Measuring device and measuring feeder

Abstract

A measuring device for measuring the electrical properties of a component is disclosed. The device includes a first body and a second body, each body having an abutment surface and a conductive component contact surface, wherein at least one of the abutment surfaces is electrically insulated from its corresponding component contact surface. A support member holds the abutment surfaces in contact while allowing relative sliding movement between the first and second bodies to ensure a proper fit. The device is capable of accurately and reliably measuring electrical properties, and is particularly suitable for small components. A method for measuring electrical properties using the device is also disclosed, as well as a component feeder integrating the measuring device.

Description

Technical Field

[0001] The present invention relates to a measuring apparatus for measuring the electrical characteristics of an element, an element feeder including such a measuring apparatus, and a method for measuring the electrical characteristics of an element. Background Technology

[0002] In the process of mounting electronic components, measuring the electrical characteristics of the components is essential. Typically, these measurements are performed to verify the integrity and functionality of the components before they are mounted onto the circuit board. In this document, the term "measurement" is used extensively so that, in its simplest case, the measurement discussed can be, for example, whether the current can be easily determined by the component, thus providing a simple indication of its integrity. Alternatively, more complex measurements can be used to determine the electrical characteristics of the component in question.

[0003] WO2020 / 152074 discloses a component mounting (or “pick-and-place”) machine, comprising: a verification unit for measuring the electrical characteristics of picked-up electronic components (i.e., electronic components held by the placement head of a pick-and-place machine). The verification unit includes a board with a plurality of test electrodes disposed on its surface. An electronic component is brought into contact with at least two of the electrodes (e.g., via the placement head of the pick-and-place machine), and an output signal is measured to determine its electrical characteristics. To improve the reliability of the measurement, at least one test electrode is disposed on a flexible portion of the board, which is configured to bend upon contact with the component. This flexibility is crucial for accommodating uneven surfaces and alignment variations commonly encountered when picking up components. By allowing the test electrode to conform to the shape and position of the component, the flexible portion ensures more reliable electrical contact and reduces the risk of measurement inaccuracies or component damage due to excessive contact pressure. In this known solution, flexibility is achieved by forming slits and hinges in the board material, thereby allowing the flexible portion to deform and adapt to changes in component shape or alignment. Figure 1 A schematic top view of this device is shown above, in which the substrate is designated as reference numeral 1, the conductive surfaces of the test electrodes are designated as reference numerals 3 and 4, and the H-shaped cutout of the substrate is designated as reference numeral 2. The H-shape allows each conductive surface 3, 4 to be bent relative to the body of the substrate 1.

[0004] However, while this method works well for many components, problems arise when testing very small components (e.g., 0201 metric components, which may be as short as 0.1 mm (100 μm)). In particular, forming such small gaps (approximately 50 μm) to enable the testing of such components presents practical difficulties. The only feasible method to form a gap of approximately 50 μm in such a board is through laser cutting. However, this process typically results in scorching and / or “wavy” edges on the board, which may be unsuitable for forming electrodes. These problems can be reduced with highly specialized cutting equipment, but such equipment is expensive; and even if the problems are reduced, they cannot be completely eliminated. Therefore, there is a lower limit to the size of testable components.

[0005] Therefore, there is a need for an improved measuring device that can accurately and reliably measure the electrical characteristics of small electronic components, while being cost-effective in manufacturing and adaptable to changes in component shape or orientation during pickup. This invention aims to meet this need.

[0006] According to the present invention, this objective is achieved by providing a measuring device formed from two individual blocks. These individual blocks can be precisely constructed separately (e.g., by machining) and then assembled together, thereby completely avoiding the problem of cutting grooves on the board. Furthermore, the solution of the present invention is compact, robust, and precise enough for application in component feeders for pick-and-place machines. Summary of the Invention

[0007] According to a first aspect of the present invention, a measuring apparatus for measuring the electrical characteristics of an element is provided, wherein the measuring apparatus comprises: A first entity and a second entity, wherein both the first entity and the second entity include: The contact surface of a conductive component; The contact surface, among which, The contact surface of at least one of the first body and the second body is electrically insulated from the contact surface of the element; The measuring device further includes a support member, wherein the support member keeps the contact surfaces of the first body and the second body in contact, while allowing the first body and the second body to move relative to each other, and during the relative movement, the contact surfaces of the first body and the second body slide against each other.

