IE20200241A1 - Edge sensor and probing method using the same - Google Patents

Abstract

The present invention provides an edge sensor which includes a probe, a multilayer circuit substrate, and a strain sensor, wherein the multilayer circuit substrate is coupled with the probe, and the strain sensor is arranged on the multilayer circuit substrate for detecting a strain status of the multilayer circuit substrate due to a force acting on the probe. In another embodiment, the present invention further provides a probing method which includes steps of providing an edge sensor including a probe, a multilayer circuit substrate coupled with the probe and a strain sensor arranged on the multilayer circuit substrate, providing a chuck supporting a device under test, making an electrical contact between the probe and the device under test, and detecting a strain status of the multilayer circuit substrate due to a force acting on the probe by the strain sensor.

Description

Various illustrative embodiments will be more fully described in the following contents and the accompanying drawings. Some illustrative embodiments are shown in the accompanying drawings. However, the concept of the present invention may be embodied in many different forms and should not be construed as being limited to the illustrative embodiments described herein. To be precise, these illustrative embodiments are provided to detail and complete the present invention, and will fully convey the scope of the present invention concept to those skillful in the art. Similar numerals always indicate similar components. In the following, a variety of embodiments will be provided 28/10/2020 with the accompanying drawings to illustrate the edge sensor and the probing method using the same. However, the following embodiments are not intended to limit the present invention.

Referring to FIG. 1, this figure is a schematic view of an embodiment of an edge sensor of the present invention. In this embodiment, the edge sensor 2 includes a probe 20, a multilayer circuit substrate 21 and a strain sensor 22, wherein the probe 20 is coupled with the multilayer circuit substrate 21 and the strain sensor 22 is arranged on the multilayer circuit substrate 21. In this embodiment, the probe 20 is electrically connected with the multilayer circuit substrate 21 through an electrically conductive cantilever 23, 10 wherein a first end 230 of the electrically conductive cantilever 23 is electrically connected with the probe 20, a cantilever structure 232 extends from the first end 230 to the multilayer circuit substrate along the longitudinal direction of the multilayer circuit substrate, and the cantilever structure 232 is provided on a terminal end thereof with a second end 231 which is electrically connected with the multilayer circuit substrate 21.

In an embodiment, the probe 20 is replaceably arranged on the first end 230 of the electrically conductive cantilever 23. For example, in the embodiment shown in FIG. 1, the probe 20 is fixed on the first end 230 by a fastening element 2300, such as a screw. In an embodiment, the electrically conductive cantilever 23 is fastened on the multilayer circuit substrate 21 by metal fastening elements 24 which attain the fastening and electrically connecting effects at the same time. In another embodiment, the second end 231 of the electrically conductive cantilever 23 may be fixed on the multilayer circuit substrate 21 by welding.

In this embodiment, the probe 20 is arranged in a horizontal probe manner, which means a rear probe section 200 of the probe 20, which is coupled with the electrically conductive cantilever 23, and the electrically conductive cantilever 23 are arranged 28/10/2020 horizontally, but it is unlimited thereto. In another embodiment, the probe may be configured as shown in FIG. 2. In the edge sensor 2a as shown in FIG. 2, the probe 20a is electrically connected with the multilayer circuit substrate 21 through the electrically conductive cantilever 23 a, but it differs from that of FIG. 1 in that the rear probe section 5 200a of the probe 20, which is coupled with the electrically conductive cantilever 23a, and the electrically conductive cantilever 23a have an included angle larger than 0 degree therebetween. Besides, the probe 20 in this embodiment is also replaceably arranged on the electrically conductive cantilever 23a. In this embodiment, the electrically conductive cantilever 23a is provided on an end portion thereof with a clamp base 230a, a clamp plate 10 230b and fastening elements 2300a, wherein the clamp base 230a is connected to the end portion of the electrically conductive cantilever 23 a, and the probe 20 is replaceably fixed on the clamp base 230a by the clamp plate 230b and the fastening elements 2300a. The manner of the arrangement of the probe 20 or 20a in FIGS. 1 and 2 is unlimited, depending on the detecting purpose of the user.

