Process for cutting flash of semiconductor packaging chip separation

Abstract

The present invention discloses a process for separating cutting flash from semiconductor packaged chips, comprising the following steps: fixing the cutting flash to a carrier film so that the fixing force between the cutting flash and the carrier film is greater than the fixing force between a good chip and the carrier film; applying a force on the back of the carrier film so that the good chip falls off the carrier film, the good chip is separated from the carrier film, and the cutting flash remains on the carrier film. The present invention adopts a method of firmly fixing the cutting flash and the bad chip on the carrier film, and then manually or ultrasonically acting on the back of the carrier film, according to the difference in adhesion to the carrier film, the good chip is peeled off from the carrier film, while the cutting flash and the bad chip remain on the carrier film, so as to separate the good chip from the cutting flash and the bad chip; the labor for scraping the flash is greatly reduced, automation is easily realized, the process is simple, and production efficiency can be greatly improved, while the yield rate of semiconductor packaged chips is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging detection, and in particular to a process for separating and cutting flash edges of semiconductor packaging chips. Background Art

[0002] In the existing semiconductor packaging process, an injection molding machine wraps the chip, leads and metal lead frames with resin material to form a whole substrate, and then adheres the substrate to a carrier film, which is generally a UV film, blue film or green film. A cutting machine cuts the substrate on the carrier film into independent packaged semiconductor units.

[0003] Since the metal lead frame and plastic encapsulation area are larger than the chip area, "flash" will be generated around the chip area of ​​each substrate, that is, waste material in the edge area of ​​the metal lead frame and plastic encapsulation. After the entire substrate is cut, the flash forms fine "cutting flash". "Cutting flash" mixed with the chip will frequently trigger alarms and shutdowns of the detection equipment in the subsequent inspection process, greatly reducing production efficiency. Therefore, the cutting flash must be removed to prevent mixing with the chip.

[0004] The removal of cutting flash usually requires manual operation, and the cutting flash is manually scraped off from the carrier film. Because the carrier film has strong elasticity, large deformation, and is thin and easy to break, once the carrier film is scraped, the scraping work cannot continue. Therefore, the scraping process has not been automated so far.

[0005] In the above existing processes, most companies use manual scraping to remove the cutting flash, which is prone to the following defects: first, the process of scraping the flash is prone to static electricity that damages the chip; second, manual operation is prone to scratching and damaging the chip; third, it is easy to accidentally scrape the chip into the cutting flash. Other companies use manual tape to seal the cutting flash, and then make the chip fall off the carrier film, while the cutting flash is fixed on the carrier film by the tape, but this method has the following defects: first, the efficiency is low, and taping is very labor-intensive; second, the cutting flash is often not well adhered to the tape, and a part of the flash is still mixed into the chip. It is more labor-intensive to pick out the flash from the chip again, and it is difficult to clean the flash.

[0006] In the existing process, during the chip appearance inspection process, it is necessary to use a needle tip or tweezers to remove defective chips from the carrier film under a magnifying glass or microscope, and this process also consumes a lot of manpower. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention aims to provide a process for separating and cutting flash of semiconductor package chips.

[0008] In order to achieve the above purpose, the technical solution provided by an embodiment of the present invention is as follows:

[0009] A process for separating and cutting flash edges of semiconductor packaging chips, comprising the following steps:

[0010] (1) Fixing the cutting burr to the carrier film so that the fixing force between the cutting burr and the carrier film is greater than the fixing force between the good chip and the carrier film;

[0011] (2) Applying force on the back side of the carrier film causes the good chip to fall off the carrier film, the good chip is separated from the carrier film, and the cutting burr remains on the carrier film.

[0012] As a further improvement of the present invention, in the step (1), the cutting burrs are fixed on the carrier film by heating.

[0013] As a further improvement of the present invention, the cutting burr or the carrier film below the cutting burr is irradiated with laser so that the cutting burr is fixed on the carrier film.

[0014] As a further improvement of the present invention, before step (2), the method further includes fixing the defective chips on the carrier film so that the fixing force between the defective chips and the carrier film is greater than the fixing force between the good chips and the carrier film.

[0015] As a further improvement of the present invention, the defective chips are fixed on the carrier film by heating.

[0016] As a further improvement of the present invention, the defective chip or the carrier film under the defective chip is irradiated with laser so that the defective chip is fixed on the carrier film.

[0017] As a further improvement of the present invention, in the step (1), the cutting burr is fixed on the carrier film by dispensing glue.

[0018] As a further improvement of the present invention, before the step (1), it also includes identifying cutting burrs / cutting burrs and defective chips through a machine vision system.

