Wafer transfer method

Abstract

The application provides a wafer transfer method, which can be applied to fan-out panel level packaging, and the method comprises the following steps: pressing a square carrier substrate with an adhesive layer on wafers adhered to a blue film and distributed in a circular shape, so as to adhere the carrier substrate to the wafers; lifting the carrier substrate, so that the wafers in the coverage area of the carrier substrate are separated from the blue film; pressing the carrier substrate on a large-size target substrate designed with an adhesive layer pattern, the pitch of the adhesive layer pattern on the target substrate is n times the pitch of the wafers, so as to adhere the wafers to the target substrate; lifting the carrier substrate, 1 / n 2 The wafer transfer method can transfer a plurality of wafers on the carrier substrate to the target substrate. The adhesion between the carrier substrate and the wafers is greater than the adhesion between the blue film and the wafers, and smaller than the adhesion between the target substrate and the wafers. The method can simultaneously transfer a plurality of wafers from the blue film to the target square substrate through two times of transfer, and can improve the efficiency and reduce the cost of wafer reconstruction.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, and more particularly to a wafer transfer method. Background Technology

[0002] Fan-out Wafer Level Package (FOWLP) and Fan-out Panel Level Package (FOPLP) are two packaging technologies that have received widespread attention in recent years. Both FOWLP and FOPLP involve a wafer reassembly step. The general process of wafer reassembly involves dicing the wafer into multiple wafers, transferring the wafers to a carrier substrate, and then fabricating an RDL (Redistribution Layer) on the carrier substrate to expose the I / O electrodes of the wafers. In existing technologies, vacuum or electrostatic adsorption heads are typically used to transfer the wafers one by one from the blue film to the carrier substrate, which results in low wafer transfer efficiency and high process costs.

[0003] FOPLP (Fan-Out Panel Level Packaging) is considered a breakthrough technology that extends FOWLP (Fan-Out Panel Level Packaging) and enables highly integrated IC packaging. FOPLP changes the circular wafer carrier to a larger square carrier (glass or PCB), resulting in higher utilization and lower cost. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a wafer transfer method that can transfer wafers simply and efficiently, and helps to reduce the process cost of wafer reconfiguration.

[0005] According to an embodiment of the present invention, a wafer transfer method transfers a wafer on a blue film to a target substrate via a carrier substrate. The carrier substrate is capable of bonding with the wafer. The target substrate has a plurality of first adhesive bodies, with a first gap between adjacent first adhesive bodies. The target substrate is capable of bonding with the wafer through the first adhesive bodies. The adhesive force between the carrier substrate and the wafer is greater than the adhesive force between the blue film and the wafer, and the adhesive force between the carrier substrate and the wafer is less than the adhesive force between the target substrate and the wafer. The carrier substrate has a plurality of second adhesive bodies, and the carrier substrate is bonded to the wafer through the second adhesive bodies. Each first adhesive body is used to bond with one wafer, and each second adhesive body is used to bond with one wafer. The distance between adjacent first adhesive bodies is L1, and the distance between adjacent second adhesive bodies is L2, satisfying: L1 = n·L2, n ≥ 2 and n is an integer. The wafer transfer method includes the following steps: S10: Press the carrier substrate onto the wafer bonded to the blue film, so that the carrier substrate is bonded to m wafers, where m is a positive integer greater than 1; S20: Lift the carrier substrate to separate the wafer adhered to the carrier substrate from the blue film; S30: Press the carrier substrate onto the target substrate, so that a portion of the wafers are bonded to the target substrate, and make the remaining wafers not bonded to the target substrate face the first gap, wherein there are a total of (m / n) 2 Each of the aforementioned wafers is bonded to the target substrate, and (m / n) 2 () is a positive integer; S40: Lift the target substrate to separate the wafer bonded to the target substrate from the carrier substrate; S50: Determine whether all the wafers on the carrier substrate have been transferred to the destination substrate. If not, repeat steps S30 and S40 in sequence.

