A singulation process for semiconductor flat pin package structure

Abstract

The application relates to the technical field of a trimming technology of semiconductor packaging, and discloses a trimming process for a semiconductor flat pin packaging structure. In actual implementation, when the connecting pin of the product is cut off, pre-cutting is first carried out through a pre-cutting tool, and then secondary cutting is carried out, so that the stress during cutting and separation can be reduced, the damage to the product during cutting of the connecting pin can be reduced, and the product quality is improved. In addition, when the pin of the product is cut off, the pin is cut off from the welding surface of the pin downwards, the burr surface is not on the welding surface, so that the burr does not exist on the welding surface during welding, and the welding is not poor. When the pin is cut off, the pre-cutting and the secondary cutting are completed in the same station, and there is no product conveying action in the middle, so that the problem that the lengths of the pins on the two sides of the product are inconsistent due to conveying errors of the product is solved.

Description

Technical Field

[0001] This invention relates to the field of lead cutting technology in semiconductor packaging, and more specifically to a lead cutting process for semiconductor flat-lead package structures. Background Technology

[0002] Lead trimming is a crucial process in semiconductor packaging. Untrimmed leads are arranged in a matrix within a frame, and mechanical punching is used to cut and separate the leads, forming individual chips that meet the design dimensions. Traditional lead trimming processes, which directly use cutting tools, suffer from the following problems in practice: 1. The lengths of the pins on both sides of the product differ after the ribs are cut, which affects actual use; Second, the cut surface of the reinforcing bar has burrs, which affects its actual use. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention provides a lead cutting process for semiconductor flat-pin package structures. The technical problem to be solved is that the existing lead cutting process has problems such as differences in pin length and burrs on the cut surface when cutting the product from the whole frame.

[0004] To solve the above technical problems, the present invention provides the following technical solution: a lead-cutting process for semiconductor flat-lead package structures, comprising the following steps: S1: Transfer the product from the fixture to the descaling station; S2: At the glue removal station, use a glue removal tool to cut off the glue inlet of the product and remove the residual glue from the glue inlet. S3: At the adhesive removal station, use an adhesive removal tool to remove excess adhesive from both sides of the product's pins; S4: The waste adhesive generated in steps S2 and S3 is adsorbed away by vacuum adsorption. S5: Transfer the product from the glue removal station to the rib pre-cutting station, where a pre-cutting tool is used to pre-cut the ribs of the product. S6: Transfer the product from the rib pre-cutting station to the rib cutting station, and then use the cutting tool to cut the pre-cut position a second time until the rib is cut and separated. S7: Transfer the product from the rib cutting station to the pin cutting station. First, use a pre-cutting tool to pre-cut the pins from the welding surface of the product downwards. Then, use a cutting tool to cut the pins at the pre-cut position a second time until the pins of the product are cut off and separated. S8: After the pins are cut off at the pin cutting station, the product falls freely into the collection box.

[0005] In one embodiment, the glue removal tool used in step S2 is made of mold steel or tungsten steel.

[0006] In one embodiment, the distance between the glue removal tool and the edge of the product is between 0 and 0.2 mm.

[0007] In one embodiment, the material of the adhesive removal tool used in step S3 is mold steel or tungsten steel.

[0008] In one embodiment, the distance between the adhesive removal tool and the pin edge of the product is between 0 and 0.2 mm.

[0009] In one embodiment, the vacuum value of vacuum adsorption in step S4 is between 0.4 and 0.6 MPa.

[0010] In one embodiment, when pre-cutting the connecting rib in step S5, the pre-cutting depth is 1 / 3 to 1 / 2 times the thickness of the connecting rib.

[0011] In one embodiment, when pre-cutting the pin in step S7, the pre-cutting depth of the pin is 1 / 3 to 1 / 2 times the pin thickness.

[0012] In one embodiment, in step S1, after the product is transferred to the de-adhesive station, the product is subjected to anti-reverse detection. If the anti-reverse detection is successful, step S2 is executed; otherwise, step S1 ends.

[0013] In one embodiment, in step S1, after the product is transferred to the de-adhesive station, the product is also subjected to positioning detection. If the product position is incorrect, the position of the product on the de-adhesive station is adjusted until the positioning detection is qualified.

