Glass wiring substrate manufacturing method

Abstract

This eliminates the phenomenon (spine cracking) in which the glass plate itself splits into layers inside due to the action of the resin layer when cutting a glass plate with a resin film (resin layer) formed on it to manufacture a glass wiring substrate, thereby eliminating defects during manufacturing. [Solution] The film comprises a through-hole portion formed in the thickness direction from the first surface portion to the second surface portion of the glass substrate, a conductive material embedded in the through-hole portion, a plurality of resin layer portions formed on each of the first surface portion and the second surface portion of the glass substrate, a groove portion formed by cutting out the plurality of resin layer portions by a predetermined width, a closest adhesion portion that forms the bottom of the groove portion and leaves behind the resin layer portions of the plurality of resin layer portions that adhere to and cover the glass substrate, and a film cut-out portion consisting of the groove portion and the closest adhesion portion.

Description

[Technical Field]

[0001] The present invention relates to a glass wiring substrate, a method for manufacturing a glass wiring substrate, and a glass wiring substrate manufacturing apparatus, and more particularly to a glass wiring substrate that avoids cracks occurring in the glass wiring substrate, a manufacturing method thereof, and a glass wiring substrate manufacturing apparatus corresponding to said manufacturing. [Background technology]

[0002] Semiconductor elements, such as various types of memory, CPUs, and GPUs, mounted on circuit boards have terminals for electrical connection. The pitch of these connection terminals is typically several to several tens of times different from the pitch of the connection portions of the circuit board that are electrically connected to the semiconductor elements. Therefore, a relay substrate called an interposer is used to electrically connect the semiconductor elements and the circuit board. The semiconductor elements are mounted on one side of the interposer, and the circuit board is connected to the other side.

[0003] Organic resin materials have been used as materials for interposers. However, to improve the processing power of semiconductor elements and respond to higher integration, there is a demand for fine wiring formation in interposers. However, with interposers using conventional organic resin materials, the resin absorbs moisture and expands and contracts significantly due to temperature, making it difficult to accommodate fine wiring.

[0004] Therefore, to address the issues with organic resin materials, interposers (glass wiring substrates) that use glass as the base material are currently being developed. Glass wiring substrates are less susceptible to moisture absorption, and their coefficient of thermal expansion is similar to that of semiconductor elements, reducing the effects of expansion and contraction due to temperature.

[0005] However, when a wiring board is constructed using a glass plate, the glass plate is subjected to the action of stress, etc., from the resin film or laminated resin layer attached to both sides of the glass plate to form the circuit board. When cutting (cutting) a glass plate with a resin film attached or a resin layer laminated to a predetermined size and shape, it has been reported that the action occurring in the resin film (resin layer) causes the glass plate itself to split into layers within itself (layer separation phenomenon). This layer separation of a glass plate is called seware, etc.

[0006] To address the above-mentioned phenomenon of spine cracks in glass plates, various methods have been proposed, including forming holes that penetrate the front and back of the glass plate and filling them with resin (see Patent Document 1), applying a mixture of resin and inorganic filler to the glass plate (see Patent Document 2), modifying the glass plate by irradiating it with a laser (see Patent Document 3), and forming a resin layer on the glass plate and then cutting the glass plate with a rotary blade (dicing blade) (see Patent Document 4).

[0007] The adoption of techniques such as those described in Patent Documents 1 and 2 has been shown to be effective in preventing spine cracking during processing of glass plates. However, these techniques require additional steps during the manufacturing process, such as drilling holes in the glass plate, filling with resin, and applying various materials, and are not necessarily simple. Furthermore, further improvements in production efficiency are desired due to the risk of breakage during the manufacturing of glass resin substrates.

[0008] The techniques typified by Patent Documents 3 and 4 also have a certain degree of effectiveness in preventing spine cracks during processing of glass plates. However, the laser irradiation of Patent Document 3 requires time to process the glass plate, which limits production efficiency. Patent Document 4 improves production efficiency by using a rotary blade (dicing blade). However, because the glass plate is cut with the rotary blade while avoiding the resin layer present on the glass plate and taking care not to cause spine cracks, cutting the glass plate with precision is not easy. Furthermore, there is a risk of spine cracks occurring in load tests that simulate conditions in which a wiring board using the glass plate repeatedly generates heat during use and cools down when not in use. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-157982 [Patent Document 2] Japanese Patent Publication No. 2020-182006 [Patent Document 3] Japanese Patent Application Publication No. 2019-021720 [Patent Document 4] International Publication No. WO / 149374 Summary of the Invention [Problem to be solved by the invention]

[0010] The inventors have reviewed the manufacturing process and other aspects of glass wiring substrates and made extensive improvements, thereby developing effective measures to prevent the inevitable back cracking that occurs when processing glass plates, and have thus developed a glass wiring substrate and a method for manufacturing a glass wiring substrate.

[0011] The present invention has been made in consideration of the above points, and provides a glass wiring substrate and a method for manufacturing a glass wiring substrate that can eliminate the phenomenon (spine cracking) in which the glass plate itself splits into layers inside due to the action of the resin film (resin layer) when a glass plate to which a resin film is attached or a resin layer is laminated is cut to manufacture a glass wiring substrate, thereby eliminating defects during manufacturing and use and increasing productivity. [Means for solving the problem]

[0012] That is, the glass wiring substrate of the embodiment is characterized by comprising a through-hole portion formed in the thickness direction from the first surface portion to the second surface portion of the glass substrate, a conductive material embedded in the through-hole portion, a plurality of resin layer portions formed on each of the first surface portion and the second surface portion of the glass substrate, a groove portion formed on the first surface portion and the second surface portion of the glass substrate and formed by cutting out the plurality of resin layer portions by a predetermined width, a closest adhesion portion that forms the bottom of the groove portion and leaves behind resin layer portions of the plurality of resin layer portions that are in close contact with the glass substrate and cover the glass substrate, and a resin layer cut-out portion consisting of the groove portion and the closest adhesion portion.

[0013] Furthermore, in the glass wiring substrate of the embodiment, the groove may be formed on a second surface portion that is symmetrical to the first surface portion in the thickness direction of the glass substrate.

