TW202030851A - Temporary-fixing substrates, temporary-fixing method and a method of producing electronic parts - Google Patents

Abstract

To provide a temporary fixing substrate that is made of ceramic and that includes a fixing surface for adhesively attaching and temporarily fixing a silicon substrate, and a bottom surface that is on the side opposite the fixing surface, wherein the curvature amount of an attached body, obtained by adhesively attaching the temporary fixing substrate to the silicon substrate, is reduced. A temporary fixing substrate 21 is made of ceramic or glass, and has a fixing surface 21a for adhesively attaching and temporarily fixing at least one of a silicon substrate and an electronic component chip, and a bottom surface 21b that is on the side opposite the fixing surface. The temporary fixing substrate 21 has an outer peripheral flat plate section 21c and a concavely deformed section 21d that is surrounded by the outer peripheral flat plate section. The fixing surface 21a is a flat surface 21e at the outer peripheral flat plate section.

Description

Temporarily fixing substrate, temporary fixing method, and manufacturing method of electronic component

The present invention relates to a temporary fixing of a silicon substrate, a temporary fixing method, and a manufacturing method of an electronic component.

In recent years, there has been an increasing demand for miniaturization and dwarfing of electronic components, and silicon substrates used for their manufacture are increasingly used in an extremely thin state. At this time, the thinned silicon substrate cannot withstand transportation and grinding due to insufficient rigidity. For processes such as polishing, it is known that a method is to use a temporarily fixed substrate composed of glass and ceramic to support a silicon substrate (Patent Documents 1, 2, and 3).

In these prior arts, the silicon substrate is bonded to the temporarily fixed substrate by thermosetting resin, and after cooling, the silicon substrate is ground. Grinding and thinning. Next, the surface is further subjected to multilayer wiring formation, etc., after which the silicon substrate is peeled off from the temporarily fixed substrate and cut into a desired size. A release layer is provided on the adhesive layer in advance, and the release layer is irradiated with a laser from the temporarily fixed substrate side to peel the silicon substrate from the temporarily fixed substrate.

When the silicon substrate is bonded to the temporarily fixed substrate with a thermosetting resin, the adhesive may bend due to the difference in thermal expansion between the silicon substrate and the temporarily fixed substrate. Therefore, in Patent Document 2, an attempt was made to reduce the curvature of the adhesive body by bending the supporting substrate in a direction opposite to the curvature of the adhesive body. The bending of the support substrate can be adjusted by heating deformation, changing the polishing method, and removing the processed deterioration layer. [Prior technical literature] [Patent Literature]

[Patent Document 1] JP 2011-023438 [Patent Document 2] JP 2010-058989

[The problem to be solved by the invention]

However, depending on conditions such as the type of thermosetting resin, the bonding temperature, and the thickness of the temporarily fixed substrate and the silicon substrate, the amount of bending of the bonding body after bonding may increase. At this time, it may be necessary to increase the initial bending amount of the temporarily fixed substrate to the opposite side according to the bending amount of the adhesive body. However, in this case, during bonding, the operability of each substrate in the bonding equipment becomes difficult, or sometimes it is broken due to the pressure during bonding. Furthermore, after the bonding body is obtained, the silicon substrate is ground by grinding. When the thickness becomes thinner, the bending amount of the bonding body will be close to the initial bending amount of the temporarily fixed substrate before bonding the silicon substrate. Therefore, the amount of bending becomes larger than the amount of bending of the adhesive body immediately after the next, and it becomes difficult to implement subsequent processes.

The problem of the present invention is to temporarily fix the substrate, which has a fixed surface for temporarily fixing the silicon substrate and the electronic component wafer; and the bottom surface of the surface on the opposite side of the fixed surface, further reducing the problem of temporarily fixing the substrate. The amount of bending of the bonding body after the silicon substrate or electronic component wafer. [Means for solving problems]

The present invention is a type, which is composed of ceramics or glass, and is provided with: a fixing surface for bonding at least one of a silicon substrate and an electronic component wafer; and a bottom surface on the opposite side of the fixing surface, characterized in that it has: The outer peripheral flat plate portion; and the concave deformed portion surrounded by the outer peripheral flat plate portion, and the fixed surface is a flat surface on the outer peripheral flat portion.

