Portable Kelvin test contact detector and tester
By using a portable Kelvin test contact detector with an independent detection circuit and LED indicator to display the contact status, the problem of poor contact caused by test piece wear is solved, and the test force can be visually adjusted, thus improving test efficiency and accuracy.
Patent Information
- Application Number
- CN202423081770.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-12-13
AI Technical Summary
In existing technologies, wear on the test wafer during semiconductor testing leads to poor contact, resulting in test misjudgments and reduced yield. Furthermore, adjusting the test contact force relies on experience, which is inefficient and difficult to control.
Design a portable Kelvin test contact detector, including a detection unit, a switching unit, and a power supply unit. Each pin is configured with an independent detection circuit, and the contact status is displayed through an LED indicator, realizing visualization of the adjustment process.
It improves the efficiency and effectiveness of adjusting the test contact force, makes the adjustment process intuitive and convenient, reduces the risk of wear on the test piece, and improves test efficiency and accuracy.
Smart Images
Figure CN223611652U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of semiconductor testing technology, specifically relating to a portable Kelvin test contact detector and the test instrument implementing it. Background Technology
[0002] During semiconductor electrical parameter testing, the device under test is connected to the test circuit via a test chip and then connected to the measurement unit of the testing machine. The testing machine applies test conditions sequentially according to the program settings and reads the test results to determine whether the device meets the electrical specifications.
[0003] The test piece is fixed on the test holder of the sorting machine. The device is pressed down onto the test piece with moderate force, and the pins make ohmic contact with the test piece. After the test is completed, the next device is replaced, and this cycle continues. Thousands of devices come into contact with the test piece every hour, and high-speed machines can handle more than 50,000.
[0004] The continuous contact and separation cause the test piece to gradually wear down. When the wear reaches a certain level, poor contact will occur, leading to test misjudgments and reduced yield. To maintain a normal yield, engineers need to adjust the downward stroke or the height of the test socket to restore normal test contact force. While adjusting the downward stroke or the height of the test socket may seem simple, it is actually quite difficult.
[0005] The contact force during on-site testing is difficult to perceive and measure. Engineers usually rely on experience to increase the travel downwards or raise the test stand upwards to increase the contact force. This process is uncontrollable. Excessive force not only aggravates wear on the test piece but may also cause deformation of the device pins. Insufficient force leads to unstable test contact and continues to produce misjudgments.
[0006] Other engineers use offline testing with a testing machine to determine changes in contact status during the adjustment process. However, walking back and forth is inconvenient, and the Kelvin contact test in the program usually tests all pins in series, making it impossible to know which pins have made contact with the test piece and which have not during the adjustment process, thus limiting its reference value.
[0007] Therefore, some engineers use multimeters to determine whether each pin is in contact. However, since devices have dozens of pins, using a multimeter to check the contact status is not only inefficient but also quite inconvenient.
[0008] The above describes the current state of the packaging and testing industry. Adjusting the contact force between the test chip and the pins relies on experience, resulting in poor testing efficiency. There are no better methods or shortcuts. Utility Model Content
[0009] The following presents a simplified summary of embodiments of the present application in order to provide a basic understanding of some aspects of the application. This summary is not an extensive overview of the application. It is not intended to identify key or critical elements of the application or to delineate the scope of the application. Its sole purpose is to present some concepts of the application in a simplified form as a prelude to the more detailed description that is presented later.
[0010] To solve the above technical problems and improve the test efficiency, the utility model provides a kind of portable kelvin test contact detector and tester, and the downstroke adjustment of engineering technician and the height adjustment process of test seat are visualized.
[0011] As an aspect of the present application, a portable Kelvin test contact detector is provided, comprising a chip to be tested, a detection unit, a switch unit and a power supply unit, the detection unit comprising a detection circuit for each pin of the chip to be tested, each pin of the chip to be tested being connected to the power supply unit through the detection circuit and the switch unit; wherein the detection circuit comprises a driving end, a sensing end, an indicator light unit and a current limiting unit, the driving end being connected to the switch unit and the power supply unit after being connected to the current limiting unit in series, and the sensing end being connected to the switch unit and the power supply unit after being connected to the indicator light unit in series. Each detection circuit serves as a detection channel, and the strokes of the detection channels are independent of each other, and the number of channels matches the number of pins of the package to be tested.