[0008] According to a second aspect of the invention, a component feeder for a pick-and-place machine is provided, comprising the measuring device described in the first aspect.

[0009] According to a third aspect of the present invention, a method for measuring the electrical characteristics of an element is provided, the method comprising the following steps: i) Provide the measuring device according to the first aspect; ii) Press the element onto the element contact surface so that it makes electrical contact with each element contact surface; iii) Measure the electrical characteristics of the element via the element contact surface.

[0010] According to a fourth aspect of the present invention, a method for measuring the electrical characteristics of a component during the mounting process is provided, comprising the following steps: i) Provide a component feeder for storing the components, the component feeder including the measuring device according to the first aspect; ii) Pick up the component from the feeder using the placement head; iii) Using the mounting head, press the component onto the component contact surface, so that it makes electrical contact with each component contact surface; iv) Measure the electrical characteristics of the element via the contact surface of the element.

[0011] Other specific aspects and features of the invention are described in the appended claims. Attached Figure Description

[0012] The invention will now be described with reference to the accompanying drawings (not to scale), in which...

[0013] Figure 1 A known measuring device is schematically shown from above.

[0014] Figure 2 The measuring device according to the invention is schematically shown in an isometric view.

[0015] Figure 3 and Figure 4 It is shown schematically from the side. Figure 2 The measuring device used during the process.

[0016] Figure 5 A measuring device according to another embodiment of the present invention is schematically shown from the side.

[0017] Figures 6 to 8 The first and second bodies of the measuring device according to an embodiment of the present invention are schematically shown from above.

[0018] Figure 9 A feeder including the measuring device according to the invention is schematically shown from the side.

[0019] Explanation of reference numerals in the attached figures: 1: Board 2: Incision 3, 4: Conductive surfaces 10, 30: Measuring equipment 11: Support base 12: Supporting Columns 13: Support frame 14, 31: The first ontology 15, 32: Second Body 16, 17: Component contact surfaces 18, 19: Connectors 20: Measurement System 21, 22, 37: Compressible components 23: Gap 24: Compression Spring 25: Mounting nozzle 26: Components 27: Steps 28, 29: Contact surfaces 33, 34: Insulating coating 35, 36: Inclined surfaces 37: Features of convex mating 38, 39: Features of concave fit 40, 41: Electrodes 42, 43: Angled surfaces 50: Component feeder 51: Component strip 52: Component Reel 53: Drive wheel 54: Pickup Window D: Electrode gap. Detailed Implementation

[0020] The invention can be better understood by referring to the following figures and description. The components in the figures are not necessarily drawn to scale, but rather emphasize various preferred embodiments of the invention. For ease of understanding, the figures are provided with Cartesian axes. The Z-axis shown in each figure extends vertically upwards, while the X and Y axes lie in the horizontal plane, corresponding to the most common use of the measuring device.

[0021] Figure 2A measuring device according to the invention is shown in an isometric view. The measuring device 10 includes a first body 14 and a second body 15, each body being generally cuboid. The first body 14 includes an element contact surface 16 and an abutment surface 28; correspondingly, the second body 15 includes an element contact surface 17 and an abutment surface 29. In the illustrated embodiment, the element contact surfaces 16, 17 are shown as generally flat surfaces. The abutment surfaces 28, 29 are shown as surfaces generally orthogonal to the plane containing the respective element contact surfaces 16, 17. For at least one of the first body 14 and the second body 15, the abutment surfaces 28, 29 are electrically insulated from the corresponding element contact surfaces 16, 17. In the illustrated embodiment, both abutment surfaces 28, 29 are electrically insulated from the corresponding element contact surfaces 16, 17. More specifically, in this embodiment, both the first body 14 and the second body 15 comprise a monolithic ceramic block (and thus an insulating block) having a conductive coating (e.g., gold or copper) only on its upper surface (i.e., the element contact surface). Component contact surfaces 16 and 17 respectively include corresponding connectors 18 and 19, which are electrically connected to the corresponding component contact surfaces 16 and 17, and can be electrically connected to the measurement circuit (see...). Figure 3 ).

