Rework method of plastic sealed sheet

Abstract

The present invention relates to a reworking method for a plastic packaging sheet, and relates to the field of packaging technology. The reworking method divides the plastic packaging sheet to be reworked to form a plurality of first chips. Then the first chip is mounted on the first side of a provided carrier board according to a preset position. Since the first chip on the plastic packaging sheet to be reworked is reused and mounted and packaged again according to the preset position, the problem of waste of the first chip caused by the scrapping of the chip to be reworked is reduced.

Description

Technical Field

[0001] The present application relates to the field of packaging technology, and in particular to a reworking method for a plastic packaging sheet. Background Art

[0002] Chip packaging is a key step in the semiconductor manufacturing process, which involves protecting the bare semiconductor chip (die) for use in electronic devices.

[0003] The semiconductor chips before existing chip packaging are all single crystal or combination chip products. During packaging, the different single crystal or combination chips to be packaged will be aligned to provide a guarantee for the subsequent chip connection. If the chips to be packaged are relatively offset during packaging, the subsequent packaged products will be scrapped, which will lead to the waste of semiconductor chips before packaging.

[0004] Therefore, how to reduce the waste of semiconductor chips caused by packaging misalignment has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] Based on this, it is necessary to provide a reworking method for a plastic packaging sheet to solve the problem of how to reduce the waste of semiconductor chips caused by packaging misalignment in the prior art.

[0006] In order to achieve the above object, the present invention provides a reworking method for a plastic packaging sheet, the reworking method comprising:

[0007] Slicing the plastic package sheet to be reworked to form a plurality of first chips;

[0008] providing a carrier plate, the carrier plate comprising a first side;

[0009] Mounting the plurality of the first chips on the first side of the carrier board according to preset positions;

[0010] Re-seal the first chip mounted on the carrier board;

[0011] The carrier plate is removed.

[0012] In one embodiment, the plastic encapsulation sheet to be reworked comprises a first surface and a second surface, the first surface being a surface on which the first chip is disposed; and the step of dividing the plastic encapsulation sheet to be reworked into a plurality of first chips comprises:

[0013] Grinding the second surface of the plastic encapsulation sheet to be reworked to form an intermediate sheet exposing the back side of the first chip;

[0014] The intermediate sheet is diced to form a plurality of the first chips.

[0015] In one embodiment, before grinding the second surface of the plastic packaging sheet to be reworked, the method further includes:

[0016] A first film layer is mounted on the first surface of the plastic packaging sheet to be reworked, and the first film layer covers the first chip.

[0017] Providing the first film layer can protect the first chip from mechanical damage and contamination that may occur during the grinding process, thereby reducing the waste of the first chip during rework.

[0018] In one embodiment, after grinding the second surface of the plastic packaging sheet to be reworked, the method further includes:

[0019] The first film layer is removed.

[0020] In one embodiment, before the intermediate sheet is diced to form a plurality of first chips, the method further includes:

[0021] A second film layer is mounted on the surface of the intermediate sheet that exposes the back side of the first chip, and the area of ​​the second film layer is larger than the area of ​​the plastic packaging sheet to be reworked.

[0022] In one embodiment, mounting the plurality of first chips on the first side of the carrier according to preset positions includes:

[0023] The first chip is grabbed from the second film layer, and transferred and mounted to the first side of the carrier according to a preset position.

[0024] Setting the second film layer can effectively prevent the mechanical stress generated during blade cutting from damaging the first chip, and can also prevent pollutants generated during the cutting process from contaminating the first chip. It can also significantly reduce edge collapse and debris generation during the cutting process, thereby improving the yield.

[0025] In one embodiment, providing a carrier board includes:

[0026] Provide empty board;

[0027] A third film layer is formed on one side of the empty plate, and the side provided with the third film layer is the first side.

[0028] In one embodiment, removing the carrier includes: removing the third film layer to remove the carrier.

[0029] In one embodiment, the material of the third film layer is a thermal glass film material.

[0030] In one embodiment, mounting the plurality of first chips on the first side of the carrier board according to preset positions further includes:

[0031] The first chip is mounted on the first side of the carrier board at a preset position by using a flip-chip mounting method.

