A method for repairing a bonding wire in a semiconductor component

Abstract

The application relates to a rework method of a bonding wire in a semiconductor component, which comprises the following steps: placing a semiconductor component to be reworked on a wafer table of a bonding device; obtaining the diameter of the bonding wire at the target pad position of the semiconductor component by an automatic scanning system of an AOI optical automatic detection device; creating a bonding wire rework tool according to the diameter of the bonding wire at the target pad position and the metal material of the bonding wire; separating the bonding wire at the target pad of the semiconductor component from the pad by using the bonding wire rework tool; blowing the separated bonding wire by using a plasma air gun until no separated bonding wire is left in the packaging shell of the semiconductor component; and re-bonding the bonding wire at the target pad to complete the rework of the bonding wire in the semiconductor component.

Description

Technical Field

[0001] This invention belongs to the field of microelectronic packaging, and specifically relates to a method for repairing bonding wires in semiconductor components. Background Technology

[0002] During the bonding and wire bonding process of semiconductor components, issues such as solder joint misalignment, excessively high or low wire polishing arc, or collapse may occur, causing some semiconductor components to fail to meet the bonding process inspection requirements. Therefore, semiconductor components that do not meet the bonding process inspection requirements need to be reworked.

[0003] Currently, the common method for reworking defective semiconductor components is to use tweezers to remove the defective leads, then use a scalpel to scrape off the solder joints remaining on the chip and housing pads, and finally install the semiconductor component on a bonding device for re-leading. However, the tip of the scalpel is too sharp and flat, making it difficult to control precisely, which can damage the metallization layer of the chip and housing pads, affecting the rework effect or causing the device to be scrapped, thus reducing the yield. Summary of the Invention

[0004] To address the problems existing in the background art, the present invention provides a method for reworking bonding wires in semiconductor components, comprising:

[0005] S1: Place the semiconductor components to be repaired on the bonding equipment's wafer mount;

[0006] S2: Obtain the diameter of the bonding wire at the target solder joint location of the semiconductor component through the automatic scanning system of the AOI optical automatic inspection equipment; the target solder joint includes: solder joints where the bonding wire is offset from the center of the pad, the bonding wire polishing arc is higher than a set threshold, the bonding wire polishing arc is lower than a set threshold, and the solder joint is located at the location of pad collapse.

[0007] S3: Create a bond wire rework tool based on the diameter and metal material of the bond wire at the target solder joint location;

[0008] S4: Use a bonding wire rework tool to separate the bonding wire from the pad at the target solder joint of the semiconductor component;

[0009] S5: Use a plasma air gun to blow away the separated bonding wires until no separated bonding wires remain inside the package of the semiconductor component.

[0010] S6: Re-bond the bonding wires at the target solder joint to complete the rework of the bonding wires in the semiconductor component.

[0011] The present invention has at least the following technical effects

[0012] This invention, through the design of a dedicated rework tool, reduces the potential defects that may occur to semiconductor components during the rework of small-pitch bonding leads. It has a reasonable structure, high yield, is easy to process, has high safety, saves costs, and is suitable for scientific research projects and small-scale product production. It can also be extended to applications such as removing foreign matter inside packages. Attached Figure Description

[0013] Figure 1 This is a flowchart of the method of the present invention;

[0014] Figure 2 This is a structural diagram of the bonding wire repair tool of the present invention.

[0015] The names corresponding to each marker in the diagram are as follows:

[0016] 1. Knob, 2. Cylinder, 2-1 Frustum, 3. Handle, 3-1. Cutting head. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please see Figure 1 This invention provides a method for reworking bonding wires in semiconductor components, comprising:

[0019] S1: Place the semiconductor components to be repaired on the bonding equipment's substrate stage; each type of semiconductor component has a specially designed and manufactured bonding equipment substrate stage, also known in the industry as a bonding fixture, which is a conventional existing technology in this field.

[0020] S2: Obtain the diameter of the bonding wire at the target solder joint location of the semiconductor component using an AOI (Optical Automatic Inspection) scanning system; the target solder joint includes: solder joints where the bonding wire is offset from the center of the pad, the bonding wire's arc is higher than a set threshold, the bonding wire's arc is lower than a set threshold, and the solder joint is located at a collapsed pad location; the AOI scanning system is an existing conventional technology; the threshold is set according to industrial manufacturing requirements or with reference to national standards.

