TWI765312B - Edge sensor and probing method using the same - Google Patents

Abstract

The present invention provides an edge sensor comprising a probe, a PCB substrate, and a strain sensor, wherein the PCB substrate is coupled to the probe, the strain sensor is arranged onto the PCB substrate for detecting a strain status of the PCB substrate when the probe has load force acting thereon. In another embodiment, the present invention further provides a probing method comprising steps of providing the probing device, and a chuck supporting a device under test (DUT), making an electrical contact between the probe and the DUT, and detecting a strain status of the PCB substrate due to a contact force acting the probe by the strain sensor.

Description

Edge sensor and point detection method thereof

The present invention relates to a spot measurement technology, in particular to an edge sensor and a spot measurement method using a sensor to detect the load of a test pin.

With the advancement of technology, the size of electronic devices is gradually miniaturized. In order to verify the performance of miniaturized electronic devices, such as semiconductor chips or micro LED substrates, an edge sensor is required to be in electrical contact with the electrical connection terminals of the electronic device to provide electrical signals Drive the miniaturized electronic components in the electronic device, and then measure the electrical characteristics of the electronic device, such as: voltage, current, wavelength, brightness, etc., so as to judge the quality of the electronic device, and follow-up sorting and packaging can be carried out according to the quality. Operation.

However, due to the miniaturization of electronic components, the contact force between the test pins and the miniaturized electronic components will affect the detection results of the electronic components. For example, if the test needle does not generate enough contact pressure when it contacts the workpiece, it will cause inaccurate measurement results. However, if the contact pressure is too large, the test pins may be damaged, and even scratches may be formed on the surface of the test pins in contact with the workpiece, thereby affecting the yield of electronic components.

In view of this, how to detect the force information of the test pin when the test pin contacts the surface of the electronic component is an important issue. Although the aforementioned prior art can measure the strain state of the sensing piece or the swing arm through the sensing element, and then obtain information about the force between the test pin and the electronic element, in some cases, the test pin needs to be The signal wire transmits electrical signals to detect electronic components. Therefore, when the wire is coupled with the test needle, the deformation of the sensing piece or the swing arm will be affected due to the coupling of the signal wire and the test needle. The accuracy of the measurement makes the response sensitivity of the sensing element to detect the force insufficient on the smaller and smaller electronic components.

In view of the above, there is a need for an edge sensor and a point detection method to solve the problems caused by the conventional technology.

The present invention provides an edge sensor and a point measurement method thereof, which utilizes a multilayer circuit substrate to replace the conventional metal swing arm, thereby simplifying the use of signal wires, improving the response sensitivity of detecting the force of the test needle, and achieving both the detection of strain and the effect of signal transmission. In addition, since a drive device is set at the end of the fixed seat on one side of the edge sensor to drive the edge sensor to move, the design of the present invention can reduce the weight load of the drive device by replacing the metal swing arm with a multilayer circuit substrate. .

The present invention provides an edge sensor and a point measuring method thereof. In addition to replacing the conventional metal swing arm with a multi-layer circuit substrate, the signal sockets on the multi-layer circuit substrate that are coupled with the signal wires are further omitted, thereby reducing the need for the multi-layer circuit substrate. The weight of the load is increased, and the response sensitivity of detecting the force of the test needle is improved.

In one embodiment, the present invention provides an edge sensor including test pins, a multi-layer circuit substrate and a strain sensor, wherein the multi-layer circuit substrate is coupled with the test pins, and the strain sensor is disposed on the multi-layer circuit substrate , which is used to detect the strain state of the multilayer circuit substrate caused by the force of the test needle.

In one embodiment, the present invention provides a point testing method. First, an edge sensor is provided, including a test pin, a multi-layer circuit substrate and a strain sensor, wherein the multi-layer circuit substrate is coupled to the test pin. , the strain sensor is arranged on the multilayer circuit substrate. A bearing base is provided on which an object to be tested is carried. The test pin is then brought into electrical contact with the object to be tested. Then, the strain state of the multilayer circuit substrate caused by the force of the test pin is detected by the strain sensor.