[0006] The wafer transfer method according to embodiments of the present invention has at least the following beneficial effects: The transfer method of this invention first removes multiple wafers from a carrier substrate in one operation using a carrier substrate, and then repeatedly presses and separates the carrier substrate from a target substrate to transfer the multiple wafers onto the target substrate. This arrangement helps reduce the number of trips between the carrier substrate and the target substrate, thereby improving the efficiency of transferring wafers from the blue film to the target substrate. Moreover, since multiple wafers are transferred in one operation, the positional deviation between different wafers pressed onto the target substrate in the same operation is small, which helps reduce the positional deviation between different wafers on the reconstructed wafer.

[0007] The wafer transfer method of this invention first adheres the wafer to a carrier substrate, and then removes the wafer from the carrier substrate using a target substrate, thereby transferring the wafer from the blue film to the target substrate. This wafer transfer method primarily utilizes the difference in adhesive forces between the blue film, the carrier substrate, and the target substrate to achieve wafer transfer, eliminating the need for the expensive vacuum chucks or electrostatic chucks used in existing technologies to repeatedly pick up the wafer between the carrier substrate and the target substrate and transfer each wafer individually from the blue film to the target substrate. Furthermore, this wafer transfer method utilizes the difference in adhesive forces between different components and the wafer to achieve wafer transfer, eliminating the need for heating, ultraviolet light irradiation, or other methods to break the bond between the wafer and the blue film or carrier substrate.

[0008] In summary, the wafer transfer method of the present invention is simple, efficient, and helps to reduce the process cost of wafer reconstruction.

[0009] According to some embodiments of the present invention, the wafer is cut from a wafer having a square region, the length of the diagonal of the square region being equal to the diameter of the wafer; The step of pressing the carrier substrate onto the wafer bonded to the blue film, thereby bonding the carrier substrate to m wafers, is achieved by: covering the square area with the carrier substrate, and bonding the carrier substrate to all wafers disposed within the square area.

[0010] According to some embodiments of the present invention, the carrier substrate is square, and the side length of the carrier substrate is equal to the side length of the square region.

[0011] According to some embodiments of the present invention, the wafer is cut from a wafer with a diameter of D, the target substrate is rectangular, and the length of the short side of the target substrate is L3, satisfying: D≥4 inch, L3≥400mm.

[0012] According to some embodiments of the present invention, the target substrate includes a first plate body and a first adhesive body, wherein the first adhesive body is bonded to the outer surface of the first plate body, and the first plate body is a glass plate or a PCB.

[0013] According to some embodiments of the present invention, the carrier substrate includes a second plate and a plurality of second adhesives, the second adhesives being adhered to the outer surface of the second plate, and the carrier substrate being adhered to the wafer through the second adhesives; the adhesive force between the second adhesive and the second plate is greater than the adhesive force between the second adhesive and the wafer.

[0014] According to some embodiments of the present invention, the target substrate includes a first plate and a plurality of first adhesives, the first adhesives being bonded to the outer surface of the first plate; the adhesive force between the first adhesive and the first plate is greater than the adhesive force between the second adhesive and the wafer.

