Method for manufacturing a wiring board, and wiring board
By forming V-shaped grooves and chamfered edges on both surfaces of the core substrate, the method addresses the issue of laminate peeling and cracking in wiring boards, enhancing their reliability under temperature cycling tests.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- DISCO CORP
- Filing Date
- 2024-12-09
- Publication Date
- 2026-06-19
AI Technical Summary
The conventional method of dicing wiring boards results in a high defective rate due to laminate peeling off or cracking during temperature cycling tests, primarily at the outer edges.
A method involving forming V-shaped processing grooves on both surfaces of a core substrate, followed by a splitting step using a cutting blade that reaches the core substrate, and optionally removing the laminate before grooving to create chamfered edges, reducing laminate thickness at the edges.
This approach effectively prevents laminate delamination and cracking during temperature cycling tests, thereby reducing the defect rate of the wiring boards.
Smart Images
Figure 2026100760000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for manufacturing a wiring board formed by disposing a laminate on a core substrate.
Background Art
[0002] Conventionally, as disclosed in, for example, Patent Document 1, as one of printed boards and package substrates, a core substrate (glass substrate) made of an inorganic material and an insulating layer (resin layer) disposed on the core substrate and having at least one wiring layer formed therein are laminated to form a wiring board (laminate). This type of wiring board is used, for example, as a 'core substrate for packages' (relay substrate) for mounting different types of semiconductor chips on both sides and connecting both chips. Generally, a wiring board is manufactured by dicing a single material substrate into required dimensions with a known dicing device (cutting device) and separating it into individual pieces.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, when a temperature cycle test (TCT: Temperature Cycling Test) is performed on a wiring board diced into required dimensions and separated into individual pieces by a normal dicing method, there is a problem that the defective rate of the wiring board increases because the laminate peels off from the core substrate or the laminate cracks (back-cracks), and this has been an issue.
[0005] In view of the above problems, the present invention proposes a new technique for reducing the defective rate of a wiring board in which a laminate is formed on a core substrate.
Means for Solving the Problems
[0006] The problems that this invention aims to solve are as described above, and the means for solving these problems will now be explained.
[0007] According to one aspect of the present invention, a method for manufacturing a wiring board in which a laminate is formed on a first surface and / or a second surface of a core substrate, comprising at least: a first processing groove forming step of forming a processing groove with a substantially V-shaped cross-section by cutting with a cutting blade along a planned division line from the first surface; a second processing groove forming step of forming a processing groove with a substantially V-shaped cross-section by cutting with a cutting blade along the planned division line from the second surface; and a division step of dividing the core substrate along the processing grooves formed in the first processing groove forming step and the second processing groove forming step to form individual wiring boards.
[0008] Furthermore, according to one aspect of the present invention, in the cutting process in the first groove formation step and the second groove formation step, at least the tip of the cutting blade is made to reach the core substrate.
[0009] Furthermore, according to one aspect of the present invention, the splitting step is carried out by braking.
[0010] Furthermore, according to one aspect of the present invention, the process includes a laminate removal step, which is performed before the first processing groove forming step and / or the second processing groove forming step, in which the laminate is removed along the planned division line to a depth that does not reach the core substrate in an area that is at least wider than the processing groove.
[0011] Furthermore, according to one aspect of the present invention, a wiring board is provided in which a laminate is formed on the first surface side and / or the second surface side of a core substrate, and a chamfered portion is formed extending from the surface of the laminate formed on the first surface side and / or the second surface side to the end face of the core substrate, continuously chamfering the end face of the laminate and a part of the end face of the core substrate.
