A power semiconductor aluminum wire arc process

Abstract

The present invention relates to the field of semiconductor technology, and discloses a power semiconductor aluminum wire arc process, comprising the following steps: step 1: welding the first welding point, welding the aluminum wire to the first welding point through the splitter of the welding head; step 2: moving the welding head upward, after the welding of the first welding point is completed, the welding head is raised as a whole; step 3: oblique movement, after the welding head reaches a certain height, it moves a certain distance obliquely downward at a second welding point; step 4: moving toward the welding point, after the welding head moves a certain distance obliquely downward at a second welding point, it operates with the second welding point as the target; step 4: welding, after the welding head reaches the top of the second welding point, it falls vertically downward, and after detecting that it contacts the upper surface of the second welding point, the welding of the second welding point is started; step 5: production is completed. This power semiconductor aluminum wire arc process realizes the purpose of lifting the power semiconductor aluminum wire arc in the air, folding the wire, and pulling the wire, and the arc shape can be controlled.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, in particular to a power semiconductor aluminum wire arc process. Background Art

[0002] The production process of power semiconductor products is divided into three processes: design, manufacturing, and packaging and testing. In the WireBond stage of packaging and testing production, it is necessary to weld aluminum wire from the "pad point" of the wafer to the "lead point" of the lead frame; the aluminum wire between the two points forms a bridge-shaped arc in the air, and the shape of the arc in the air is directly related to the post-packaging and testing process. At the same time, aluminum wires of different wire diameters have different arc details due to different strengths. Therefore, the arc control process method of power semiconductor aluminum wire is very important.

[0003] The traditional aluminum wire arc process of ultrasonic aluminum wire bonding equipment is as follows: after the welding of the first welding point is completed, the welding head is lifted, and the aluminum wire is output from the wire tube. After being lifted to a certain height, according to the distance between the first and second welding points, the welding head moves obliquely downward to the second welding point, and welding is performed again; the wire arc produced by this process is relatively flat and has no ridges, which is not conducive to the post-stage detection and glue filling process.

[0004] To this end, we propose a wire arc process for power semiconductor aluminum wire. Summary of the invention

[0005] In order to make up for the deficiencies of the prior art, the present invention provides the following technical solution: a power semiconductor aluminum wire arc process, comprising the following steps:

[0006] Step 1: Solder the First Solder Joint

[0007] Welding the aluminum wire to the first welding point by using a splitter of the welding head;

[0008] Step 2: Solder Head Up

[0009] After the first welding point is welded, the welding head is raised in height as a whole;

[0010] Step 3: Tilt

[0011] After the welding head reaches a certain height, it moves a certain distance diagonally downward to the second welding point;

[0012] Step 4: Move to the Solder Point

[0013] After the welding head moves a certain distance obliquely downward toward the second welding point, it operates with the second welding point as the target;

[0014] Step 4: Soldering

[0015] After the welding head reaches the top of the second welding spot, it falls vertically downward, and after detecting that it contacts the upper surface of the second welding spot, welding of the second welding spot is started;

[0016] Step 5: Finished

[0017] The space aluminum wire arc is completed.

[0018] Preferably, the height to which the welding head is raised in step 2 depends on the distance between the first welding point and the second welding point, the diameter of the aluminum wire and the final wire arc height.

[0019] Preferably, in step 3, the tilt angle of the welding head is determined by the diameter of the aluminum wire and the final arc height, and the tilt distance depends on the spacing between the first welding point and the second welding point and the final arc height.

[0020] Preferably, in step 4, the welding head moves from the end point of the oblique movement in step 3 to just above the second welding point along a parabola trajectory.

[0021] Preferably, after the welding head moves to the position directly above the second welding spot in step 4, the distance between the second welding spot and the bottom of the welding head wrecking knife is 2 to 3 mm.

[0022] Preferably, the chopping knife is used to conduct ultrasonic waves to weld the aluminum wire and the welding point, and an ultrasonic generator and an ultrasonic transducer matching the ultrasonic generator are arranged on the top of the chopping knife.

[0023] Preferably, an aluminum wire feeding tube is provided on one side of the riving knife, and the aluminum wire feeding tube is close to the riving knife but does not contact the riving knife.

[0024] Preferably, a hollow tube is provided at the bottom of the aluminum wire feeding tube, and the aluminum wire passes through the hollow tube at the bottom of the aluminum wire feeding tube.

