Capacitance test fixture for high-Q-value chip

Abstract

The utility model discloses a capacitor test fixture for a high-Q-value chip, and belongs to the field of capacitor test. Comprising a support, a movement device, a product testing device and a signal transmission device. The support is composed of a base and supporting legs. The moving device comprises an elbow clamp, a guide rod, an elastic positioning wave bead and a pressing plate, the elbow clamp is located at the upper end of the clamp, and the guide rod penetrates through the pressing plate and the top shielding plate to reach the bottom support; the elastic positioning bead is located below the toggle clamp, and the pressing plate is in bead linkage with the toggle clamp through the elastic positioning bead; the product testing device comprises a micrometer head, an upper SMA three-way adapter, an upper gold-plated brass plate, an upper probe, a lower probe, a lower gold-plated brass plate and a lower SMA three-way adapter; the signal transmission device comprises a test cable, a test connector, a lower SMA three-way adapter and a shielding plate. The problem that an existing chip capacitor testing clamp cannot test a high-Q-value chip capacitor with the Q value of 10000 or above is solved. The method is widely applied to the technical field of chip capacitance testing.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of capacitor test, further relates to the field of chip capacitor test fixture, specifically, a kind of for high Q value chip capacitor test fixture. BACKGROUND

[0002] In the production process of high Q value chip capacitor, the performance of component is tested, sorted, to eliminate the product with flaw, to ensure that the product screened can reliably work in long time.

[0003] Existing fixture can only be used for Q value <2000 chip capacitor test, and when the Q value of high Q value chip capacitor is above 10000, ordinary fixture cannot meet the test requirement. Since high Q value chip capacitor product is applied to high-frequency signal circuit component, there is essential difference in signal transmission mode with ordinary capacitor component, high Q value chip capacitor has higher requirement to signal transmission path, and capacitor value is generally small, so it is necessary to ensure impedance matching consistency of transmission path, signal guarantee, reduce attenuation, which has higher requirement to its fixture design.

[0004] Therefore, the utility model is proposed. SUMMARY

[0005] The utility model solves the technical problems that existing chip capacitor test fixture cannot test high Q value chip capacitor with Q value above 10000.

[0006] Therefore, the utility model provides a kind of for high Q value chip capacitor test fixture, as shown in Figures 1-3 Including support, motion device, product testing device, signal transmission device.

[0007] The support is composed of base 16 and support leg 17, and the base 16 is fixed on the support leg 17.

[0008] The motion device includes elbow clamp 1, guide rod 2, elastic positioning wave bead 3 and pressing plate 4. The elbow clamp is located at the upper end of the fixture and is installed on the bottom bracket base. The guide rod has four roots and is evenly distributed around the fixture to ensure uniform stress on the test part when pressed down and ensure test accuracy. The guide rod penetrates the pressing plate, top shielding plate and bottom bracket. The elastic positioning wave bead 3 is located below the elbow clamp 1 and can adjust the stroke and has elasticity, which can ensure that the test device completely contacts the product and improve the test accuracy. The pressing plate 4 is used to fix the differential head 5 and upper SMA tee joint adapter 6, and is connected with the elbow clamp 1 through the elastic positioning wave bead 3.

[0009] The product testing device consists of a micrometer head 5, an upper SMA tee adapter 6, an upper gold-plated bronze plate 7, an upper probe 8, a lower probe 9, a lower gold-plated bronze plate 10, and a lower SMA tee adapter 11. The probes are divided into upper probe 8 and lower probe 9. Upper probe 8 is an elastic probe with a gold-plated surface, embedded in and fixed to the upper SMA tee adapter 6 and the upper gold-plated bronze plate 10. The other two connectors of the upper SMA tee adapter 6 are connected to the test cables. Lower probe 9 is a non-elastic probe, embedded in the lower SMA tee adapter 11 and fixed to the lower gold-plated bronze plate 10. During testing, the product is placed on the lower probe 9, and the rest is basically the same as the upper probe. The micrometer head 5 is located between the rear of the pressure plate 4 and the rear of the top plate 15, fixed to the rear of the pressure plate 4, and is used for open-circuit testing of the test fixture. The height of the micrometer head 5 is adjustable for testing the distance between the downward-pressing upper probe 8 and lower probe 9.