[0014] Furthermore, in the glass wiring substrate of the embodiment, the glass substrate may be rectangular, and the resin layer cut-out portions may be provided on each of the four sides of the first surface and the four sides of the second surface of the glass substrate.

[0015] Furthermore, in the glass wiring substrate of the embodiment, the resin layer cut-off portion may have an inclined portion that widens the width of the groove in the direction away from the glass substrate.

[0016] Furthermore, in the glass wiring substrate of the embodiment, the plurality of resin layer portions may be a plurality of resin film portions.

[0017] In addition, the manufacturing method of the glass wiring substrate of the embodiment is characterized by comprising a through hole forming process for forming a through hole in the thickness direction from the first surface portion to the second surface portion of the glass substrate; a conductive material filling process for filling the through hole with a conductive material; a forming process for forming a plurality of resin layer portions on each of the first surface portion and the second surface portion of the glass substrate; a groove forming process for forming grooves of a predetermined width and a predetermined depth in the plurality of resin layer portions formed on the first surface portion and the second surface portion of the glass substrate, while leaving the closest adhesion portion, which is the resin layer portion that is in close contact with the glass substrate and covers the glass substrate; and a cutting process for cutting the glass substrate in the thickness direction in the grooves to separate the closest adhesion portion of the first surface portion, the glass substrate, and the closest adhesion portion of the second surface portion.

[0018] Furthermore, in the manufacturing method of the glass wiring substrate according to the embodiment, the grooves may be formed by cutting or dissolving in the groove forming step.

[0019] Furthermore, in the method for manufacturing a glass wiring substrate according to the embodiment, the groove may be formed on a second surface portion that is symmetrical to the first surface portion in the thickness direction of the glass substrate.

[0020] Furthermore, in the manufacturing method of the glass wiring substrate according to the embodiment, in the groove forming step, an inclined portion may be formed in the groove such that the width of the groove increases in a direction away from the glass substrate.

[0021] Furthermore, in the manufacturing method of the glass wiring substrate according to the embodiment, the plurality of resin layer portions may be a plurality of resin film portions.

[0022] In addition, the glass wiring substrate manufacturing apparatus used in the manufacturing method of the glass wiring substrate of the embodiment is characterized by including a first rotary blade that forms grooves of a predetermined width and a predetermined depth in a plurality of resin layer portions, a second rotary blade that cuts the glass substrate from the grooves in the thickness direction, and a control unit that controls the positions of the first rotary blade and the second rotary blade. [Effects of the Invention]

[0023] The glass wiring substrate of the present invention comprises a through-hole formed in the thickness direction from the first surface to the second surface of the glass substrate, a conductive material filled in the through-hole, a plurality of resin layer portions formed on each of the first surface and the second surface of the glass substrate, groove portions formed on the first surface and the second surface of the glass substrate and formed by cutting out the plurality of resin layer portions by a predetermined width, a closest adhesion portion that forms the bottom of the groove and leaves behind resin layer portions that are in close contact with the glass substrate and cover the glass substrate, and a resin layer cut-out portion consisting of the groove portion and the closest adhesion portion.Therefore, it is possible to eliminate the phenomenon (spine cracking) in which the glass substrate itself splits into layers inside during production and use due to the effects that occur in the plurality of resin layer portions and resin films when a glass plate having the plurality of resin layer portions and resin films is cut to produce a glass wiring substrate.

[0024] and a cutting step of cutting the glass substrate in the thickness direction to separate the closest adherent portions of the first surface portion, the glass substrate, and the closest adherent portions of the second surface portion. Therefore, the method for manufacturing a glass wiring substrate of the present invention includes a through-hole forming step of forming a through-hole in the thickness direction from the first surface portion to the second surface portion of the glass substrate, a conductive material filling step of filling the through-hole with a conductive material, a forming step of forming a plurality of resin layer portions on each of the first surface portion and the second surface portion of the glass substrate, a groove forming step of forming grooves of a predetermined width and a predetermined depth in the plurality of resin layer portions formed on the first surface portion and the second surface portion of the glass substrate, while leaving behind the closest adherent portions, which are the resin layer portions that adhere to the glass substrate and cover the glass substrate. Therefore, the method for manufacturing a glass wiring substrate of the present invention includes a through-hole forming step of forming a through-hole in the thickness direction from the first surface portion to the second surface portion of the glass substrate, a conductive material filling step of filling the through-hole with a conductive material, a forming step of forming a plurality of resin layer portions on each of the first surface portion and the second surface portion of the glass substrate, a groove forming step of forming grooves of a predetermined width and a predetermined depth in the plurality of resin layer portions while leaving behind the closest adherent portions, which are the resin layer portions that adhere to the glass substrate and cover the glass substrate

[0025] In addition, the glass wiring substrate manufacturing apparatus used in the method for manufacturing a glass wiring substrate of the present invention is equipped with a first rotary blade that forms grooves of a predetermined width and depth in multiple resin layer portions, a second rotary blade that cuts the glass substrate from the grooves in the thickness direction of the glass substrate, and a control unit that controls the positions of the first rotary blade and the second rotary blade.Therefore, when a glass plate to which a resin film has been attached or a resin layer portion has been laminated is cut to manufacture a glass resin substrate, the phenomenon of the glass plate itself cracking into layers inside it (spine cracking) due to the action of the resin film (resin layer portion) can be eliminated, and a manufacturing apparatus can be provided that eliminates manufacturing defects and increases productivity. [Brief explanation of the drawings]

