Method for ablating laminated excessive glue of FCBGA packaging substrate
By ablating only the overglue in the process card number area during the first two layers of the FCBGA package substrate, and laser edge burning of the entire plate is performed on the subsequent dielectric layer, the damage problem of laser edge burning on the copper surface and substrate is solved, and the effect of improving edge burning efficiency and product yield is achieved.
Patent Information
- Application Number
- CN202411927839.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-04-11
AI Technical Summary
During the production process of FCBGA packaging substrate, the thermal effect caused by laser burning on the copper surface and substrate is greatly damaged, resulting in substrate separation and plate edge curling, affecting production efficiency and product yield.
A method of ablation of a FCBGA packaged substrate is proposed. By ablating only the overflowing glue in the process card number area during the first two accumulations of the substrate, and laser edge burning of the entire plate is performed on the subsequent dielectric layer, the influence of laser edge burning on the copper surface and substrate is reduced.
This method effectively reduces the damage to the copper surface and substrate by laser burning, reduces the risk of separation of substrate and copper skin, improves the burning efficiency, saves time and cost, and improves the product yield.
Smart Images
Figure CN119812006A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of semiconductor packaging, and in particular to a method for ablation of overflow glue of a stacked layer of an FCBGA packaging substrate. Background Art
[0002] In the process of making FCBGA (Flip Chip Ball Grid Array) package substrate, a dielectric layer, such as ABF film material, is needed as the build-up material. Since the dielectric layer material itself has fluidity, glue overflow will occur during the lamination of the dielectric layer. Therefore, a laser glue remover is needed to burn the edge of the board to remove the glue overflow.
[0003] In the related technology, the energy, aperture, pulse width and number of laser glue removers are adjusted to obtain the appropriate edge burning parameters to remove the overflowed glue; however, during the ablation process, due to the thinness of the plate and the large laser ablation energy, the thermal effect generated by the laser causes great damage to the plate; in the case of continuous layer addition, the copper surface and the substrate are easily separated and the edge of the plate warps after multiple laser edge burning. Therefore, a new edge burning method is urgently needed to reduce the impact of the laser on the copper surface and the substrate. Summary of the invention
[0004] The present invention aims to solve at least one of the technical problems in the above-mentioned technology to a certain extent. To this end, the purpose of the present invention is to propose a method for ablation of overflow glue of a built-up layer of a FCBGA package substrate, so as to reduce the influence of laser edge burning on the copper surface and the substrate, and at the same time improve the edge burning efficiency and save time cost.
[0005] To achieve the above object, the first aspect of the present invention provides a method for ablation of overflow glue of a FCBGA package substrate, comprising the following steps:
[0006] S1. Provide a substrate and a laser drilling machine; the laser drilling machine has a laser ablation tool;
[0007] S2, forming a first dielectric layer on the surface of the substrate to obtain a first FCBGA package substrate structure;
[0008] S3, transferring the first FCBGA package substrate structure to the laser drilling machine for partial ablation, wherein the laser ablation tool ablates n circles in sequence from close to the first dielectric layer to away from the first dielectric layer in the overflow area at the edge of the process card number area of the first FCBGA package substrate structure, where n≥2;
[0009] S4, performing wiring on the first dielectric layer of the first FCBGA package substrate structure after ablation to obtain a second FCBGA package substrate structure having a redistribution layer;
[0010] S5, repeating steps S2 to S4 on the redistribution layer of the second FCBGA package substrate structure to prepare a third FCBGA package substrate structure having two redistribution layers;
[0011] S6, forming a third dielectric layer on the redistribution layer of the third FCBGA package substrate structure to obtain a fourth FCBGA package substrate structure;
[0012] S7. Transfer the fourth FCBGA package substrate structure to the laser drilling machine for whole-board ablation. The laser ablation tool performs n turns of ablation in sequence in the overflow area at the edge of the fourth FCBGA package substrate structure, from close to the third dielectric layer to away from the third dielectric layer, where n≥2.