[0032] Compared with the prior art, the above technical solution has the following advantages:

[0033] The present application provides a reworking method for a plastic packaging sheet, wherein the plastic packaging sheet to be reworked is divided and processed to form a plurality of first chips. The first chips are then mounted on a first side of a provided carrier board according to a preset position. Since the first chips on the plastic packaging sheet to be reworked are reused and remounted and packaged according to the preset position, the problem of first chip waste caused by the scrapping of the chips to be reworked is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 It is a structural schematic diagram of an existing plastic sealing sheet with accurate alignment;

[0036] Figure 2 A schematic diagram of a structure of an existing plastic sealing sheet with relative position offset;

[0037] Figure 3 A schematic diagram of another existing structure of a plastic sealing sheet with relative position offset;

[0038] Figure 4 A schematic flow chart of a method for reworking a plastic sealing sheet is provided for an embodiment of the present application;

[0039] Figure 5 A schematic diagram of the structure of a plastic sealing sheet to be reworked provided in an embodiment of the present application;

[0040] Figure 6 A partial process diagram of a plastic-sealed sheet to be reworked provided in an embodiment of the present application;

[0041] Figure 7 A schematic diagram of the structure of another plastic packaging sheet to be reworked provided in an embodiment of the present application;

[0042] Figure 8 A schematic diagram of the structure of another plastic sealing sheet to be reworked provided in an embodiment of the present application;

[0043] Fig. 9 A schematic diagram of the structure of a plastic-encapsulated sheet to be reworked after dicing provided in an embodiment of the present application;

[0044] Fig.10 A schematic diagram of the structure of a carrier board provided in an embodiment of the present application;

[0045] Fig.11 A schematic structural diagram of a new plastic packaging sheet provided in an embodiment of the present application.

[0046] Description of reference numerals:

[0047] Explanation of the reference numerals: 10 - plastic packaging sheet to be reworked; 20 - first chip; 30 - first film layer; 40 - second film layer; 50 - empty carrier board; 60 - third film layer. DETAILED DESCRIPTION

[0048] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0050] It should be understood that although the terms first, second, third, etc. can be used to describe various layers, these layers should not be limited by these terms. These terms are only used to distinguish one layer from another layer. Therefore, without departing from the teachings of the present invention, the first layer discussed below can be represented as the second layer.

[0051] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein to describe the relationship of one element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms also include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the drawings is turned over, an element or feature described as "under" or "beneath" or "below" the other elements would be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both the above and below orientations.

[0052] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0053] Based on the content in the background technology, when the existing chips are repackaged, the customer's incoming materials are single crystal or combination chip products. When repackaging (Recon), the existing combination chip products need to be mounted according to the Unit pitch (unit pitch) on the drawing and the relative center position of each chip at the DA flip (Direct Attach) operation site. If the relative position of the chip is offset due to position parameter confirmation errors during the DA process, or abnormal parameters during the molding process, it will affect the subsequent redistribution layer (RDL) layer manufacturing and cause the opening to deviate from the substrate. In other words, the subsequent redistribution layer operation cannot be carried out and the product can only be scrapped. Reference Figure 1 , Figure 1 This is a structural schematic diagram of an existing plastic sealing sheet with accurate alignment; Figure 2 , Figure 2 This is a schematic diagram of the structure of an existing plastic packaging sheet relative position offset; Figure 3 , Figure 3 It is a schematic diagram of another existing structure of relative position offset of plastic packaging sheet; wherein, Figure 1 The pre-designed alignment position is shown in the figure. The first alignment distance X between chip A and chip B is 137 μm, and the second alignment distance Y is 280.81 μm. Figure 2 The first alignment hole 01 and the second alignment hole 01' produce a relative position offset. Figure 2 When aligning the alignment holes in Figure 3 The alignment information between chip A and chip B shown in the figure is wrong, such as Figure 3 The third alignment spacing a between the chip A and the chip B is 73.49 μm, and the fourth alignment spacing b is 373.76 μm. The third alignment spacing a is not equal to the first alignment spacing X, and the fourth alignment spacing b is not equal to the second alignment spacing Y, that is, it is different from the pre-designed alignment spacing.

[0054] When the first alignment interval X and the second alignment interval Y between chip A and chip B are accurately aligned, the RDL layer can be subsequently produced on the plastic package sheet, otherwise the plastic package sheet and the packaged chip products will be scrapped.

[0055] Based on this, the present application provides a reworking method for a plastic packaging sheet. The above reworking method divides the plastic packaging sheet to be reworked to form multiple first chips, and then mounts the first chip on the first side of a provided carrier board according to a preset position. Since the first chip on the plastic packaging sheet to be reworked is reused and re-mounted and packaged according to the preset position, the problem of waste of the first chip caused by the scrapping of the chip to be reworked is reduced.

