure, reliable pin contact, high test station density, ease of large-scale testing, and protection against physical stress damage and deformation. It solves the problem of live vibration testing for surface-mount integrated circuits, featuring simple design, high reliability, low cost, and no surface scratches. It is easy to promote and use, and suitable for live vibration and other environmental testing of surface-mount integrated circuits with pins. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the fixture.

[0017] Figure 2 This is a schematic diagram of the disassembled structure of the fixture.

[0018] Figure 3 This is a schematic diagram of the H14X2-03 type ceramic patch packaging limiting base structure.

[0019] Figure 4 This is an exploded view of the installation structure of the limiting base and the circuit board.

[0020] Figure 5 This is a schematic diagram of the mounting structure of the limiting base and the circuit board.

[0021] Figure 6 This is a schematic diagram of the fastener structure.

[0022] Figure 7 This is a schematic diagram of the layout structure of the H14X2-03 type ceramic surface mount packaged circuit board.

[0023] In the diagram: 1 is the limiting base, 2 is the fixing buckle, 3 is the silicone sheet, 4 is the circuit board, 5 is the plastic fixing screw of the limiting base, 6 is the plastic fixing screw of the fixing buckle, 7 is the plastic fixing nut of the limiting base, and 8 is the device under test. Detailed Implementation

[0024] like Figure 1-7 As shown, the specific implementation of the leaded surface-mount integrated circuit live vibration test fixture, taking the H14X2-03 ceramic surface-mount packaged integrated circuit as an example, is as follows: The circuit board and the limiting base are square.

[0025] The length and width of the positioning groove are 0.1 mm ± 0.05 mm larger than the device.

[0026] like Figure 3 The image shows the H14X2-03 type ceramic patch encapsulation limiting base, made of ABS. The mounting screw holes of the fixing buckle need to be fitted with metal thread sleeves to improve durability and increase the service life of the fixture.

[0027] like Figure 4 The diagram shown is an exploded view of the installation of the limiting base and the circuit board. Screws pass through the limiting base and the circuit board. Nuts are used at the bottom of the circuit board to firmly fix the limiting base and the circuit board. Then, the device is placed so that the pins of the device are just aligned with the circuit board package pads.

[0028] like Figure 5 The diagram shows the installation of the limiting base and the circuit board. The components are placed in the mounting slot of this part to provide positioning and prevent large displacement during vibration, which would affect the reliability of the contact.

[0029] like Figure 6 The diagram shows the design of the fixing clip, which is made of ABS. It adopts a "bridge-shaped" design, which does not contact the surface of the device to avoid scratches. When the device is fixed and installed with screws and a limiting base, the silicone sheet presses the device pins to make them directly contact the circuit board pads. After the silicone sheet undergoes stress deformation, it can fill the gaps between the pins, further limiting the displacement of the device during vibration and improving contact reliability.

[0030] like Figure 7 The diagram shows the layout of the H14X2-03 ceramic surface mount package circuit board. The pads of the device under test are placed on the top layer of the circuit board, while the peripheral components of the test circuit are arranged on the bottom layer of the printed circuit board. This facilitates the placement of fixtures for dense design with multiple positioning slots, increasing the load capacity of the fixtures. The size and position of the openings on the printed circuit board and the device pads correspond precisely to the limiting base. The surface of the pads is pre-tinned to increase the reliability of the device pin contact.

[0031] For example Figure 1After installation according to the overall design drawing shown, 40 H14X2-03 ceramic chip packaged devices were subjected to 1 hour of endurance vibration in each of the XYZ directions in accordance with the provisions of GJB150-2009 Equipment Laboratory Environmental Test Method. No contact failures were found, indicating extremely high reliability.

[0032] Finally, it should be noted that the above embodiments are merely examples for clear illustration. This invention includes, but is not limited to, the above embodiments, and it is neither necessary nor possible to exhaustively describe all possible implementations. Those skilled in the art can make other variations or modifications based on the above description. All implementation schemes that meet the requirements of this invention are within the protection scope of this invention.

Claims

1. A surface-mount integrated circuit live vibration test fixture with pins, characterized in that: Includes limit base, fixing buckle, silicone sheet, circuit board, limit base plastic fixing screw, fixing buckle plastic fixing screw, limit base plastic fixing nut; The test circuit electronic components are assembled on the bottom surface of the circuit board, and the test electrode disk is set on the top surface. The shape, position and size of the electrode disk correspond one-to-one with the pins of the chip integrated circuit. The limiting base is located on the top surface of the circuit board. A positioning groove for the chip integrated circuit is formed on the limiting base, and the shape and size of the positioning groove are consistent with the shape and size of the chip integrated circuit, which facilitates the placement and removal of the chip integrated circuit. The layout and position of the positioning groove correspond one-to-one with the test electrode disk of the chip integrated circuit on the circuit board. Fixing holes for fixing buckles are formed on the limiting base at both ends of the positioning groove. The limiting base is screwed to the circuit board through a limiting bottom fixing hole, a limiting base plastic fixing screw, and a limiting base plastic fixing nut. The fixing buckle is a bridge-type fixing buckle, with thin horizontal bridge piers on both sides of the center of the fixing buckle, forming a bridge and pier structure. The bridge-type fixing buckle is used to press and fix the pins of the chip integrated circuit. When pressing the chip integrated circuit, the fixing buckle bridge does not contact the chip integrated circuit, ensuring that the chip integrated circuit is not damaged. Each positioning slot is equipped with an independent fixing buckle to increase the reliability of contact. The fixing buckle is connected by screws through the fixing buckle plastic fixing screw, the fixing holes of the two positions of the fixing buckle, and the corresponding fixing holes on the limiting base; The silicone sheet is fixed to the bottom of the bridge pier, and the shape and size of the silicone sheet are consistent with the shape and size of the bottom of the bridge pier.

2. The leaded surface-mount integrated circuit live vibration test fixture as described in claim 1, characterized in that: The circuit board and the limiting base are square.

3. The leaded surface-mount integrated circuit live vibration test fixture as described in claim 1, characterized in that: The limiting base is made of insulating material.

4. The leaded surface-mount integrated circuit live vibration test fixture as described in claim 3, characterized in that: The insulating material is ABS.

5. The leaded surface-mount integrated circuit live vibration test fixture as described in claim 1, characterized in that: The mounting screw holes of the fixing buckle have metal thread sleeves.

6. The leaded surface-mount integrated circuit live vibration test fixture as described in claim 1, characterized in that: The surface of the test electrode disk is plated with tin.

7. The leaded surface-mount integrated circuit live vibration test fixture as described in claim 1, characterized in that: The length and width of the positioning groove are 0.1 mm ± 0.05 mm larger than the device.

Images