[0019] As a further improvement of the present invention, in the step (2), ultrasound or manual operation is applied to the back side of the carrier film so that the good chips fall off the carrier film.

[0020] As a further improvement of the present invention, the carrier film is a UV film, a blue film or a green film.

[0021] The beneficial effects of the present invention are:

[0022] (1) The present invention adopts a method of firmly fixing the cutting flash and defective chips on the carrier film, and then acts on the back side of the carrier film manually or ultrasonically. Based on the fact that the good chips have low adhesion to the carrier film, while the cutting flash and defective chips have high adhesion to the carrier film, the difference in adhesion between the two to the carrier film is utilized to peel the good chips off the carrier film, while the cutting flash and defective chips remain on the carrier film, thereby achieving separation of the good chips from the cutting flash and defective chips.

[0023] (2) The process of the present invention greatly reduces the labor for scraping off flash and removing defective products, is easy to automate, has a simple process, can greatly improve production efficiency, and at the same time improve the yield rate of semiconductor packaging chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a schematic diagram of the state of laser heating fixed cutting flash according to the preferred embodiment 1 of the present invention;

[0026] Figure 2 This is a schematic diagram of the state of fixing defective chips by laser heating according to the first preferred embodiment of the present invention;

[0027] Figure 3 1 is a schematic diagram of the state of ultrasonically separating good chips from cutting flash and defective chips according to the first preferred embodiment of the present invention;

[0028] Figure 4 It is a schematic diagram of the state of fixing the cutting flash with glue and fixing the defective chip with laser heating in the second preferred embodiment of the present invention;

[0029] Figure 5 1 is a schematic diagram of the state of ultrasonically separating good chips from cutting flash and defective chips according to the second preferred embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of the state of the glue-dispensing fixed cutting flash edge of the preferred embodiment 3 of the present invention;

[0031] Figure 7 It is a schematic diagram of the state of ultrasonic separation and cutting of flash and semiconductor chip unit according to the preferred embodiment 3 of the present invention. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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 should fall within the scope of protection of the present invention.

[0033] A process for separating and cutting flash edges of semiconductor packaging chips, comprising the following steps:

[0034] (1) Fixing the cutting burr to the carrier film so that the fixing force between the cutting burr and the carrier film is greater than the fixing force between the good chip and the carrier film;

[0035] (2) A force is applied to the back side of the carrier film so that the good chips fall off the carrier film, the good chips of the semiconductor chip are separated from the carrier film, and the cutting burrs remain on the carrier film.

[0036] Wherein, in step (1), the cutting burr is fixed on the carrier film by heating.

[0037] Specifically, the cutting burrs are fixed on the carrier film by laser irradiation.

[0038] In other embodiments, the laser irradiates the carrier film below the cutting flash and the laser irradiates the back of the carrier film, so that the cutting flash is fixed on the carrier film. More specifically, the laser irradiates the carrier film directly below the cutting flash, so that the cutting flash is more firmly fixed on the carrier film.

[0039] Optionally, for some products, such as integrated chips, before step (2), the process further includes fixing the defective chips on the carrier film so that the fixing force between the defective chips and the carrier film is greater than the fixing force between the good chips and the carrier film. That is, this step is added between step (1) and step (2). Of course, it is understandable that for some products, such as LED chips, appearance inspection is not required in this process, so the process of fixing the defective chips on the carrier film can be omitted.

[0040] Specifically, the defective chips are fixed on the carrier film by heating.

[0041] More specifically, the defective chips are fixed on the carrier film by irradiating the defective chips with laser.

[0042] In other embodiments, the defective chip is fixed on the carrier film by irradiating the carrier film below the defective chip with laser and irradiating the back side of the carrier film with laser. More specifically, the defective chip is more firmly fixed on the carrier film by irradiating the carrier film directly below the defective chip with laser.

[0043] In another embodiment, in step (1), the cutting burr is fixed on the carrier film by dispensing glue.

[0044] Before step (1), the method further includes identifying the cutting burrs and defective chips by a machine vision system. Of course, it is understandable that when appearance inspection is not required, only the cutting burrs are identified by machine vision.

[0045] Specifically, in step (2), ultrasound is applied to the back of the carrier film to cause the good chips to fall off the carrier film. However, this method is not limited to this method, and manual operation can also be used to apply ultrasound to the back of the carrier film to cause the good chips to fall off the carrier film.

[0046] In one embodiment, the carrier film is a UV film, but is not limited to a UV film, and may also be a blue film or a green film.

[0047] The above process greatly reduces the labor required for scraping off flash and removing defective products; combined with the machine vision system to detect chip appearance defects, it can realize the automation of detection, removal of defective products and scraping off flash, greatly improving production efficiency.