[0026] [Figure 1] 1A to 1C are (A) a first cross-sectional schematic diagram, (B) a second cross-sectional schematic diagram, and (C) a third cross-sectional schematic diagram illustrating a layer-wise splitting phenomenon (back crack) of a glass substrate. [Figure 2] 1 is a cross-sectional view of a glass wiring substrate according to an embodiment of the present invention; [Figure 3] FIG. 1A is a first enlarged schematic view of a portion of a film cut off, and FIG. 1B is a second enlarged schematic view of a portion of a film cut off. [Figure 4] This is an enlarged photograph (200 times magnification) of Figure 3(B). [Figure 5] 1A to 1C are (A) a first cross-sectional view, (B) a second cross-sectional view, and (C) a third cross-sectional view showing a manufacturing process of a glass wiring substrate. [Figure 6] FIG. 10 is a fourth schematic cross-sectional view showing a manufacturing process of the method for manufacturing a glass wiring substrate. [Figure 7] 1A is a schematic cross-sectional view showing a manufacturing process of a glass wiring substrate when a first rotary blade is used, and FIG. 1B is a schematic cross-sectional view showing a manufacturing process of a glass wiring substrate when a second rotary blade is used. [Figure 8] FIG. 5 is a fifth cross-sectional view schematically illustrating a manufacturing process of the method for manufacturing a glass wiring substrate. [Figure 9] 1 is an overall perspective view of a glass wiring substrate manufacturing apparatus according to an embodiment, viewed from above; [Figure 10](A) is a cross-sectional photograph of a glass wiring substrate on which one resin film portion with a thickness of 40 μm is formed, and (B) is a cross-sectional photograph of a glass wiring substrate on which two resin film portions with a thickness of 20 μm are formed. [Figure 11] (A) is an enlarged cross-sectional photograph of a glass wiring substrate on which three 20 μm-thick resin film layers are formed, and (B) is an enlarged cross-sectional photograph of a glass wiring substrate on which three 40 μm-thick resin film layers are formed. [Figure 12] (A) An enlarged cross-sectional photograph of a glass wiring substrate on which three 40 μm-thick resin film layers have been formed and film cut-off sections have been created. (B) An enlarged cross-sectional photograph of a glass wiring substrate on which eight 20 μm-thick resin film layers have been formed and film cut-off sections have been created. [Figure 13] This is an enlarged cross-sectional photograph of a glass wiring substrate in which three layers of 40 μm-thick resin film were formed and cut without forming any film cut-off portions. DETAILED DESCRIPTION OF THE INVENTION

[0027] The glass wiring substrate of the embodiment is a glass substrate having through-holes penetrating the front and back surfaces of the glass substrate, with a conductive metal material disposed in the through-holes, and is primarily used as an interposer. The glass interposer referred to here is a member that serves as a relay substrate for electrically connecting semiconductor elements, such as various memories, CPUs, and GPUs, mounted on a circuit board to the circuit board via wiring. In particular, since the glass interposer itself is formed only from glass and a conductive material for wiring, it does not include materials with different thermal expansion coefficients, such as resin, and thus reduces deformation due to heat exposure during use. Of course, the glass wiring substrate of the embodiment can be used for various applications other than interposers.

[0028] First, using the cross-sectional view of Figure 1, we will explain the phenomenon of laminar cleavage (spine cracking) of a glass substrate 10 and the number of resin film portions 20 laminated by adhering to the glass substrate 10. Note that the same phenomenon can be considered when, instead of the resin film portion 20, a resin coating agent is applied multiple times to form layers.

[0029] 1(A) is a schematic cross-sectional view of a glass substrate 10 cut in the thickness direction when there is no resin film portion 20 (0 sheet). When there is no resin film portion 20, the glass substrate 10 is cut as is and no particular problem occurs.

[0030] 1(B) is a schematic cross-sectional view of glass substrate 10 cut in the thickness direction when only one resin film portion 20 is attached to glass substrate 10. When there is only one resin film portion 20, even if stress is applied to resin film portion 20 during cutting, glass substrate 10 is not affected by the deformation force of resin film portion 20 because the thickness of glass substrate 10 is relatively large. As a result, glass substrate 10 is cut as is, and no particular problems occur.

[0031] 1(C) is a cross-sectional schematic diagram of a glass substrate 10 cut in the thickness direction when four resin film portions 20 are attached to the glass substrate 10. When there are four resin film portions 20, deformation of the multiple resin film portions 20 that occurs during cutting becomes stress, and the attached glass substrate 10 is pulled by the stress of the multiple resin film portions 20. As a result, a phenomenon in which layers split inside the glass substrate 10 (so-called spine cracking) occurs. As shown in the figure, spine cracking region C is shown.

[0032] Thus, whether or not spine cracks occur in the glass substrate 10 depends on the number of laminated resin film portions 20. Based on this knowledge, when cutting the glass substrate 10 into individual substrates, it is thought that it is possible to reduce the stress applied to the glass substrate 10 from the multiple resin film portions 20 (multiple resin layer portions) by reducing the number of laminated resin film portions 20 as much as possible, and similarly, by reducing the number of resin layer portions laminated by coating or the like. Therefore, the glass wiring substrate and its manufacturing method of the embodiment are characterized in that, in order to prevent spine cracks, the number of laminated resin film portions 20 (number of laminated resin layer portions) at the cutting portion of the glass substrate 10 is reduced in advance.

[0033] Furthermore, in the embodiment, the resin film portions 20 are not completely eliminated by reducing the number of laminated layers (the number of laminated resin layer portions) of the resin film portions 20 on the cutting portions of the glass substrate 10. Even after the resin film portions 20 are reduced, the resin film portions 20 always remain on the cutting portions of the glass substrate 10, and the glass substrate 10 is cut together with the resin film portions 20 as described below in a state where the glass substrate 10 is covered with the resin film portions 20.

[0034] Based on the knowledge of FIG. 1, the structure of a glass wiring substrate 1 of an embodiment will be described using the cross-sectional schematic diagrams of FIGS. 2 and 3. The glass wiring substrate 1 includes a glass substrate 10 that constitutes the main structure of the substrate. The glass substrate 10 is made of a material such as alkali glass, alkali-free glass, or borosilicate glass. A through-hole 13 is formed in the thickness direction of the glass substrate 10 from the first surface 11 to the second surface 12. Resin film portions 20, 20 are attached to each of the first surface 11 and the second surface 12 of the glass substrate 10. In the illustration, multiple resin film portions 20, 20 (four resin film portions 21, 22, 23, and 24) are attached to each of the first surface 11 and the second surface 12. The resin film portion 20 is made of a material with good stretchability and insulating properties, and a film of epoxy resin, for example, is used.