Referring to FIG. 1 again, the multilayer circuit substrate 21 is a printed circuit board (PCB), which is made from polymeric material and capable of elastic deformation. The multilayer circuit substrate 21 is provided therein and on the surfaces thereof with circuit layout, and has a function of transmitting electrical signal. In this embodiment, one of the surfaces of the multilayer circuit substrate 21 is formed with an electrically 20 connecting portion 25 for being electrically connected with the probe 20. The electrically connecting portion 25 is electrically connected with the probe 20 through electrically conductive lines formed on the multilayer circuit substrate 21. It is to be mentioned that the actual layout of the electrically connecting portion 25, such as the amount of electrical contacts thereof, depends on the number of electrical signals needed to be inputted or 25 outputted, and there is no certain limit. In this embodiment, the electrically connecting 28/10/2020 portion 25 is adapted to be electrically connected with a signal cable belonging to triaxial cable, so the electrically connecting portion 25 includes a signal contact 250 (force), a protection contact 251 (guard) and a ground contact 252 (shield or gnd). It is to be mentioned that the electrical contacts on the electrically connecting portion 25 are 5 unlimited to include only the electrical contacts for being electrically connected with the probe 20, but may further include electrical contacts for outputting electrical strain signal produced by the strain sensor 22 in another embodiment.

In this embodiment, the edge sensor 2 further includes a mount 26 having an accommodating trough 260 and a connecting seat 261. The multilayer circuit substrate 21 10 is disposed in the accommodating trough 260 through an opening 262 of the accommodating trough 260. The multilayer circuit substrate 21 is provided on an end thereof with a plurality of connecting through holes 212 for being connected with connecting holes 2610 inside the connecting seat 261 by connecting elements 6, e.g. screws or rivets, to make the multilayer circuit substrate 21 have cantilever effect. The 15 probe 20 is located outside the opening 261 of the accommodating trough 260. The connecting seat 261 and the accommodating trough 260 are connected together. The connecting seat 261 is arranged thereon with a signal socket 27 electrically connected with the electrically connecting portion 25 on the multilayer circuit substrate 21. As shown in FIGS. 3A and 3B, a first signal cable 90 is coupled with the signal socket 27 20 through a signal connector 900, thereby electrically connected with the multilayer circuit substrate 21. The first signal cable 90 transmits electrical signal to the probe 20 through the electrically connecting portion. The electrical signal may be voltage signal or current signal. In this embodiment, the electrical signal is transmitted to the electrically connecting portion 25 through the first signal cable 90, and then transmitted to the 25 electrically conductive cantilever 23 through the circuit in the multilayer circuit substrate 28/10/2020 21. Then, the electrical signal is transmitted to the probe 20. In this embodiment, the first signal cable 90 is a triaxial cable, but unlimited thereto. For example, in another embodiment, the first signal cable 90 may be a coaxial cable. It is to be mentioned that in this embodiment, the first signal cable 90 is connected to the end of the multilayer circuit substrate 20 opposite to the probe 20. Because the first signal cable 90 is not directly connected with the probe 20 or the electrically conductive cantilever 23 around the probe 20, the signal cable is relatively less influential in the stress status of the probe, and thereby the strain sensitivity of the multilayer circuit substrate 21 under stress is relatively higher.

The strain sensor 22 is arranged on the multilayer circuit substrate 21 for detecting the strain status of the multilayer circuit substrate 21 due to the force acting on the probe 20. In this embodiment, the strain sensor 22 senses the strain of the multilayer circuit substrate 21 on XY plane due to the contact between the probe 20 and the device under test, and generates electrical strain signal to be outputted by a second signal cable 91 electrically connected with the strain sensor 22 directly. In this embodiment, the second signal cable 91 can be any conductive wire capable of transmitting signal, the material of which is unlimited. It is to be mentioned that in this embodiment, because the signal cable is not directly connected with the probe 20 or the electrically conductive cantilever 23 around the probe 20, the stress status of the probe will be less influenced by the signal cable, such that the strain sensitivity of the multilayer circuit substrate under stress can be enhanced.

Besides, the mount 26 of the edge sensor 2 is connected with a drive device 29 for driving the edge sensor 2 to displace on at least one axis, e.g. X-axis, Y-axis or Z-axis. The drive device 29 is a structure composed of a motor, a screw and a guideway, for 25 driving the mount 26 to move, thereby controlling the position of the probe 20. The detail 28/10/2020 of the structure is well-known to those skilled in the art, thereby not detailedly described here. Besides, it is to be mentioned that the strain sensor 22 is unlimited to be arranged on a top surface 210 of the multilayer circuit substrate 21. In another embodiment, the strain sensor 22 may be arranged on a bottom surface 211 of the multilayer circuit 5 substrate 21.