[0013] According to a method for ablating overflow glue of a FCBGA package substrate during build-up of the present invention, the overflow glue ablation method only ablates the overflow glue in the process card number area during the first two build-ups of the substrate to prevent the overflow glue from covering the card number and affecting identification, and the overflow glue in other areas is not ablated; after the substrate has undergone two build-ups, the substrate forms two layers of redistribution layers, that is, the copper layers are electroplated twice, and the copper skin on the substrate is thicker. When laser edge burning of the entire board is performed on the subsequent dielectric layer, the influence of laser edge burning on the copper surface and the substrate can be reduced, and the risk of separation between the substrate and the copper skin is reduced, while the edge burning efficiency is improved, saving time and cost.
[0014] In addition, the method for ablation of overflow glue of a FCBGA package substrate according to the present invention may also have the following additional technical features:
[0015] Optionally, it also includes:
[0016] S8, performing wiring on the ablated third dielectric layer of the fourth FCBGA package substrate structure to obtain a fifth FCBGA package substrate structure having three redistribution layers.
[0017] Furthermore, it also includes:
[0018] S9, repeating steps S6 to S8 on the redistribution layer of the fifth FCBGA package substrate structure to prepare a FCBGA package substrate structure with four or more redistribution layers.
[0019] The laser ablation tool comprises a first parameter ablation tool and a second parameter ablation tool;
[0020] When ablating the third dielectric layer or each dielectric layer after the third dielectric layer, the first parameter ablation tool first performs a first ablation in the glue overflow area, and the first ablation is performed in a direction from close to the dielectric layer to away from the dielectric layer in sequence. Each circle of ablation includes a full circle of ablation along the glue overflow area to be ablated, forming N1 first ablation holes, and the centers of two adjacent first ablation holes have a first spacing, wherein n1≥2, N1≥2; subsequently, the second parameter ablation tool performs a second ablation in the glue overflow area, and the second ablation is performed by the The final position of the first ablation is moved away from the dielectric layer by a preset distance, the preset distance does not exceed the radius of the first ablation hole, and n2 circles of ablation are performed in sequence from close to the dielectric layer to away from the dielectric layer, at least to the boundary of the overflowing glue area, each circle of ablation includes a full circle of ablation along the overflowing glue area to be ablated, forming N2 second ablation holes, the aperture of the second ablation hole is larger than the aperture of the first ablation hole, and there is a second spacing between the centers of two adjacent second ablation holes, and the second spacing is larger than the first spacing, wherein n2≥2, N2≥2;
[0021] When ablating the first dielectric layer and the second dielectric layer, the second parameter ablation tool performs ablation once in the overflow glue area, and the ablation is performed in a direction from close to the dielectric layer to away from the dielectric layer in sequence for n2 circles, at least to the boundary of the overflow glue area, and each circle of ablation includes a full circle of ablation along the overflow glue area that needs to be ablated, forming N2 second ablation holes, N2≥2.
[0022] Furthermore, the n1 rounds of ablation performed are 2 rounds of ablation, and the apertures of the first ablation holes formed by each round of ablation are the same.
[0023] Furthermore, in the n2 rounds of ablation being performed, the apertures of the second ablation holes formed in each round of ablation are the same.
[0024] Optionally, in step S7, the whole board ablation is to ablate the overflowed glue area at the edge of the whole board avoiding the electroplating clamping point and the area where the two-dimensional code is located.
[0025] Optionally, the laser ablation tool comprises a CO2 laser drill.
[0026] To achieve the above object, the second aspect of the present invention provides a FCBGA packaging structure, wherein the FCBGA packaging structure adopts the above-mentioned method for ablation of overflow glue of the build-up layer of the FCBGA packaging substrate to remove the overflow glue.