[0035] In addition to the above-described laminate of multiple resin film portions 20, the glass wiring substrate 1 of the embodiment can also employ a configuration in which a resin coating is applied multiple times to form layers, forming a resin layer of a predetermined thickness. Therefore, the "resin layer portion" encompasses both the form of a "resin film portion" and the form of a "resin layer" derived from the resin coating. Of course, as mentioned above, the resin coating is made of a material such as epoxy resin. The following explanations and drawings illustrate and explain the form of the resin film portion in which the resin layer portion is formed. Regarding the most adherent portion and the resin layer cut-off portion described below, the most adherent portion and the resin layer cut-off portion encompass both the form of a "resin film portion" and the form of a "resin layer" derived from the resin coating. When the resin layer portion is in the form of a resin film portion, the most adherent portion is the most adherent film portion, and the resin layer cut-off portion is the film cut-off portion.

[0036] The through-holes 13 are formed in the glass substrate 10 by known methods such as laser light irradiation or etching with an acid or alkaline chemical solution. A conductive material 14 is embedded inside the through-holes 13. The conductive material 14 is a conductive resin paste containing fine particles of metal such as copper, silver, gold, platinum, nickel, or lead. This ensures the conductivity of the through-holes 13 from the first surface 11 to the second surface 12. Alternatively, the inside of the through-holes 13 can be plated with copper or silver to make them conductive.

[0037] A wiring portion 15 is formed on the resin film portions (resin layer portions) 20, 20 (resin film portions 21, 22, 23, 24, respectively), and electrical conductivity is achieved on both the first surface portion 11 side and the second surface portion 12 side of the glass substrate 10. The structure and position of the wiring portion 15 may be determined appropriately depending on the design of the glass wiring substrate 1, and the illustration is merely a schematic example.

[0038] A structural feature of the glass wiring substrate 1 of the embodiment is that a groove 31 of a predetermined width is formed in a plurality of resin film portions 20, 20 (a plurality of resin layer portions) laminated by adhesion on the first surface portion 11 and the second surface portion 12 of the glass substrate 10. In Fig. 1, the groove portion 31 is formed by removing some of the resin film portions 20 (a plurality of resin layer portions) from the plurality of resin film portions 20 (a plurality of resin layer portions) to leave a most adhesive film portion 34 (a most adhesive portion) in which the resin film portion 20 that is in close contact with the glass substrate 10 and covers the glass substrate 10 remains. The most adhesive film portion shown in the figure corresponds to the resin film portion 21.

[0039] The vertical groove 31 and the horizontal most adhesive film portion (resin film portion 21) form a film cut-off portion 30. The film cut-off portion 30 has a structure in which a plurality of resin film portions 20 (a plurality of resin layer portions) are cut away from the side edge 10e of the glass substrate 10 in the width direction of the glass substrate 10, while leaving the most adhesive film portion.

[0040] The groove portion 31 is formed by cutting out a predetermined width at a position on the second surface portion 12 that is symmetrical (line symmetrical) to the first surface portion 11 in the thickness direction of the glass substrate 10. As will be described later in the manufacturing method, the glass substrate 10 is cut together with the most adhesive film portion 34 (most adhesive portion) of the resin film portions 20, 20 (resin layer portions). Therefore, in a single cutting operation, the positions of the groove portions 31 need to be aligned in order to separate the glass substrate 10 at the center of the groove portion 31, and the formation positions of the groove portions 31 are aligned on the front and back of the glass substrate 10.

[0041] The glass wiring substrate 1 of the embodiment is square or rectangular to match the shape of the semiconductor element mounted on the circuit board. Therefore, the glass substrate 10 is rectangular (square or rectangular). The film cutout portions 30 are provided around the periphery of the rectangular glass substrate 10, on each of the four sides of the first surface 11 and the second surface 12. FIG. 2 is a cross-sectional schematic diagram of the glass wiring substrate 1. As can be seen from the illustration, the film cutout portions 30 are provided at the four corners of the first surface 11 side and the four corners of the second surface 12 side of the glass substrate 10 (the illustration only partially shows the cross section). In other words, at each of the four corners of the first surface 11 side and the four corners of the second surface 12 side of the glass substrate 10, the laminated resin film portions 20, 20 (resin layer portions) are formed with a long, L-shaped cross-section. The film cutout portions 30 are formed by the vertical wall surfaces of the groove portions 31 and the surface of the most closely-adhering film portion 34.

[0042] There are two types of film cut-off portions 30, as shown in the enlarged schematic diagrams of FIG. 3. The film cut-off portion 30 of FIG. 3(A) is formed perpendicular to the multiple resin film portions 20, 20 (resin film portions 21, 22, 23, 24) (multiple resin layer portions). In contrast, the film cut-off portion 30a of FIG. 3(B) is provided with an inclined portion 32 that widens the width of the groove portion 31a in the direction away from the glass substrate 10 (in the order of resin film portions 21, 22, 23, 24). The method of forming the film cut-off portions 30, 30a (resin layer cut-off portions) of FIGS. 3(A) and 3(B) will be described later in the manufacturing method section.

[0043] 3(B) shows a gradually larger opening in the film cut-off portion 30a than in the film cut-off portion 30 in FIG. 3(A). In other words, the layered amount of the resin film portion 20 gradually decreases. This suggests that the stress generated in the resin film portion 20 (resin layer portion) decreases with increasing distance from the glass substrate 10, resulting in a smaller force acting on the glass substrate 10.

[0044] Figure 4 is an enlarged photograph (magnified 200 times) of a prototype of the film cut-off portion 30a in Figure 3(B). The thickness of the glass substrate in the photograph is 495.52 μm, the film thickness of the most closely-adhered film portion is 25.07 μm on the upper side and 27.60 μm on the lower side, and the layer thickness of the resin film portion excluding the most closely-adhered film portion is 210.79 μm on the upper side and 177.08 μm on the lower side. As can be seen from the photograph, the opening of the film cut-off portion 30a gradually increases, and in side view (cross-section), the film cut-off portion 30a is roughly "J" shaped.