[0025] Preferably, the aluminum wire extends out from the bottom of the aluminum wire feeding tube, and the extending portion of the aluminum wire is located directly below the riving knife.

[0026] Preferably, the aluminum wire is released by a wire feeding tube as the welding head moves, and the lead-out length of the aluminum wire is calculated based on the aluminum wire diameter, the final wire arc height, and the distance between the first welding point and the second welding point to obtain the optimal lead-out length.

[0027] Beneficial Effects

[0028] Compared with the prior art, the present invention provides a power semiconductor aluminum wire arc process, which has the following beneficial effects:

[0029] 1. A power semiconductor aluminum wire arc process, after the aluminum wire is welded to the first welding point by the splitter of the welding head, the welding head is raised to a certain height, and then moves obliquely, and finally moves to the top of the second welding point by a parabolic trajectory. During the movement of the welding head, the aluminum wire continuously emerges from the aluminum wire feeding tube to form an arc. The arc control needs to be calculated based on the aluminum wire diameter and the final arc height as well as the distance between the first welding point and the second welding point to obtain the optimal length of the wire. Through the movement of the welding head, the aluminum wire arc is lifted, folded and pulled in the air, so that the arc shape can be controlled.

[0030] 2. This power semiconductor aluminum wire arc process determines the lifting height of the welding head by the distance between the first welding point and the second welding point, the aluminum wire diameter and the final arc height. After the welding head is pulled and lifted to the corresponding highest point, it needs to fold downward obliquely. After the folding is completed, it needs to move to the second welding point in a parabola, and finally form the required aluminum wire arc. The shape of the arc is related to the aluminum wire diameter, the discount angle distance and the parabolic motion path. By controlling the aluminum wire diameter, the discount angle distance and the parabolic motion path, the aluminum wire arc can be formed in a controllable manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the welding head structure of the present invention.

[0032] In the figure: 1. Ultrasonic transducer; 2. Aluminum wire feeding tube; 3. Cutter.

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] See also Figure 1 , a power semiconductor aluminum wire arc process, comprising the following steps:

[0035] Step 1: Solder the First Solder Joint

[0036] The aluminum wire is welded to the first welding point by using the chopper 3 of the welding head;

[0037] Step 2: Solder Head Up

[0038] After the first welding spot is welded, the welding head is raised as a whole. The height of the welding head is determined by the distance between the first welding spot and the second welding spot, the diameter of the aluminum wire and the final arc height.

[0039] Step 3: Tilt

[0040] After the welding head reaches a certain height, it moves a certain distance obliquely downward to the second welding point. The oblique movement angle of the welding head is determined by the diameter of the aluminum wire and the final arc height, and the oblique movement distance depends on the distance between the first welding point and the second welding point and the final arc height.

[0041] Step 4: Move to the Solder Point

[0042] After the welding head moves a certain distance obliquely downward to the second welding point, it moves to the top of the second welding point along a parabola trajectory with the second welding point as the target;

[0043] Step 4: Soldering

[0044] After the welding head reaches 2 to 3 mm above the second welding point, it falls vertically downward, and after detecting that it contacts the upper surface of the second welding point, welding of the second welding point begins;

[0045] Step 5: Finished

[0046] The space aluminum wire arc is completed.

[0047] As an embodiment of the present invention, the splitting knife 3 is used to conduct ultrasonic waves to weld the aluminum wire and the welding point. An ultrasonic generator and an ultrasonic transducer 1 matched with the ultrasonic generator are arranged on the top of the splitting knife 3.

[0048] As an embodiment of the present invention, an aluminum wire feeding tube 2 is disposed on one side of the riving knife 3 , and the aluminum wire feeding tube 2 is close to the riving knife 3 but does not contact the riving knife 3 .

[0049] As an embodiment of the present invention, a hollow tube is provided at the bottom of the aluminum wire feeding tube 2 , and the aluminum wire passes through the hollow tube at the bottom of the aluminum wire feeding tube 2 .

[0050] As an implementation mode of the present invention, the aluminum wire extends out from the bottom of the aluminum wire feeding tube 2 , and the extended portion of the aluminum wire is located directly below the riving knife 3 .

[0051] As an embodiment of the present invention, the aluminum wire is released by a wire feeding tube as the welding head moves. The length of the aluminum wire is calculated based on the aluminum wire diameter, the final wire arc height, and the distance between the first welding point and the second welding point to obtain the optimal length of the aluminum wire.