[0027] The FCBGA packaging structure according to the present invention has a good yield rate and improved production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 It is a schematic flow chart of a method for ablation of overflow glue of a build-up layer of a FCBGA package substrate according to an embodiment of the present invention;
[0029] Figure 2 A cross-sectional view of a FCBGA package substrate structure according to an embodiment of the present invention;
[0030] Figure 3 This is an ablation appearance diagram of a test board after the design parameters of an embodiment of the present invention are tested;
[0031] Figure 4 This is an apparent ablation image of a test board after repeatability testing of the design parameters of an embodiment of the present invention;
[0032] Figure 5 This is an ablation appearance diagram of a test plate after the first parameter ablation tool and the second parameter ablation tool of an embodiment of the present invention are tested;
[0033] Figure 6 It is a partial schematic diagram of the first ablation and the second ablation of an embodiment of the present invention;
[0034] Figure 7 A schematic diagram of a process card number area on a substrate according to an embodiment of the present invention;
[0035] Figure 8 A schematic diagram of a region on a substrate that needs to be ablated throughout the entire substrate according to an embodiment of the present invention;
[0036] Fig. 9 The appearance of the FCBGA package substrate after multiple ablation is shown in the embodiment of the present invention.
[0037] Fig.10 This is the appearance of the FCBGA package substrate after multiple ablation in the comparative example of the present invention. DETAILED DESCRIPTION
[0038] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.
[0039] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.
[0040] Please refer to Figure 1 The present application provides a method for ablation of overflow glue of a FCBGA package substrate, comprising the following steps:
[0041] S1. Provide a substrate and a laser drilling machine; the laser drilling machine has a laser ablation tool;
[0042] S2, forming a first dielectric layer on the surface of the substrate to obtain a first FCBGA package substrate structure;
[0043] S3, transferring the first FCBGA package substrate structure to the laser drilling machine for partial ablation, wherein the laser ablation tool ablates n circles in sequence from close to the first dielectric layer to away from the first dielectric layer in the overflow area at the edge of the process card number area of the first FCBGA package substrate structure, where n≥2;
[0044] S4, performing wiring on the first dielectric layer of the first FCBGA package substrate structure after ablation to obtain a second FCBGA package substrate structure having a redistribution layer;
[0045] S5, repeating steps S2 to S4 on the redistribution layer of the second FCBGA package substrate structure to prepare a third FCBGA package substrate structure having two redistribution layers;
[0046] S6, forming a third dielectric layer on the redistribution layer of the third FCBGA package substrate structure to obtain a fourth FCBGA package substrate structure;
[0047] S7. Transfer the fourth FCBGA package substrate structure to the laser drilling machine for whole-board ablation. The laser ablation tool performs n turns of ablation in sequence in the overflow area at the edge of the fourth FCBGA package substrate structure, from close to the third dielectric layer to away from the third dielectric layer, where n≥2.
[0048] That is to say, the method for ablating overflow glue of the FCBGA packaging substrate of the present application is to only ablate the overflow glue in the process card number area on the substrate when burning the edges of the dielectric layer (first dielectric layer) formed for the first time and the dielectric layer (second dielectric layer) formed for the second time, and ablate the overflow glue of the entire board starting from the third layer addition; while the ablation method in the related art is to ablate the overflow glue of the entire board each time a layer is added.
[0049] It should be noted here that by connecting the laser drilling machine to a computer, the ablation program used can be set up in advance on the computer and can be called up at any time to control the laser ablation tool to ablate the overflowed glue area.
[0050] It can be seen that this method only ablates the overflow glue in the process card number area during the first two build-ups of the substrate to prevent the overflow glue from covering the card number and affecting recognition, and the overflow glue in the remaining areas is not ablated; after the substrate has undergone two build-ups, the substrate forms two layers of redistribution layers, that is, the copper layers are electroplated twice, and the copper skin on the substrate is thicker. When the laser edge burning of the entire board is performed on the subsequent dielectric layer, the impact of the laser edge burning on the copper surface and the substrate can be reduced, reducing the risk of separation between the substrate and the copper skin, while improving the edge burning efficiency and saving time costs.
[0051] See also Figures 1 to 9 The present embodiment will be described in more detail below with reference to the accompanying drawings.