[0014] The beneficial effects of this invention compared to existing conventional technologies are: First, when cutting the connecting ribs and leads of the product, pre-cutting is performed using a pre-cutting tool, followed by a secondary cut. This reduces the stress during the cutting and separation process, minimizes damage to the product when cutting the connecting ribs and leads, and thus improves product quality. Secondly, when cutting the product's pins, since the cutting is done from the soldering surface downwards, the burr surface is not on the soldering surface. This effectively avoids poor soldering caused by burrs on the soldering surface during soldering at the customer's location. Finally, when cutting the pins, both the pre-cutting and secondary cutting are completed at the same station, without any product transfer in between, which solves the problem of inconsistent pin lengths on both sides of the product due to product transfer errors. Attached Figure Description

[0015] Figure 1 This is a process flow diagram of the present invention in the embodiments; Figure 2This is a schematic diagram of the glue removal tool cutting off the glue injection port in the embodiment; Figure 3 This is a schematic diagram of the adhesive removal tool used in the embodiment cutting off the excess adhesive on both sides of the pin; Figure 4 A schematic diagram illustrating the pre-cutting of the connecting ribs for the product; Figure 5 A schematic diagram illustrating the secondary cutting of the connecting ribs in the product; Figure 6 A schematic diagram illustrating the pre-cutting of the product's pins; Figure 7 A schematic diagram of a product's pins being cut off a second time. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0017] like Figure 1 As shown, a lead-cutting process for a semiconductor flat-lead package structure includes the following steps: S1: Transfer product 1 from the fixture to the degumming station.

[0018] Specifically, in actual implementation, a track can be used to transfer product 1 from the fixture to the degumming station.

[0019] To ensure that product 1 is correctly positioned at the adhesive removal station, i.e., to ensure that the adhesive removal position is correct, in this embodiment, after product 1 is transferred to the adhesive removal station, anti-reverse detection is performed on product 1. If the anti-reverse detection is successful, step S2 is executed; otherwise, step S1 is terminated. The image information of product 1 at the adhesive removal station can be captured by a camera, and then the captured image information is processed according to a visual algorithm to determine whether product 1 is anti-reverse.

[0020] In addition, in step S1, after product 1 is transferred to the de-adhesive station, product 1 can be positioned and detected. If the position of product 1 is incorrect, the position of product 1 on the de-adhesive station can be adjusted until the positioning detection is qualified. In this process, the image information of the product on the de-adhesive station can be captured by a camera, and then the captured image information can be processed according to the vision algorithm to determine whether the product position meets the requirements.

[0021] It should be noted that Product 1 in this embodiment can be any package in the field of semiconductor packaging, and is not necessarily limited to a specific package.

[0022] S2: At the glue removal station, use the glue removal tool 41 to cut off the glue inlet of product 1 and remove the residual glue 51 from the glue inlet of the product.

[0023] A schematic diagram of the glue removal tool 41 cutting off the residual glue 51 is shown below. Figure 2 As shown.

[0024] In addition, in this embodiment, the glue removal tool 41 used in step S2 is made of mold steel or tungsten steel. Preferably, the glue removal tool 41 is made of tungsten steel.

[0025] In addition, in this embodiment, when the actual cutting is performed, the distance between the glue removal tool 41 and the product 1 is between 0 and 0.2 mm. Preferably, the distance between the glue removal tool 41 and the product 1 is 0.05 mm.

[0026] S3: At the adhesive removal station, use the adhesive removal tool 42 to cut off the excess adhesive on both sides of the pin 3 of product 1, and remove the excess adhesive 52 on both sides of the pin of product 1.

[0027] A schematic diagram of the adhesive removal tool 42 cutting off the excess adhesive 52 is shown below. Figure 3 As shown, in Figure 3 In the process, the glue removal tool 42 is provided with a cutting part on both sides of each pin 3 for cutting; in addition, when the structure of the pin 3 of the product 1 changes, the glue removal tool 42 with the corresponding structure can be used for cutting.

[0028] Specifically, in this embodiment, the material of the glue removal tool 42 used in step S3 is mold steel or tungsten steel. Preferably, the material of the glue removal tool 42 is tungsten steel.

[0029] In addition, in actual implementation, the distance between the glue removal tool 42 and the edge of the pin 3 of the product 1 is between 0 and 0.2 mm. Preferably, the distance between the glue removal tool 42 and the edge of the pin 3 of the product 1 is 0.05 mm.

[0030] In actual implementation, after the residual adhesive on product 1 of the entire frame is removed, the matrix-arranged products 1 of the entire frame need to be cut and separated to obtain individual products. To facilitate product separation, the waste adhesive generated in steps S2 and S3 needs to be removed. Based on this, step S4 is executed after step S3, and step S4 is as follows: S4: The waste adhesive generated in steps S2 and S3 is adsorbed away by vacuum adsorption.

[0031] In practice, the vacuum value of vacuum adsorption in step S4 is between 0.4 and 0.6 MPa. For example, the vacuum value can be 0.45 MPa, 0.5 MPa, and 0.55 MPa. A dust collection box can also be provided to collect the adsorbed waste adhesive.

[0032] S5: Transfer product 1 from the degumming station to the rib pre-cutting station. Use the pre-cutting tool 61 to pre-cut the ribs 2 of product 1 at the rib pre-cutting station.

[0033] A schematic diagram of the pre-cutting blade 61 pre-cutting the connecting rib 2 of product 1 is shown below. Figure 4 As shown in the diagram, the cutting tool 62 performs a secondary cut at the pre-cut position. Figure 5 As shown.