[0045] In the glass wiring substrate 1 of this embodiment, the multiple resin film portions 20, 20 (multiple resin layer portions) are cut away, leaving only a portion. However, a most adhesive film portion 34 (most adhesive portion) remains, which is the resin film portion 20 that adheres to and covers the glass substrate 10. As will be apparent from the verification of the examples described later, the most adhesive film portion 34 (most adhesive portion) is intentionally formed in this way to prevent spine cracks when the glass substrate 10 is cut. Furthermore, this also has the effect of maintaining durability in consideration of the use conditions of the glass wiring substrate 1, which are subject to repeated temperature increases and decreases.

[0046] Next, a method for manufacturing the glass wiring substrate 1 of the embodiment will be described with reference to the schematic diagrams of Figures 5 to 8. In Figure 5(A), a glass substrate 10 constituting the glass wiring substrate 1 of the embodiment is prepared. In Figure 5(B), through-holes 13 are formed in the glass substrate 10 in the thickness direction from the first surface 11 to the second surface 12 ("through-hole forming step"). The through-holes 13 in the glass substrate 10 are formed by perforation by immersion (etching) in an acidic chemical solution such as hydrofluoric acid or an alkaline chemical solution such as caustic soda, or by perforation by laser light irradiation, or a combination of both.

[0047] In FIG. 5(C), after the through-holes 13 are formed, a conductive material is filled into the through-holes 13 (the "conductive material filling step"). The conductive material 14 is a conductive resin paste containing fine particles of metal such as copper, silver, gold, platinum, nickel, or lead. Thus, the conductivity of the through-holes 13 from the first surface 11 to the second surface 12 is ensured by the conductive material 14. Alternatively, copper or silver plating is formed inside the through-holes 13 to make the through-holes 13 conductive.

[0048] In FIG. 6, a plurality of resin layer portions are formed on each of the first surface portion 11 and the second surface portion 12 of the glass substrate 10. In the embodiment, a resin film portion 20 is attached to each of the first surface portion 11 and the second surface portion 12 ("forming process / attaching process"). As in the example of FIG. 1, wiring portions 15 are formed on the resin film portions 20, 20 (resin film portions 21, 22, 23, 24, respectively), and electrical conductivity is achieved on both the first surface portion 11 side and the second surface portion 12 side of the glass substrate 10. The illustrated resin film portion 21 corresponds to the most closely adhered film portion (most closely adhered portion) that adheres to the glass substrate 10.

[0049] 7(A) and (B), grooves 31, 31a of a predetermined width and a predetermined depth that form the most adhesive film portion 34 are formed in the plurality of resin film portions (plurality of resin layer portions) ("groove forming step"), leaving a most adhesive film portion 34 (resin film portion 21 in the drawing) (most adhesive portion) that remains, which is at least the resin film portion 20 that is in close contact with and covers the glass substrate 10, among the plurality of resin film portions 20, 20 attached to the first surface portion 11 and the second surface portion 12 of the glass substrate 10. In the formation of the grooves 31, 31a, in the embodiment, cutting wheels 50, 50a (rotary blades, dicing blades) containing diamond powder are brought into contact with the plurality of resin film portions 20, 20, and are cut (ground) so as to leave the most adhesive film portion 34 (most adhesive portion).

[0050] The cutting wheel 50 (rotary blade) is preferred for forming the grooves 31 in the groove forming step because position control is accurate and easy. Note that cutting that leaves the most adherent film portion is not so strict as to leave only the most adherent film portion, but includes cases where cutting reaches a portion of the most adherent film portion and even cases where cutting ends halfway through another resin film portion laminated to the most adherent film portion. Of course, when forming the grooves 31 in the groove forming step, known methods may be used, such as dissolving the resin portion using a chemical solution such as an organic solvent for resin, or cutting the resin portion by irradiating it with laser light (cutting by melting).

[0051] To form the groove 31 in FIG. 7(A), a cutting wheel 50 (rotary blade) with a squared end is used. This corresponds to the production of the film cut-off portion 30 (resin layer cut-off portion) in FIG. 3(A). To form the groove 31a in FIG. 7(B), a cutting wheel 50a (rotary blade) with a chamfered arc end is used. This corresponds to the production of the film cut-off portion 30a (resin layer cut-off portion) in FIG. 3(B). Due to the shape of the cutting wheel 50a (rotary blade, dicing blade), an inclined portion 32 that widens the width of the groove 31a is simultaneously formed. In this case, the groove 31a has an approximately U-shape in cross section.

[0052] When forming the grooves 31, 31a, the positions of the grooves 31 are formed on the second surface 12, which is symmetrical (line-symmetrical) to the first surface 11 in the thickness direction of the glass substrate 10. This is to align the positions during cutting, as described below. The size of the grooves with a predetermined width and depth in the multiple resin film portions (multiple resin layer portions) that remain in the most closely adhered film portion (resin film portion 21 in the illustration) (most closely adhered portion) in the groove forming process is affected by various factors such as the type of resin, amount of thermal expansion, elasticity, and groove forming method, and therefore it is not easy to define a range for the size of the grooves in general.

[0053] In Fig. 8, in the grooves 31, 31a, the most adhesive film portion (resin film portion 21) of the first surface portion 11, the glass substrate 10, and the most adhesive film portion (resin film portion 21) of the second surface portion 12 are cut in the thickness direction of the glass substrate 10 ("cutting process"). A cutting wheel 50 (rotary blade, dicing blade) with a square end is used for cutting. The most adhesive film portion corresponds to the most adhesive portion.

[0054] In the cutting process shown in Fig. 8, when the groove 31 in Fig. 7(A) is cut by the cutting wheel 50, the film cut-off portion 30 (resin layer cut-off portion) in Fig. 3(A) is formed on the end surface. That is, the film cut-off portion 30 having an L-shaped end surface is formed from the rectangular groove 31. Furthermore, in the cutting process, when the groove 31a in Fig. 3(B) is cut by the cutting wheel 50, the film cut-off portion 30a (resin layer cut-off portion) in Fig. 3(B) is formed on the end surface. That is, the film cut-off portion 30 having a J-shaped end surface is formed from the U-shaped groove 31.