[0021] S3: Create a bonding wire rework tool based on the diameter and metal material of the bonding wire at the target solder joint location; because the size of the solder joint formed by bonding wires of different diameters and materials is not consistent, there are strict requirements on the size of the rework tool during the rework process of small-pitch bonding wires, which can improve the success rate of rework.

[0022] S4: Use a bonding wire rework tool to separate the bonding wire from the pad at the target solder joint of the semiconductor component;

[0023] S5: Use a plasma air gun to blow away the separated bonding wires until no separated bonding wires remain inside the package of the semiconductor component.

[0024] S6: Re-bond the bonding wires at the target solder joint to complete the rework of the bonding wires in the semiconductor component.

[0025] Please see Figure 2 Preferably, the bonding wire rework tool includes: a PET plastic handle, a miniature flat-head pusher, and a knob 1; the PET plastic handle has a through-hole and an internal thread on the inner wall of the through-hole; the miniature flat-head pusher includes: a handle 3 and a blade 3-1; the outer side of the handle 3 has an external thread, and the handle 3 and the PET plastic handle are threaded together; the blade 3-1 is located at the lower end of the handle 3; the blade 3-1 is flat-headed (similar in shape to the tip of a flat-head screwdriver); the knob 1 is fixedly connected to the upper end of the miniature flat-head pusher; the knob 1 is rotatably connected to the PET plastic handle;

[0026] In the packaging process of semiconductor components, necessary electrostatic discharge (ESD) protection measures must be taken to avoid defects and failures caused by static electricity. From the perspective of processability and ease of forming, this invention patent selects antistatic PET material (polyethylene terephthalate). The basic characteristics of this material are as follows: surface resistivity of 10⁶Ω~10⁸Ω, exhibiting excellent antistatic properties; superior surface hardness and resistance to chemical solvent corrosion; good stability, with antistatic properties not easily affected by temperature and humidity; smooth surface, suitable for hand grip; high mechanical strength and excellent processing performance.

[0027] The miniature flat-blade pusher is made of tungsten-rhenium alloy. Tungsten needles are slender tungsten products made of pure tungsten or tungsten alloys, possessing excellent mechanical properties and ductility. They are characterized by high temperature resistance, high hardness, and good electrical conductivity. They can be used as electrode materials in argon arc welding, as instrument probes, and as dissecting needles. Using high-purity tungsten and rhenium as raw materials, and through a special production process, the tungsten-rhenium alloy is ensured to have high uniformity and density. The produced probes meet user requirements in terms of conductivity, elastic modulus, durability, and mechanical strength. Tungsten-rhenium alloys can be precision machined from micrometers to nanometers, with a minimum diameter of 50μm to 100μm. They can be made into needle-tip shapes, platform shapes, and arc shapes, with a minimum needle tip curvature controllable to 50 nanometers and a surface finish of Ra0.25. The lead material is typically gold or aluminum wire, forming spherical or wedge-shaped solder joints. Since bonding wires are atomically bonded, the adhesion density and strength between the wires and the pads are very high. In addition, the minimum solder joint size is 60 micrometers. Therefore, the processing tool material must not only be sufficiently hard, but also capable of micro-precision machining.

[0028] When the bonding wire is a gold wire with a diameter of 25μm, the width of the cutting head is 100μm;

[0029] When the bonding wire is a gold wire with a diameter of 30μm or an aluminum wire with a diameter of 25μm, the width of the cutting head is 150μm.

[0030] When the bonding wire is a gold wire with a diameter of 35μm, the width of the cutting head is 200μm;

[0031] When the bonding wire is an aluminum wire with a diameter of 38 μm, the width of the cutting head is 250 μm.

[0032] Preferably, the PET plastic handle is composed of a frustum 2-1 and a cylinder 2, wherein the largest circular surface of the frustum 2-1 corresponds to the circular surface of the cylinder.