[0015] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a planar schematic diagram of the wafer; Figure 2 for Figure 1 A schematic diagram of the cross-section of the wafer in the diagram; Figure 3This is a schematic diagram of a wafer transfer method according to an embodiment of the present invention; Figure 4 This is a schematic diagram showing the bonding of a substrate to a single wafer on a blue film. Figure 5 A schematic diagram showing the separation of a single wafer from the blue film to support the substrate; Figure 6 A schematic diagram showing a single wafer being pressed onto a target substrate to serve as a carrier substrate; Figure 7 A schematic diagram illustrating the process of lifting the substrate and retaining a single wafer on the target substrate; Figure 8 This is the front view of the carrier substrate pressing onto the target substrate for the first time when n=2. Figure 9 The front view of the second embodiment when n=2, showing the first lifting of the carrier substrate from the target substrate; Figure 10 A front view of the second embodiment where the carrier substrate is pressed onto the target substrate for the second time when n=2; Figure 11 This is a planar schematic diagram of the substrate when n=2; Figure 12 This is a planar schematic diagram of the target substrate when n=2; Figure 13 This is a planar schematic diagram showing the first pressing of the carrier substrate onto the target substrate when n=2. Figure 14 This is a planar schematic diagram showing the second pressing of the carrier substrate onto the target substrate when n=2. Figure 15 This is a planar schematic diagram of the carrier substrate pressing onto the target substrate for the third time when n=2. Figure 16 This is a planar schematic diagram of the fourth pressing of the carrier substrate onto the target substrate when n=2. Figure 17 This is the front view of the carrier substrate pressing onto the target substrate for the first time when n=3. Figure 18 This is a front view of the carrier substrate pressing onto the target substrate for the second time when n=3. Figure 19 This is a front view of the carrier substrate pressing onto the target substrate for the third time when n=3.

[0017] Figure label: 101 - Wafer, 102 - Square area, 103 - Chip, 104 - Blue film; 201 - Target substrate, 202 - Supporting substrate, 203 - First plate, 204 - First adhesive, 205 - Second plate, 206 - Second adhesive, 207 - First gap. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0019] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0020] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0021] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0022] The wafer transfer method of the present invention transfers a wafer 103 on a blue film 104 to a target substrate 201 via a carrier substrate 202. To facilitate the explanation of the wafer transfer method of the present invention, the basic structures of the wafer 103, the carrier substrate 202, and the target substrate 201 will be described below.

[0023] Chip 103 is formed by cutting wafer 101. Figure 1 The image shows wafer 101 after it has been cut. (Combined with...) Figure 1 and Figure 2 Before the wafer 101 is cut, a blue film 104 is attached to the bottom of the wafer 101; after the complete wafer 101 is cut, multiple wafers 103 are formed, and the bottom of the wafers 103 are bonded to the blue film 104.

[0024] The target substrate 201 can be bonded to the chip 103. For example, see reference. Figure 4In one embodiment, the target substrate 201 includes a first plate 203 and a first adhesive 204, the first adhesive 204 being bonded to the outer surface of the first plate 203. The first adhesive 204 is formed by applying adhesive to the first plate 203 by dispensing. The first plate 203 may be made of aluminum alloy, titanium alloy, or other metallic or non-metallic materials.

[0025] The substrate 202 can also be bonded to the chip 103 (e.g.) Figure 7 (As shown). Refer to... Figure 4 In one embodiment, the carrier substrate 202 includes a second plate 205 and a second adhesive 206, the second adhesive 206 being bonded to the outer surface of the second plate 205. Similar to the formation of the first adhesive 204, the second adhesive can be formed by applying adhesive to the second plate 205 via dispensing. However, the materials of the first adhesive 204 and the second adhesive 206 are different.

[0026] The target substrate 201 is bonded to the wafer 103 via its first adhesive element 204; the carrier substrate 202 is bonded to the wafer 103 via its second adhesive element 206. The adhesive force between the carrier substrate 202 and the wafer 103 is greater than the adhesive force between the wafer 103 and the blue film 104. The adhesive force between the carrier substrate 202 and the wafer 103 is less than the adhesive force between the wafer 103 and the target substrate 201. In this invention, the adhesive force between two objects already bonded together can be detected as follows: one object is fixed, and a tensile force is applied to the other object; when the two objects just separate, the applied tensile force is the adhesive force between the two objects. The adhesive force between the carrier substrate 202 and the wafer 103 can also be equivalent to the adhesive force between the second adhesive element 206 and the wafer 103. The adhesive force between the target substrate 201 and the chip 103 can also be equivalent to the adhesive force between the first adhesive 204 and the chip 103.

