Probe pin and method of manufacturing probe pin

Abstract

To provide a probe pin having good physical characteristics.SOLUTION: The probe pin includes a body portion, and a top portion and a tip portion respectively connected to both end portions of the body portion, wherein the body portion includes a first side surface and a third side surface facing each other, and a second side surface and a fourth side surface crossing the first and third side surfaces and facing each other, and a bending portion formed to be curved in at least a portion thereof is provided, the top portion and the tip portion have a circular cross-section perpendicular to an axis of the probe pin, the top portion, the body portion, and the tip portion are integrally formed, the tip portion has a circular cross-section perpendicular to the axis of the body portion, a size of the cross-section gradually decreases toward a distal end, and a distal end is located at a center without being biased to one side, and the body portion has a rectangular shape with rounded corners in the cross-section perpendicular to the axis of the body portion.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a probe pin and a method for manufacturing the probe pin. [Background technology]

[0002] The semiconductor manufacturing process consists of a front-end process of making a plurality of semiconductor dies on a wafer, and a back-end process of connecting wiring to each semiconductor die to make a semiconductor package.

[0003] Generally, an Electrical Die Sorting (EDS) process is performed to test the electrical characteristics of each semiconductor die that constitutes a wafer. Specifically, the EDS process is performed by contacting the contact pads of the semiconductor die with probe pins provided on a probe card, passing electrical signals from a separate semiconductor testing device through the probe pins, and reading the electrical signals output at that time. This is called a probe test.

[0004] In recent years, the miniaturization of semiconductors has led to a demand for fine pitches not only at the wafer level but also at the semiconductor package level. In addition, as the pads on semiconductor packages have become smaller, it has become necessary to manufacture miniaturized probe tip portions of sockets for inspecting semiconductor packages (semiconductor chips).

[0005] In order to inspect such semiconductor packages, there are probe pins that come into contact with pads on the semiconductor packages, and recently, such probe pins are generally manufactured through a MEMS (Micro Electro Mechanical System) process. The MEMS process is a process used in semiconductor manufacturing processes, and such probe pins are manufactured through, for example, a photolithography process.

[0006] However, the probe pins manufactured through the MEMS process have problems in that they have poor physical properties and it is difficult to manufacture the probe tip portion in various shapes. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made to solve the above-mentioned problems in the conventional technology, and has an object to provide a probe pin with good physical characteristics by diversifying the material and shape of the tip portion. [Means for solving the problem]

[0008] As a means for solving the above-mentioned technical problems, one embodiment of the present invention is a probe pin including a body portion, and a top portion and a tip portion respectively connected to both ends of the body portion, the body portion including first and third sides facing each other, and second and fourth sides intersecting the first and third sides and facing each other, at least a portion of which is provided with a bending portion formed to be curved, the top portion and the tip portion have a circular cross section, and the top portion, body portion, and tip portion are integrally formed.

[0009] In one embodiment, the first to fourth sides are planar.

[0010] In one embodiment, the cross section of the body portion is formed as a rectangle with rounded corners.

[0011] In one embodiment, the top portion is hemispherical and the tip portion is conical.

[0012] In one embodiment, the tip of the tip portion is centrally located without being offset to one side.

[0013] In one embodiment, the bent portion is formed with an insulating coating material surrounding the outer periphery.

[0014] Yet another embodiment of the present invention is a method for manufacturing a probe pin, comprising the steps of drawing a blank, grinding one end of the drawn blank into a cone shape and the other end into a round shape, performing free forging to form flat surfaces on a side surface extending in the longitudinal direction of the ground blank, and performing die forging to bend a portion of the free forged blank.

[0015] In another embodiment, the free forging step includes forming a first side and a third side on the ground material using a press, rotating the material with the first side and the third side formed by 90 degrees, and then forming a second side and a fourth side.

[0016] In another embodiment, the step of performing the free forging process includes simultaneously forming first to fourth side surfaces on the ground material using a press.