[0034] In addition, in actual implementation, when pre-cutting the connecting bar in step S5, the pre-cutting depth is 1 / 3 to 1 / 2 times the thickness of the connecting bar.

[0035] S6: Transfer product 1 from the rib pre-cutting station to the rib cutting station, and then use the cutting tool 62 to cut the pre-cut position a second time until the rib 2 is cut off.

[0036] S7: Transfer product 1 from the rib cutting station to the pin cutting station. First, use the pre-cutting tool 71 to pre-cut the pin 3 from the welding surface of product 1 downwards. Then, use the cutting tool 72 to cut the pin 3 at the pre-cut position for a second time until the pin 3 is cut off.

[0037] A schematic diagram of the pre-cutting tool 71 pre-cutting pin 3 of product 1 is shown below. Figure 6 As shown in the diagram, the cutting tool 72 performs a secondary cut at the pre-cut position. Figure 7 As shown.

[0038] In addition, in actual implementation, when pre-cutting pin 3 in step S6, the pre-cutting depth of pin is 1 / 3 to 1 / 2 times the thickness of pin 3.

[0039] S8: After the pins are cut off at the pin cutting station, the product falls freely into the collection box.

[0040] In summary, the method of the present invention pre-cuts the connecting ribs 2 and pins 3 of product 1 by first using pre-cutting tools 61 and 71, and then performs a secondary cut, which can reduce the stress during the cutting and separation, reduce the damage to the product when cutting the connecting ribs, and thus improve the product quality. Secondly, when cutting off pin 3 of product 1, since the cutting is performed from the soldering surface of pin 3 downwards, the burr surface is not on the soldering surface. This can effectively avoid poor soldering caused by burrs on the soldering surface when soldering at the customer's site. Finally, when cutting pin 3, both the pre-cutting and secondary cutting are completed at the same station, without any product transfer in between, which solves the problem of inconsistent pin lengths on both sides of product 1 due to product transfer errors.

[0041] Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this invention. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A lead-cutting process for semiconductor flat-lead package structures, characterized in that, Includes the following steps: S1: Transfer the product from the fixture to the descaling station; S2: At the glue removal station, use a glue removal tool to cut off the glue inlet of the product and remove the residual glue from the glue inlet. S3: At the adhesive removal station, use an adhesive removal tool to remove excess adhesive from both sides of the product's pins; S4: The waste adhesive generated in steps S2 and S3 is adsorbed away by vacuum adsorption. S5: Transfer the product from the glue removal station to the rib pre-cutting station, and use a pre-cutting tool to pre-cut the ribs of the product at the rib pre-cutting station. S6: Transfer the product from the rib pre-cutting station to the rib cutting station, and then use the cutting tool to cut the pre-cut position a second time until the rib is cut and separated. S7: Transfer the product from the rib cutting station to the pin cutting station. First, use a pre-cutting tool to pre-cut the pins from the welding surface of the product downwards. Then, use a cutting tool to cut the pins at the pre-cut position a second time until the pins of the product are cut off and separated. S8: After the pins are cut off at the pin cutting station, the product falls freely into the collection box. In step S1, after the product is transferred to the adhesive removal station, the product is subjected to anti-reverse detection. If the anti-reverse detection is successful, step S2 is executed; otherwise, the process ends. In step S1, after the product is transferred to the de-adhesive station, the product is also subjected to positioning detection. If the product position is incorrect, the position of the product on the de-adhesive station is adjusted until the positioning detection is qualified.

2. The lead-cutting process for a semiconductor flat-lead package structure according to claim 1, characterized in that, The glue removal tool used in step S2 is made of mold steel or tungsten steel.

3. The lead-cutting process for a semiconductor flat-lead package structure according to claim 1, characterized in that, The distance between the glue removal tool and the edge of the product is between 0 and 0.2 mm.

4. The lead-cutting process for a semiconductor flat-lead package structure according to claim 1, characterized in that, The material of the adhesive removal tool used in step S3 is mold steel or tungsten steel.

5. The lead-cutting process for a semiconductor flat-lead package structure according to claim 1, characterized in that, The distance between the adhesive removal tool and the edge of the product's pins is between 0 and 0.2 mm.

6. The lead-cutting process for a semiconductor flat-lead package structure according to claim 1, characterized in that, The vacuum value of vacuum adsorption in step S4 is between 0.4 and 0.6 MPa.

7. The lead-cutting process for a semiconductor flat-lead package structure according to claim 1, characterized in that, In step S5, when pre-cutting the connecting reinforcement, the pre-cutting depth is 1 / 3 to 1 / 2 times the thickness of the connecting reinforcement.

8. The lead-cutting process for a semiconductor flat-lead package structure according to claim 1, characterized in that, In step S7, when pre-cutting the pin, the pre-cutting depth is 1 / 3 to 1 / 2 times the pin thickness.

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