[0052] First, step S1 is performed to provide a substrate and a laser drilling machine; the laser drilling machine has a laser ablation tool.
[0053] In this embodiment, Figure 2 As shown, taking the glass substrate 100 as an example, the inner wiring pattern 200 can be made on the surface of the glass substrate 100 by conventional processes such as a subtractive method, a semi-additive method or a Damascus process, but the preparation method of the substrate is not limited thereto, and the substrate is not limited to glass.
[0054] In this embodiment, the laser ablation tool is a CO2 laser drilling machine, which is used to laser ablate the overflowed glue area to remove the overflowed glue area. Of course, the laser ablation tool includes but is not limited to the CO2 laser drilling machine, and can also be other ablation tools as long as it can meet the ablation requirements in this embodiment.
[0055] Next, step S2 is performed to form a first dielectric layer 310 on the surface of the substrate (inner layer pattern 200) to obtain a first FCBGA package substrate structure.
[0056] Specifically, the first dielectric layer 310 is formed through lamination, curing and other process flows. At this time, the first dielectric layer 310 forms overflow glue at the edge of the FCBGA package substrate structure, that is, there is overflow glue at the edge of the entire board. The material of the first dielectric layer 310 can be ABF material containing silicon oxide and epoxy resin, or PP material containing glass fiber and epoxy resin, etc. The type of dielectric layer material and the specific thickness can be set according to specific actual requirements, and are not limited here.
[0057] Subsequently, step S3 is executed to transfer the first FCBGA package substrate structure to a laser drilling machine for partial ablation. The laser ablation tool performs n turns of ablation in sequence from close to the first dielectric layer 310 to away from the first dielectric layer 310 in the overflow area at the edge of the process card number area of the first FCBGA package substrate structure, where n≥2.
[0058] Before ablation, the computer needs to call the program required for ablation to control the laser ablation tool to ablate the overflowed glue area. It can be seen from step S2 that the first dielectric layer 310 has overflowed glue at the edge of the entire board of the FCBGA package substrate structure, but in step S3 of this embodiment, only the overflowed glue area at the edge of the process card number area is ablated. Figure 7 As shown, Figure 7 The red area is the process card number area. Only the overflow glue in the process card number area is ablated, which is convenient for tracing the subsequent layer addition. Compared with ablation of the entire board, it greatly saves ablation time and improves production capacity.
[0059] Then, if Figure 2 As shown, step S4 is performed to perform wiring on the first dielectric layer 310 of the ablated first FCBGA package substrate structure to obtain a second FCBGA package substrate structure having a redistribution layer (first redistribution layer 320).
[0060] In a specific example, the redistribution layer 320 can be made by the conventional process used in the prior art for preparing the FCBGA package structure, for example, a laser blind hole is formed on the first dielectric layer 310 of the first FCBGA package substrate structure after ablation, and then the process of desmearing and chemical copper deposition is performed, and then the pattern transfer and electroplating, film stripping, and flash etching processes are continued to complete the production of the redistribution layer (first redistribution layer 320). Since this part of the content is well known to those skilled in the art, the specific process will not be repeated here one by one.
[0061] Then, if Figure 2As shown, step S5 is performed, and steps S2 to S4 are repeated on the redistribution layer (first redistribution layer 320) of the second FCBGA package substrate structure to prepare a third FCBGA package substrate structure having two redistribution layers. Specifically, a second dielectric layer 330 is first formed on the first redistribution layer 320 of the second FCBGA package substrate structure, and then the FCBGA package substrate structure is transferred to a laser drilling machine for partial ablation. The laser ablation tool ablates n circles in sequence from close to the second dielectric layer 330 to away from the second dielectric layer 330 in the overflow area at the edge of the process card number area corresponding to the second dielectric layer 330, where n≥2; finally, wiring is performed on the second dielectric layer 330 of the ablated FCBGA package substrate structure to obtain a third FCBGA package substrate structure having two redistribution layers.