In one embodiment, the multilayer circuit substrate has a signal socket for being electrically connected with the first signal wire, and the first signal wire transmits electrical signals to the test pins. In another embodiment, the first signal wire is directly electrically connected to the multilayer circuit substrate without passing through the signal socket, so as to transmit electrical signals to the test pins. The aforementioned signal wires are triaxial cable signal wires or coaxial cable signal wires.

In another embodiment, the strain sensor is electrically connected to the multilayer circuit substrate, and the strain sensor generates a corresponding strain electrical signal according to the strain state and outputs the signal through the multilayer circuit substrate. In another embodiment, the strain sensor generates a corresponding strain electrical signal according to the strain state, not through the multilayer circuit substrate, but through the second signal wire.

In another embodiment, the test pin is electrically connected to the first end of the electrically conductive cantilever, and the second end of the electrically conductive cantilever is electrically connected to the multilayer circuit substrate.

Various illustrative embodiments may be described more fully hereinafter with reference to the accompanying drawings, in which some illustrative embodiments are shown. However, the inventive concepts may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these illustrative embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Similar numbers always indicate similar elements. In the following, various embodiments are used in conjunction with the drawings to describe the edge sensor and its spot measurement method. However, the following embodiments are not intended to limit the present invention.

Please refer to FIG. 1 , which is a schematic diagram of an embodiment of the edge sensor of the present invention. In this embodiment, the edge sensor 2 includes a test pin 20 , a multilayer circuit substrate 21 and a strain sensor 22 , wherein the test pin 20 is coupled to the multilayer circuit substrate 21 , and the strain sensor 22 is disposed on the multilayer circuit substrate 21 . superior. In this embodiment, the test pins 20 are electrically connected to the multilayer circuit substrate 21 through the electrically conductive cantilevers 23 , wherein the first ends 230 of the electrically conductive cantilevers 23 are electrically connected to the test pins 20 , and the first ends 230 are further connected with the test pins 20 . The cantilever structure 232 extends to the multi-layer circuit substrate along the length direction of the multi-layer circuit substrate, and the end of the cantilever structure 232 has a second end 231 that is electrically connected to the multi-layer circuit substrate 21 . In one embodiment, the test pin 20 is detachably disposed on the first end 230 of the electrically conductive cantilever 23 . For example, in the embodiment of FIG. 1 , the test pin 20 is fixed on the first end 230 by means of a fixing element 2300 , such as a screw. In one embodiment, the electrically conductive cantilever 23 is locked on the multi-layer circuit substrate 21 through the metal locking element 24 to achieve the effect of locking and electrical connection at the same time. In another embodiment, the second end 231 of the electrically conductive cantilever 23 can also be fixed on the multilayer circuit substrate 21 by soldering.

In this embodiment, the test needle 20 is a flat needle arrangement, that is, the rear needle segment 200 and the electrically conductive cantilever 23 where the test needle 20 is coupled to the electrically conductive cantilever 23 are arranged horizontally, but not limited thereto. In another embodiment, the test pins can also be as shown in FIG. 2 . In the edge sensor 2a shown in FIG. 2, the test pins 20a are electrically connected to the multilayer circuit substrate 21 through the electrically conductive cantilevers 23a, but the difference from FIG. 1 is that the test pins 20 are coupled to the electrically conductive cantilevers 23a The connected rear needle segment 200a and the electrically conductive cantilever 23a form an included angle greater than 0 degrees. In addition, in this embodiment, the test needle 20 is also detachably disposed on the electrically conductive arm 23a. In this embodiment, the end of the electrically conductive cantilever 23a has a clip seat 230a, a clip plate 230b and a fixing element 2300a, wherein the clip seat 230a is connected to the end of the electrically conductive cantilever 23a, and the clamping plate 230b and the fixing element 2300a fix the test needle 20 on the clamping base 230a detachably. The manner in which the test pins 20 or 20a are arranged in FIG. 1 and FIG. 2 is determined according to the purpose of the user's detection, and there is no certain limitation.