[0017] In another embodiment, the method further includes the step of insulating coating the bent portion of the die-forged material. Effect of the Invention

[0018] According to any one of the above-mentioned means for solving the problems of the present invention, by diversifying the material and shape of the tip portion, it is possible to provide a probe pin having good physical characteristics. [Brief description of the drawings]

[0019] [Figure 1] 1(a) is a side view of a probe pin according to an embodiment of the present invention, (b) is a cross-sectional view taken along line A-A' in FIG. 1(a), (c) is a cross-sectional view taken along line B-B' in FIG. 1(a), and (d) is a cross-sectional view taken along line C-C' in FIG. 1(a). [Diagram 2]2(a) is a cross-sectional view of a probe pin according to an embodiment of the present invention, and (b) is a conceptual diagram of a mounting plate having a mounting hole into which the probe pin of FIG. 2(a) can be inserted. [Diagram 3] 1A is a diagram showing a top portion of a probe pin according to an embodiment of the present invention, and FIG. 1B is a diagram showing a top portion of a probe pin manufactured by a MEMS process. [Figure 4] 1A is a diagram showing a tip portion of a probe pin according to an embodiment of the present invention, and FIG. 1B is a diagram showing a tip portion of a probe pin manufactured by a MEMS process. [Diagram 5] 4 is a flowchart of a method for manufacturing a probe pin according to an embodiment of the present invention. [Figure 6] 4 is a perspective view showing a schematic change in the shape of a material during the process of manufacturing a probe pin according to an embodiment of the present invention; FIG. [Figure 7] 1A is a schematic diagram of a press device used for free forging according to one embodiment of the present invention, and FIG. 1B is a schematic diagram of a press device used for free forging according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. In the drawings, in order to clearly explain the present invention, parts that are not related to the description are omitted, and similar parts are designated by similar reference numerals throughout the specification.

[0021] In this specification, the singular expression includes the plural expression unless the context clearly indicates otherwise.

[0022] In describing the embodiments disclosed in this specification, if it is determined that a detailed description of related publicly known technology may obscure the gist of the embodiments disclosed in this specification, the detailed description will be omitted.

[0023] In this specification, terms indicating positions or directions such as "upper," "lower," "left," "right," "front," and "rear" are used only to describe the relative positions and directions of objects with reference to the drawings, and are not intended to limit the present invention.

[0024] The attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and are not intended to limit the technical ideas disclosed in this specification, but should be understood to include all modifications, equivalents, and alternatives included in the spirit and technical scope of the present invention.

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0026] FIG. 1 shows a probe pin attached to a probe card according to one embodiment of the present invention, where FIG. 1a is a side view of probe pin 100, FIG. 1b is a cross-sectional view of portion A-A' in FIG. 1a, FIG. 1c is a cross-sectional view of portion B-B' in FIG. 1a, and FIG. 1d is a cross-sectional view of portion C-C' in FIG. 1a.

[0027] As shown in the drawings, the probe pin 100 may include a body portion 110, and a top portion 130 and a tip portion 120 formed at both ends of the body portion 110. The probe pin 100 may be made of an alloy, and the body portion 110, the top portion 130, and the tip portion 120 may be integrally formed.

[0028] The probe pin 100 may have a tip portion 120 that contacts a contact pad of a semiconductor chip to be tested and a top portion 130 that is connected to the testing device to form an electrical connection between the contact pad of the semiconductor chip to be tested and the testing device.

[0029] When the tip portion 120 of the probe pin 100 contacts a contact pad of a semiconductor chip, a load acts on the probe pin 100 in the contact direction. Therefore, at least a portion, preferably the middle portion, of the body portion 110, which generally extends vertically, may be provided with a bending portion 110a that is curved and / or bent.

[0030] The bending portion 110a may be insulated with a material such as polymide, acrylic, parylene, or a combination thereof. The insulated coating may be provided so as to wrap the outer periphery of the bending portion 110a.