[0022] The measuring device 10 also includes supports for the first body 14 and the second body 15. More specifically, the supports include a support base 11 with a first compressible component 21 and a second compressible component 22, a support column 12 extending upward from one end of the support base 11, and a support frame 13 extending upward from the distal end near the support base 11. Therefore, as shown, but not necessarily required by the invention: the support column 12 is integrally formed with the support base 11, i.e., has an "L"-shaped cross-section; while the support frame 13 is rigidly attached to the support base 11. Although Figure 2As not shown, the support bracket 13 may include flanges or other laterally extending protrusions to facilitate a rigid connection with the support base 11. In an alternative embodiment (not shown), the support bracket 13 may be integrally formed with the support base 11, and / or the support column 12 may be rigidly attached to the support base 11. The compressible components 21 and 22, spaced along the length of the support base 11, both comprise an elastically deformable material, such as rubber or another elastomeric polymer. The first body 14 and the second body 15 are correspondingly supported by the compressible components 21 and 22, positioned such that their abutment surfaces 28 and 29 contact each other. As will be described in more detail below, the contours of the abutment surfaces 28 and 29 are such that even when they are in contact with each other, a very small gap 23 remains between the element contact surfaces 16 and 17 of the first and second bodies 14 and 15 (e.g., less than or equal to about 100 μm when testing 0402 metric components; preferably, less than or equal to about 50 μm when testing 0201 metric components). The first body 14 and the second body 15 can be fixed to the respective compressible components 21, 22 in various known ways, for example, by gluing or using a physical connection structure. Due to the elastically deformable nature of the compressible components 21, 22, when a downward force is applied to the contact surfaces of the respective components, the first body 14 and the second body 15 can each move downward independently relative to the support base 11.

[0023] Although Figure 2 Invisible in the middle, compression spring 24 (see Figure 3 An offsetting member is located between the support frame 13 and the second body 15 to offset the second body 15 toward the first body 14, thereby causing the first body 14 to abut against the support column 12. Thus, the offsetting member maintains contact between the abutment surfaces 28 and 29, while still allowing relative movement between the first body 14 and the second body 15 in a direction parallel to the vertical axis or Z-axis, during which the abutment surfaces 28 and 29 remain in contact and slide against each other. It should also be noted that the vertical movement of the first body 14 will also cause it to slide against the support column 12. As described above, the preferred material for the first body 14 and the second body 15 is ceramic. This choice is advantageous because it not only has insulating properties but is also very robust and can be made very smooth, thus ensuring that this sliding movement can proceed smoothly without damaging the first and second bodies 14 and 15 or the support column 12.

[0024] Figure 3 It was shown from the side. Figure 2 The measuring device 10 is used during this process, at which point the electronic component 26 is about to be pressed downwards onto the component contact surfaces 16 and 17. However, it should be noted that the distance between the support frame 13 and the second body 15 in the figure is greater than that between them. Figure 2The distance is such that the compression spring 24 can be clearly seen. In practice, this distance can be flexibly set. The compression spring 24 can extend at least partially into the second body 15, for example, into a hole (not shown) provided in the second body 15 for this purpose, and / or at least partially into the support frame 13, for example, into a hole provided for this purpose.