Referring back to FIG. 1 , the multilayer circuit substrate 21 is a printed circuit board (PCB), which is made of a polymer material and has elastic deformation capability. The multilayer circuit substrate 21 has circuit layout inside and on the surface, and has the function of telecommunication transmission. In this embodiment, an electrical connection portion 25 is formed on one surface of the multilayer circuit substrate 20 to be electrically connected to the test pins 20 . The electrical connection portion 25 is electrically connected to the test pins 20 via conductive lines formed on the multilayer circuit board 21 . It should be noted that the actual layout of the electrical connection portion 25 , such as how many electrical contacts there are, is determined according to the number of electrical signals to be output or input, and there is no certain limitation. In this embodiment, the electrical connection portion 25 is used for electrical connection with a signal wire belonging to a triaxial cable. Therefore, the electrical connection portion 25 includes a signal contact 250 (force), a guard contact 251 (guard). ) and ground contact 252 (shield) or (gnd). It should be noted that, the electrical contacts on the electrical connection portion 25 are not limited to only the electrical contacts used for electrical connection with the test pins 20 . In another embodiment, the electrical contacts may further include The electrical contact for outputting the strain electrical signal generated by the strain sensor 22 .

In this embodiment, the edge sensor 2 further includes a fixing base 26 having an accommodating groove 260 and a connecting base 261 , wherein the multilayer circuit substrate 21 is installed in the accommodating groove 260 by the opening 262 of the accommodating groove 260 . Inside, one end of the multilayer circuit substrate 21 has a plurality of connecting through holes 212 that can be connected to the connecting holes 2610 inside the connecting seat 261 through the connecting elements 6, such as connecting elements such as screws or rivets, so that the multilayer circuit substrate 21 can generate a cantilever. Effect. The test needle 20 is located outside the opening 261 of the accommodating groove 260 , and the connecting seat 261 is connected with the accommodating groove 260 . The connector 261 is provided with a signal socket 27 which is electrically connected to the electrical connection portion 25 on the multilayer circuit substrate 21 . As shown in FIG. 3A and FIG. 3B , the first signal wire 90 is coupled to the signal socket 27 through the signal connector 900 , and is further electrically connected to the multilayer circuit substrate 21 . The first signal wire 90 transmits an electrical signal to the test needle 20 through the electrical connection portion, and the electrical signal can be a voltage signal or a current signal. In this embodiment, the electrical signal is transmitted to the electrical connection portion 25 through the first signal wire 90 , and then to the electrically conductive cantilever 23 through the circuit in the multilayer circuit substrate 20 , and then to the test pin 20 . In this embodiment, the first signal wire 90 is a triaxial cable, but not limited thereto. For example, in another embodiment, the first signal wire 90 can also be a coaxial cable. It should be noted that, in this embodiment, the first signal wire 90 is connected to the other end of the multilayer circuit substrate 20 relative to the test pins 20 because the first signal wire 90 is not directly electrically conductive with the test pins 20 or its surroundings The connection of the cantilever 23 reduces the influence of the signal wire on the stress state of the test needle, so that the sensitivity of the multi-layer circuit substrate 21 to strain caused by stress can be improved.

The strain sensor 22 is disposed on the multilayer circuit substrate 21 for detecting the strain state of the multilayer circuit substrate 21 caused by the force of the test needle 20 . In this embodiment, the strain sensor 22 senses the strain on the XY plane of the multilayer circuit substrate 21 due to the contact between the test needle 20 and the object to be tested, and generates a strain electrical signal that is directly electrically connected to the strain sensor 22 . The connected second signal wire 91 is output. In this embodiment, the second signal wire 91 can be any wire that can conduct wire signals, and its material is not limited. It should be noted that, in this embodiment, because the signal wire is not directly connected to the test pin 20 or the electrically conductive cantilever 23 around it, the influence of the signal wire on the stress state of the test pin is reduced, so the multilayer circuit substrate can be improved. Sensitivity to stress and strain.