[0048] The present invention is further described below in conjunction with specific embodiments.

[0049] Embodiment 1

[0050] like Figure 1 As shown, the material ring 1-1 is attached to the carrier film 1-2, and the carrier film 1-2 is a UV film, but is not limited to a UV film, and can also be a blue film or a green film. The cutting machine cuts the substrate into semiconductor chip units 1-3, wherein the substrate is formed by wrapping the chip, the lead wire and the metal lead wire frame with a resin material by an injection molding machine, and there are cutting flashes 1-4 around the semiconductor chip unit 1-3, and the semiconductor chip unit 1-3 includes a defective chip 1-5 and a good chip 1-6. The light spot 2-2 of the laser 2-1 is focused on the cutting flash 1-4, and the heat of the light spot 2-2 is transferred to the cutting flash 1-4. Since the cutting flash 1-4 is made of metal material, the heat can be quickly transferred to the carrier film 1-2, and the high temperature destroys the adhesive layer on the surface of the carrier film 1-2. The cutting flash 1-4 and the carrier film 1-2 begin to melt due to the heat. This process can achieve the melting of the carrier film 1-2 and the cutting flash 1-4 without completely destroying the carrier film 1-2 by controlling the power and irradiation time of the laser 2-1. According to the material and size of the cutting flash 1-4 and the characteristics of the carrier film 1-2, the power of the laser 2-1 is 5W to 50W, and the irradiation time is 0.1 seconds to 2 seconds. After the cutting flash 1-4 and the carrier film 1-2 are cooled, the cutting flash 1-4 is fixed on the front of the carrier film 1-2.

[0051] like Figure 2As shown, the spot 2-2 of the laser 2-1 is concentrated on the defective chip 1-5, and the heat of the spot 2-2 is transferred to the defective chip 1-5, the defective chip 1-5 is ablated and the heat is transferred to the carrier film 1-2, and the carrier film 1-2 and the defective chip 1-5 begin to melt due to the effect of heat. This process can achieve the melting of the carrier film 1-2 and the defective chip 1-5 without completely destroying the carrier film 1-2 by controlling the power and irradiation time of the laser 2-1. According to the material and size of the defective chip 1-5 and the characteristics of the carrier film 1-2, the power of the laser 2-1 is 5W to 50W, and the irradiation time is 0.1 seconds to 2 seconds. After the defective chip 1-5 and the carrier film 1-2 are cooled, the defective chip 1-5 is fixed on the front of the carrier film 1-2.

[0052] like Figure 3 As shown, after the cutting flash 1-4 and the defective chip 1-5 are fixed on the carrier film 1-2, since the adhesion between the good chip 1-6 and the carrier film 1-2 is relatively weak, the adhesion between the cutting flash 1-4 and the defective chip 1-5 and the carrier film 1-2 is relatively strong. An ultrasonic head 4 of appropriate specifications is used, and the power of the ultrasonic head 4 is 10W to 100W. The ultrasonic head 4 scans the back side of the carrier film 1-2, that is, the side of the carrier film 1-2 without glue, so that the cutting flash 1-4 and the defective chip 1-5 with relatively strong adhesion are still attached to the carrier film 1-2, and the good chip 1-6 of the semiconductor chip unit 1-3 with relatively weak adhesion is shaken off by the ultrasonic head 4. In this way, the separation of the good chip 1-6 from the cutting flash 1-4 and the defective chip 1-5 is achieved.

[0053] Embodiment 2

[0054] like Figure 4 As shown, the material ring 1-1 is attached to the carrier film 1-2, and the carrier film 1-2 is a UV film, but is not limited to a UV film, and can also be a blue film or a green film. The cutting machine cuts the substrate into semiconductor chip units 1-3, wherein the substrate is formed by wrapping the chip, the lead wire and the metal lead frame with a resin material by an injection molding machine, and there are cutting flashes 1-4 around the semiconductor chip unit 1-3, and the semiconductor chip unit 1-3 includes a defective chip 1-5 and a good chip 1-6. The syringe 3 containing the curable glue 3-3 extrude the curable glue 3-3, dispenses the glue according to a specific motion trajectory, and applies the glue 3-3 on the cutting flash 1-4, and the glue 3-3 extends to the carrier film 1-2. After the curable glue 3-3 is cured, a glue strip 3-2 is formed, and the glue strip 3-2 fixes the cutting flash 1-4 to the carrier film 1-2.