[0025] Figure 3 Recesses or steps 27 formed in one or both abutment surfaces 28, 29 can also be seen (in this case, a step 27 is formed in each abutment surface 28, 29), so that the top of at least one of the first and second bodies 14, 15 will be slightly shorter. This creates a gap 23 between the corresponding element contact surfaces 16, 17, which in turn ensures that the elements are electrically isolated from each other. Such steps 27 can be formed in ceramic materials, etc. (e.g., by machining). Since it can be performed on an accessible surface of ceramic (i.e., machining the individual bodies before assembling them into the measuring device 10), the steps can be formed very small, thus creating the corresponding small gaps 23.

[0026] Figure 3 A measurement circuit is also shown, including a measurement system 20 electrically connected to each component contact surface 16, 17 via corresponding connectors 18, 19. The measurement system 20 can take various forms known in the art itself, for example, it can be used to indicate the resistance or conductivity of a component 26 when connected across component contact surfaces 16, 17, such as... Figure 3 As shown.

[0027] As described above, the electronic component 26, held by the placement nozzle 25 (e.g., the placement nozzle 25 of the placement head of a pick-and-place machine (not shown),) is brought to and positioned in contact with the component contact surfaces 16 of the first body 14 and the second body 15, and then pressed down with slight pressure to avoid damaging the electronic component 26. More specifically, the illustrated electronic component 26 has two downwardly projecting electrodes 40, 41 extending therefrom. The placement nozzle 25 is operated to bring the electronic component 26 down onto the measuring device 10 such that one electrode contacts each component contact surface 16, 17, thereby electrically bridging these surfaces (assuming the electronic component 26 is functional). As the electronic component 26 is pressed against the component contact surface 16, the first body 14 and the second body 15 can each move downward relative to the support base 11. The use of compressible components 21, 22 ensures that this process can be performed smoothly and ensures that once the electronic component 26 is removed, the first body 14 and the second body 15 return to their initial positions. The removal operation can be performed when it is determined that the electronic component 26 has made contact with both component contact surfaces 16 and 17, for example, when the measurement system 20 indicates that the measurement circuit is complete, or the operation can be performed by controlling the vertical position of the mounting nozzle 25.

[0028] Figure 4 The measuring device 10 is shown from the side in operation when the lower part of the electronic component 26 is not completely horizontal. As shown, because one electrode 40 is longer than the other electrode 41, the electronic component 26 is slightly deformed and held by the mounting nozzle 25 in a non-horizontal orientation, which exacerbates the difference in downward extension of the two electrodes 40, 41. It can be seen that when the electronic component 26 is pressed downward by the mounting nozzle 25, the leftmost electrode 40 will contact the component contact surface 16 of the first body 14 before the rightmost electrode 41 contacts the component contact surface 17 of the second body 15. This causes the first body 14 to move downward relative to both the second body 15 and the support base 11, at least until the rightmost electrode 41 contacts the component contact surface 17 of the second body 15. Figure 4 It can be seen that when the compressible part 21 is pressed in this way, its vertical length decreases.

[0029] Figure 5 A measuring device 30 according to another embodiment of the present invention is shown from the side. This embodiment is very similar to the first embodiment, but has three main changes: i) In this embodiment, neither the first body 31 nor the second body 32 is formed of a single ceramic material, but only on their contact surfaces ( Figure 5 An insulating layer or coating 33, 34 (e.g., made of ceramic material) is disposed near the first body 31 and the second body 32. The remainder of the first body 31 and the second body 32 may be formed of any rigid material (including conductive materials such as steel). Component contact surfaces 16, 17 are provided in the manner described above.

[0030] ii) A single compressible component 37 is provided, on which both the first body 31 and the second body 32 are supported. This compressible component 37 may, for example, comprise a rubber sheet or other elastomeric polymer material. As long as this compressible component 37 is sufficiently flexible, the desired relative vertical movement between the first body 31 and the second body 32 can still be achieved.