In addition, the present invention is characterized in that it has: the fixing surface of the temporarily fixing substrate, the step of obtaining an adhesive body from at least one of the silicon substrate and the electronic component wafer; and removing the silicon layer from the temporarily fixing substrate Separation steps.

In addition, the method for manufacturing an electronic component of the present invention is characterized in that it has: The step of attaching the silicon substrate to the fixed surface of the temporarily fixed substrate to obtain an adhesive body; The step of arranging electronic component wafers in or on the silicon layer; and The step of separating the silicon layer and the electronic component wafer from the temporarily fixed substrate.

In addition, a method of manufacturing an electronic component of the present invention is characterized in that it has: The step of applying the electronic component wafer to the fixed surface of the temporarily fixed substrate to obtain an adhesive body; and The step of separating the electronic component wafer from the temporarily fixed substrate. [Effects of Invention]

According to the present invention, when temporarily fixing the substrate, it is made of ceramics and has a fixing surface for temporarily fixing at least one of the silicon substrate and the electronic component wafer; and the bottom surface of the surface opposite to the fixing surface, even if temporarily The initial bending of the fixed substrate is the same, and the bending amount of the bonding body after the silicon substrate and the electronic component wafer are bonded to the substrate is temporarily fixed. As a result, it is not necessary to make the initial bending amount of the temporarily fixed substrates excessively large, and the operation of each substrate in the bonding equipment is easy, and it is also possible to suppress cracking due to pressure during bonding. In addition, after the adhesive body is obtained, for example, the silicon substrate is ground. After grinding and thinning, the bending amount of the adhesive body can be reduced, and the subsequent handling of the adhesive body becomes easier.

Initially, referring to Figs. 1 and 2, the method of temporarily fixing and separating a silicon substrate using a temporarily fixed substrate will be described. First, in the example shown in FIG. 1(a), a predetermined conductor 3 is provided on the bonding surface 2a side of the silicon substrate 2. Then, an adhesive layer 4 and a peeling layer 5 are provided on the surface 2a of the silicon substrate 2. The bonding surface 1 a of the temporarily fixed substrate 1 faces the surface 5 a of the peeling layer 5.

Next, as shown in FIG. 1(b), the silicon substrate 2 and the temporarily fixed substrate 1 are joined to obtain an adhesive body. Next, the non-bonding surface 2b of the silicon substrate 2 is processed, and the silicon layer 2A is thinned as shown in FIG. 1(c). 2c is the processed surface. In this example, when the silicon layer 2A is thinned, the conductor 3A penetrates the silicon layer 2A.

Next, as shown in Figure 2(a), a predetermined wiring layer 6 is formed on the silicon substrate 2A. 7 is used to supply power to the rewiring layer of the device chip (electronic component wafer) provided on the wiring layer, and light It is formed by engraving process or plating method. A plurality of wafers (not shown) are placed on the wiring layer as required, and then laser light of a predetermined wavelength and energy is irradiated from the side of the temporarily fixed substrate to cause peeling of the temporarily fixed substrate 1 in the peeling layer 5. Thereby, as shown in FIG. 2(b), the silicon layer 2A, together with the adhesive layer 4 and the wiring layer 6, are separated from the temporarily fixed substrate, and the next processing step is provided.

Here, when the silicon substrate is bonded to the temporarily fixed substrate with a thermosetting resin, the adhesive body may be bent due to the difference in thermal expansion between the silicon substrate and the temporarily fixed substrate. Therefore, as shown in FIG. 3(a), a method of bending the temporarily fixed substrate 11 in a direction opposite to the bending of the adhesive body in advance is known. That is, the bonding surface 11a of the temporarily fixed substrate 11 is recessed, and 11b is swollen. 12a is the joining surface, and 12b is the non-joining surface. Here, L is the imaginary surface when the temporarily fixed substrate 11 is not bent, and W is the amount of bending. However, when the bonding surface is concave, it is represented by a negative sign, and when the bonding surface is protruding, it is represented by a positive sign.