[0027] Reference Figure 6There is a first gap 207 between adjacent first adhesive bodies 204. If the distance between adjacent first adhesive bodies 204 is denoted as L1, and the distance between adjacent second adhesive bodies 206 is denoted as L2, then the relationship between L1 and L2 satisfies: L1 = n·L2, where n ≥ 2 and n is an integer. It should be noted that L1 should be the distance between corresponding parts of the two first adhesive bodies 204; for example, L1 is the distance between the right ends of the first and second first adhesive bodies 204. L1 has a different width than the first gap 207. Similarly, L2 should be the distance between corresponding parts of the two second adhesive bodies 206; for example, L2 is the distance between the right ends of the first and second second adhesive bodies 206.

[0028] It should be noted that the structure of the target substrate 201 and the carrier substrate 202 can also be configured in other forms, as long as the target substrate 201 and the carrier substrate 202 can adhere to the chip 103.

[0029] The wafer transfer method of the present invention will now be described. Figure 3 The image illustrates a wafer transfer method according to one embodiment of the present invention, the method comprising the following steps: S10: Press the carrier substrate 202 onto the wafer 103 bonded to the blue film 104, so that the carrier substrate 202 is bonded to m wafers 103, where m is a positive integer greater than 1. S20: Lift the carrier substrate 202, thereby separating all the wafers 103 (a total of m) bonded to the carrier substrate 202 from the blue film 104; S30: Press the carrier substrate 202 onto the target substrate 201, so that a portion of the wafers 103 are bonded to the target substrate 201, and make the remaining wafers 103 not bonded to the target substrate 201 face the first gap, wherein the number of wafers 103 bonded to the target substrate 201 in this step is equal to (m / n) 2 That is, equal to m divided by n 2 The obtained quotient, and (m / n 2 () is a positive integer; S40: Lift up the target substrate 201, thereby separating the wafer 103 bonded to the target substrate 201 from the carrier substrate 202; S50: Determine whether all the wafers 103 on the carrier substrate 202 (referring to all the wafers 103 that were glued to the carrier substrate 202 in step S20) have been transferred to the target substrate 201. If not, repeat steps S30 and S40 in sequence.

[0030] Although the above method removes multiple wafers 103 from the blue film 104 at once using the carrier substrate, for ease of explanation, the following will first combine... Figures 4 to 7 The entire process of how a single wafer 103 is transferred from the blue film 104 to the target substrate 201 will be explained, and then the process of how multiple wafers 103 are transferred to the target substrate 201 in steps S30 to S50 will be explained.

[0031] You can refer to them in sequence. Figures 4 to 7 . Figure 4 The diagram shows the state when the wafer 103 on the blue film 104 is in contact with the carrier substrate 202. Figure 4 After the carrier substrate 202 rises, the relative positions between the carrier substrate 202, the wafer 103, and the blue film 104 are as follows: Figure 5 As shown, Figure 5 The wafer 103 has separated from the blue film 104. After separation, the wafer 103 can move together with the carrier substrate 202. Subsequently, the carrier substrate 202 moves first above the carrier substrate 202, and then moves downward, thereby pressing the wafer 103 onto the target substrate 201. The state of the wafer 103 pressed onto the target substrate 201 by the carrier substrate 202 is as follows. Figure 6 As shown, the side of the chip 103 facing away from the carrier substrate 202 is bonded to the target substrate 201. Figure 6 After the carrier substrate 202 rises, the relative positions between the carrier substrate 202, the wafer 103, and the target substrate 201 are as follows: Figure 7 As shown, at this time, the wafer 103 and the target substrate 201 are fixed to each other, the carrier substrate 202 is separated from the wafer 103, and the wafer 103 is transferred to the target substrate 201.

[0032] In step S20, since the adhesive force between the carrier substrate 202 and the chip 103 is greater than the adhesive force between the blue film 104 and the chip 103, the chip 103 will separate from the blue film 104 first during the lifting of the carrier substrate 202. Even when the chip 103 and the blue film 104 have just separated, the chip 103 will still adhere to the carrier substrate 202 and will not detach from it. After the chip 103 separates from the blue film 104, since the chip 103 remains adhered to the carrier substrate 202, the chip 103 will move along with the carrier substrate 202.