[0031] The body portion 110 may include a first side surface 111, a second side surface 112, a third side surface 113, and a fourth side surface 114, and the first side surface 111 and the third side surface 113 may face each other, and the second side surface 112 and the fourth side surface 114 may face each other. The first side surface 111 and the third side surface 113 may intersect with the second side surface 112 and the fourth side surface 114. Each side surface may be a flat surface or may be formed as a substantially flat surface.

[0032] The body portion 110 may have a cross section that is generally quadrangular, preferably rectangular, and in particular may be rectangular in shape in which the lengths of the second and fourth sides 112, 114 are different from the lengths of the first and third sides 111, 113.

[0033] The probe pin 100 having the body portion 110 with a rectangular cross section can predict the direction in which the probe pin 100 will bend when a load is applied to the probe pin 100. This can prevent interference between adjacent probe pins 100 that may occur when a continuous load is applied to the probe pin 100 and the probe pin 100 bends.

[0034] In other words, since a circular probe pin has the same thickness (diameter) in any direction, when a sustained load is applied, the circular probe pin can bend in any direction, whereas when a sustained load is applied, the probe pin 100, which has a rectangular cross section, can only bend to the side where it is thinner, and not in the angular direction or to the side where it is thicker,

[0035] Therefore, the probe pin 100 having a rectangular cross section can be configured so that the bending direction of the probe pin 100 does not cause interference between adjacent probe pins 100. This can improve the reliability of semiconductor chip inspection.

[0036] The cross section of the body part 110 may be formed in a substantially square shape, preferably a rectangle shape, and may be formed in a rectangle shape with rounded corners. That is, the first and third side surfaces 111, 113 and the second and fourth side surfaces 112, 124 intersecting each other may be formed at an angle of approximately 90 degrees, and the meeting portion of each side may be formed in a rounded shape. The cross section of the rounded rectangle can be matched with the shape of the mounting hole 251 of the mounting plate 250 used when connecting the probe pin to a board (printed circuit board or space transformer board) when manufacturing a probe card for a semiconductor wafer or a socket for a semiconductor package. That is, when forming the mounting hole 251 in the mounting plate 250, a laser is generally used, and if the hole is formed by irradiating the laser on the mounting plate 250, the hole has a rounded square shape. When a probe pin having a circular cross section is inserted into such a hole, the cross-sectional shape of the probe pin and the hole of the mounting plate are not matched, and the inspection may become unstable. The present invention enables more stable testing by forming the body portion of the probe pin in a rounded rectangular shape that is matched with the shape of the hole in the mounting plate.

[0037] Meanwhile, the tip portion 120 may be formed on one side of the body portion 110. The tip portion 120 may be configured to have a pointed tip 121, and may be formed in a pyramidal shape, preferably a conical shape. The tip portion 120 may have a circular cross section, and the cross-sectional size may gradually decrease toward the tip. Since the cross section of the tip portion 120 is circular, point contact is possible when the tip portion comes into contact with a contact pad on a semiconductor wafer or a semiconductor package, and thus the size of scrub marks can be minimized. The present invention solves the problem that the size of scrub marks is relatively large when the tip portion is formed by a MEMS process because the cross-sectional area of ​​the tip portion is rectangular.

[0038] The tip 121 of the tip portion 120 may be located in the center without being biased to either side. Such a tip portion 120 may be formed in the shape of a right circular cone. The present invention can solve the problem of the tip of the tip portion being biased to one side when the tip portion is formed by the MEMS process. The tip of the tip portion can also be formed in the center by the MEMS process, but in this case, several photolithography processes must be performed, which inevitably increases the manufacturing cost.

[0039] The top portion 130 may be formed in a gentle shape that is bent without any sharp corners on the other side of the body portion 110. The top portion 130 may be formed with a rounded tip, and in particular, may be formed in a hemispherical shape. The cross section of the top portion 130 may be formed in a circular shape.