In addition, the fixing base 26 of the edge sensor 2 is further connected with a driving device 29 for driving the edge sensor 2 to perform displacement movement in at least one axial direction, such as the X axis, the Y axis or the Z axis. The driving device 29 is a structure composed of a motor, a screw rod and a guide rail to drive the fixed seat 26 to move, thereby controlling the position of the test needle 20 . In addition, it should be noted that the strain sensor 22 is not limited to being installed on the upper surface 210 of the multilayer circuit substrate 21 . In another embodiment, the strain sensor 22 can also be installed on the upper surface of the multilayer circuit substrate 21 . Lower surface 211 .

Please refer to FIG. 4 , which is a three-dimensional schematic diagram of another embodiment of the edge sensor of the present invention. In this embodiment, the edge sensor 2b is basically similar to that in FIG. 3A , the difference is that the connector 261a of this embodiment does not have the signal socket 27 shown in FIG. 3A , so that the load of the multilayer circuit substrate 21 can be reduced, The sensitivity of the multi-layer circuit substrate 21 to the cantilever bending moment caused by the force of the test needle 20 is improved. For example, under the configuration of FIG. 4 , due to the reduced signal socket 27 , in one embodiment, the test pin 20 can be sensed by the strain sensor 22 when the force of 0.1 g is applied, which further improves the sensing sensitivity. In addition, in this embodiment, the strain sensor 22 does not directly output the electrical strain signal of the strain sensor 22 by using the second signal wire as shown in FIG. 3A , and the strain sensor 22 in this embodiment passes through a multilayer circuit The circuit in the substrate 21 is electrically connected to the multilayer circuit substrate 21 , that is, the part of the strain sensor 22 that outputs the strain electrical signal is transmitted to the electrical connection portion 25 through the circuit inside the multilayer circuit substrate 21 . The electrical connection portion 25 further includes electrical connection terminals required by the second signal wire 91 . The first and second signal wires 90 and 91 are directly electrically connected to each other through the through holes 262 opened on the connecting seat 261 a and the electrical connecting portion 25 on the multilayer circuit substrate 21 by the electrical connection portion 25 being unified as an interface for signal output and input. sexual connection.

Please refer to FIG. 5A to FIG. 5C , wherein FIG. 5A is a schematic flowchart of an embodiment of the point detection method of the present invention; FIGS. 5B and 5C are schematic diagrams of the edge sensor and the point detection process in the point detection method. As shown in FIG. 5A and FIG. 5B , in this embodiment, the process of the point detection method 4 first provides an edge sensor in step 40 , which may be the edge sensor shown above. In step 41, a chuck 5 is provided on which the object to be tested 50 is carried. The object to be tested 50 may be a wafer with a plurality of electronic components or light-emitting components or a carrier with a plurality of miniaturized electronic components. Next, step 42 is performed to make the test pins 20 electrically contact the electronic components on the DUT 50 . In this step, the object to be tested 50 can be electrically contacted with the test pins 20 by moving the carrier 5 , or the object to be tested 50 can be electrically contacted with the test pins 20 by moving the edge sensor 2 .

After the test needles 20 are in electrical contact with the object to be tested 50 , step 43 is performed to detect the strain state of the multilayer circuit substrate 21 caused by the force of the test needles 20 by the strain sensor 20 . In this step, taking controlling the movement of the edge sensor 2 as an example, when the driving device 29 controls the movement of the edge sensor 2 so that the electrical contacts on the object 50 are in contact with the test pins 20, as shown in FIG. 5C As shown, the force of the test pins 20 will be transmitted to the multilayer circuit substrate 21, so that the multilayer circuit substrate 21 will be strained and bent. The degree of bending represents the force experienced by the test needle 20 . As mentioned above, if the contact pressure between the test needle 20 and the object to be tested 50 does not generate enough contact pressure, the problem of inaccurate measurement results will be caused. On the contrary, if the contact pressure is too large, the test pins may be damaged, and even scratches may be formed on the surface of the test pins in contact with the workpiece, thereby affecting the yield of electronic components. Therefore, during the contact between the object to be tested 50 and the test needle 20 , the strain sensor 22 continuously generates a strain electrical signal and outputs it to the control unit 3 through the second signal wire 91 . As shown in step 44, the control unit 3 determines whether the strain state corresponding to the electrical strain signal generated by the strain sensor 20 reaches the threshold value, and if it reaches the threshold value, the control unit 3 proceeds to step 45, that is, sends a stop signal to the driving device 29, so that the driving device 29 Stop driving the edge sensor 2 to move, so as to prevent the surface of the object to be tested 50 from being over-compressed by the test needle 20 . Otherwise, proceed to step 46, continue to control the movement of the edge sensor 2, and then go back to step 44 to determine whether the strain state corresponding to the electrical strain signal generated by the strain sensor 20 reaches the threshold value.