[0033] Similarly, in step S40, since the adhesive force between the carrier substrate 202 and the wafer 103 is less than the adhesive force between the target substrate 201 and the wafer 103, the wafer 103 will separate from the carrier substrate 202 first during the lifting process of the carrier substrate 202; after the wafer 103 separates from the carrier substrate 202, the wafer 103 remains bonded to the target substrate 201 and is thus fixed on the target substrate 201.

[0034] Next, let's combine... Figures 8 to 10The process of transferring multiple wafers 103 onto the target substrate 201 is described. Figures 8 to 10 In the embodiment shown, in order to transfer all the wafers 103 bonded to the carrier substrate 202 onto the target substrate 201, the carrier substrate 202 is pressed onto the target substrate 201 a total of twice. Figures 8 to 10 In this case, L1 = 2L2. For example... Figure 8 As shown, each time the carrier substrate 202 presses against the target substrate 201, only (m / n) 2 One chip 103 is bonded to the first adhesive 204 of the target substrate 201, while the remaining chips 103 still bonded to the carrier substrate 202 are positioned opposite to the first gap 207 so as not to contact any of the first adhesives 204.

[0035] The transfer method of the present invention first removes multiple wafers 103 from the carrier substrate 202 in one go, and then repeatedly presses and separates the carrier substrate 202 from the target substrate 201, thereby transferring the multiple wafers 103 onto the target substrate 201. This arrangement helps to reduce the number of round trips between the carrier substrate 202 and the target substrate 201, thereby improving the efficiency of transferring the wafers 103 from the blue film to the target substrate 201. Moreover, since multiple wafers 103 are transferred in one go, the positional deviation between different wafers 103 that are pressed onto the target substrate 201 in the same go is small, which helps to reduce the positional deviation between different wafers 103 on the reconstructed wafer.

[0036] Furthermore, in the wafer transfer method of the present invention, the wafer 103 is first bonded together using the carrier substrate 202, and then the wafer 103 is detached from the carrier substrate 202 using the target substrate 201, thereby transferring the wafer 103 from the blue film 104 to the target substrate 201. The wafer transfer method of the present invention mainly utilizes the difference in adhesion forces between the blue film 104, the carrier substrate 202, and the target substrate 201 to achieve the transfer of the wafer 103, eliminating the need for the use of expensive vacuum chucks or electrostatic chucks in the prior art to pick up the wafer 103. The wafer transfer method of the present invention utilizes the difference in adhesion forces between different components and the wafer 103 to achieve the transfer of the wafer 103, eliminating the need for heating, ultraviolet light irradiation, or other means to break the bond between the wafer 103 and the blue film 104 or the carrier substrate 202.

[0037] In summary, the wafer transfer method of the present invention is simple, efficient, and helps to reduce the process cost of wafer reconstruction.

[0038] The wafer transfer method of the present invention is applicable to fan-out panel-level packaging (FOPLP) because for fan-out panel-level packaging, the size of the target substrate 201 is usually much larger than the size of the wafer 101 and the size of the carrier substrate, and the distance between different wafers 103 on the target substrate 201 is also relatively large.

[0039] Figure 11 and Figure 12 The diagrams show planar views of the carrier substrate 202 and the target substrate 201 when n=2. Sixteen first adhesive bodies 204 are arranged in 4 rows and 4 columns, and sixteen second adhesive bodies 206 are also arranged in 4 rows and 4 columns. When the carrier substrate 202 is pressed onto the blue film, it can hold 16 wafers 103 at once. Each wafer 103 is bonded to one first adhesive body 204, and the wafers 103 bonded to the carrier substrate 202 are also arranged in 4 rows and 4 columns. Figure 11 After all the first adhesive bodies 204 on the carrier substrate 202 have been attached with a wafer 103, if it is necessary to transfer all the wafers 103 on the carrier substrate 202 to the target substrate 201, then the carrier substrate 202 needs to be pressed onto the target substrate 201 four times (as shown below). Figures 13 to 16 (As shown).