[0056] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0057] Please refer to Figure 4 , Figure 4 A schematic diagram of a process for reworking a plastic sheet is provided for reference in the embodiment of the present application. Figure 5 , Figure 5 A structural schematic diagram of a plastic packaging sheet to be reworked provided in an embodiment of the present application; a rework method of the plastic packaging sheet includes:

[0058] S100 : Slicing the plastic packaging sheet 10 to be reworked to form a plurality of first chips 20 .

[0059] In this step, the plastic packaging sheet 10 to be reworked is the plastic packaging sheet after the relative position is dislocated during the plastic packaging. Multiple chips have been plastic-sealed in the plastic packaging sheet. In order to avoid wasting chips, the plastic packaging sheet 10 to be reworked is reworked. First, the plastic packaging sheet 10 to be reworked is divided to form multiple first chips 20, wherein different first chips 20 may be the same or different. There is no specific limitation on the first chip 20, and multiple first chips 20 may be obtained according to the design of the plastic packaging product.

[0060] It should be noted that the segmentation process of the reworked plastic packaging sheet 10 includes grinding and dicing the reworked plastic packaging sheet 10 . The segmentation process of the reworked plastic packaging sheet 10 will be described below.

[0061] Optionally, in another embodiment of the present application, refer to Figure 6 , Figure 6 A partial process diagram of a plastic package sheet to be reworked provided in an embodiment of the present application; the plastic package sheet to be reworked 10 comprises a first surface and a second surface, the first surface being a surface on which a first chip 20 is provided; the plastic package sheet to be reworked 10 is divided into a plurality of first chips 20, comprising:

[0062] S1001 : Grinding the second surface of the plastic packaging sheet 10 to be reworked to form an intermediate sheet exposing the back side of the first chip 20 .

[0063] In this step, the first surface of the plastic packaging sheet 10 to be reworked is the side on which the first chip 20 is provided, that is, the front side of the plastic packaging sheet, and the second surface is the back side of the plastic packaging sheet 10 to be reworked. The second surface is ground to remove part of the plastic packaging material to expose the middle sheet on the back side of the first chip 20. At this time, the thickness of the first chip 20 is the thickness of the chip before packaging, that is, the thickness of the original single crystal or combination chip.

[0064] It should be noted that the grinding method may be mechanical grinding, chemical mechanical polishing (CMP), etc. There is no specific limitation on the grinding method and it can be selected according to specific needs.

[0065] Optionally, in another embodiment of the present application, refer to Figure 7 , Figure 7 A schematic diagram of the structure of another plastic packaging sheet to be reworked provided in an embodiment of the present application; before the second surface of the plastic packaging sheet 10 to be reworked is ground, it also includes:

[0066] The first film layer 30 is mounted on the first surface of the plastic packaging sheet 10 to be reworked, and the first film layer 30 covers the first chip 20 .

[0067] Specifically, before grinding the second surface of the plastic packaging sheet 10 to be reworked, it is necessary to first mount a first film layer 30 on the first surface of the plastic packaging sheet 10 to be reworked. The first film layer 30 is a thin film. The mounting of the thin film can reduce defects such as edge chipping and corner chipping when grinding the second surface of the plastic packaging sheet 10 to be reworked, thereby reducing the probability of breakage. In other words, mounting the thin film can protect the first chip 20, so that the first chip 20 is not subject to mechanical damage and contamination that may be generated during the grinding process, thereby reducing the waste of the first chip 20 during rework.

[0068] Optionally, in another embodiment of the present application, after grinding the second surface of the plastic packaging sheet 10 to be reworked, the method further includes:

[0069] The first film layer 30 is removed.

[0070] Specifically, since the first film layer 30 is used to protect the first chip 20, after grinding, the first film layer 30 needs to be removed to prepare for subsequent dicing. The method of removing the first film layer 30 is not specifically limited and can be selected according to specific needs. After removing the first film layer 30, multiple first chips 20 are exposed. At this time, multiple first chips 20 are located on the intermediate sheet. It should be noted that the intermediate sheet is only used to illustrate the position of the first chip 20 at this time and is not specifically limited. Slicing is performed after grinding.

[0071] S1002 : Slicing the intermediate wafer to form a plurality of first chips 20 .