[0062] Thus, it can be known that in both the first dielectric layer 310 in step S3 and the second dielectric layer 330 in step S5, only the overflowed glue area at the edge of the process card number area is ablated to remove the overflowed glue.
[0063] Then, if Figure 2 As shown, step S6 is performed to form a third dielectric layer 350 on the redistribution layer (second redistribution layer 340) of the third FCBGA package substrate structure to obtain a fourth FCBGA package substrate structure. In this embodiment, the third dielectric layer 350 and the second dielectric layer 330 are formed in the same manner as the first dielectric layer 310.
[0064] Subsequently, step S7 is executed to transfer the fourth FCBGA package substrate structure to a laser drilling machine for whole-board ablation. The laser ablation tool performs n turns of ablation in sequence from close to the third dielectric layer 350 to away from the third dielectric layer 350 in the overflow area at the edge of the fourth FCBGA package substrate structure, where n≥2.
[0065] Before ablation, it is necessary to call the program required for ablation on the computer and control the laser ablation tool to ablate the overflowed glue area. It can be seen from step S6 that the third dielectric layer 350 has overflowed glue at the edge of the entire board of the FCBGA package substrate structure. In step S7 of this embodiment, the overflowed glue area of the entire board is ablated, avoiding the electroplating pinch point, QR code and other locations. Specifically, Figure 8 As shown, Figure 8 The red area in the middle is the glue overflow area of the whole board. Before step S7, Figure 2 As shown, the substrate has been built up twice and has two redistribution layers (the first redistribution layer 320 and the second redistribution layer 340) thereon. It has been copper plated twice, and the copper foil on the substrate is thicker. The laser edge burning has less impact on the substrate. At this time, the entire board is ablated to reduce the risk of separation between the substrate and the copper foil.
[0066] Then, step S8 may be performed to perform wiring on the ablated third dielectric layer 350 of the fourth FCBGA package substrate structure to obtain a fifth FCBGA package substrate structure having three redistribution layers, wherein the third redistribution layer 360 and the second redistribution layer 340 are formed in the same manner as the first redistribution layer 320.
[0067] Finally, step S9 can be executed, and steps S6 to S8 can be repeated on the redistribution layer (third redistribution layer 360) of the fifth FCBGA package substrate structure to prepare an FCBGA package substrate structure with a redistribution layer greater than or equal to four layers. In the preparation of the package substrate, the number of repetitions can be set according to the wiring layer required in the actual FCBGA package substrate, and is no longer limited here. Repeating multiple burn edges and wiring can refer to the above embodiment. Since it adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.
[0068] For the above-mentioned ablation steps, the laser ablation tool includes a first parameter ablation tool and a second parameter ablation tool. When ablating the first dielectric layer 310 and the second dielectric layer 330, that is, when executing step S3 and step S5, only the second parameter ablation tool is used to perform ablation once. Specifically, the ablation is performed in a direction from close to the dielectric layer to away from the dielectric layer, and n2 circles are ablated in sequence, at least to the boundary of the overflow area. Each circle of ablation includes a full circle of ablation along the overflow area to be ablated, forming N2 second ablation holes 12, N2 ≥ 2. When ablating each dielectric layer starting from the third dielectric layer 350, that is, when executing step S7 and step S9, the first ablation is performed with the first parameter ablation tool, and then the second ablation is performed with the second parameter ablation tool. Specifically, Figure 6 As shown, the first ablation tool with the first parameter performs the first ablation in the overflow glue area. The first ablation is performed in a direction from close to the dielectric layer to away from the dielectric layer in sequence. N1 circles of ablation are performed in a direction from close to the dielectric layer to away from the dielectric layer. Each circle of ablation includes a full circle of ablation along the overflow glue area to be ablated, forming N1 first ablation holes 11. The centers of two adjacent first ablation holes 11 have a first spacing, wherein n1≥2, N1≥2; subsequently, the second ablation tool with the second parameter performs the second ablation in the overflow glue area. The second ablation is performed from the final position of the first ablation to away from the dielectric layer. The ablation is performed by moving a preset distance in the direction of the dielectric layer, the preset distance does not exceed the radius of the first ablation hole 11, and n2 circles of ablation are performed in sequence from close to the dielectric layer to away from the dielectric layer, at least to the boundary of the overflowing glue area, each circle of ablation includes a full circle of ablation along the overflowing glue area to be ablated, to form N2 second ablation holes 12, the aperture of the second ablation hole 12 is larger than the aperture of the first ablation hole 11, and there is a second spacing between the centers of two adjacent second ablation holes 12, the second spacing is larger than the first spacing, wherein n2≥2, N2≥2.
