Chip ceramic capacitor high and low temperature testing device

Abstract

The utility model discloses a high and low temperature testing device for a chip ceramic capacitor. The high and low temperature testing device comprises a multi-channel capacitance testing clamp mechanism and an external measuring device which is connected with a metal probe in the multi-channel capacitance testing clamp mechanism through a lead, the multi-channel capacitor test fixture mechanism is a mechanism which adopts a plurality of contact pairs to respectively contact two end electrodes of a plurality of capacitors, one contact in each contact pair comprises an elastic movable metal probe, and the other contact in each contact pair comprises a fixed metal probe. According to the utility model, a plurality of capacitors or capacitors with different sizes can be tested at one time in different high and low temperature environments, the test precision can meet the requirement, and the test requirement of a large number of capacitors can be met.

Description

Technical Field

[0001] This utility model relates to a high and low temperature testing device for chip ceramic capacitors. Background Technology

[0002] When evaluating the temperature stability of MLCCs (Multilayer Ceramic Capacitors), it is typically necessary to test their capacitance and other parameters under different temperature conditions to obtain the relationship between capacitance and temperature changes. Simultaneously, it is important to measure loss parameters as minimally as possible, such as capacitors made of Class 1 ceramic materials (i.e., high-frequency ceramic capacitors).

[0003] Furthermore, the capacitance values ​​range widely, from 1pF or even smaller, up to tens and hundreds of uF. Additionally, the sizes of MLCC (Multilayer Ceramic Capacitor) chips range from 01005 and 0201 to larger sizes such as 1206 and above (the series of surface mount capacitors include 0402, 0603, 0805, 1206, 1210, 1808, 1812, 2010, 2225, and 2512; these are in inches, where 04 indicates a length of 0.04 inches, 02 indicates a width of 0.02 inches, and other similar models have the same dimensions (mm)).

[0004] Because measurements at different temperatures require temperature changes and a certain holding time at each temperature, the measurement process takes a long time. To improve testing efficiency, it is usually required to test multiple capacitors at once and to be able to adapt to a wide range of capacitor sizes.

[0005] The test items include capacity and loss parameters without DC bias voltage, as well as AC parameters such as capacity and loss with DC bias voltage. It can also perform DC parameters such as withstand voltage and insulation resistance tests.

[0006] Existing test fixtures fall into two categories. One type, introduced by Agilent Technologies (now Keysight Technologies), is a single-capacitor fixture that measures only one capacitor at a time. Inside the fixture, a horizontal, flexible cylindrical metal electrode contacts one end of a horizontally placed capacitor, pushing the capacitor to press its other end onto the contact electrode of another horizontally placed fixed cylindrical metal electrode within the fixture. Both the flexible and fixed cylindrical metal electrodes have coaxial metal sleeves that are secured in a straight line by a highly insulating dielectric material. Four BNC connectors are connected to the other ends of the flexible and fixed cylindrical electrodes, with the metal shells of the BNC connectors connected to these sleeves. The connector spacing is the same as the four BNC sockets on Agilent's LCR bridge instrument. During testing, the fixture containing one capacitor is simply inserted into the instrument socket for high-precision testing. This type of fixture offers high testing accuracy, is suitable for a wide range of capacitance and size values ​​for MLCC capacitors, and can also test the lower loss parameters of Class 1 ceramic capacitors. It meets the requirements for parameter measurement under normal temperature conditions but cannot meet the need to measure multiple capacitors simultaneously under high or low temperature conditions.