[0031] iii) Since the abutting surfaces of the first body 31 and the second body 32 have different contours, inclined surfaces 35 and 36 are provided in the upper region of the respective abutting surfaces, instead of steps. This embodiment is easier to process than steps and can form a smaller gap than providing steps.

[0032] Figures 6 to 8 A first body 14 and a second body 15 of a measuring device according to various embodiments of the present invention are shown from above. Figure 6 In the middle, the shapes of the first body 14 and the second body 15 are as described above. Figure 3 That is, it has a step 27 formed in each abutment surface.

[0033] exist Figure 7 In this embodiment, the steps 27 in the first body 14 and the second body 15 are formed to provide angled surfaces 42, 43, such that the width of the gap formed between the component contact surfaces 16, 17 varies with its width, i.e., parallel to the Y-axis shown. This configuration may be advantageous if a relatively wide variety of electronic components need to be tested; the electrode spacing of the electronic components can have a correspondingly wide range. Testing relatively large electronic components at the relatively large portion of the gap between the component contact surfaces 16, 17 can reduce the likelihood that the electrodes of such components will simultaneously contact both component contact surfaces 16, 17.

[0034] exist Figure 8 In this embodiment, the first body 14 and the second body 15 are configured to restrict movement of the bodies only in a direction parallel to the vertical axis or the Z-axis. A convex fitting feature 37 is formed in the abutment surface of the first body 14, configured to engage with a corresponding concave fitting feature 38 formed in the abutment surface of the second body 15. Here, the convex fitting feature 37 includes a protruding bead extending along the vertical length of the corresponding abutment surface, while the concave fitting feature 38 includes a groove extending along the vertical length of the corresponding abutment surface, both in a direction parallel only to the Z-axis. Additionally, a similar fitting feature, here a concave fitting feature 39, is formed on the distal side of the first body 14, configured to engage with a corresponding convex fitting feature (not shown) formed in the support column 12. All these features serve to restrict movement of the first and second bodies only in the vertical direction.

[0035] Figure 9 A component feeder 50, including a measuring device 30 according to the invention, is shown from the side. Such a component feeder is commonly used to supply electronic components to pick-and-place machines (“pick-and-place” machines) in the surface mount technology (“SMT”) industry. The component feeder 50 is arranged to feed components from a component tape 51 initially wound on a component reel 52 to a pick-up window 54, where components can be picked up from the pick-up window by the placement nozzle 25 of the placement head (not shown) of the pick-and-place machine (not shown). The component tape 51 is advanced by a drive wheel 53. The measuring device 30 is positioned such that the electrical characteristics of the component can be measured immediately after the placement nozzle 25 removes the component 26 at the pick-up window 54. It should be understood that the positioning of the measuring device 30 has a certain degree of flexibility. For example, it can be positioned in reverse such that the support frame is to the left as shown. Optionally or additionally, if the emptied component tape 51 is discharged from the component feeder 50 via an internal channel (not shown) in the component feeder 50, the measuring device 30 can be positioned in front of the pick-up window 54, i.e., closer to the interior of the pick-and-place machine.

[0036] In a preferred method of operation, the component is mounted on the contact surface and pressed down therein, and then the electrical characteristics of the component are measured by a measuring circuit. If the measured value is out of range, the component is considered unacceptable and may be discarded.

[0037] When a component feeder is equipped with a measuring device, the component is first picked up by the placement head of the pick-and-place machine, wherein the component feeder, including the measuring device, is inserted into the pick-and-place machine. Then, the placement head is used to place the component onto the contact surface and press it down. The measuring circuit measures the electrical characteristics of the component. If the measured value is out of range, it indicates that the component is unacceptable and may be discarded.

[0038] The above detailed description has provided several embodiments of the invention. For measurement purposes, the use of a gold-plated block ensures good electrical contact. The use of a ceramic block makes the parts robust and easier to manufacture. However, other materials can also be used, such as metal blocks with an electrically insulating coating. By employing two parts, a very small electrical gap can be created, thereby enabling the measurement of very small components.