Next, as shown in FIG. 3(b), the temporarily fixed substrate 11 and the silicon substrate 12 are sandwiched between the jigs 13, and the pressure is heated as indicated by the arrow A. A thermosetting adhesive (not shown) is interposed between the substrate 11 and the silicon substrate 12 to temporarily fix the substrate 11, so that the effect is to bond the substrate 11 to the silicon substrate temporarily. At this point, by heating and pressing, both the temporarily fixed substrate 11 and the silicon substrate 12 are in a flat state.

When the bonding is completed, as shown in FIG. 3(c), the adhesive body 14 for temporarily fixing the substrate 11A and the silicon substrate 12A can be obtained. However, in the adhesive body, the temporarily fixed substrate 11A is bent to the opposite side of the initial stage. In this system, since the thermal expansion coefficient of the temporarily fixed substrate 11A is larger than that of silicon, it shrinks as indicated by the arrow B during cooling, and as a result, the entire adhesive body 14 is bent to the opposite side. The bending amount W has a positive sign.

Next, as shown in FIG. 4(a), the adhesive body 14A is placed on the flat surface 15a of the jig 15, and pressure is applied as indicated by the arrow C to make the adhesive body flat and processed. Thereby, the silicon substrate is thinned to form a thin silicon layer 12B, and at the same time, the silicon layer and the temporarily fixed substrate 11A are planarized. Next, the adhesive body 14A is removed from the jig 15, and as shown in FIG. 4(b), the adhesive body 14A is bent again. However, the bending amount W of the adhesive 14A is smaller than the bending amount W before the thin plate processing shown in FIG. 3(c), and is close to the bending of the temporarily fixed substrate before bonding (FIG. 3(a)).

Next, as shown in FIG. 4(c), the silicon layer is separated from the temporarily fixed substrate. At this time, the shape of the temporarily fixed substrate 11A tends to return to the initial shape. On the other hand, since the silicon layer has been thinned, it is roughly flat.

Here, by setting the initial bending amount W of the temporarily fixed substrate 11 in FIG. 3(a) to a negative direction, the bending amount W of the bonding body 14 shown in FIG. 3(c) can be increased (The positive sign opposite to the initial stage) becomes smaller. However, depending on conditions such as the type of thermosetting resin, the bonding temperature, and the thickness of the temporarily fixed substrate and the silicon substrate, the amount of bending of the bonding body after bonding may increase (Figure 3(c)). At this time, the initial bending amount of the temporarily fixed substrate to the opposite side needs to be increased according to the bending amount of the adhesive body (FIG. 3(a)). However, when doing so, during the bonding shown in FIG. 3(b), the substrates may become difficult to handle with the bonding equipment or may be broken due to the pressure during bonding. In addition, after the adhesive body is obtained, the silicon substrate is ground by grinding. When the thickness becomes thinner, the bending amount of the bonding body will be close to the initial bending amount of the temporarily fixed substrate before bonding the silicon substrate (Figure 4(b)). Therefore, the amount of bending becomes larger than the amount of bending of the adhesive body shortly after the next step, making it difficult to implement subsequent processes.

Figures 5 to 8 relate to embodiments of the present invention. Fig. 5(a) shows the material 20 for temporarily fixing the substrate. The thickness of the temporarily fixed substrate material 20 (the interval between the pair of main surfaces 20a and 20b) is constant.