[0007] Another type of fixture uses a row of multiple horizontally parallel elastic probes, corresponding to the ends of another row of multiple horizontally parallel fixed metal cylinders as fixed contacts. Each elastic probe and a fixed metal cylinder are arranged in a line, forming a pair of capacitance test contacts. Each pair of contacts has a support surface at its bottom for horizontally placed capacitors. The elastic probe contacts are pulled apart, and the capacitor is placed horizontally on the support surface between the two contacts, with the two electrodes of the capacitor corresponding to the two contact directions. After the elastic probe presses down on one electrode of the capacitor, the other electrode of the capacitor is also pressed onto the fixed contact end. This probe fixing mechanism does not use a coaxial structure; that is, each probe is not shielded by an externally grounded metal body. When measuring small capacitance values ​​and small loss parameters using high-frequency signals, the error is relatively large. Although it can meet the requirement of measuring multiple capacitors for high and low temperature capacitance parameter testing, the test accuracy cannot meet the requirements. In addition, the probe array of this scheme is arranged in a one-dimensional manner, and the number of capacitors that can be installed in one fixture is limited, which cannot meet the testing requirements of a larger number of capacitors. The spacing between the pair of probes for each capacitor is a non-adjustable structure, and it can only rely on the elastic function of the probes to cope with capacitors of different lengths and sizes, thus limiting the range of capacitor sizes it can adapt to. Utility Model Content

[0008] The purpose of this invention is to overcome the defects in the existing technology and provide a high and low temperature testing device for chip ceramic capacitors, which can test multiple capacitors at the same time under different temperature environments, and the testing accuracy can meet the requirements, thus satisfying the testing requirements of a large number of capacitors.

[0009] To achieve the above objectives, the technical solution of this utility model is to design a high and low temperature testing device for chip ceramic capacitors, including a multi-channel capacitor testing fixture mechanism and an external measuring device connected to the metal probes in the multi-channel capacitor testing fixture mechanism via wires.

[0010] The aforementioned multi-channel capacitance test fixture mechanism is a mechanism that uses multiple pairs of contacts to contact the two end electrodes of multiple capacitors respectively. In each pair of contacts, one contact includes a flexible movable metal probe and the other contact includes a fixed metal probe.

[0011] A further technical solution is that the multi-channel capacitance test fixture mechanism includes a temperature-variable enclosed area, with the external measuring device located outside the enclosed area. The enclosed area enables testing under different temperature environments, including high and low temperatures.

[0012] The high and low temperature testing device for chip ceramic capacitors is characterized in that the multi-channel capacitor testing fixture mechanism includes a fixture base plate, a positioning seat for placing chip ceramic capacitors is provided in the middle of the fixture base plate, and movable metal probe seats and fixed metal probe seats are provided above the fixture base plate and on both sides of the positioning seat. The movable metal probe seats, fixed metal probe seats and the fixture base plate are located in the enclosed area.

[0013] A further technical solution is that an adjustable fixing device is provided between the movable metal probe holder and the fixture base plate, forming an adjustable distance device between the movable probe positioning seat and the fixed probe positioning seat.

[0014] A further technical solution is that the multi-channel capacitance test fixture mechanism includes a row of paired contact pairs; or the multi-channel capacitance test fixture mechanism includes two rows of vertically paired contact pairs. It can be a row of multiple pairs of metal pillars arranged in one dimension, with cables leading out from both sides of the arrangement. Alternatively, it can be a two-dimensional arrangement of metal pillars arranged vertically, forming a fixture array with multiple fixtures closely arranged to reduce the space occupied by multiple fixtures. The device can also be a two-dimensional arrangement of metal pillars arranged vertically, where the fixed metal pillar portion has a positioning slot for the capacitor at the front of its contact end, and the contact of the flexible metal pillar portion aligns with the slot. When the capacitor is inserted into the slot, the flexible metal pillar can press on one electrode of the capacitor, pressing the other electrode of the capacitor onto the contact end of the fixed metal pillar.

[0015] A further technical solution involves a positioning base comprising a strip, the top surface of which has several spaced V-shaped grooves forming an inclined support surface for placing chip ceramic capacitors. This inclined support surface saves space and meets the testing requirements for a larger number of capacitors.

[0016] A further technical solution is that the middle part of the strip is provided with an opening for placing a chip ceramic capacitor, and the opening is set through the strip along the width direction of the strip.