[0069] It can be seen from this that the above-mentioned first dielectric layer 310 and second dielectric layer 330 are ablated once by the second parameter ablation tool in the overflow area; the ablation of each dielectric layer starting from the third dielectric layer 350 to the outermost dielectric layer in the overflow area is successively ablated by the first parameter ablation tool and then ablated by the second parameter ablation tool.
[0070] As an example, Figure 6 As shown, the n1-circle ablation is 2-circle ablation. At this time, the first parameter ablation tool performs 2 circles of ablation in the overflow glue area from close to the dielectric layer to away from the dielectric layer. Each circle of ablation includes a full circle of ablation along the overflow glue area to be ablated, forming N1 first ablation holes 11. The first ablation is to remove the part of the overflow glue area close to the dielectric layer through intensive laser ablation. Of course, the first n-circle ablation includes but is not limited to 2 circles, and can also be greater than 2 circles. It can be set according to actual needs and is not limited here; the N first ablation holes 11 formed by each circle of ablation include but are not limited to 2, and can also be greater than 2.
[0071] Among them, the aperture of the first ablation holes 11 formed by each circle of n1 circles of ablation is the same, and the number of ablation holes is the same. In the first ablation, as an example, it is preferred that, whether in the same circle of ablation holes or in two adjacent circles of ablation holes, the first spacing between the centers of two adjacent first ablation holes 11 is not less than the radius of the first ablation holes 11. The denser the spacing, the easier it is to remove the overflow area.
[0072] In addition, the second parameter ablation tool ablates in the glue overflow area from the direction close to the dielectric layer to the direction away from the dielectric layer, or moves a preset distance from the final position of the first ablation to the direction away from the dielectric layer. When the aperture of the first circle of first ablation holes is the same as the aperture of the second circle of first ablation holes, the preset distance does not exceed the radius of the first circle of first ablation holes and the second circle of first ablation holes. The second ablation continues to ablate along the direction of the first ablation, that is, along the direction away from the dielectric layer, at least ablate to the boundary of the glue overflow area, or ablate beyond the boundary of the glue overflow area.
[0073] As an example, in the n2-cycle ablation, the aperture of the second ablation hole 12 formed by each ablation is the same. Compared with the first ablation, the density of the second ablation is relatively small. Two ablations with different apertures and densities can shorten the ablation time to the greatest extent without affecting the efficiency of ablation of the overflowed glue area. In addition, ablation of the overflowed glue area twice can shorten the process time, which is conducive to controlling the energy required by the two ablation tools.
[0074] In a more specific embodiment, before ablation, the ablation parameters need to be confirmed in advance and the parameters required for ablation are input into a computer to form a program required for ablation; the parameters of laser ablation need to be designed and tested in advance to determine the ablation parameters.
[0075] Specifically, firstly, the aperture of the patchwork hole is 90 and the pitch is 50 to test the ablation effect, as shown in Table 1 below.
[0076] Table 1
[0077]
[0078]
[0079] The test board made with the parameters in Table 1 is shown in the following figure after Desmear. Figure 3 As shown, the results of No. 1, 2, and 4 meet the apparent requirements, and the parameters No. 1, 2, and 4 are used for repeatability testing; Figure 4 As shown, the set of parameters numbered 4 is finally selected.