[0012] Furthermore, according to one aspect of the present invention, a wiring board is provided in which a laminate is formed on the first surface side and / or the second surface side of a core substrate, wherein a chamfered portion is formed from the surface of the laminate formed on the first surface side and / or the second surface side to the end face of the core substrate, and a part of the end face of the laminate is continuously chamfered. [Effects of the Invention]
[0013] The present invention provides the following effects: In other words, according to one aspect of the present invention, the thickness of the laminate with different coefficients of thermal expansion can be reduced at the outer edge of the wiring board, effectively preventing defects such as delamination of the laminate from the glass substrate (core substrate) or cracking (back cracking) of the laminate at the outer edge when a temperature cycling test (TCT) is performed, thereby reducing the defect rate of the wiring board. [Brief explanation of the drawing]
[0014] [Figure 1] (A) is a perspective view showing an example of a material substrate. (B) is an enlarged view of a cross-section of a part of the material substrate. [Figure 2] This is a flowchart illustrating the steps involved in the manufacturing process. [Figure 3] (A) is a diagram illustrating the first groove formation step. (B) is a diagram illustrating the second groove formation step. [Figure 4] (A) is a diagram illustrating the division step. (B) is a diagram illustrating the individualized wiring board. [Figure 5] (A) is a diagram illustrating the laminate removal step. (B) is a diagram illustrating the first groove formation step. [Figure 6] (A) is a diagram illustrating the laminate removal step. (B) is a diagram illustrating the first groove formation step. [Figure 7](A) is a diagram for explaining the dividing step. (B) is a diagram for explaining the fragmented wiring board. [Figure 8] It is a diagram for explaining an example in which the laminate removal step is performed by laser ablation processing. [Figure 9] (A) is a diagram for explaining a wiring board in which only the laminate is chamfered and the glass substrate is not chamfered at the chamfered portion. (B) is a diagram for explaining a wiring board in which only the laminate is chamfered and the glass substrate is not chamfered at the chamfered portion.
Embodiments for Carrying Out the Invention
[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1(A) is a perspective view schematically showing a configuration example of the material substrate 1 before being divided into control substrates, and FIG. 1(B) is an enlarged view of a partial cross-section of the material substrate 1.
[0016] As shown in FIG. 1(A), the material substrate 1 is formed with laminates 15a and 15b on both surfaces of a plate-shaped glass substrate 11, and is configured as a rectangular plate-shaped substrate as a whole. The size of the material substrate 1 is, for example, 500 mm x 500 mm, but the size is not particularly limited, and the material substrate 1 may be disk-shaped.
[0017] The glass substrate 11 is, for example, non-alkali glass and functions as a so-called core substrate.
[0018] As shown in FIG. 1(B), on the first surface (front surface) 11a and the second surface (back surface) 11b opposite to the first surface 11a of the glass substrate 11, laminates 15a and 15b formed by laminating a plurality of layers (films) are formed respectively. These laminates 15a and 15b include, for example, a wiring layer 17 made of a conductor such as metal and an insulating layer 19 made of an insulator such as resin, and adjacent wiring layers 17 are insulated by the insulating layer 19.
[0019] A through-hole 11c is formed in the glass substrate 11, penetrating from the first surface 11a to the second surface 11b. An electrode 21 made of a conductor such as metal is embedded in the through-hole 11c, and the wiring layer 17 on the first surface 11a side and the wiring layer 17 on the second surface 11b side are connected via the electrode 21.
[0020] In this embodiment, a material substrate 1 having laminates 15a and 15b on both the first surface 11a and the second surface 11b of the glass substrate 11 is illustrated, but the laminates 15a and 15b may be provided on only one of the first surface 11a and the second surface 11b. In that case, through holes 11c and electrodes 21, etc., can be omitted. Furthermore, there are no particular restrictions on the configuration and formation methods of the laminates 15a and 15b (wiring layer 17, insulating layer 19), through holes 11c, electrodes 21, etc. In addition to using the glass substrate 11 as the core substrate, a substrate made of a semiconductor material such as silicon, or an organic substrate formed by impregnating glass material fibers with a resin such as epoxy may also be used as the core substrate.
[0021] As shown in Figure 1(A), multiple wiring boards 3 (core boards for packages) are manufactured by dividing the material substrate 1, which is configured as described above, along the division lines 13. The division lines 13 (streets) are, for example, set up in a grid pattern on the material substrate 1, and are divided along the division lines 13 through the steps described later, forming individual rectangular wiring boards 3. The size of the wiring board 3 is, for example, 50mm x 50mm, but the size is not particularly limited.
[0022] Next, we will explain a method for manufacturing a wiring board 3 by dividing the material substrate 1 shown in Figure 1(A). Figure 2 is a flowchart showing the steps included in the manufacturing method.
[0023] <First groove formation step> As shown in Figure 3(A), the step involves forming a machining groove M1 with a roughly V-shaped cross-section by cutting along the planned division line 13 from the first surface side using a cutting blade.