[0072] Optionally, in another embodiment of the present application, refer to Figure 8 , Figure 8 A schematic diagram of the structure of another plastic encapsulation sheet to be reworked provided in an embodiment of the present application; before the intermediate sheet is diced to form a plurality of first chips, the present invention further includes:

[0073] The second film layer 40 is mounted on the surface of the intermediate sheet where the back of the first chip 20 is exposed. The area of ​​the second film layer 40 is larger than the area of ​​the plastic packaging sheet 10 to be reworked.

[0074] Specifically, the second film layer 40 is a dicing film, and the second film layer 40 is mounted on the surface of the intermediate film that exposes the back side of the first chip 20. When dicing, the area of ​​the second film layer 40 is larger than the area of ​​the plastic packaging film 10 to be reworked. This can effectively prevent the mechanical stress generated by the blade cutting from damaging the first chip 20, and the dicing film can also prevent contaminants generated during the cutting process from being contaminated on the first chip 20. These contaminants may affect the electrical performance and reliability of the chip. During the dicing process, a large amount of debris is generated due to friction and cutting. The dicing film can effectively block these debris and prevent them from contacting the surface of the first chip 20. The use of the dicing film can also significantly reduce the edge collapse and fragmentation generation during the cutting process, thereby improving the yield.

[0075] It should be noted that after the dicing is completed, a plurality of first chips 20 are obtained. Fig. 9 , Fig. 9 A schematic diagram of a plastic encapsulation sheet to be reworked after dicing provided in an embodiment of the present application; the first chip 20 is cut according to the edge of the larger chip, so some of the original plastic encapsulation material may be left on the smaller chip, but it will not affect the subsequent rework, for example, Fig. 9 The first chip 20A is larger than the first chip 20B, and the first chip 20A is diced and cut by the edge thereof. After a plurality of first chips 20 are obtained, the chips are re-encapsulated.

[0076] Before re-sealing, you need to do some preliminary preparations, which will be explained below.

[0077] S101: providing a carrier board, wherein the carrier board comprises a first side.

[0078] Optionally, in another embodiment of the present application, refer to Fig.10 , Fig.10 A schematic diagram of the structure of a carrier provided in an embodiment of the present application; the carrier provided comprises:

[0079] A blank plate 50 is provided.

[0080] The third film layer 60 is formed on one side of the dummy plate 50 , and the side provided with the third film layer 60 is the first side.

[0081] Optionally, in another embodiment of the present application, the material of the third film layer 60 is a thermal glass film material.

[0082] Specifically, the empty carrier plate 50 may be a metal carrier plate. There is no specific limitation on the material of the empty carrier plate 50 and the material may be selected according to specific needs.

[0083] A third film layer 60 is formed on the first side of the empty carrier board 50. The material of the third film layer 60 may be a hot glass film material, which is equivalent to a double-sided adhesive. When the first chip is transferred, the first chip can be adhered to the first side of the carrier board, that is, to the side provided with the third film layer 60. It should be noted that the material of the third film layer 60 is not specifically limited.

[0084] S102: Mounting a plurality of first chips 20 on a first side of a carrier according to preset positions.

[0085] In this step, the position of the first chip 20 is first set, that is, the preset position of the first chip 20 is designed first, and then the preset position and the first chip 20 are accurately aligned, so that the first chip 20 can be reused to avoid waste.

[0086] Optionally, in another embodiment of the present application, Figure 8 As shown, and reference Fig.11 , Fig.11 A schematic diagram of a new plastic package sheet provided in an embodiment of the present application; a plurality of first chips 20 are mounted on a first side of a carrier board according to preset positions, including:

[0087] The first chip 20 is grabbed from the second film layer 40 and transferred and mounted to the first side of the carrier according to a preset position.

[0088] Specifically, since the first chip 20 is still located on the second film layer 40 after being diced, in order to mount the first chip 20 on the carrier, it is necessary to first grab the first chip 20 from the second film layer 40, and then mount all the first chips 20 on the first side of the carrier according to the preset position to complete the transfer of the first chip 20.

[0089] Optionally, in another embodiment of the present application, a plurality of first chips 20 are mounted on the first side of the carrier according to preset positions, further comprising:

[0090] The first chip 20 is mounted on the first side of the carrier board at a preset position by flip-chip mounting.