[0010] The signal transmission device consists of a test cable 13, a test connector 14, a lower SMA tee adapter 11, and a shielding plate 12. The shielding layer of the test connector 14 is welded to the rear shielding plate to maximize its shielding effect; the shielding plate is fixed to the rear of the lower frame.

[0011] The test fixture described in this utility model is simple and convenient to operate, has a reasonable structure, facilitates loading and unloading, ensures reliable contact between the fixture's test contacts and the product, is easy to clamp, has a reasonable material design, and provides good signal shielding performance, significantly reducing attenuation and ensuring high accuracy during testing. It can be widely used in the field of chip capacitor testing technology. Attached Figure Description

[0012] Figure 1 This is a front view schematic diagram of the high-Q value chip capacitor test fixture.

[0013] Figure 2 This is a schematic diagram of the rear view structure of a high-Q value chip capacitor test fixture.

[0014] Figure 3 Axiometric view of the structure of a high-Q chip capacitor test fixture

[0015] In the diagram: 1 is the elbow clamp, 2 is the guide rod, 3 is the elastic positioning ball, 4 is the pressure plate, 5 is the micrometer head, 6 is the upper SMA tee adapter, 7 is the upper gold-plated brass plate, 8 is the upper probe, 9 is the lower probe, 10 is the lower gold-plated brass plate, 11 is the lower SMA tee adapter, 12 is the shielding plate, 13 is the test cable, 14 is the test connector, 15 is the top plate, 16 is the base, and 17 is the support foot. Detailed Implementation

[0016] like Figures 1-3 As shown, the specific implementation of the high-Q value chip capacitor testing fixture is as follows:

[0017] The support feet 17 are four, distributed in the bottom four corner areas of the base 16.

[0018] The micro-differentiating head 5 is a thousand-level micro-differentiating head.

[0019] The material of the pressing plate 4 is aluminum, and the surface is subjected to sandblasting oxidation treatment, and the surface is an aluminum oxide layer.

[0020] The test cable 13 adopts an RG316 radio frequency connecting cable, the inside of the test cable is a silver-plated copper core wire, and the outside is composed of a sheath, a shielding layer and an insulation layer, and is suitable for high-frequency testing.

[0021] The SMA joint and the adapter are gold-plated brass flange joints, which ensure strong shielding and play a role in stabilizing the test signal.

[0022] The test joint 14 is a BNC joint, the inside of the test joint is a full copper inner core, and the outside is a shielding insulation layer. The upper and lower test parts of the product testing device have four BNC joints, and the shielding layers are all parallelly welded to the shielding plate at the back to maximize the shielding effect.

[0023] The shielding plate is made of tin-plated brass.

[0024] The assembly process is as follows:

[0025] 1. Install the shielding plate on the support, the shielding plate is divided into five parts (one each for the front, back, left, right and top), install the lower SMA tee joint in the central area of the support, the joint is installed in the center of the top shielding plate, the lower probe is installed inside the lower SMA tee joint, the probe extends to the same level as the lower gold-plated brass plate, and the upper side is the lower gold-plated brass plate.

[0026] 2. Four moving guide rods pass through the pressing plate, the top shielding plate and the bottom support.

[0027] 3. Install the upper SMA tee joint and the upper gold-plated brass plate in the center of the pressing plate, and install the upper probe inside the joint.

[0028] 4. The elastic positioning wave beads are installed below the elbow clamp, and the elbow clamp is installed on the bottom of the bottom support.

[0029] 5. The thousand-level micro-differentiating head is installed on the back side of the pressing plate for height adjustment and limiting.

[0030] Product testing mechanism:

[0031] After the elbow clamp is pulled up to reset after debugging, the test product is placed into the lower probe slot by a tweezer, and then the elbow clamp is pressed down to full stroke, at this time, the upper probe contacts the product and is retracted, the bottom of the product is in close contact with the lower probe, and the test signal of the upper and lower probes is transferred to the SMA joint, the SMA joint is connected to the instrument through the test cable and the other end BNC, and then the test can be performed.