[0012] As an embodiment, the detection circuit further comprises a protection resistor connected in series between the switch unit and the indicator light unit.
[0013] As an embodiment, the indicator light unit comprises a green LED (light-emitting diode).
[0014] As a further embodiment, the indicator light unit further comprises a red LED (light-emitting diode) for power supply indication.
[0015] Specifically, the anode of the green LED is connected to the sensing end, the cathodes of the green LED and the red LED are grounded, and the anode of the red LED is connected to the switch unit after being connected to the protection resistor in series.
[0016] As an embodiment, the current limiting unit is implemented by a resistor or a resistor circuit connected in series and parallel. In addition, the current limiting unit of the detection circuit can be a common circuit part of the detection unit or can be separately provided for each detection circuit.
[0017] As an implementation, the switch unit is implemented by mechanical switch or electronic switch, the mechanical switch can be button switch, fluctuation switch or rotary switch, and the electronic switch can be implemented by relay, transistor, field effect transistor or the like.
[0018] As an implementation, the power supply unit comprises a battery.
[0019] In addition, as a further implementation, the detection circuit further comprises a switching switch for switching the passage between the chip pin and the power supply unit.
[0020] The utility model discloses a series of detection circuits as detection unit are designed by the above scheme, and when actually realizing, can be connected with test piece through the plug matched with test circuit board socket. The detection circuit configures an LED indicator lamp for each pin, and the detection channel (loop) of independent travel is matched with the pin number of the measured package.
[0021] Each detection channel is in series by Force test piece (driving end), pin, Sence test piece (sensing end), current-limiting resistance and indicator lamp unit (LED lamp) in turn, and then is incorporated into power supply unit, and can detect and indicate through LED lamp: when the pin is in contact with Force test piece and Sence test piece simultaneously, the circuit is closed, and the LED lamp is lighted up. When any one of Force test piece and Sence test piece is separated from the pin, the circuit is opened, and the LED lamp is extinguished, indicating that the contact is poor or there is no contact.
[0022] Wherein, since the detection circuit of each pin is independent, the indicator lamp unit of the detector respectively indicates the contact state of the corresponding pin, is convenient and intuitive to use, and can significantly improve the efficiency and effectiveness of test contact force adjustment.
[0023] Compared with the prior art, the portable Kelvin test contact detector and the detector are convenient to carry and easy to use, have low power consumption with self-charging battery, are simple in principle and convenient to manufacture and maintain, can be applied to Kelvin test contact fields of various packages by changing the connecting plug, and greatly improve the detection efficiency. BRIEF DESCRIPTION OF DRAWINGS
[0024] The utility model can be better understood by referring to the description given below in conjunction with the accompanying drawings, wherein the same or similar reference signs are used to represent the same or similar parts in all the drawings. The drawings, together with the following detailed description, are included in the specification and form part of the specification, and are used to further illustrate the preferred embodiments of the utility model and explain the principles and advantages of the utility model. In the drawings:
[0025] Figure 1Fig. 1 is a schematic diagram of the prior art for testing the contact force, 1 is a chip to be tested (device under test), 2 is a suction nozzle, 3 is a pin, 4 is a test sheet, wherein a is a schematic diagram of a test contact failure or no contact state, b is a schematic diagram of a test contact force moderate, and c is a schematic diagram of a test contact force too large;
[0026] Figure 2 Fig. 1 is a schematic diagram of the prior art for testing the contact force, 1 is a chip to be tested (device under test), 2 is a suction nozzle, 3 is a pin, 4 is a test sheet, wherein a is a schematic diagram of a test contact failure or no contact state, b is a schematic diagram of a test contact force moderate, and c is a schematic diagram of a test contact force too large;
[0027] Figure 3 Fig. 1 is a schematic diagram of the prior art for testing the contact force, 1 is a chip to be tested (device under test), 2 is a suction nozzle, 3 is a pin, 4 is a test sheet, wherein a is a schematic diagram of a test contact failure or no contact state, b is a schematic diagram of a test contact force moderate, and c is a schematic diagram of a test contact force too large; DETAILED DESCRIPTION
[0028] Embodiments of the present application will be described below with reference to the accompanying drawings. The elements and features described in one drawing or one embodiment of the present application can be combined with the elements and features shown in one or more other drawings or embodiments. It should be noted that, for the purpose of clarity, the representations and descriptions of components and processes unrelated to the present application and known to those of ordinary skill in the art are omitted from the drawings and the description.