[0024] Specifically, as shown in Figure 3(A), first, the material substrate 1 is fixed to the tape 41 by attaching the other side 1b to the tape 41 so that one side 1a of the material substrate 1 is exposed upwards. Next, the first blade B1 is used to cut into one of the laminates 15a (the laminate on the side of the first surface 11a of the glass substrate 11) to form a processing groove M1 in the laminate 15a.
[0025] Here, the first blade B1 is a disc-shaped cutting blade made of abrasive grains such as artificial diamond and a binder, and is a so-called bevel blade with a roughly V-shaped tip. This makes it possible to form a machining groove M1 with a roughly V-shaped cross-section. The first blade B1 is mounted on a spindle (not shown) and rotates at a predetermined rotational speed, cutting into the laminate 15a of the material substrate 1 to form the machining groove M1.
[0026] Furthermore, in the cutting process during the first groove formation step, at least the tip of the first blade B1 is made to reach the glass substrate 11. As a result, the groove M1 is formed to remove and penetrate the laminate 15a, and further remove the surface of the first surface 11a of the glass substrate 11, so that, as shown in Figures 3(A) and 3(B), the bottom Md of the groove M1 is positioned inside the glass substrate 11 beyond the first surface 11a. In this way, the tip of the first blade B1 is cut into the first surface 11a of the glass substrate 11.
[0027] In the first groove formation step, the grooves M1 are formed on one side 1a of the material substrate 1 shown in Figure 1(A) for all of the planned division lines 13.
[0028] <Second processing groove formation step> As shown in Figure 3(B), this step involves forming a machining groove M2 with a roughly V-shaped cross-section by cutting along the planned division line 13 from the second surface side using a cutting blade.
[0029] Specifically, after completing the first groove formation step shown in Figure 3(A), the material substrate 1 is peeled off the tape 41, and as shown in Figure 3(B), the material substrate 1 is inverted and one side 1a (the side on which the groove M1 is formed) is attached to another tape 42, thereby fixing the material substrate 1 to the tape 42. Next, similar to Figure 3(A), as shown in Figure 3(B), the first blade B1 is used to cut into the other laminate 15b (the laminate 15b on the second side 11b of the glass substrate 11), forming a groove M2 with a roughly V-shaped cross-section in the laminate 15b.
[0030] This processing groove M2 is formed in the same way as the processing groove M1 on the first surface 11a side of the glass substrate 11, such that the bottom Md of the processing groove M2 is positioned inside the glass substrate 11 beyond the second surface 11b. In other words, the tip of the first blade B1 is processed so as to cut into the second surface 11b of the glass substrate 11.
[0031] In the second machining groove formation step, the machining groove M2 is formed on the other surface 1b shown in Figure 1(A) for all of the planned division lines 13.
[0032] In addition, the second groove formation step may be performed using the same first blade B1 as in the first groove formation step, or it may be performed using a different blade.
[0033] <Splitting Steps> As shown in Figure 4(A), this step involves dividing the glass substrate 11 (core substrate) along the processing grooves M1 and M2 formed in the first and second processing groove formation steps to form individual wiring boards.
[0034] Specifically, as shown in Figure 4(A), the glass substrate 11 is braked (cut) by pressing the glass substrate 11 with the pressing member 50 at the positions of the processing grooves M1 and M2 formed along the planned division line 13.
[0035] In this embodiment, the material substrate 1 is supported from below by support members 51 and 52 so as to straddle the processing grooves M1 and M2 (planned division lines 13), and the glass substrate 11 (material substrate 1) is cut by pressing a pressing member 50 having a wedge-shaped tip against the processing groove M1.
[0036] In this embodiment, since the bottom Md of the processed grooves M1 and M2 is positioned on the inside of the glass substrate 11, the fracture can be initiated from the bottom Md. After the fracture begins, the crack extends perpendicular to the thickness direction of the glass substrate 11, thereby increasing the flatness of the end surface after fracture.
[0037] Furthermore, the configuration of the braking device is not particularly limited and is not limited to the so-called three-point type using the pressing member 50 and support members 51, 52 shown in Figure 4(A).
[0038] Furthermore, if braking can be performed without problems even if the bottom Md of the processed grooves M1 and M2 are not formed on the inside of the glass substrate 11, the processed grooves M1 and M2 may not reach the glass substrate 11. In other words, the processed grooves M1 and M2 may be formed only in the laminates 15a and 15b.