[0040] Figures 13 to 16 In the diagram, the larger dashed box indicates the position of the outer edge of the carrier substrate 202 (i.e. the outer edge of the second plate 205), the smaller dashed box indicates the wafer 103 that is bonded to the carrier substrate 202 but not to the target substrate 201, and the square filled with diagonal lines indicates the wafer 103 that is bonded to the target substrate 201.

[0041] Combination Figure 13 and Figure 5 When the carrier substrate 202 is first pressed onto the target substrate 201, the four chips 103 in the first row, first column, first row, third column, third row, first column, and third row, third column are bonded to the target substrate 201. The remaining chips 103 still bonded to the carrier substrate 202 are not bonded to the second adhesive 206 of the target substrate 201. When the carrier substrate 202 is first lifted off the target substrate 201 (e.g. Figure 6 As shown, the carrier substrate 202 can move laterally and then be pressed down.

[0042] Combination Figure 14When the carrier substrate 202 presses onto the target substrate 201 for the second time, the four chips 103 in the first row and second column, the first row and fourth column, the third row and second column, and the third row and fourth column of the carrier substrate 202 are bonded to the target substrate 201. The remaining chips 103 that are still bonded to the carrier substrate 202 are not bonded to the second adhesive 206 of the target substrate 201. After the carrier substrate 202 is lifted off the target substrate 201 for the second time, the position of the carrier substrate 202 changes again, and then the carrier substrate 202 is pressed down for the third time.

[0043] Reference Figure 15 When the carrier substrate 202 is pressed onto the target substrate 201 for the third time, the four wafers 103 in the second row, first column, second row, third column, fourth row, first column, and fourth row, third column of the carrier substrate 202 are bonded to the target substrate 201. The remaining wafers 103 still bonded to the carrier substrate 202 are not bonded to the second adhesive 206 of the target substrate 201. After the carrier substrate 202 is lifted off the target substrate 201 for the third time, the position of the carrier substrate 202 changes again, and then the carrier substrate 202 is pressed down for the fourth time.

[0044] Reference Figure 16 When the carrier substrate 202 is pressed onto the target substrate 201 for the fourth time, the four wafers 103 in the second row, second column, second row, fourth column, fourth row, and fourth column of the carrier substrate 202 are bonded to the target substrate 201. The remaining wafers 103 still bonded to the carrier substrate 202 are not bonded to the second adhesive 206 of the target substrate 201. After the carrier substrate 202 is lifted off the target substrate 201 for the fourth time, all the wafers 103 on the carrier substrate 202 have been transferred to the target substrate 201.

[0045] The process of transferring all the wafers 103 on the carrier substrate 202 to the destination substrate 201 can be summarized as follows: In step S10, the m wafers 103 bonded to the carrier substrate 202 are arranged in p columns and p rows, where p 2 =m, where p is a positive integer; In step S30, the chip 103 bonded to the target substrate 201 is the chip 103 in the j-th row and i-th column, the j-th row and (i+n)-th column, the (j+n)-th row and n-th column, and the (j+n)-th row and (i+n)-th column. Moreover, when step S30 is executed for the first time, i=1 and j=1. In step S50, determining whether all wafers 103 on the carrier substrate 202 have been transferred to the destination substrate 201 specifically involves: if j+n<p and i+n<p, then reassigning a value to i, making i=i+1, and then returning to step S30; if j+n<p and i+n=p, then reassigning a value to j and i, making i=1 and j=j+1, and then returning to step S30; when j+n=p and i+n<p, then reassigning a value to i, making i=i+1, and then returning to step S30; if j+n=p and i+n=p, then whether all wafers 103 on the carrier substrate 202 have been transferred to the destination substrate 201 is determined, and step S30 does not need to be executed again.