[0080] Since a small hole and small aperture are used, the efficiency of ablation will be reduced. Therefore, as mentioned above, the laser ablation tool is set to a first parameter ablation tool and a second parameter ablation tool. The first parameter ablation tool uses a small aperture and a small pitch to burn the trimming edge, and the second parameter ablation tool uses a large aperture and a large pitch to burn the remaining ABF residual area. Specifically, the parameters of the first parameter ablation tool and the second parameter ablation tool are designed to test the ablation effect, as shown in Table 2 below.
[0081] Table 2
[0082]
[0083] The test board made with the parameters in Table 2 is shown in the following figure after Desmear. Figure 5 As shown, it is finally confirmed that the first parameter ablation tool is T1: AP(8)16*1(4.0 2.0 4) (hole diameter 90, Pitch 50, burn two circles); the second parameter ablation tool is T2: AP(1)24*1(8.0 6.0 3) (hole diameter 180, Pitch 135, burn the remaining ABF overflow area). The actual number of ablation circles of the second parameter ablation tool is determined according to the actual overflow area, and is not limited here.
[0084] Therefore, in step S3 of the present embodiment, the second parameter ablation tool with the above parameters is used to ablate the overflowed glue area at the edge of the process card number area on the first dielectric layer 310; in step S5, the second parameter ablation tool with the above parameters is used to ablate the overflowed glue area at the edge of the process card number area on the second dielectric layer 330; in step S7, the first parameter ablation tool and the second parameter ablation tool with the above parameters are used to ablate the overflowed glue area at the edge of the entire board on the third dielectric layer 350 (avoiding the electroplating pinch points, the QR code, etc.); or in step S9, the first parameter ablation tool and the second parameter ablation tool with the above parameters are used to ablate the overflowed glue area at the edge of the entire board such as the fourth dielectric layer and the fifth dielectric layer (avoiding the electroplating pinch points, the QR code, etc.) twice. The appearance of the FCBGA packaging structure after multiple ablations is as follows. Fig. 9 As shown, it has a good yield.
[0085] Comparative Example
[0086] The steps and principles of this comparative example are substantially the same as those of the embodiment, and the same parts are not described in detail. The difference is that in this comparative example, the first dielectric layer 310 in step S3 is as follows: Figure 8 As shown, the first parameter ablation tool and the second parameter ablation tool with the above parameters are used to ablate the overflow area at the edge of the entire board twice; on the second dielectric layer 330 in step S5, Figure 8 As shown, the first parameter ablation tool and the second parameter ablation tool with the above parameters are used to ablate the overflow area at the edge of the entire board twice; the third dielectric layer 350 in step S7 is also ablated as above. Figure 8 As shown in FIG. 1 , the first parameter ablation tool and the second parameter ablation tool with the above parameters are used to ablate the overflow area at the edge of the entire board twice. The appearance of the FCBGA package structure after multiple ablation is as follows: Fig.10 As shown, part of the copper foil is warped, and the warped copper foil may fall off in the subsequent process, seriously affecting the product yield.
[0087] In summary, the method for ablation of overflow glue of the FCBGA package substrate provided in the embodiment of the present invention can reduce the impact of laser edge burning on the copper surface and the substrate, while improving the edge burning efficiency, saving time and cost, and ensuring product yield.
[0088] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.
[0089] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0090] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0091] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.
[0092] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.
[0093] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.
Claims
1. A method for ablation of overflow glue of a FCBGA package substrate, characterized in that: The following steps are involved: S1. Provide a substrate and a laser drilling machine, wherein the laser drilling machine has a laser ablation tool; S2, forming a first dielectric layer on the surface of the substrate to obtain a first FCBGA package substrate structure; S3, transferring the first FCBGA package substrate structure to the laser drilling machine for partial ablation, wherein the laser ablation tool ablates n circles in sequence from close to the first dielectric layer to away from the first dielectric layer in the overflow area at the edge of the process card number area of the first FCBGA package substrate structure, where n≥2; S4, performing wiring on the first dielectric layer of the first FCBGA package substrate structure after ablation to obtain a second FCBGA package substrate structure having a redistribution layer; S5, repeating steps S2 to S4 on the redistribution layer of the second FCBGA package substrate structure to prepare a third FCBGA package substrate structure having two redistribution layers; S6, forming a third dielectric layer on the redistribution layer of the third FCBGA package substrate structure to obtain a fourth FCBGA package substrate structure; S7. Transfer the fourth FCBGA package substrate structure to the laser drilling machine for whole-board ablation. The laser ablation tool performs n turns of ablation in sequence in the overflow area at the edge of the fourth FCBGA package substrate structure, from close to the third dielectric layer to away from the third dielectric layer, where n≥2.