In view of the above, the present invention replaces the traditional metal structure with a circuit board that can generate the bending moment effect of the cantilever due to the force, so as to achieve the effect of transmitting signals and detecting the force state of the test needle. On the other hand, by the method of the present invention, the signal wire that transmits the signal does not directly contact the test pin or its peripheral components, thus reducing the factor that the force state of the test pin is affected by the wire, thereby improving the response of detecting the force of the test pin sensitivity.

The above descriptions are merely for describing the preferred embodiments or examples of the technical means adopted by the present invention to solve the problems, and are not intended to limit the scope of the patent implementation of the present invention. That is, all the equivalent changes and modifications that are consistent with the context of the scope of the patent application of the present invention, or made in accordance with the scope of the patent of the present invention, are all covered by the scope of the patent of the present invention.

2, 2a, 2b: edge sensors 20, 20a: Test pins 200, 200a: back needle segment 21: Multilayer circuit substrate 210: Upper surface 211: Lower surface 212: Connection through hole 22: Strain sensor 23, 23a: Electrically Conductive Cantilever 230: First End 230a: clip seat 2300, 2300a: Fixed elements 232: Cantilever Structure 231: Second End 24: Metal locking element 25: Electrical connection part 250: Signal contact 251: Protection contacts 252: ground contact 26, 26a: Fixed seat 260: accommodating slot 261, 261a: Connector 262: Opening 2610: Connection hole 27: Signal socket 29: Drive 3: Control device 4: Process 40~46: Steps 6: Connecting elements 90: The first signal wire 900: Signal connector

FIG. 1 is a schematic diagram of an embodiment of an edge sensor of the present invention. FIG. 2 is a schematic diagram of another embodiment of the edge sensor of the present invention. 3A and 3B are schematic perspective and side views of an embodiment of the edge sensor of the present invention, respectively. FIG. 4 is a three-dimensional schematic diagram of another embodiment of the edge sensor of the present invention. FIG. 5A is a schematic flowchart of an embodiment of the point measurement method of the present invention. FIG. 5B and FIG. 5C are schematic diagrams of the edge sensor and the point detection process in the point detection method.

2: Edge sensor

20: Test pin

200: back needle segment

21: Multilayer circuit substrate

212: Connection through hole

22: Strain sensor

23: Electrically Conductive Cantilever

230: First End

2300: Fixed element

231: Second End

232: Cantilever Structure

24: Metal locking element

25: Electrical connection part

250: Signal contact

251: Protection contacts

252: ground contact

26: Fixed seat

260: accommodating slot

261: Connector

262: Opening

2610: Connection hole

27: Signal socket

6: Connecting elements

Claims (12)