[0039] Those skilled in the art will understand that the present invention is not limited to the embodiments specifically described herein, and that various features of the invention can be implemented in different arrangements and combinations. For example, while the use of a spring to provide a good way of biasing the abutment surfaces together has been shown, other biasing members may also be employed. Similarly, it will be apparent to those skilled in the art that other types of compressible elements, such as compression springs, may be used to support the first and second bodies.

[0040] In addition, additional components can be provided to ensure that the first and second bodies remain properly aligned throughout operation. For example, guide rails can be provided near the lateral side of the bodies, extending, for instance, between the support column and the support frame, which physically constrain the first and second bodies to move only in the vertical direction.

Claims

1. A measuring device for measuring the electrical characteristics of an element, wherein, The measuring device includes: A first entity and a second entity, wherein both the first entity and the second entity include: The contact surface of a conductive component; The contact surface, among which, The contact surface of at least one of the first body and the second body is electrically insulated from the contact surface of the element; The measuring device further includes a support member, wherein the support member keeps the contact surfaces of the first body and the second body in contact, while allowing the first body and the second body to move relative to each other, and during the relative movement, the contact surfaces of the first body and the second body slide against each other.

2. The measuring device according to claim 1, wherein, The first body and the second body are shaped such that when the abutting surfaces come into contact, the contact surfaces of the elements are separated by a gap; optionally, the gap is ≤100μm, or optionally, the gap is about 50μm.

3. The measuring device according to claim 2, wherein, The gap is formed by providing a step or angle in at least one abutting surface.

4. The measuring device according to claim 2, wherein, The first body and the second body are shaped such that the width of the gap varies throughout the entire range of the body.

5. The measuring device according to claim 1, further comprising a measuring circuit connected to each of the component contact surfaces.

6. The measuring device according to claim 5, wherein, Each component contact surface includes a connector for connection to the measurement circuit.

7. The measuring device according to claim 1, wherein, At least one of the first body and the second body includes an integral insulating material, and the component contact surface of the at least one body includes a conductive coating or layer disposed thereon.

8. The measuring device according to claim 7, wherein, The overall insulating material is selected from the group consisting of ceramic, glass, and polymer materials; optionally, the insulating material includes ceramic materials.

9. The measuring device according to claim 1, wherein, At least one of the first body and the second body comprises an integral conductive material, and the contact surface of the at least one body comprises an electrically insulating coating or layer disposed thereon.

10. The measuring device according to claim 1, wherein, At least one contact surface includes a coating.

11. The measuring device according to claim 1, wherein, The contact surfaces of the first body and the second body include corresponding mating features, which make the first body and the second body aligned in a transverse direction orthogonal to the relative motion.

12. The measuring device according to claim 1, wherein, The support includes a compressible component that connects the support to at least one of the first body and the second body.

13. The measuring device according to claim 12, wherein, The compressible component includes an elastically deformable material; optionally, the elastically deformable material includes an elastomeric polymer; optionally, the elastomeric polymer includes rubber.

14. The measuring device according to claim 1, wherein, The support includes a biasing member for biasing the abutment surfaces of each of the first body and the second body together for contact. Optionally, the biasing member includes a spring.

15. A component feeder for a pick-and-place machine, comprising the measuring device according to any one of the preceding claims.

16. A method for measuring the electrical characteristics of an element, the method comprising the following steps: i) Provide the measuring device according to claim 1; ii) Press the element onto the element contact surface so that it makes electrical contact with each element contact surface; iii) Measure the electrical characteristics of the element via the element contact surface.

17. A method for measuring the electrical characteristics of a component during the mounting process, comprising the following steps: i) Provide a component feeder for storing the components, the component feeder comprising the measuring device according to claim 1; ii) Pick up the component from the feeder using the placement head; iii) Using the mounting head, press the component onto the component contact surface, so that it makes electrical contact with each component contact surface; iv) Measure the electrical characteristics of the element via the contact surface of the element.

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