[0055] As can be seen from the figure, film cut-off portions 30, 30a (resin layer cut-off portions) derived from grooves 31, 31a are formed on each of the first surface 11 and second surface 12 of the glass substrate 10. That is, in the film cut-off portions 30, 30a, the resin film portion (resin layer portion) that adheres to the glass substrate 10 is limited to the minimum closest film portion (closest adhesion portion). Therefore, when the cutting wheel 50 (rotary blade, dicing blade) comes into contact with the closest adhesion film portion, the stress generated in the closest adhesion film portion is small compared to the entirety of the multiple laminated resin film portions 20, 20 (multiple resin layer portions), and the transmission of stress from the closest adhesion film portion (closest adhesion portion) to the glass substrate 10 is suppressed. By reducing the volume of the resin film portions 20, 20 (resin layer portions) at the cutting locations in advance, the impact of excess stress generated from the resin film portions 20, 20 (resin layer portions) on the glass substrate 10 is mitigated, and deformation of the glass substrate 10 is avoided. As a result, this is an effective measure against the phenomenon (spine cracking) in which the glass plate itself splits into layers inside.

[0056] Although repetitive, in the glass wiring substrate 1 of the embodiment, the multiple resin film portions 20, 20 (multiple resin layer portions) are cut away, leaving a portion. However, a most adhesive film portion 34 (most adhesive portion) remains, which is the resin film portion 20 that adheres to and covers the glass substrate 10. As will be apparent from the verification of the examples described later, the most adhesive film portion 34 (most adhesive portion) is intentionally formed in this way to prevent spine cracks when the glass substrate 10 is cut. In other words, by intentionally thinning the multiple resin film portions 20, 20 (multiple resin layer portions), the stress applied to the glass substrate 10 from the resin film portions 20, 20 is reduced.

[0057] If the most adhesive film portion 34 (most adhesive portion) were completely removed, leaving only the glass substrate 10 exposed, and then the glass substrate 10 was cut using a cutting wheel 50 (rotary blade, dicing blade), it would appear that the stress caused by the resin film portions 20, 20 would be further reduced, further reducing spine cracking during cutting. However, when the glass substrate 10 is exposed without the most adhesive film portion 34 (most adhesive portion) of the resin film portions 20, 20, a cutting wheel 50 (rotary blade, dicing blade) with a finer coarseness must be used to cut the hard glass substrate 10, resulting in significant wear on the cutting wheel 50. If a coarser cutting wheel 50 (rotary blade, dicing blade) is used, fine cracks are likely to occur at the cut location, and these cracks become larger with repeated temperature increases and decreases, resulting in damage and defects such as spine cracking in the glass wiring substrate 1 and reduced durability. Therefore, in consideration of improving the cutting efficiency of the glass substrate 10 and improving the durability of the glass wiring substrate 1 after it is made into a product, the glass substrate 10 is cut with the most adhesive film portion 34 (most adhesive portion) remaining.

[0058] 9 shows an example of a glass wiring substrate manufacturing apparatus 500 for manufacturing the glass wiring substrate 1 described above. The glass wiring substrate manufacturing apparatus 500 includes a first rotary blade 501 that forms grooves 31, 31a of a predetermined width and a predetermined depth in the multiple resin layer portions 20 (resin film portions 21, 22, 23, 24) of the glass substrate 10, and a second rotary blade 502 that cuts the grooves 31, 31a in the glass substrate 10 in the thickness direction.

[0059] The glass wiring substrate manufacturing apparatus 500 also includes a control unit 505 inside the base 507, which controls the positions of the first rotary blade 501 and the second rotary blade 502. The control unit 505 is a control device or control board equipped with a known arithmetic element such as a microcomputer or a programmable logic controller.

[0060] In the illustrated embodiment of the glass wiring substrate manufacturing apparatus 500, a workpiece W is placed at a predetermined position on a turntable 508 of a base 507. The workpiece W is rotated by the turntable 508 in accordance with the cutting process performed by a first rotary blade 501 and a second rotary blade 502. The workpiece W is a glass wiring substrate 1.

[0061] The first rotary blade 501 is held by a first arm 503, and the second rotary blade 502 is held by a second arm 504. The first rotary blade 501 and the second rotary blade 502 are known rotary blades (cutting wheels, dicing blades) used for processing glass, silicon wafers, and the like, such as grinding wheels containing diamonds. The first rotary blade 501 is a thick (wide and thick) rotary blade used to form grooves 31 and 31a of a predetermined width in the resin film portion 20 (resin film portions 21, 22, 23, and 24). In contrast, the second rotary blade 502 is a thinner (thinner) rotary blade than the first rotary blade 501, so that it cuts each glass substrate 10 of the laminate 45 in sequence.

[0062] Base 507 is provided with a motor (servo motor, stepping motor, etc.) (not shown) that rotates turntable 508. Base 507 also has case 509, which is provided with rails and motors (servo motor, stepping motor, etc.) (not shown) for moving first arm 503 and second arm 504 in each direction (see arrows) up and down, front and back, and left and right. The amount of movement of first arm 503 and second arm 504 is controlled under the control of control unit 505.

[0063] The glass wiring substrate manufacturing apparatus 500 of the embodiment can ultimately manufacture the glass wiring substrate 1 by selectively using the first rotary blade 501 and the second rotary blade 502 depending on the target groove width and the object to be processed. Because processing is performed using only the rotary blade, processing can be performed more quickly than processing using laser irradiation. This is particularly advantageous for mass production of the glass wiring substrate 1. [Example]

[0064] The inventors fabricated glass wiring substrates based on the manufacturing method for glass wiring substrates disclosed in the embodiments, varying the thickness (film thickness) of the resin film portion of the epoxy resin and the number of layers. They then evaluated the appearance of each glass wiring substrate and conducted temperature durability tests to evaluate the occurrence of defects such as spine cracks that occurred in the glass wiring substrates. Figures 10, 11, 12, and 13 are enlarged photographs of the cross sections of the fabricated glass wiring substrates. All photographs are enlarged 150 times.