[0046] The case when n=3 can be roughly referred to. Figures 17 to 19 , Figures 17 to 19 This diagram only shows which columns of wafers 103 are bonded to the target substrate 201. The number of rows of wafers 103 bonded to the target substrate 201 can be substituted into the above summary when n=3, and will not be described in detail here. When n=3, the carrier substrate 202 needs to be pressed onto the target substrate 201 a total of nine times to transfer all wafers 103 on the carrier substrate 202 to the target substrate 201. Specifically, when the carrier substrate 202 is pressed onto the target substrate 201 for the first time, wafers 103 in the first and fourth columns of the carrier substrate 202 are bonded to the target substrate 201; when the carrier substrate 202 is pressed onto the target substrate 201 for the second time, wafers 103 in the second and fifth columns of the carrier substrate 202 are bonded to the target substrate 201; and when the carrier substrate 202 is pressed onto the target substrate 201 for the third time, wafers 103 in the third and fifth columns of the carrier substrate 202 are bonded. Cases with larger values ​​of n are not illustrated in this invention.

[0047] The following supplements other contents regarding the carrier substrate 202, the target substrate 201, and the wafer transfer method. Unless otherwise specified, the supplementary contents can be incorporated into the wafer transfer method of any of the embodiments described above.

[0048] like Figure 1As shown, wafer 101 is circular and has a square region 102, the length of which is equal to the diameter of wafer 101. The square region 102 of wafer 101 contains a relatively large proportion of wafers 103 (approximately 80%). In one embodiment, in step S10, "pressing the carrier substrate 202 onto the wafers 103 bonded to the blue film 104, so that the carrier substrate 202 is bonded to m wafers 103" is specifically achieved by covering the square region 102 with the carrier substrate 202, thereby bonding the carrier substrate 202 to all wafers 103 within the square region 102. The advantage of this arrangement is that the carrier substrate 202 can remove a larger number of wafers 103 from the blue film 104 at once, thereby improving the efficiency of wafer 103 transfer.

[0049] Accordingly, in order to adapt the carrier substrate 202 to the square region 102 of the wafer 101, the carrier substrate 202 can be set as a square (for example, the second plate 205 is set as a square), and the side length of the carrier substrate 202 is equal to the side length of the square region 102.

[0050] The wafer 103 located outside the square region 102 can be transferred to the target substrate 201 after the wafer 103 in the square region 102 has been completely transferred to the target substrate 201. The wafer 103 outside the square region 102 can also be transferred to the target substrate 201 using another carrier substrate 202 (with a different shape), or it can be adsorbed and transferred by a vacuum chuck or an electrostatic chuck.

[0051] In one embodiment, to make the wafer transfer method applicable to fan-out panel-level packaging (FOPLP), the following settings can be made: the diameter of the wafer 101 is denoted as D, the target substrate 201 is rectangular, the length of the short side of the target substrate 201 is denoted as L3, D ≥ 4 inches, and L3 ≥ 400 mm. Furthermore, if the wafer transfer method of the present invention is applied to fan-out panel-level packaging, the second plate 205 can be a glass substrate or a PCB (printed circuit board).

[0052] In one embodiment, the adhesive force between the second adhesive 206 and the second plate 205 is greater than the adhesive force between the second adhesive 206 and the wafer 103. Because the adhesive force between the second adhesive 206 and the second plate 205 is greater than the adhesive force between the second adhesive 206 and the wafer 103, during the process of lifting the carrier substrate 202 from the target substrate 201 (corresponding to step S40), when the second adhesive 206 separates from the wafer 103, the second adhesive 206 can still remain adhered to the second plate 205 and will not detach from the second plate 205. Therefore, this arrangement is to prevent the second adhesive 206 from separating from the second plate 205 during the process of lifting the carrier substrate 202 from the target substrate 201, thereby preventing the second adhesive 206 from remaining on the carrier substrate 202, and further preventing the second adhesive 206 remaining on the wafer 103 from affecting subsequent wafer reconstruction steps.