[0029] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", and "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0030] The following is the explanation of the English abbreviations used in this application: Force detection sheet, or drive end or Force end or Force test sheet, used to apply current or voltage signal to the chip pin. In the Kelvin connection test, the role of the Force end is to provide test excitation, such as applying current, so as to measure the response at the Sense end. The principle is to use the protection diode inside the chip to judge whether the pin is conducting by measuring the voltage of the pin. If the pin is in good contact with the test seat, the current applied at the Force end will produce a corresponding voltage change at the Sense end.
[0031] Sense sensing piece, or sensing end or Sense end or Sense test piece, is used to measure the current or voltage value of the chip pin. In the Kelvin connection test, the role of the Sense end is to monitor the current or voltage signal applied by the Force end, so as to judge whether the chip pin is in conduction. If there is a short circuit between the pins, or an open circuit between the pins and the power supply or ground, the measurement result of the Sense end will reflect these abnormalities.
[0032] Kelvin test contact: when testing a semiconductor device, each pin is in contact with both the Force detection piece and the Sence sensing piece, which can better ensure the accuracy of the applied test conditions and the measured results.
[0033] Figure 1 Fig. 1 is a schematic diagram of the prior art test contact force, 1 is a chip to be tested (device under test), 2 is a suction nozzle, 3 is a pin, 4 is a test piece, wherein a is a test contact failure or non-contact state schematic diagram, b is a test contact force moderate schematic diagram, and c is a test contact force too large schematic diagram. To solve the problems of the prior art and improve the test efficiency, the state of each pin contacting the test piece is intuitively presented during adjustment, the application provides a portable Kelvin test contact detector, which can not only be used to develop adjustment standards for contact force, but also can make the implementation of the standards easy.
[0034] As a specific embodiment, see Figure 2 The portable Kelvin test contact detector of the utility model is illustrated by taking SOT23-6 as an example. SOT23-6 has six pins, and the portable Kelvin test contact detector comprises a chip to be tested (SOT23-6), a detection unit composed of six detection circuits, a switch and a power supply Vcc, the detection unit has six Force detection pieces (driving ends), six Sense sensing pieces (sensing ends), six green LEDs (D1, D2, D3, D4, D5 and D6), one red LED (D7), one current limiting resistor R2 and one protection resistor R1, each pin of the SOT23-6 is connected with one Force detection piece and one Sense sensing piece, each Force detection piece is connected with the current limiting resistor R2 and then connected to the switch, each Sense sensing piece is connected with the anode of each green LED, the cathodes of each green LED and the cathode of the red LED are grounded, and the anode of the red LED is connected to the switch after being connected with the protection resistor R1 in series. Each detection circuit comprises one Force detection piece (driving end), one Sense sensing piece (sensing end) and one green LED, which serves as a detection channel, the strokes of the detection channels are independent of each other, and the number of channels matches the number of pins of the package to be tested.
[0035] In this embodiment, all detection circuits share current limiting resistors, greatly simplifying the circuit structure.
[0036] In actual use, the plug matched with the test circuit board socket is connected with the test pieces (Force detection pieces, Sense sensing pieces). The detection circuit is configured with an LED indicator for each pin, and the detection channels with independent strokes are matched with the pin number of the measured package.
[0037] Each detection channel (circuit) is connected in series by the Force test piece, the pin, the Sence test piece, the current limiting resistor and the LED in turn, and then connected to the power supply, so that the detection can be carried out and the LED can indicate that when the pin is in contact with the Force test piece and the Sence test piece at the same time, the circuit is closed, and the LED is lit; if any one of the Force test piece and the Sence test piece is separated from the pin, the circuit is opened, and the LED is extinguished, indicating that the contact is poor or there is no contact.