[0032] The clamp is shielded from the test probe, the SMA adapter, the cable, the BNC adapter and the like, and the effective accuracy of the test is ensured.

[0033] Finally, it should be noted that: the above examples are only examples for clearly illustrating the present application, the present application includes but is not limited to the above examples, all the embodiments do not need to be exhausted here. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Any embodiment meeting the requirements of the present application belongs to the protection scope of the present application.

Claims

1. A fixture for testing high-Q value chip capacitors, characterized in that: Includes supports, motion devices, product testing devices, and signal transmission devices; The bracket consists of a base and support legs, with the base fixed to the support legs; The motion device includes an elbow clamp, a guide rod, elastic positioning beads, and a pressure plate; The elbow clamp is located at the upper end of the clamp and is mounted on the bottom support base; there are four guide rods, evenly distributed around the clamp, which pass through the pressure plate, the top shielding plate and the bottom support; the elastic positioning ball is located below the elbow clamp, and a micro head and an upper SMA tee adapter are fixed on the pressure plate. The pressure plate and the elbow clamp are linked by the elastic positioning ball. The product testing device includes a micrometer head, an upper SMA tee adapter, an upper gold-plated bronze plate, an upper probe, a lower probe, a lower gold-plated bronze plate, and a lower SMA tee adapter. The upper probe is an elastic probe with a gold-plated surface, which is embedded in the upper SMA tee adapter and fixed to the upper gold-plated bronze plate. The upper SMA tee adapter and the upper gold-plated bronze plate are installed in the central area of ​​the pressure plate, and the other two connectors of the upper SMA tee adapter are respectively connected to the test cables. The lower probe is a non-elastic probe, which is embedded in the lower SMA tee adapter and fixed to the lower gold-plated bronze plate. The micrometer head is located between the rear of the pressure plate and the rear of the top plate and is fixed to the rear of the pressure plate. The signal transmission device comprises a test cable, a test connector, a lower SMA tee adapter, and a shielding plate. The shielding layer of the test connector is welded to the rear shielding plate, and the shielding plate is fixed to the rear of the lower frame.

2. The high-Q chip capacitor testing fixture as described in claim 1, characterized in that: The support feet are four in number and are distributed in the four corner areas at the bottom of the base.

3. The high-Q chip capacitor testing fixture as described in claim 1, characterized in that: The differential head is a thousand-level differential head.

4. The high-Q chip capacitor testing fixture as described in claim 1, characterized in that: The pressure plate is made of aluminum, and its surface is covered with an aluminum oxide layer.

5. A testing fixture for high-Q chip capacitors as described in claim 1, characterized in that: The test cable is an RG316 RF connection cable, with a silver-plated copper core wire inside and an outer sheath, shielding layer, and insulation layer.

6. The high-Q chip capacitor testing fixture as described in claim 1, characterized in that: Both the SMA connector and the adapter are gold-plated brass flange connectors.

7. A testing fixture for high-Q chip capacitors as described in claim 1, characterized in that: The test connector is a BNC connector with an inner copper core and an outer shielding insulation layer. The upper and lower test sections of the product testing device have a total of 4 BNC connectors, and the shielding layers are all welded in parallel to the rear shielding plate.

8. A testing fixture for high-Q chip capacitors as described in claim 1, characterized in that: The shielding plate is made of tin-plated brass.

9. A testing fixture for high-Q chip capacitors as described in claim 1, characterized in that: The shielding plate consists of one each at the front, back, left, right, and top, and is mounted on a bracket.

10. A high-Q chip capacitor testing fixture as described in claim 1, characterized in that: The lower SMA tee connector is installed in the central area of ​​the bracket, and the connector is installed on the lower side of the center of the top shield plate; the lower probe is installed inside the lower SMA tee connector, and the protruding part of the probe is flush with the lower gold-plated bronze plate.

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