[0040] 2A and 2B are diagrams showing a cross section of a body part 210 side of a probe pin according to one embodiment of the present invention and a comparison of the shape of a mounting hole 251 into which the probe pin is inserted, in which FIG. 2A shows a cross section of a body part 210 side of a probe pin according to one embodiment of the present invention, and FIG. 2B is a conceptual diagram of a mounting plate 250 formed with a mounting hole 251 into which the probe pin is inserted.

[0041] As shown in FIG. 2a, in the probe pin according to the embodiment of the present invention, the cross section of the body portion 210 may be formed in a rectangular shape with rounded corners.

[0042] The probe pin is one component of the probe card and is attached to a mounting plate 250, which is another component of the probe card. Specifically, as shown in FIG. 2b, a mounting hole 251 is formed in the mounting plate 250, and the probe pin may be attached to the mounting plate 250 with a portion of the probe pin inserted into the mounting hole 251.

[0043] The mounting holes 251 formed on the mounting plate 250 are formed by irradiating the mounting plate 250 with a laser, and at this time, the mounting holes 251 are formed into a rectangular shape with rounded corners that are not sharp.

[0044] Therefore, since the cross section of the body portion 210, which is a rectangle with rounded corners, corresponds to the shape of the mounting hole 251 formed in the mounting plate 250 using a laser, when the probe pin is attached to the mounting plate 250, a portion of the probe pin can be stably inserted and fixed in the mounting hole 251.

[0045] FIG. 3 is a diagram showing a comparison between a top portion 330 of a probe pin according to one embodiment of the present invention and a top portion 360 of a probe pin manufactured by a MEMS process, where FIG. 3a is a diagram showing the top portion 330 of a probe pin according to one embodiment of the present invention and FIG. 3b is a diagram showing the top portion 360 of a probe pin manufactured by a MEMS process.

[0046] Since the MEMS process uses a photolithography process, it is difficult to make the tip of the top portion 360 rounded without making it sharp.

[0047] As shown in the drawing, the top portion 330 of the probe pin according to one embodiment of the present invention is rounded, whereas the top portion 360 of the probe pin manufactured by the MEMS process includes an angular portion.

[0048] The top part of the probe pin is the part that comes into contact with the conductor formed on the inspection device, and if a sustained load is applied to the probe pin, the relative position of the top part of the probe pin that comes into contact with the conductor formed on the inspection device continues to change.

[0049] In other words, when a load is applied to the probe pin, the probe pin bends, and the position of the top part of the probe pin that contacts the conductor formed on the inspection device side before the load is applied may differ from the position of the top part of the probe pin that contacts the conductor formed on the inspection device side while the load is applied.

[0050] In this case, when the tip of the top portion 330 of the probe pin is rounded as shown in FIG. 3a, even if the relative position of the top portion 330 of the probe pin that contacts the conductor formed on the inspection device side changes, the contact area between the conductor and the top portion 330 can be maintained constant.

[0051] 3b, if the tip of the top portion 360 of the probe pin includes an angular portion and its shape is not constant at a specific position, the relative position of the top portion 360 of the probe pin that contacts the conductor formed on the inspection device side will change every time a load is applied to the probe pin, and the contact area between the conductor and the top portion 360 will also change. This can act as a factor that prevents stable contact between the conductor formed on the inspection device side and the top portion of the probe pin.

[0052] Therefore, the probe pin according to one embodiment of the present invention has the advantage, compared to a probe pin manufactured by a MEMS process, of maintaining stable contact between the top portion of the probe pin and the conductor (terminal) formed on the inspection device side.

[0053] FIG. 4 is a diagram showing a comparison between a tip portion 420 of a probe pin according to one embodiment of the present invention and a tip portion 460 of a probe pin manufactured by a MEMS process, where FIG. 4a is a diagram showing the tip portion 420 of a probe pin according to one embodiment of the present invention and FIG. 4b is a diagram showing the tip portion 460 of a probe pin manufactured by a MEMS process.

[0054] The tip portion of the probe pin is the portion that comes into contact with the contact pad of the semiconductor chip, and as shown in FIG. 4a, the tip portion 420 of the probe pin according to one embodiment of the present invention is formed with a pointed tip, and the tip 421 may be located in the center without being offset to one side.