[0091] Specifically, the flip-chip mounting method may be a DA flip-chip mounting method, which can achieve a higher degree of automation and production speed, thereby greatly improving the overall production efficiency, and the reliability of mounting the first chip 20 using the DA flip-chip mounting method is higher. For example, using a DA device, the first chip 20 is lifted up by a pin, and then the first chip 20 is removed by a suction column, and then the first chip 20 is placed on the first side of the carrier, that is, on the side of the carrier where the third film layer 60 is provided, and the mounting is completed and the subsequent steps are entered.

[0092] S103: re-seal the first chip 20 mounted on the carrier.

[0093] In this step, the first chip 20 transferred and mounted on the carrier is again plastic-encapsulated. It should be noted that the plastic encapsulation material used may be epoxy molding compound (EMC for short), and of course there is no specific limitation on the plastic encapsulation material.

[0094] It should be noted that at this time, one side of the third film layer 60 is adhered to the empty carrier board 50 , and the other side is adhered to the new plastic packaging sheet. In order to form the final plastic packaging sheet, the carrier board needs to be removed.

[0095] S104: removing the carrier board.

[0096] Optionally, in another embodiment of the present application, removing the carrier includes: removing the third film layer 60 to remove the carrier.

[0097] Specifically, in order to obtain the final plastic packaging sheet, the carrier needs to be removed. The third film layer 60 can be foamed and debonded by thermal debonding to remove the carrier.

[0098] At this time, the surface of the plastic sealing sheet facing the third film layer 60 is the front side. After the plastic sealing sheet is completed, the plastic sealing sheet is marked to determine the product model.

[0099] It should be noted that after obtaining the new plastic packaging sheet obtained in this application, the appearance of the plastic packaging sheet will be inspected to ensure the yield of the plastic packaging sheet. In addition, the warpage of the plastic packaging sheet will be measured to ensure its reliability. In addition, the glue will be removed to ensure that there is no glue residue on the plastic packaging sheet, thereby completing the rework operation of the plastic packaging sheet.

Claims

1. A method for reworking a plastic package sheet, characterized in that: The rework method comprises: The plastic sealing sheet to be reworked is divided to form a plurality of first chips, wherein the plastic sealing sheet to be reworked is a plastic sealing sheet in which the relative positions of the chips to be packaged are misaligned during plastic sealing; providing a carrier plate, the carrier plate comprising a first side; Mounting the plurality of the first chips on the first side of the carrier board according to preset positions; Re-seal the first chip mounted on the carrier board; removing the carrier plate; The plastic packaging sheet to be reworked comprises a first surface and a second surface, wherein the first surface is a surface on which the first chip is arranged; and the plastic packaging sheet to be reworked is divided into a plurality of first chips, comprising: Mounting a first film layer on the first surface of the plastic packaging sheet to be reworked, wherein the first film layer covers the first chip; Grinding the second surface of the plastic encapsulation sheet to be reworked to form an intermediate sheet exposing the back side of the first chip; The intermediate sheet is diced to form a plurality of the first chips, wherein the first chips include first-type chips and second-type chips, the size of the first-type chips is larger than the size of the second-type chips, and the edges of the first-type chips are used as dicing edges during dicing.

2. The reworking method according to claim 1, characterized in that: After the second surface of the plastic packaging sheet to be reworked is ground, the method further includes: The first film layer is removed.

3. The reworking method according to claim 1, characterized in that: Before the intermediate sheet is diced to form a plurality of the first chips, the method further includes: A second film layer is mounted on the surface of the intermediate sheet that exposes the back side of the first chip, and the area of ​​the second film layer is larger than the area of ​​the plastic packaging sheet to be reworked.

4. The reworking method according to claim 3, characterized in that: The step of mounting the plurality of first chips on the first side of the carrier board according to preset positions includes: The first chip is grabbed from the second film layer, and transferred and mounted to the first side of the carrier according to a preset position.

5. The reworking method according to claim 1, characterized in that: The carrier board is provided, comprising: Provide empty board; A third film layer is formed on one side of the empty plate, and the side provided with the third film layer is the first side.

6. The reworking method according to claim 5, characterized in that: The removing of the carrier includes: removing the third film layer to remove the carrier.

7. The reworking method according to claim 5, characterized in that: The material of the third film layer is a thermal glass film material.

8. The reworking method according to claim 1, characterized in that: The step of mounting the plurality of the first chips on the first side of the carrier board according to preset positions further includes: The first chip is mounted on the first side of the carrier board at a preset position by using a flip-chip mounting method.

Images