[0017] A further technical solution involves covering both the movable and fixed metal probes with insulating sleeves, and then further enclosing these sleeves with a metal shielding layer. The probes are then shielded by a grounded metal body. This design minimizes errors and improves testing accuracy when measuring small capacitance and loss parameters using high-frequency signals.

[0018] A further technical solution is that several adjacent insulating sleeves are fixedly connected to a connecting plate, and the connecting plate is fixedly connected to the movable end lever; the metal probe is cylindrical.

[0019] A spring is fitted around the outer layer of the metal shield. One end of the spring is fixedly connected to the insulating sleeve or the outer layer of the metal shield, and the other end is fixedly connected to the connecting plate. By manually turning the movable lever, the movable metal column (i.e., the movable metal probe) can be moved forward and backward, making it convenient to insert and remove the capacitor from the test fixture.

[0020] A further technical solution is to provide a fixing end locking screw on the fixed metal probe holder for fixing the fixed metal probe holder to the fixture base plate;

[0021] The fixed metal probe holder is provided with an adapter hole for accommodating the fixed metal probe, its surrounding insulating sleeve, and the outer metal shielding layer around the insulating sleeve; the movable metal probe holder is provided with an adapter hole for accommodating the movable metal probe, its surrounding insulating sleeve, and the outer metal shielding layer around the insulating sleeve.

[0022] The wires are connected to the external measuring device via connectors.

[0023] A further technical solution is that the external measuring device is either an LCR testing device located outside the temperature-sealed area for testing capacitance and loss parameters, or an LCR testing device located outside the temperature-sealed area for testing capacitor withstand voltage and insulation resistance. This allows the device to have two types of testing stations: one station for testing parameters such as capacitor capacitance and loss; and the other for testing parameters such as capacitor withstand voltage and insulation resistance.

[0024] The advantages and benefits of this utility model are: forming a clamp array by arranging multiple clamps closely together, thereby reducing the space occupied by multiple clamps.

[0025] The inclined support surface saves more space and meets the testing requirements of a larger number of capacitors.

[0026] The probe is shielded by a grounded metal body, which reduces the error and improves the test accuracy when measuring small capacitance and loss parameters using high-frequency signals.

[0027] By manually turning the movable lever, the movable metal cylinder (i.e., the movable metal probe) can be moved forward and backward, making it convenient to insert and remove the capacitor from the test fixture.

[0028] This device is equipped with two types of test stations. One type is used to test parameters such as capacitance loss; the other type is used to test parameters such as withstand voltage and insulation resistance of capacitors. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a high and low temperature testing device for chip ceramic capacitors according to this utility model;

[0030] Figure 2 yes Figure 1 A diagram from another perspective;

[0031] Figure 3 yes Figure 1 A magnified view of the right-middle section;

[0032] Figure 4 yes Figure 1 A magnified view of the middle left section;

[0033] Figure 5 yes Figure 2 A magnified view of the right-middle section;

[0034] Figure 6 yes Figure 2 A magnified view of the middle left section;

[0035] Figure 7 yes Figure 1 Side view;

[0036] Figure 8 yes Figure 7 A schematic diagram of the AA direction;

[0037] Figure 9 yes Figure 7 A schematic diagram of the BB direction;

[0038] Figure 10 yes Figure 8 A magnified view of the upper middle section.

[0039] In the diagram: 1. Enclosed area; 2. Capacitor; 3. Movable metal column; 4. Insulating material; 5. Wire; 6. Connector; 7. Fixed metal column; 8. Movable lever; 9. Fixture base plate; 10. Positioning seat; 11. Strip plate; 12. V-groove; 13. Spring; 14. Connecting plate; 15. Movable metal probe holder; 16. Fixed metal probe holder; 17. Fixed end locking screw. Detailed Implementation

[0040] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0041] like Figures 1 to 10 As shown (for ease of illustration), Figure 2 (Spring not shown in the figure) This utility model is a high and low temperature testing device for chip ceramic capacitors, which includes a temperature-variable closed area 1. The device employs a multi-channel capacitor testing fixture placed in the closed area, and the capacitor testing device placed outside the closed area 1.