[0038] Since the detection circuits of each pin are independent of each other, each LED of the detector indicates the contact state of the corresponding pin, which is convenient and intuitive to use, and can significantly improve the efficiency and effectiveness of the test contact force adjustment.
[0039] The detector made by the scheme has a built-in charging battery (3.3V charging battery), low power consumption; it is convenient to carry, and by changing the connecting plug, it can be applied to various packaging Kelvin test contact sites. The red LED with power indication, the independent detection and indication of each pin (6 green LEDs are used to indicate the on-off of each detection circuit), the simple principle, the convenience of production and maintenance; the number of detection channels is expanded according to the number of pins of the package; in addition, the plug matched with the test circuit board is used, which is convenient to use.
[0040] As another embodiment, refer to Figure 3 , in the figure, 11 is a DUT device to be tested, 12 is an LED indicator, 13 is a power switch, 14 is a current limiting resistor, 15 is a battery, 16 is a power indication, the DUT device 11 has six pins, each pin is divided into two paths, one path is connected to the negative electrode of the battery 15 after being connected in series with the LED indicator 12, and the other path is connected to the positive electrode of the battery 15 after being connected in series with the power switch 13 and the current limiting resistor 14.
[0041] As another embodiment, the utility model also provides a test instrument, which comprises the above test circuit, which can comprise a shell, and the shell is provided with a power switch, a red power indication lamp, a plug, a green indication lamp and the like.
[0042] Through the above scheme, the down stroke adjustment of the engineering and technical personnel and the height adjustment process of the test seat in the test process are visualized, the state of each pin contacting the test piece in the adjustment process is intuitively presented, not only the adjustment standard of the contact force can be used to develop, but also the implementation of the standard becomes easy. Compared with the tools such as the universal meter, the cost is low, the use efficiency is high, and the effect is intuitive and significant. In summary, the application has good innovation, advancement and practicability.
[0043] Although the utility model has been disclosed through the description of the specific embodiments of the utility model above, it should be understood that all the above embodiments and examples are exemplary but not restrictive. Those skilled in the art can design various modifications, improvements or equivalents of the utility model within the spirit and scope of the appended claims. The utility model is not limited to the above version and specific packaging, and the design using the same or similar principles as the above embodiments of the utility model, through the scheme of the conductivity between the pins of the LED display semiconductor device, these modifications, improvements or equivalents should also be considered to be included in the protection scope of the utility model.
Claims
1. A portable Kelvin test contact detector characterized by: The chip under test, a detection unit, a switch unit and a power supply unit are included, the detection unit includes detection circuits equal in number to the number of pins of the chip under test, each pin of the chip under test is connected to the power supply unit through the detection circuit and the switch unit; The detection circuit includes a driving end, a sensing end, an indicator light unit and a current limiting unit, the driving end is connected to the switch unit and the power supply unit after being connected with the current limiting unit in series, the sensing end is connected to the switch unit and the power supply unit after being connected with the indicator light unit in series.
2. The portable Kelvin test contact detector of claim 1, wherein: The detection circuit further includes a protection resistor connected between the switch unit and the indicator light unit.
3. The portable Kelvin test contact detector of claim 2, wherein: The indicator light unit includes a green LED.
4. The portable Kelvin test contact detector of claim 3, wherein: The indicator light unit further includes a red LED for power supply indication; the positive pole of the green LED is connected to the sensing end, the negative poles of the green LED and the red LED are grounded, and the positive pole of the red LED is connected to the switch unit after being connected with the protection resistor in series.
5. The portable Kelvin test contact detector of claim 1, wherein: The current limiting unit is implemented by using a resistor or a series-parallel connected resistor circuit.
6. The portable Kelvin test contact detector of claim 1, wherein: The switch unit is implemented by using a mechanical switch or an electronic switch.
7. The portable Kelvin test contact detector of claim 1, wherein: The power supply unit includes a battery.
8. A portable Kelvin tester characterized by: The portable Kelvin test contact detector includes the Kelvin test contact detector according to any one of claims 1 to 7.