2. The method for ablation of build-up glue overflow of FCBGA package substrate according to claim 1, characterized in that: Also includes: S8, performing wiring on the ablated third dielectric layer of the fourth FCBGA package substrate structure to obtain a fifth FCBGA package substrate structure having three redistribution layers.
3. The method for ablation of overflow glue of FCBGA package substrate as claimed in claim 2, characterized in that: Also includes: S9, repeating steps S6 to S8 on the redistribution layer of the fifth FCBGA package substrate structure to prepare a FCBGA package substrate structure with four or more redistribution layers.
4. The method for ablation of overflow glue of a FCBGA package substrate as claimed in claim 1 or 3, characterized in that: The laser ablation tool comprises a first parameter ablation tool and a second parameter ablation tool; When ablating the third dielectric layer or each dielectric layer after the third dielectric layer, the first parameter ablation tool first performs a first ablation in the glue overflow area, and the first ablation is performed in a direction from close to the dielectric layer to away from the dielectric layer in sequence. Each circle of ablation includes a full circle of ablation along the glue overflow area to be ablated, forming N1 first ablation holes, and the centers of two adjacent first ablation holes have a first spacing, wherein n1≥2, N1≥2; subsequently, the second parameter ablation tool performs a second ablation in the glue overflow area, and the second ablation is performed by the The final position of the first ablation is moved away from the dielectric layer by a preset distance, the preset distance does not exceed the radius of the first ablation hole, and n2 circles of ablation are performed in sequence from close to the dielectric layer to away from the dielectric layer, at least to the boundary of the overflowing glue area, each circle of ablation includes a full circle of ablation along the overflowing glue area to be ablated, forming N2 second ablation holes, the aperture of the second ablation hole is larger than the aperture of the first ablation hole, and there is a second spacing between the centers of two adjacent second ablation holes, and the second spacing is larger than the first spacing, wherein n2≥2, N2≥2; When ablating the first dielectric layer and the second dielectric layer, the second parameter ablation tool performs ablation once in the overflow glue area, and the ablation is performed in a direction from close to the dielectric layer to away from the dielectric layer in sequence for n2 circles, at least to the boundary of the overflow glue area, and each circle of ablation includes a full circle of ablation along the overflow glue area that needs to be ablated, forming N2 second ablation holes, N2≥2.
5. The method for ablation of overflow glue of a FCBGA package substrate as claimed in claim 4, characterized in that: The n1 rounds of ablation performed are 2 rounds of ablation, and the apertures of the first ablation holes formed by each round of ablation are the same.
6. The method for ablation of overflow glue of a FCBGA package substrate as claimed in claim 4, characterized in that: In the ongoing n2-round ablation, the apertures of the second ablation holes formed by each round of ablation are the same.
7. The method for ablation of overflow glue of a FCBGA package substrate as claimed in claim 1, characterized in that: In step S7, the whole board is ablated to ablate the overflowed glue area at the edge of the whole board avoiding the electroplating clamping point and the area where the two-dimensional code is located.
8. The method for ablation of overflow glue of a FCBGA package substrate as claimed in claim 1, characterized in that: The laser ablation tool includes a CO2 laser drill.
9. A FCBGA packaging structure, characterized in that: The FCBGA packaging structure adopts the method for ablation of overflow glue of the FCBGA packaging substrate according to any one of claims 1 to 8 to remove overflow glue.