[0055] When the tip portion 420 and the contact pad are brought into contact with each other, the pointed tip 421 enables the tip portion 420 to break through the oxide film formed on the contact pad and make contact with the contact pad without error.

[0056] Furthermore, since the tip 421 of the tip portion 420 is positioned in the center, when the tip portion 420 and the contact pad come into contact with each other, the tip 421 can come into contact with the center of the contact pad without leaving the contact pad area, thereby helping to ensure stable contact.

[0057] In contrast, in the case of a probe pin manufactured by a MEMS process, due to the nature of the process, it is not easy to create a tip portion that is sharp and has a tip located in the center, as shown in FIG. 4b.

[0058] Therefore, the probe pin according to the embodiment of the present invention has an advantage in maintaining stable contact between the probe pin and the contact pad, as compared to a probe pin manufactured by a MEMS process.

[0059] FIG. 5 is a flowchart of a method for manufacturing a probe pin according to one embodiment of the present invention, FIG. 6 is a diagram illustrating a schematic change in the shape of a material that occurs during the process of manufacturing a probe pin according to one embodiment of the present invention, and FIG. 7 is a conceptual diagram of a press device used for free forging according to one embodiment of the present invention, where FIG. 7a relates to a press device that performs free forging in two stages and FIG. 7b relates to a press device that performs free forging in one stage.

[0060] As shown in FIG. 5, the method for manufacturing a probe pin may include the steps of drawing a material, polishing one end and the other end of the drawn material, free forging the polished material, and die forging the free forged material.

[0061] Referring to FIG. 6, the drawn blank 610 may be in the form of a longitudinally extending cylinder having a circular cross section.

[0062] The material of the probe pin may be selected from an alloy having excellent conductivity as necessary. Therefore, unlike the probe pin manufactured by the MEMS process in which deposition materials are formed in multiple layers, the drawn material 610 does not require a separate plating step and does not form layers, so it can provide stable physical properties.

[0063] The blank drawn into a cylindrical shape may have one end ground into a tapered shape, preferably a conical shape.

[0064] For example, the drawn material may be ground by a machining device, and the material drawn into a cylindrical shape may be ground by a grindstone while rotating about a central axis (a), and at this time, the grindstone may grind one end of the drawn material into a conical shape.

[0065] Specifically, the end of the drawn material can be machined relatively easily due to the rotation of the drawn material and the two-dimensional movement of the grindstone, and if the grindstone moves closer and closer to the axis of rotation as the drawn material rotates, one end of the drawn material can be ground into a cone-like shape. In particular, the drawn material may be ground into a right circular cone shape with the tip of the cone located in the center.

[0066] Simultaneously with the grinding step on one end of the drawn blank, or before or after the grinding step on the other end, the other end of the drawn blank may be ground round.

[0067] The ground blank 620 may be free-formed to flatten the rounded surfaces on its longitudinally extending sides.

[0068] In order to subject the ground material to free forging, a press device having a pair of opposing hammers 700 as shown in FIG. 7 may be used to subject the ground material to free forging.

[0069] In one embodiment, as shown in Fig. 7a, a pair of hammers 700 may press the ground blank 720 between them to form a unidirectional free forged blank 720a. The unidirectional free forged blank 720a may have a pair of opposing flat surfaces, i.e., a first side surface and a third side surface.

[0070] Then, after rotating this by 90 degrees, pressure may be applied again to form a second side surface and a fourth side surface that intersect with the first side surface and the third side surface and face each other.

[0071] When the ground material is subjected to free forging, the pressure applied to the material by the press device may be adjusted so that the corners of the cross section of the forged portion are not sharp.

[0072] At this time, the blank 730 processed by free forging has a rectangular shape when viewed from the front, preferably a rectangular shape with rounded corners or a rectangular shape with rounded corners, and a tip may be formed in the center.