An edge sensor, comprising: a test pin; a multi-layer circuit substrate with elastic deformation ability, coupled with the test pin, one end of the multi-layer circuit substrate is connected with a fixing seat, so that the multi-layer circuit substrate cantilevered As a result, when the test pin is subjected to force, it will be transmitted to the multi-layer circuit substrate, causing the multi-layer circuit substrate to produce strain bending, and an electrical connection portion is formed on one of the surfaces of the multi-layer circuit substrate adjacent to the fixing seat. The electrical connection The part is electrically connected to the test pin through the conductive circuit formed in the interior or surface of the multilayer circuit substrate, and the electrical connection part is used to provide electrical connection with a first signal wire; a strain sensor is arranged on the On the multi-layer circuit substrate, it is used to detect the state of strain bending of the multi-layer circuit substrate due to the force of the test needle, and generate a corresponding strain electrical signal, which is output through the conductive lines inside or on the surface of the multi-layer circuit substrate; and an electrically conductive cantilever, a first end of which is electrically connected to the test pin, a second end of the electrically conductive cantilever is electrically connected to the multi-layer circuit substrate, and the test pin is detachably arranged on the electrical on the conduction cantilever. The edge sensor of claim 1, wherein a signal socket is coupled to the multilayer circuit substrate for electrically connecting with the first signal wire, and the first signal wire transmits an electrical signal to the test pin. The edge sensor according to claim 1, further comprising a first signal wire for electrically connecting with the multilayer circuit substrate to transmit an electrical signal to the test pin. The edge sensor as claimed in claim 1, wherein the strain sensor is electrically connected to the multilayer circuit substrate, and the strain sensor generates a corresponding strain electrical signal according to the strain state to output through the multilayer circuit substrate. The edge sensor according to claim 1, wherein the strain sensor generates a corresponding strain electrical signal according to the strain state and outputs it through a second signal wire. The edge sensor according to claim 1, wherein the fixing base is further coupled to a driving device for driving the edge sensor to perform a displacement movement. The edge sensor according to claim 1, further comprising: a driving device coupled to the fixing seat, the driving device is used for driving the edge sensor to perform a displacement movement, and the fixing seat has a through hole; The first signal wire is electrically connected to the multilayer circuit substrate through the through hole to transmit an electrical signal to the test pin; and a second signal wire is electrically connected to the multilayer circuit substrate through the through hole, using to receive the strain sensor and generate a corresponding strain electrical signal according to the strain state. A point testing method includes: providing an edge sensor, including a test pin, an electrically conductive cantilever, a multi-layer circuit substrate with elastic deformation ability, and a strain sensor, wherein the multi-layer circuit substrate and the test Pin coupling, one end of the multi-layer circuit substrate is connected with a fixed seat, so that the multi-layer circuit substrate has a cantilever effect. When the test pin is stressed, it will be transmitted to the multi-layer circuit substrate, causing the multi-layer circuit substrate to produce strain and bending, and the multi-layer circuit substrate is deformed. An electrical connection portion is formed on one surface of the circuit substrate adjacent to the fixing seat, and the electrical connection portion is electrically connected to the test pin via a conductive circuit formed in the interior or surface of the multilayer circuit substrate. The connecting part is used to provide a The first signal wire is electrically connected, the strain sensor is arranged on the multilayer circuit substrate, a first end of the electrically conductive cantilever is electrically connected to the test pin, and the first end is in a cantilever structure along the extending to the multi-layer circuit substrate along the length direction of the multi-layer circuit substrate, a second end of the electrically conductive cantilever is electrically connected to the multi-layer circuit substrate, wherein the test pin is detachably arranged on the electrically conductive cantilever ; provide a carrier on which an object to be tested is carried; make the test pin and the object to be tested in electrical contact; and detect the strain of the multilayer circuit substrate caused by the force of the test pin by the strain sensor In the bending state, a corresponding strain electrical signal is generated and outputted through the conductive lines inside or on the surface of the multi-layer circuit substrate. The point measurement method as claimed in claim 8, wherein the strain sensor is electrically connected to the multilayer circuit substrate, and the strain sensor generates a corresponding strain electrical signal according to the strain state to output through the multilayer circuit substrate. The point measurement method according to claim 8, wherein the strain sensor generates a corresponding strain electrical signal according to the strain state and outputs it through a second signal wire. The point measuring method according to claim 8, wherein the fixing base is further coupled to a driving device for driving the edge sensor to perform a displacement movement. The point detection method according to claim 8, further comprising: a driving device coupled to the fixing seat, the driving device is used for driving the edge sensor to perform a displacement movement, the fixing seat has a through hole; the a first signal wire, which is electrically connected to the multilayer circuit substrate through the through hole, so as to transmit an electrical signal to the test pin; and A second signal wire is electrically connected to the multilayer circuit substrate through the through hole, and is used for receiving the strain sensor to generate a corresponding strain electrical signal according to the strain state.

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