[0039] As described above, by forming the division groove M3 along the planned division line 13 (Figure 1(A)) on the material substrate 1, individual wiring boards 3 are formed as shown in Figure 4(B).
[0040] <Laminate Removal Step> Furthermore, as shown in Figures 5(A)(B) and 6(A)(B), before the first processing groove formation step and / or the second processing groove formation step, there is a step of removing the laminates 15a and 15b along the division line 13 to a depth that does not reach the glass substrate 11 (core substrate) in an area that is wider than the processing grooves M1 and M2 that will be formed later.
[0041] This laminate removal step is an additional step and may be omitted.
[0042] Specifically, as shown in Figure 5(A), first, the material substrate 1 is fixed to the tape 41 by attaching the other side 1b to the tape 41 so that one side 1a of the material substrate 1 is exposed upwards. Next, the wide third blade B3 is used to cut into one of the laminates 15a of the glass substrate 11 (the laminate on the first side 11a of the glass substrate 11), forming a processing groove M3 in the laminate 15a.
[0043] As shown in Figure 5(B), when the processing groove M3 is formed, a portion of the laminate 15a remains between the bottom of the processing groove M3 and the glass substrate 11. In other words, the tip of the third blade B3 is prevented from reaching the glass substrate 11.
[0044] Furthermore, the width of the third blade B3 only needs to be wider than the width of the first blade B1 (Figure 5(B)), and it should be possible to form a machining groove M3 that is wider than the machining groove M1 (Figure 3(A)).
[0045] Then, as shown in Figure 5(B), a processing groove M1a is formed at the location of processing groove M3 along the planned division line 13 using the first blade B1. In forming this processing groove M1a, at least the tip of the first blade B1 is made to reach the glass substrate 11, similar to the formation of processing groove M1 in Figure 3(A). This makes the bottom of the processing groove M1a formed in the glass substrate 11 the starting point for cleavage during braking. Alternatively, the tip of the first blade B1 may not be made to reach the glass substrate 11.
[0046] Next, as shown in Figure 6(A), the material substrate 1 is peeled off the tape 41, the material substrate 1 is inverted and one side 1a is attached to another tape 42, and the material substrate 1 is fixed to the tape 42. Then, the wide third blade B3 is used to cut into the other laminate 15b (the laminate 15b on the second side 11b of the glass substrate 11) to form a processing groove M4 in the laminate 15b.
[0047] Then, as shown in Figure 6(B), a machining groove M1b is formed at the location of machining groove M4 along the planned division line 13 using the first blade B1. The machining grooves M4 and M1b shown in Figures 6(A) and 6(B) can be constructed in the same form as the machining grooves M3 and M1a shown in Figures 5(A) and 5(B).
[0048] In this example, the machining groove Ma shown in Figure 5(B) is formed after the machining groove M3 shown in Figure 5(A). However, it is also possible to form the machining groove M4 shown in Figure 6(A) after the machining groove M3 shown in Figure 5(A), and then form the machining grooves M1a and M1b shown in Figure 5(B).
[0049] Then, as shown in Figure 7(A), by performing braking on the material substrate on which the processed grooves M3, M4, M1a, and M1b have been formed as described above, individual wiring boards 3A are formed as shown in Figure 7(B).
[0050] In the embodiments described above, the laminate removal step was performed using a third blade B3 (Figure 6(A)(B)). However, as shown in Figure 8, a laser beam L1 may be irradiated along the planned division line 13 to form a processing groove M3a that is wider than the processing groove M1 that will be formed later.
[0051] Specifically, as shown in Figure 8, for the laminate 15a on the first surface 11a side, a laser beam L1 is irradiated from the laser beam irradiation unit 61 of the laser processing device along the planned division line 13 to perform laser ablation processing, thereby forming a processing groove M3a parallel to the planned division line 13. The same procedure is followed for the laminate 15b on the second surface 11b side.
[0052] The present invention can be implemented in the manner described above. As shown in Figure 4(B), the wiring board 3 manufactured according to the present invention has a chamfered portion T formed that continuously chamfers the end faces 15s (side faces) of the laminates 15a and 15b, and a part of the end face 11s of the core substrate, from the exposed surfaces 15c and 15d of the laminates 15a and 15b formed on the first surface 11a and / or the second surface 11b of the core substrate to the end face 11s (side face) of the core substrate.