Referring to FIG. 4, this figure is a schematic perspective view of another embodiment of an edge sensor of the present invention. In this embodiment, the edge sensor 2b is basically similar to that of FIG. 3 A, but the difference is that the connecting seat 261a in this embodiment is not provided with the signal socket 27 as shown in FIG. 3 A, so that the weight loaded on the multilayer circuit substrate 21 is reduced, and the sensitivity of cantilever bending moment of the multilayer circuit substrate 21 due to the force acting on the probe 20 is raised. For example, in the arrangement shown in FIG. 4, because there is no such signal socket 27, in an embodiment the force of 0.1 gram acting on the probe 20 can be sensed by the strain sensor 22, so that the detecting sensitivity is raised. Besides, in this embodiment, the strain sensor 22 is not as that shown in FIG. 3 A.

In FIG. 3 A, the electrical strain signal of the strain sensor 22 is outputted by the second signal cable directly. The strain sensor 22 in this embodiment is electrically connected with the multilayer circuit substrate 21 through the circuits in the multilayer circuit substrate 21, which means the electrical strain signal outputted by the strain sensor 22 is 20 transmitted to the electrically connecting portion 25 through the internal line of the multilayer circuit substrate 21. Therefore, the electrically connecting portion 25 in this embodiment further includes electrically connecting contacts necessary for the second signal cable 91. By using the electrically connecting portion 25 as a unified interface for outputting and inputting signal, the first and second signal cables 90 and 91 are inserted 25 through a through hole 262 provided on the connecting seat 261a to be electrically 28/10/2020 connected with the electrically connecting portion 25 on the multilayer circuit substrate 21 directly.

Referring to FIGS. 5A to 5C, FIG. 5A is a schematic flow diagram of an embodiment of a probing method of the present invention, and FIGS. 5B and 5C are 5 schematic views of an edge sensor and a probing process in the probing method. As shown in FIGS. 5A and 5B, in this embodiment the process of the probing method 4 has a first step 40 of providing an edge sensor, which may be the above-described edge sensor. In a step 41, a chuck 5 is provided, which supports a device under test 50. The device under test 50 may be a wafer having a plurality of electronic components or light emitting 10 components, or a carrier having a plurality of miniaturized electronic components. Then, a step 42 is performed to make an electrical contact between the probe 20 and the electronic component on the device under test 50. In this step, the chuck 5 may be moved to make the device under test 50 electrically contact the probe 20, or the edge sensor 2 may be moved to make the device under test 50 electrically contact the probe 20.

After making the probe 20 and the device under test 50 electrically contact with each other, a step 43 is performed to use the strain sensor 20 to detect the strain status of the multilayer circuit substrate 21 due to the force acting on the probe 20. In this step, taking the condition that the edge sensor 2 is controlled to move as an example, when the drive device 29 controls the edge sensor 2 to move to make an electrical contact on the 20 device under test 50 contact the probe 20, as shown in FIG. 5C, the force acting on the probe 20 will be transmitted to the multilayer circuit substrate 21 to strain and bend the multilayer circuit substrate 21. The bending extent represents the magnitude of the force acting on the probe 20. As the above description, if the contact between the probe 20 and the device under test 50 provides insufficient contact pressure, it will cause inaccurate measure results. On the contrary, if the contact pressure is overmuch, it may damage the 28/10/2020 probe, and even produce scratches on the surface of the workpiece in contact with the probe, thereby affecting the yield rate of the electronic components. Therefore, in the process of the device under test 50 in contact with the probe 20, the strain sensor 22 continuously generates electrical strain signal, which is outputted to a control unit 3 5 through the second signal cable 91. As shown in a step 44, the control unit 3 determines if the strain status corresponding to the electrical strain signal generated by the strain sensor 20 attains a threshold or not. If it attains the threshold, a step 45 is performed to send a stop signal to the drive device 29 to stop the drive device 29 driving the edge sensor 2 to move so as to prevent the surface of the device under test 50 from over-compression 10 by the probe 20. On the contrary, a step 46 is performed to keep controlling the edge sensor 2 to move, and then the step 44 is performed again to enable the control unit 3 to determine if the strain status corresponding to the electrical strain signal generated by the strain sensor 20 attains the threshold or not.