[0033] Preferably, the step of using a bonding wire rework tool to separate the bonding wire from the pad at the target solder joint of the semiconductor component includes:

[0034] Move the bonding wire rework tool to a preset distance from the target solder joint, approximately 1000 μm. Adjust the knob to slowly expose the tip of the miniature flat-blade pusher from the PET plastic handle. Use the tip of the miniature flat-blade pusher to separate the bonding wire from the pad of the target solder joint. After the bonding wire from the pad of the target solder joint is separated, adjust the knob to retract the tip of the miniature flat-blade pusher back into the PET plastic handle.

[0035] This invention utilizes a threaded connection between a PET plastic handle and a miniature flat-blade pusher in a wire bonding repair tool. This ensures that there are no sharp parts at the predetermined distance from the target solder joint, preventing secondary damage to semiconductor components. For small-pitch wire bonding repair, this invention sets the blade width according to the diameter of the wire bonding, ensuring that no damage is caused to nearby solder joints during the separation of the wire bonding from the pad at the target solder joint.

[0036] This invention creates a small-pitch bonding wire rework tool and process, which has strong operability, reduces the defects that may occur in the rework process, and ensures the yield of rework products.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for reworking bonding wires in semiconductor components, characterized in that, include: S1: Place the semiconductor components to be repaired on the bonding equipment's wafer mount; S2: Obtain the diameter of the bonding wire at the target solder joint location of the semiconductor component through the automatic scanning system of the AOI optical automatic inspection equipment; the target solder joint includes: solder joints where the bonding wire is offset from the center of the pad, the bonding wire polishing arc is higher than a set threshold, the bonding wire polishing arc is lower than a set threshold, and the solder joint is located at the location of pad collapse. S3: Create a bond wire rework tool based on the diameter and metal material of the bond wire at the target solder joint location; S4: Use a bonding wire rework tool to separate the bonding wire from the pad at the target solder joint of the semiconductor component; S5: Use a plasma air gun to blow away the separated bonding wires until no separated bonding wires remain inside the package of the semiconductor component. S6: Re-bond the bonding wires at the target solder joint to complete the rework of the bonding wires in the semiconductor component.

2. The method for reworking bonding wires in semiconductor components according to claim 1, characterized in that, The bonding wire repair tool includes: a PET plastic handle, a miniature flat-mouth pusher, and a knob; the PET plastic handle has a through-hole and an internal thread on the inner wall of the through-hole; the miniature flat-mouth pusher includes: a handle and a blade; the outer side of the handle has an external thread, and the handle and the PET plastic handle are threaded together; the blade is located at the lower end of the handle; the blade is flat-mouthed; the knob is fixedly connected to the upper end of the miniature flat-mouth pusher; the knob is rotatably connected to the PET plastic handle.

3. The method for reworking bonding wires in semiconductor components according to claim 2, characterized in that, The miniature flat-blade pusher is made of tungsten-rhenium alloy.

4. The method for reworking bonding wires in semiconductor components according to claim 2, characterized in that, When the bonding wire is a gold wire with a diameter of 25μm, the width of the cutting head is 100μm; When the bonding wire is a gold wire with a diameter of 30μm or an aluminum wire with a diameter of 25μm, the width of the cutting head is 150μm. When the bonding wire is a gold wire with a diameter of 35μm, the width of the cutting head is 200μm; When the bonding wire is an aluminum wire with a diameter of 38 μm, the width of the cutting head is 250 μm.

5. A method for reworking bonding wires in semiconductor components according to claim 2, characterized in that, The PET plastic handle consists of a frustum and a cylinder, with the largest circular surface of the frustum corresponding to the circular surface of the cylinder.

6. A method for reworking bonding wires in semiconductor components according to claim 2, characterized in that, The step of using a bonding wire rework tool to separate the bonding wire from the pad at the target solder joint of a semiconductor component includes: Move the bonding wire rework tool to a preset distance from the target solder joint. Adjust the knob to slowly expose the tip of the miniature flat-blade pusher from the PET plastic handle. Use the tip of the miniature flat-blade pusher to separate the bonding wire from the pad of the target solder joint. After the bonding wire from the pad of the target solder joint is separated, adjust the knob to retract the tip of the miniature flat-blade pusher back into the PET plastic handle.

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