[0053] Similarly, in case 1 where the laminate removal step described above is performed, as shown in Figure 7(B), a chamfered portion TA is formed on the wiring board 3A, extending from the exposed surfaces 15c, 15d of the laminates 15a, 15b formed on the first surface 11a side and / or the second surface 11b side of the core substrate (glass substrate 11) to the end surface 11s (side surface) of the core substrate, continuously chamfering the end surface 15s (side surface) of the laminates 15a, 15b and a part of the end surface 11s of the core substrate.
[0054] Furthermore, by forming the chamfered portion T (Figure 4(B)) and chamfered portion TA (Figure 7(B)) as described above, the thickness of the laminates 15a and 15b, which have different coefficients of thermal expansion, can be reduced at the outer edge of the wiring board. This effectively prevents the defect of the laminates 15a and 15b peeling (back cracking) from the glass substrate 11 (core substrate) at the outer edge when a temperature cycling test (TCT) is performed, thereby reducing the defect rate of the wiring board 3.
[0055] In addition to the above, as shown in Figures 9(A) and 9(B), the glass substrate 11 may not be chamfered in the chamfered portions T1 and T1A, respectively, while only the laminates 15a and 15b are chamfered. This embodiment corresponds to the case where the processed grooves M1 and M2 (Figures 3(A) and 3(B)) or the processed grooves M1a and M2a (Figures 6(A) and 6(B)) do not reach the glass substrate 11. [Explanation of Symbols]
[0056] 1. Substrate material 3 Wiring board 11 Glass substrate 11a 1st page 11b Side 2 11c through hole 11s end face 13 planned division lines 15a Laminate 15b Laminate 15c Exposed surface 15d Exposed surface 15s End surface 17 Wiring layer 19. Insulating layer 21 electrodes 41 Tapes 42 tapes 50 Pressing member 51 Support member 52 Support member 61 Laser beam irradiation unit B1 First Blade B3 Third Blade L1 laser beam M1 Machining groove M1a Machining groove M1b Machining groove M2 machining groove M3 machining groove M4 processing groove Ma machining groove Mb Machining groove md bottom T-shaped chamfered section TA chamfered section
Claims
1. A method for manufacturing a wiring board in which a laminate is formed on the first surface and / or the second surface of a core substrate, A first machining groove forming step is performed by cutting with a cutting blade along the planned division line from the first surface side to form a machining groove with a substantially V-shaped cross-section, A second machining groove forming step is performed by cutting with a cutting blade along the planned division line from the second surface side to form a machining groove with a substantially V-shaped cross-section, A division step in which the core substrate is divided along the processed grooves formed in the first processed groove forming step and the second processed groove forming step to form individual wiring substrates, A method for manufacturing a wiring board having at least the following.
2. In the cutting process in the first groove formation step and the second groove formation step, To ensure that at least the tip of the cutting blade reaches the core substrate, The method for manufacturing a wiring board according to claim 1.
3. The splitting step is carried out by braking. A method for manufacturing a wiring board according to claim 1 or 2.
4. Before the first groove forming step and / or the second groove forming step, The process includes a laminate removal step, in which the laminate is removed along the planned division line to a depth that does not reach the core substrate in an area wider than the processing groove, A method for manufacturing a wiring board according to claim 1 or 2.
5. Before the first groove forming step and / or the second groove forming step, The process includes a laminate removal step, in which the laminate is removed along the planned division line to a depth that does not reach the core substrate in an area wider than the processing groove, The method for manufacturing a wiring board according to claim 3.
6. A wiring substrate in which a laminate is formed on the first surface side and / or the second surface side of a core substrate, From the surface of the laminate formed on the first surface side and / or the second surface side to the end face of the core substrate, A wiring board having chamfered portions formed on the end face of the laminate and a portion of the end face of the core substrate, which are continuously chamfered.
7. A wiring substrate in which a laminate is formed on the first surface side and / or the second surface side of a core substrate, From the surface of the laminate formed on the first surface side and / or the second surface side to the end face of the core substrate, A wiring board having a chamfered portion formed on a part of the end face of the laminate, which is continuously chamfered.