[0053] In one embodiment, the adhesive force between the first adhesive 204 and the first plate 203 is greater than the adhesive force between the second adhesive 206 and the wafer 103. Specifically, if the adhesive force between the first adhesive 204 and the first plate 203 is less than the adhesive force between the second adhesive 206 and the wafer 103, then during the process of lifting the carrier substrate 202 from the target substrate 201 (corresponding to step S40), before the wafer 103 separates from the second adhesive 206, the first adhesive 204 may have already separated from the first plate 203, resulting in the wafer 103 and the first adhesive 204 being lifted together with the carrier substrate 202, and the wafer 103 failing to be fixed to the carrier substrate 202. Therefore, the above arrangement is mainly to avoid the separation of the first adhesive 204 from the first plate 203 when the carrier substrate 202 is lifted from the target substrate 201, thereby preventing the wafer 103 from failing to be fixed to the target substrate 201.

[0054] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A wafer transfer method, characterized in that, A wafer on a blue film is transferred to a target substrate via a carrier substrate. The carrier substrate is capable of bonding with the wafer. The target substrate has multiple first adhesive bodies with a first gap between adjacent first adhesive bodies. The target substrate is bonded to the wafer through the first adhesive bodies. The adhesive force between the carrier substrate and the wafer is greater than the adhesive force between the blue film and the wafer, and less than the adhesive force between the target substrate and the wafer. The carrier substrate has multiple second adhesive bodies, and the carrier substrate is bonded to the wafer through the second adhesive bodies. Each first adhesive body is used to bond to one wafer, and each second adhesive body is used to bond to one wafer. The distance between adjacent first adhesive bodies is L1, and the distance between adjacent second adhesive bodies is L2, satisfying: L1 = n·L2, n ≥ 2 and n is an integer. The wafer transfer method includes the following steps: S10: Press the carrier substrate onto the wafer bonded to the blue film, so that the carrier substrate is bonded to m wafers, where m is a positive integer greater than 1; S20: Lift the carrier substrate to separate the wafer adhered to the carrier substrate from the blue film; S30: Press the carrier substrate onto the target substrate, so that a portion of the wafers are bonded to the target substrate, and make the remaining wafers not bonded to the target substrate face the first gap, wherein there are a total of (m / n) 2 Each of the aforementioned wafers is bonded to the target substrate, and (m / n) 2 () is a positive integer; S40: Lift the target substrate to separate the wafer bonded to the target substrate from the carrier substrate; S50: Determine whether all the wafers on the carrier substrate have been transferred to the destination substrate. If not, repeat steps S30 and S40 in sequence.

2. The wafer transfer method according to claim 1, characterized in that, The wafer is cut from a wafer, the wafer having a square region, the length of the diagonal of the square region being equal to the diameter of the wafer; The step of pressing the carrier substrate onto the wafer bonded to the blue film, thereby bonding the carrier substrate to m wafers, is achieved by: covering the square area with the carrier substrate, and bonding the carrier substrate to all wafers disposed within the square area.

3. The wafer transfer method according to claim 1, characterized in that, The supporting substrate is square, and the side length of the supporting substrate is equal to the side length of the square region.

4. The wafer transfer method according to claim 1, characterized in that, The wafer is cut from a wafer with a diameter of D. The target substrate is rectangular with a short side length of L3, satisfying: D≥4 inch, L3≥400mm.

5. The wafer transfer method according to claim 1, characterized in that, The target substrate includes a first plate and a first adhesive, wherein the first adhesive is bonded to the outer surface of the first plate, and the first plate is a glass plate or a PCB.

6. The wafer transfer method according to claim 1, characterized in that, The carrier substrate includes a second plate and a plurality of second adhesives. The second adhesives are bonded to the outer surface of the second plate, and the carrier substrate is bonded to the wafer through the second adhesives. The adhesive force between the second adhesive and the second plate is greater than the adhesive force between the second adhesive and the wafer.

7. The wafer transfer method according to claim 6, characterized in that, The target substrate includes a first plate and a plurality of first adhesives, wherein the first adhesives are bonded to the outer surface of the first plate; The adhesive force between the first adhesive and the first plate is greater than the adhesive force between the second adhesive and the wafer.

Images