[0065] Figure 10(A) shows a glass wiring substrate fabricated by laminating a single layer of epoxy resin film (40 μm thick) on both sides of a glass substrate and then cutting it with a dicing blade. This is an enlarged cross-sectional photograph of the substrate after 160 cycles of thermal shock testing, with each cycle consisting of cooling and heating at -65°C for 30 minutes and at 125°C for 30 minutes. Figure 10(B) shows a glass wiring substrate fabricated by laminating two layers of epoxy resin film (20 μm thick) on both sides of a glass substrate of the same specifications and then cutting it with a dicing blade. This is an enlarged cross-sectional photograph of the substrate after 160 cycles of the same thermal shock testing. Neither the glass wiring substrates in Figures 10(A) nor (B) showed any cracks on the spine of the glass substrate or peeling of the resin film.

[0066] Figure 11(A) shows a glass wiring substrate made by laminating three layers of epoxy resin film (20 μm thick) on both sides of a glass substrate of the same standard and then cutting it with a dicing blade. It is an enlarged cross-section photograph of the glass wiring substrate after a heat resistance test in which the glass wiring substrate was heated at 260°C for 60 minutes. At this time, a black streak appeared within the ellipse shown. This is a peeling phenomenon that occurred in the glass substrate, known as spine cracking. It is believed that the difference in the thermal expansion coefficient between the glass substrate and the resin film caused the distortion.

[0067] Figure 11(B) shows a glass wiring substrate made by laminating three layers of epoxy resin film (40 μm thick) on one side of a glass substrate of the same specifications and cutting it with a dicing blade. When the glass substrate was cut together with the resin film, a large back crack occurred in the glass substrate, as shown in the oval in the figure. This is thought to be because the glass substrate was pulled together by stress caused by the elasticity of the resin film.

[0068] Thus, experiments have shown that the adverse effect of spine cracking increases as the resin film layer formed on the surface of the glass substrate becomes thicker. Therefore, we investigated the effect of reducing the thickness of the resin film layer that has been laminated beforehand when cutting with a dicing blade.

[0069] Figure 12(A) shows a glass wiring substrate produced by laminating three layers of epoxy resin film (40 μm thick) on both sides of a glass substrate, then removing the resin film with a dicing blade, leaving approximately 30 μm of resin film on both sides of the glass substrate. The glass substrate was then cut together with the resin film using the dicing blade. This is an enlarged cross-sectional photograph of the glass wiring substrate after 160 cycles of temperature shock testing, with one cycle consisting of cooling and heating at -65°C for 30 minutes and at 125°C for 30 minutes.

[0070] Figure 12(B) shows a glass wiring substrate produced by laminating eight layers of epoxy resin film (20 μm thick) on both sides of a glass substrate of the same specifications, then removing the resin film with a dicing blade, leaving approximately 30 μm of resin film on both sides of the glass substrate. The glass substrate was then cut together with the resin film using the dicing blade, and the resulting glass wiring substrate was then subjected to 160 cycles of the same temperature shock test.

[0071] 12(A) and (B), the resin film portion is cut away while leaving the most adhesive film portion. This allows for lamination of the resin film portion while enabling cutting with a dicing blade, and is particularly effective in preventing damage during temperature shock testing.

[0072] Figure 13 shows a glass wiring substrate produced by laminating three layers of epoxy resin film (40 μm thick) on both sides of a glass substrate, and then completely removing the resin film from both sides of the glass substrate using a dicing blade. The glass substrate was then cut together with the resin film using a dicing blade. This shows an enlarged cross-section of the glass wiring substrate after 160 cycles of thermal shock testing, with each cycle consisting of cooling and heating at -65°C for 30 minutes and at 125°C for 30 minutes. While no spine cracks were observed when the glass substrate was cut, after the thermal shock testing, a large spine crack opened in the glass substrate, as shown in the oval in the figure. This is thought to be due to strain and deformation caused by the difference in the thermal expansion coefficients of the glass substrate and the resin film.

[0073] Based on the test results in Figures 10 to 13, we further confirmed the frequency and variability of spine cracks during manufacturing. Specifically, five prototypes were manufactured for the following examples, and the percentage of defects such as spine cracks was confirmed (0 out of 5 defects or 5 out of 5 defects). The confirmation was carried out at three points: (a) when the glass substrate was cut, (b) after a heat resistance test in which the substrate was heated at 260°C for 60 minutes, and (c) after 160 cycles of a temperature shock test in which one cycle consisted of cooling and heating at -65°C for 30 minutes and then at 125°C for 30 minutes.

[0074] (Prototype 1) Only the glass substrate was cut with a dicing blade. (a) When cutting the glass substrate: 0 out of 5 products had defects (b) After heat resistance test: 0 out of 5 products had defects (c) After the temperature shock test: 0 out of 5 products had defects

[0075] (Prototype 2) The substrate was fabricated by laminating one layer of epoxy resin film (40 μm thick) on both sides of a glass substrate, and then cutting the glass substrate together with the resin film using a dicing blade. (a) When cutting the glass substrate: 0 out of 5 products had defects (b) After heat resistance test: 0 out of 5 products had defects (c) After the temperature shock test: 0 out of 5 products had defects

[0076] (Prototype 3) Two layers of epoxy resin film (40 μm thick) were laminated on both sides of a glass substrate, and then the glass substrate was cut together with the resin film using a dicing blade. (a) When cutting the glass substrate: 0 out of 5 products had defects (b) After heat resistance test: 5 out of 5 products had defects (c) After the temperature shock test: Unmeasurable

[0077] (Prototype 4) Three layers of epoxy resin film (40 μm thick) were laminated on both sides of a glass substrate, and then the glass substrate was cut together with the resin film using a dicing blade. (a) When cutting the glass substrate: 5 out of 5 products were defective (b) After heat resistance test: Unmeasurable (c) After the temperature shock test: Unmeasurable

[0078] (Prototype 5) The substrate was fabricated by laminating one layer of epoxy resin film (20 μm thick) on both sides of a glass substrate, and then cutting the glass substrate together with the resin film using a dicing blade. (a) When cutting the glass substrate: 0 out of 5 products had defects (b) After heat resistance test: 0 out of 5 products had defects (c) After the temperature shock test: 0 out of 5 products had defects