[0042] The test fixture described above uses multiple contact points to form a device for contacting the electrodes of multiple capacitors. One of the contact points is composed of a flexible movable metal column 3, with an insulating material 4 (insulating sleeve) surrounding the side of the movable metal column 3. This insulating material 4 forms a directional guide rail for the movable metal column. The metal column is connected to an external measuring device via a wire 5 (the wire 5 is connected to the external measuring device via a connector 6). The capacitor is placed between the flexible contact points formed by the ends of two metal columns (i.e., the movable metal column 3 and the fixed metal column 7; metal columns are also called probes in the industry), and is connected by the contact points.

[0043] The movable metal cylinder 3 is connected to a movable lever 8. By manually turning the movable lever 8, the movable metal cylinder can move forward and backward, making it convenient to put the capacitor 2 into and take out the test fixture.

[0044] The device includes a fixture base plate 9, and a positioning seat 10 for placing a chip ceramic capacitor 2 is provided in the middle of the fixture base plate 9. The positioning seat 10 includes a strip plate 11, and the top surface of the strip plate is provided with a plurality of spaced V-shaped grooves 12 for forming an inclined support surface for placing the chip ceramic capacitor.

[0045] The positioning base 10 has movable metal probe seats 15 and fixed metal probe seats 16 on both sides. The movable metal probe seats 15, fixed metal probe seats 16 and the fixture base plate 9 form the closed area 1. The fixed metal probe seats 16 are provided with fixed end locking screws 17 for fixing the fixed metal probe seats to the fixture base plate.

[0046] The fixtures are arranged in a close arrangement to form a fixture array, thereby reducing the space occupied by multiple fixtures.

[0047] The fixture used for testing capacitance and loss has an outer metal shielding layer around the insulator (insulating material 4) used for the fixed contact metal body (i.e., the fixed metal column) and the elastic metal column (i.e., the movable metal column). A spring 13 is fitted around the outer metal shielding layer, with one end of the spring fixedly connected to the insulating sleeve or the outer metal shielding layer and the other end fixedly connected to the connecting plate 14.

[0048] The clamp array consisting of the above-mentioned multiple clamps can be configured by sharing a single movable lever 8 to open multiple movable metal cylinders at once, which can facilitate the placement or removal of multiple capacitors from the clamps (several adjacent insulating materials 4 are fixedly connected to a connecting plate 14, and the connecting plate 14 is fixedly connected to the movable lever 8).

[0049] In the device, conductor 5 is a coaxial high-frequency cable. The metal body outside the insulation material and the metal column inside the insulation material form a coaxial structure. The outer metal body is connected to the outer conductor layer of the coaxial cable, and the metal column is connected to the core wire of the coaxial cable.

[0050] Each metal column is connected to two coaxial cables, and the two contacts of a capacitor are connected to a total of four coaxial cables that are connected to the external test device.

[0051] The device can be a pair of contacts consisting of multiple pairs of metal cylinders arranged in a row and one dimension, with cables leading out from both sides of the arrangement.

[0052] The fixed metal column portion, as described above, can also be constructed using a circuit board, which forms a fixed array of contact points.

[0053] The device can be configured with two types of test stations: one for testing parameters such as capacitance and loss, and the other for testing parameters such as withstand voltage and insulation resistance. The fixtures used for testing capacitance and loss parameters include...

[0054] The capacitance loss test station is connected to the LCR test device outside the temperature-sealed area; the fixtures used to test the withstand voltage and insulation resistance of the capacitor are connected to the LCR test device outside the temperature-sealed area.

[0055] The device, in its capacitance testing unit, includes a capacitance loss testing section containing a DC bias device.