[0055] The light spot 2-2 of the laser 2-1 is concentrated on the defective chip 1-5, and the heat of the light spot 2-2 is transferred to the defective chip 1-5, the defective chip 1-5 is ablated and the heat is transferred to the carrier film 1-2, and the carrier film 1-2 and the defective chip 1-5 begin to melt due to the heat. This process can achieve the melting of the carrier film 1-2 and the defective chip 1-5 without completely destroying the carrier film 1-2 by controlling the power and irradiation time of the laser 2-1. According to the material and size of the defective chip 1-5 and the characteristics of the carrier film 1-2, the power of the laser 2-1 is 5W to 50W, and the irradiation time is 0.1 seconds to 2 seconds. After the defective chip 1-5 and the carrier film 1-2 are cooled, the defective chip 1-5 is fixed on the front of the carrier film 1-2.

[0056] like Figure 5 As shown, after the cutting flash 1-4 and the defective chip 1-5 are fixed on the carrier film 1-2, since the adhesion between the good chip 1-6 and the carrier film 1-2 is relatively weak, the adhesion between the cutting flash 1-4 and the defective chip 1-5 and the carrier film 1-2 is relatively strong. An ultrasonic head 4 of appropriate specifications is used, and the power of the ultrasonic head 4 is 10W to 100W. The ultrasonic head 4 scans the back side of the carrier film 1-2, that is, the side of the carrier film 1-2 without glue, so that the cutting flash 1-4 and the defective chip 1-5 with relatively strong adhesion are still attached to the carrier film 1-2, and the good chip 1-6 of the semiconductor chip unit 1-3 with relatively weak adhesion is shaken off by the ultrasonic head 4. In this way, the separation of the good chip 1-6 from the cutting flash 1-4 and the defective chip 1-5 is achieved.

[0057] Embodiment 3

[0058] like Figure 6 As shown, the material ring 1-1 is attached to the carrier film 1-2, and the carrier film 1-2 is a UV film, but is not limited to a UV film, and can also be a blue film or a green film. The cutting machine cuts the substrate into semiconductor chip units 1-3, wherein the substrate is formed by wrapping the chip, the lead wire and the metal lead frame with a resin material by an injection molding machine. The semiconductor chip can be an LED chip. The semiconductor chip unit 1-3 has cutting burrs 1-4 around it, and the semiconductor chip unit 1-3 includes defective chips 1-5 and good chips 1-6. The syringe 3 containing the curable glue 3-3 extrude the curable glue 3-3, dispenses the glue according to a specific motion trajectory, and applies the glue 3-3 on the cutting burrs 1-4. The glue 3-3 extends to the carrier film 1-2. After the curable glue 3-3 is cured, a glue strip 3-2 is formed, and the glue strip 3-2 fixes the cutting burrs 1-4 to the carrier film 1-2.

[0059] like Figure 7As shown, after the cutting flash 1-4 is fixed on the carrier film 1-2, since the adhesion between the semiconductor chip unit 1-3 and the carrier film 1-2 is relatively weak, the adhesion between the cutting flash 1-4 and the carrier film 1-2 is relatively strong. An ultrasonic head 4 of appropriate specifications is used, and the power of the ultrasonic head 4 is 10W to 100W. The ultrasonic head 4 scans the back of the carrier film 1-2, so that the cutting flash 1-4 with relatively strong adhesion is still attached to the carrier film 1-2, and the semiconductor chip unit 1-3 with relatively weak adhesion is shaken off by the ultrasonic head 4. In this way, the semiconductor chip unit 1-3 is separated from the cutting flash 1-4, and the defective chips 1-5 and good chips 1-6 that fall off the carrier film 1-2 are then subjected to subsequent full inspection and classification.

[0060] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0061] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A process for separating and cutting flash of semiconductor packaging chips, characterized in that: The following steps are involved: (1) Fixing the cutting flash and the defective chip to the carrier film by laser irradiation or by dispensing glue, so that the fixing force between the cutting flash and the carrier film and the fixing force between the defective chip and the carrier film are greater than the fixing force between the good chip and the carrier film; (2) Apply force on the back side of the carrier film so that the good chip falls off the carrier film. The good chip is separated from the carrier film, and the cutting burr remains on the carrier film.

2. The process for separating and cutting flash of semiconductor packaging chips according to claim 1, characterized in that: Prior to step (1), the method further includes identifying cutting burrs / cutting burrs and defective chips through a machine vision system.

3. The process for separating and cutting flash of semiconductor packaging chips according to claim 1, characterized in that: In the step (2), ultrasound or manual operation is applied to the back of the carrier film so that the good chips fall off the carrier film.

4. The process for separating and cutting flash of semiconductor packaging chips according to claim 1, characterized in that: The carrier film is a UV film, a blue film or a green film.

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