[0079] (Prototype 6) Two layers of epoxy resin film (20 μm thick) were laminated on both sides of a glass substrate, and then the glass substrate was cut together with the resin film using a dicing blade. (a) When cutting the glass substrate: 0 out of 5 products had defects (b) After heat resistance test: 0 out of 5 products had defects (c) After the temperature shock test: 0 out of 5 products had defects

[0080] (Prototype 7) Three layers of epoxy resin film (20 μm thick) were laminated on both sides of a glass substrate, and then the glass substrate was cut together with the resin film using a dicing blade. (a) When cutting the glass substrate: 0 out of 5 products had defects (b) After heat resistance test: 5 out of 5 products had defects (c) After the temperature shock test: Unmeasurable

[0081] (Prototype 8) Four layers of epoxy resin film portions (20 μm thick) were laminated on both sides of a glass substrate, and then the glass substrate was cut together with the resin film portions using a dicing blade. (a) When cutting the glass substrate: 5 out of 5 products were defective (b) After heat resistance test: Unmeasurable (c) After the temperature shock test: Unmeasurable

[0082] (Prototype 9) Three layers of epoxy resin film (40 μm thick) were laminated on both sides of the glass substrate, and then the resin film was completely removed from both sides of the glass substrate using a dicing blade.Then, the glass substrate was cut together with the resin film using a dicing blade to produce the substrate. (a) When cutting the glass substrate: 0 out of 5 products had defects (b) After heat resistance test: 0 out of 5 products had defects (c) After the temperature shock test: 5 out of 5 products were found to be defective

[0083] (Prototype 10) Three layers of epoxy resin film (40 μm thick) were laminated on both sides of a glass substrate, and then the resin film was removed using a dicing blade, leaving approximately 30 μm of resin film on both sides of the glass substrate.Then, the glass substrate was cut together with the resin film using a dicing blade to produce the product. (a) When cutting the glass substrate: 0 out of 5 products had defects (b) After heat resistance test: 0 out of 5 products had defects (c) After the temperature shock test: 0 out of 5 products had defects

[0084] (Prototype 11) Eight layers of epoxy resin film (20 μm thick) were laminated on both sides of a glass substrate, and then the resin film was removed using a dicing blade, leaving approximately 30 μm of resin film on both sides of the glass substrate.Then, the glass substrate was cut together with the resin film using a dicing blade to produce the product. (a) When cutting the glass substrate: 0 out of 5 products had defects (b) After heat resistance test: 0 out of 5 products had defects (c) After the temperature shock test: 0 out of 5 products had defects

[0085] When there is no resin film portion, as in prototype 1, there is no need to consider the stress caused by the resin film portion. Comparing prototypes 2, 5, and 6 with prototypes 3, 4, 7, and 8, the problem of spine cracking increases as the thickness of the resin film portion increases.

[0086] Based on Prototype 1, Prototype 9, in which the resin film portion was completely removed, showed significant deterioration after the temperature shock test. It is presumed that the spine cracks were probably caused by tiny cracks that occurred in the glass substrate when the exposed glass substrate was cut with a dicing blade, which then led to the stress caused by the repeated expansion and contraction of the resin film portion due to temperature changes.

[0087] In contrast, it is presumed that the intentional presence of the most adhesive film portion (most adhesive portion) as in Prototype Examples 10 and 11 adequately alleviates the impact on the glass substrate when it is cut by the dicing blade, thereby preventing the occurrence of fine cracks in the glass substrate. Therefore, the superiority of the glass wiring substrate having the most adhesive film portion (most adhesive portion) disclosed in the embodiments and the manufacturing method thereof has been demonstrated. [Explanation of symbols]

[0088] 1 Glass wiring board 10 Glass substrate 10e side edge 11 First side 12 Second side part 13 Through-hole section 14 Conductive Materials 15 Wiring section 20 (21, 22, 23, 24) Resin film part (resin layer part) 30, 30a Film cut-off portion (resin layer cut-off portion) 31,31a Groove 32 Slope 34 Most adhesive film part (most adhesive part) 50,50a Cutting wheel (rotary blade) 500 Glass wiring board manufacturing equipment 501 First rotary blade 502 Second rotary blade 503 First Arm 504 Second Arm 505 Control Unit 506 Rotary blade moving part 507 Taibe 508 Turntable C. Split spine W Processing object

Claims

1. a through-hole forming step of forming a through-hole in a thickness direction from a first surface portion to a second surface portion of the glass substrate; a conductive material filling step of filling the through-hole portion with a conductive material; a forming step of forming a plurality of resin layer portions of the same type on each of the first surface portion and the second surface portion of the glass substrate; a groove forming step of forming a groove of a predetermined width and a predetermined depth on the second surface portion symmetrical to the first surface portion in a thickness direction of the glass substrate, the groove forming step being performed by forming a closest adhesion portion on the plurality of resin layer portions of the same type formed on the first surface portion and the second surface portion of the glass substrate while leaving a closest adhesion portion where the resin layer portion adheres to the glass substrate and covers the glass substrate; a cutting step of cutting the glass substrate in a thickness direction using a cutting wheel with a rotary blade to separate the closest contact portion of the first surface portion, the glass substrate, and the closest contact portion of the second surface portion while both of the closest contact portion of the first surface portion and the closest contact portion of the second surface portion remain in close contact with the glass substrate in the groove portion. A method for manufacturing a glass wiring substrate, comprising:

2. 2. The method for manufacturing a glass wiring substrate according to claim 1, wherein the grooves are formed by cutting or dissolving in the groove forming step.

3. 2. The method for manufacturing a glass wiring substrate according to claim 1, wherein in the groove forming step, an inclined portion is formed in the groove such that the width of the groove increases in a direction away from the glass substrate.

4. 2. The method for manufacturing a glass wiring substrate according to claim 1, wherein the plurality of resin layer portions of a single type are a plurality of resin film portions of a single type.

Images