[0073] In another embodiment, as shown in Fig. 7b, the ground blank 720 may be subjected to free forging on the first to fourth sides at the same time, in which the press machine has a pair of opposing hammers 700, each of which may have a corresponding "V" shaped notch formed on the opposing side. When the pair of hammers 700 are adjacent to each other, the notch formed on each hammer may form a square.

[0074] Although not shown in the drawings, the press device may have a pair of hammers facing each other and another pair of hammers intersecting and facing each other, thereby performing free forging on all four sides of the ground material at the same time.

[0075] The ground blank may be placed between a pair of hammers, and by applying pressure to the blank, first and third sides and second and fourth sides may be simultaneously formed on the longitudinally extending side of the blank.

[0076] Similarly, when the four sides of a ground material are simultaneously subjected to free forging, the corners of the cross section of the forged portion can be prevented from becoming sharp.

[0077] Referring again to FIG. 6, the free forged blank 630 may be die forged to form a curved and / or bent portion.

[0078] The method may further include a step of insulating coating the bent portion of the die-forged blank 640 according to an embodiment of the present invention.

[0079] The above description of the present invention is for illustrative purposes only, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. Therefore, it should be understood that the above-described embodiments are illustrative in all respects and are not limiting. For example, each component described as a single type may be implemented in a distributed form, and similarly, each component described as a distributed type may be implemented in a combined form.

[0080] The scope of the present invention is indicated by the claims set forth below rather than by the above detailed description, and all modifications and variations derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included within the scope of the present invention.

Claims

1. A probe pin, The body portion includes a top portion and a tip portion, each of which is connected to both ends of the body portion. the body portion includes a first side surface and a third side surface facing each other, and a second side surface and a fourth side surface intersecting the first and third side surfaces and facing each other, and a bending portion is provided that is curved at least in a portion thereof; the top portion and the tip portion have a circular cross section perpendicular to an axis of the probe pin, and the top portion, the body portion, and the tip portion are integrally formed; The tip portion is formed in a circular shape in a cross section perpendicular to the axis of the body portion, the cross-sectional size gradually decreases toward the end, and the tip is located in the center without being biased to one side, The body portion of the probe pin is formed into a rectangular shape with rounded corners in a cross section perpendicular to the axis of the body portion.

2. The probe pin according to claim 1 , wherein the first to fourth side surfaces are flat surfaces.

3. The probe pin of claim 1 , wherein the top portion is hemispherical.

4. The probe pin according to claim 1 , wherein an insulating coating material is formed around the outer periphery of the bent portion.

5. A method for manufacturing a probe pin, comprising the steps of: A step of drawing the material; grinding one end of the drawn blank into a cone shape to form a tip portion that is connected to one end of the body portion, and grinding the other end into a round shape to form a top portion that is connected to the other end of the body portion; performing a free forging process on the ground blank so that a flat surface is formed on a side surface extending in a longitudinal direction of the ground blank to form the body portion; performing die forging so that a part of the material subjected to the free forging is bent; Including, The material processed by the free forging is The cross section perpendicular to the axis of the body is circular, the cross section size gradually decreases toward the tip, and the tip is located in the center without being biased to one side. The body portion is formed into a rectangular shape with rounded corners in a cross section perpendicular to the axis of the body portion. A method for manufacturing a probe pin.

6. The step of performing the free forging process includes: forming a first side surface and a third side surface facing each other in the body portion by using a press on the ground material; 6. The method for manufacturing a probe pin according to claim 5, further comprising rotating a material on which the first side and the third side are formed by 90 degrees, and then forming a second side and a fourth side which intersect with the first and third sides in the body portion and are opposed to each other.

7. The step of performing the free forging process includes:

6. The method for manufacturing a probe pin according to claim 5, further comprising the steps of: pressing the polished material to simultaneously form a first side and a third side facing each other, and a second side and a fourth side intersecting the first and third sides and facing each other in the body portion.

8. The method for manufacturing a probe pin according to claim 5, further comprising the step of insulating coating the bent portion of the die-forged blank.

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