[0056] The device, whose bias device is isolated from the capacitance and loss testing device by a DC isolation device, constitutes a capacitance and loss testing device with DC bias. This device is connected to the clamps of multiple capacitors in the measuring device described in 1 through a multiplexer switch (existing high and low temperature testing devices for capacitors usually only include AC test items for capacitance and loss, and do not have DC test items; this setting also allows for the testing of DC items of capacitors).

[0057] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A high and low temperature testing device for chip ceramic capacitors, characterized in that, It includes a multi-channel capacitance test fixture mechanism and an external measuring device connected to the metal probes in the multi-channel capacitance test fixture mechanism via wires. The aforementioned multi-channel capacitance test fixture mechanism is a mechanism that uses multiple pairs of contacts to contact the two end electrodes of multiple capacitors respectively. In each pair of contacts, one contact includes a flexible movable metal probe and the other contact includes a fixed metal probe.

2. The high and low temperature testing device for chip ceramic capacitors according to claim 1, characterized in that, The multi-channel capacitance test fixture mechanism includes a temperature-variable enclosed area, and the external measuring device is located outside the enclosed area.

3. The high and low temperature testing device for chip ceramic capacitors according to claim 2, characterized in that, The multi-channel capacitor test fixture mechanism includes a fixture base plate, a positioning seat for placing chip ceramic capacitors is provided in the middle of the fixture base plate, and movable metal probe seats and fixed metal probe seats are provided above the fixture base plate and on both sides of the positioning seat. The movable metal probe seats, fixed metal probe seats and fixture base plate constitute the fixture mechanism.

4. A high and low temperature testing device for a chip ceramic capacitor according to claim 2 or 3, characterized in that, An adjustable fixing device is provided between the movable metal probe holder and the fixture base plate, forming an adjustable distance device between the movable probe positioning seat and the fixed probe positioning seat.

5. A high and low temperature testing device for a chip ceramic capacitor according to claim 2 or 3, characterized in that, The multi-channel capacitance test fixture mechanism includes a row of paired contact pairs; or the multi-channel capacitance test fixture mechanism includes two rows of paired contact pairs arranged vertically.

6. The high and low temperature testing device for chip ceramic capacitors according to claim 4, characterized in that, The positioning seat includes a strip plate, and the top surface of the strip plate is provided with several spaced V-shaped grooves for forming an inclined support surface for placing chip ceramic capacitors.

7. The high and low temperature testing device for chip ceramic capacitors according to claim 6, characterized in that, The strip is also provided with an opening in the middle for placing a chip ceramic capacitor, and the opening extends through the strip along the width direction.

8. The high and low temperature testing device for chip ceramic capacitors according to claim 3, characterized in that, Both the movable and fixed metal probes are covered with insulating sleeves, and the insulating sleeves are surrounded by a metal shielding outer layer.

9. The high and low temperature testing device for chip ceramic capacitors according to claim 7, characterized in that, Several adjacent insulating sleeves are fixedly connected to a connecting plate, which is fixedly connected to the movable end lever; the metal probe is cylindrical. A spring is fitted on the outside of the metal shielding outer layer. One end of the spring is fixedly connected to the insulating sleeve or the metal shielding outer layer, and the other end is fixedly connected to the connecting plate.

10. The high and low temperature testing device for a chip ceramic capacitor according to claim 8, characterized in that, The fixed metal probe holder is provided with a fixing end locking screw for fixing the fixed metal probe holder to the fixture base plate; The fixed metal probe holder is provided with an adapter hole for accommodating the fixed metal probe, its surrounding insulating sleeve, and the outer metal shielding layer around the insulating sleeve; the movable metal probe holder is provided with an adapter hole for accommodating the movable metal probe, its surrounding insulating sleeve, and the outer metal shielding layer around the insulating sleeve. The wires are connected to the external measuring device via connectors.

11. The high and low temperature testing device for a chip ceramic capacitor according to claim 9, characterized in that, The external measuring device is either an LCR testing device located outside the temperature-sealed area for testing capacitance and loss parameters, or an LCR testing device located outside the temperature-sealed area for testing the withstand voltage and insulation resistance of capacitors.

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