[0052] It should be noted that after the aluminum wire is welded to the first welding point by the splitter 3 of the welding head, the welding head is raised to a certain height, and then moved obliquely, and finally moved to the top of the second welding point with a parabolic trajectory. During the movement of the welding head, the aluminum wire continuously emerges from the aluminum wire feeding tube 2 to form a wire arc. The wire arc control needs to be calculated based on the aluminum wire diameter and the final wire arc height as well as the distance between the first welding point and the second welding point to obtain the optimal wire length. The movement of the welding head makes the aluminum wire arc lift, fold and pull in the air , so that the shape of the wire arc is controllable, and the lifting height of the welding head is determined by the distance between the first welding point and the second welding point, the wire diameter of the aluminum wire and the final wire arc height. After the welding head is pulled and lifted to the corresponding highest point, it needs to be folded obliquely downward. After the folding is completed, it needs to move to the second welding point in a parabola, and finally form the required aluminum wire arc. The shape of the wire arc is related to the wire diameter of the aluminum wire, the discount angle distance, and the parabolic motion path. By controlling the wire diameter of the aluminum wire, the discount angle distance and the parabolic motion path, the aluminum wire arc can be controllably formed.

[0053] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power semiconductor aluminum wire arc process, characterized in that: The following steps are involved: Step 1: Solder the First Solder Joint The aluminum wire is welded to the first welding point by means of a splitting knife (3) of the welding head; wherein the splitting knife (3) is used to conduct ultrasonic waves to weld the aluminum wire to the welding point, and an ultrasonic generator and an ultrasonic transducer (1) matching the ultrasonic generator are arranged on the top of the splitting knife (3); an aluminum wire feeding tube (2) is arranged on one side of the splitting knife (3), and the aluminum wire feeding tube (2) is close to the splitting knife (3) but does not contact the splitting knife (3); a hollow tube is arranged at the bottom of the aluminum wire feeding tube (2), and the aluminum wire passes through the hollow tube at the bottom of the aluminum wire feeding tube (2); the aluminum wire extends from the bottom of the aluminum wire feeding tube (2), and the extended portion of the aluminum wire is located directly below the splitting knife (3); Step 2: Solder Head Up After the first welding point is welded, the welding head is raised in height as a whole; Step 3: After the oblique welding head reaches a certain height, it is moved a certain distance obliquely downward at the second welding point, that is, after the welding head is pulled up to the corresponding highest point, it moves in an oblique downward folding line; Step 4: Move to the Solder Point After the welding head moves a certain distance obliquely downwardly toward the second welding point, that is, after the line folding is completed, the second welding point is taken as the target, and the welding head moves from the end point of the oblique movement in step 3 to the top of the second welding point with a parabola as the trajectory; during the movement of the welding head, the aluminum wire continuously comes out of the aluminum wire feeding tube (2) to form a wire arc, and the wire arc control needs to be calculated according to the aluminum wire diameter and the final wire arc height and the distance between the first welding point and the second welding point to obtain the optimal wire length, and the aluminum wire arc is lifted, folded and pulled in the air by the movement of the welding head, so that the shape of the wire arc is controllable, and the lifting height of the welding head is determined by the distance between the first welding point and the second welding point, the aluminum wire diameter and the final wire arc height, and the wire arc shape is related to the aluminum wire diameter, the folding angle distance and the parabolic movement path, and the aluminum wire arc can be controllably formed by controlling the aluminum wire diameter, the folding angle distance and the parabolic movement path; Step 5: Soldering After the welding head reaches the top of the second welding spot, it falls vertically downward, and after detecting that it contacts the upper surface of the second welding spot, welding of the second welding spot is started; Step 6: Finished The space aluminum wire arc is completed.

2. A power semiconductor aluminum wire arc process according to claim 1, characterized in that: In step 3, the tilt angle of the welding head is determined by the diameter of the aluminum wire and the final arc height, and the tilt distance depends on the distance between the first welding point and the second welding point and the final arc height.

3. The power semiconductor aluminum wire arc process according to claim 1, characterized in that: After the welding head moves to the top of the second welding spot in step 4, the distance between the second welding spot and the bottom of the welding head splitter (3) is 2 to 3 mm.

4. The power semiconductor aluminum wire arc process according to claim 1, characterized in that: The aluminum wire is released by the wire feeding tube as the welding head moves. The wire length of the aluminum wire is calculated according to the aluminum wire diameter, the final wire arc height, and the distance between the first welding point and the second welding point to obtain the optimal wire length.

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