From the above description, the present invention replaces the traditional metal 15 structure by the circuit board having cantilever bending effect when receiving a force, which attains the effects of transmitting signal and detecting the stress status of the probe. In another aspect, the design of the present invention prevents the signal cable for transmitting signal from direct contact with the probe or elements around the probe, thereby reducing the influence of the cable on the stress status of the probe, so as to raise 20 the response sensitivity of detecting the force acting on the probe.

The above description only describes the preferred implementing manners or embodiments for presenting the technical means adopted by the present invention to solve the problems, not intended to limit the scope of implementation of the present invention. All the equivalent variations and modifications conforming to the meaning of the claims 25 of the present invention or made in accordance with the claims of the present invention are included within the scope of the claims of the present invention.

Claims (12)

1. An edge sensor comprising: a probe; a multilayer circuit substrate coupled with the probe; 5 a strain sensor arranged on the multilayer circuit substrate for detecting a strain status of the multilayer circuit substrate due to a force acting on the probe; and an electrically conductive cantilever having a first end electrically connected with the probe and a second end electrically connected with the multilayer circuit substrate, the probe being replaceably arranged on the electrically conductive cantilever.

2. The edge sensor as claimed in claim 1, wherein the multilayer circuit substrate is coupled with a signal socket for being electrically connected with a first signal cable; the first signal cable transmits an electrical signal to the probe. 15

3. The edge sensor as claimed in claim 1, further comprising a first signal cable for being electrically connected with the multilayer circuit substrate to transmit an electrical signal to the probe.

4. The edge sensor as claimed in claim 1, wherein the strain sensor is 20 electrically connected with the multilayer circuit substrate; the strain sensor generates an electrical strain signal corresponding to the strain status; the electrical strain signal is outputted through the multilayer circuit substrate.

5. The edge sensor as claimed in claim 1, wherein the strain sensor generates 25 an electrical strain signal corresponding to the strain status, and the electrical strain signal is outputted through a second signal cable. 28/10/2020

6. The edge sensor as claimed in claim 1, wherein the edge sensor is fixed on a mount; the mount is further coupled with a drive device for driving the edge sensor to 5 displace.

7. The edge sensor as claimed in claim 1, wherein the edge sensor further comprises: a mount coupled with a drive device for driving the edge sensor to displace, the 10 mount having a through hole; a first signal cable electrically connected with the multilayer circuit substrate through the through hole for transmitting an electrical signal to the probe; and a second signal cable electrically connected with the multilayer circuit substrate through the through hole for receiving an electrical strain signal generated by the strain 15 sensor in correspondence to the strain status.

8. A probing method comprising: providing an edge sensor which comprises a probe, an electrically conductive cantilever, a multilayer circuit substrate and a strain sensor, wherein the multilayer circuit 20 substrate is coupled with the probe, the strain sensor is arranged on the multilayer circuit substrate, a first end of the electrically conductive cantilever is electrically connected with the probe, a cantilever structure extends from the first end to the multilayer circuit substrate along a longitudinal direction of the multilayer circuit substrate, a second end of the electrically conductive cantilever is electrically connected with the multilayer 25 circuit substrate, and the probe is replaceably arranged on the electrically conductive 28/10/2020 cantilever; providing a chuck supporting a device under test; making an electrical contact between the probe and the device under test; and detecting a strain status of the multilayer circuit substrate due to a force acting 5 on the probe by the strain sensor.

9. The probing method as claimed in claim 8, wherein the strain sensor is electrically connected with the multilayer circuit substrate; the strain sensor generates an electrical strain signal corresponding to the strain status, and the electrical strain signal is 10 outputted through the multilayer circuit substrate.

10. The probing method as claimed in claim 8, wherein the strain sensor generates an electrical strain signal corresponding to the strain status, and the electrical strain signal is outputted through a second signal cable.

11. The probing method as claimed in claim 8, wherein the edge sensor is fixed on a mount; the mount is further coupled with a drive device for driving the edge sensor to displace. 20

12. The probing method as claimed in claim 8, wherein the edge sensor further comprises: a mount coupled with a drive device for driving the edge sensor to displace, the mount having a through hole; a first signal cable electrically connected with the multilayer circuit substrate 25 through the through hole for transmitting an electrical signal to the probe; and a second signal cable electrically connected with the multilayer circuit substrate through the through hole for receiving an electrical strain signal generated by the strain sensor in correspondence to the strain status.