Next, as shown in FIGS. 5(b) and (c), the main surface 20a side of the material 20 is recessed and deformed, and the temporarily fixed substrate 21 is obtained. Here, the thickness of the temporarily fixed substrate 21 (the interval between the pair of main surfaces 21a and 21b) is fixed. An outer peripheral flat plate portion 21 c is provided on the peripheral edge of the temporarily fixed substrate 21, and a concave deformed portion 21 d is provided inside the temporarily fixed substrate 21. The outer peripheral flat plate portion 21c is formed into an annular flat plate shape, and maintains the shape before processing as shown in FIG. 5(a). L is an imaginary surface along the main surface 21a (flat surface 21e) of the outer peripheral flat plate portion 21c. On the other hand, the concave deformed portion 21d is deformed from the virtual surface L to the lower side (the main surface 21b side) and is recessed. In this example, the planar shape of the concave deformed portion 21d is circular. The maximum value of the depression of the virtual surface L of the concave deformed portion 21b is defined as the amount of curvature W.

In the example shown in FIG. 6(a), the bonding surface 22a of the silicon substrate 22 and the bonding surface 21a of the temporarily fixed substrate 21 are opposed to each other. Here, on the bonding surface 22a side of the silicon substrate 22, a predetermined adhesive layer and a release layer can be further formed. Next, as shown in FIG. 6(b), the substrate 21 and the silicon substrate 22 are temporarily fixed between the jigs 13, and the arrow mark A is pressed and heated. Between the temporarily fixed substrate 21 and the silicon substrate 22, a thermosetting adhesive not shown in the figure is interposed, so that the temporarily fixed substrate 21 and the silicon substrate 22 are bonded together. At this point, by heating and pressing, both the temporarily fixed substrate 21 and the silicon substrate 22 are in a flat state.

When the bonding is completed, as shown in FIG. 6(c), an adhesive body 23 that temporarily fixes the substrate 21A and the silicon substrate 22 can be obtained. However, in the adhesive body, the thermal expansion coefficient of the temporarily fixed substrate 21A is larger than that of silicon, so it shrinks as indicated by the arrow B during cooling. As a result, the entire adhesive body 23 bends to the opposite side.

Next, as shown in FIG. 7(a), the bonding body 23 is placed on the flat surface 15a of the jig 15, and pressure is applied as indicated by the arrow C to make the bonding body flat and processed. Thereby, the silicon substrate 22A is thinned to form a thin silicon layer 22B, and the silicon layer and the temporarily fixed substrate are planarized. 22c is the processed surface. Next, the bonding body 23A is removed from the jig 15, and as shown in FIG. 7(b), the bonding body 23A is bent again. However, temporarily fixing the substrate will approach the initial shape. That is, the bending amount W of the adhesive 23A becomes smaller than the bending amount W before the thin plate processing shown in FIG. 6(c), and is close to the shape of the temporarily fixed substrate before joining.

Next, as shown in FIG. 7(c), the silicon layer 22B is separated from the temporarily fixed substrate. At this time, the shape of the temporarily fixed substrate 21 tends to return to the initial shape. On the other hand, since the silicon layer has been thinned, it is roughly flat.

Here, in the present invention, as shown in FIG. 6(a), even if the initial bending amount of the temporarily fixed substrate is the same, when the temporarily fixed substrate is attached to the silicon substrate (refer to FIG. 6(b)), the outer peripheral flat portion 21c will not Deformed, and only the concave deformed portion 21d is deformed flat by the jig 13. Then, the outer peripheral flat plate portion has a ring shape and surrounds the concave deformed portion, so it functions as an anchor that does not greatly deform the shape of the temporarily fixed substrate. As a result, it is possible to reduce the amount of bending after the adhesive body 23 is removed from the jig 13 (see FIG. 6(c)).

As a result, even if the initial bending amount of the temporarily fixed substrate is the same, the bending amount after the adhesive body 23 is removed from the jig 13 can be reduced. In addition, when the bending amount after removing the adhesive body 23 from the jig 13 is the same, the initial bending amount of the temporarily fixed substrate can be reduced. Therefore, the handling of each substrate in the bonding equipment is easy, and it is possible to suppress cracking due to pressure during bonding. In addition, after the adhesive body is obtained, the silicon substrate is ground by grinding. After polishing and thinning (see FIG. 7(b)), the bending amount of the adhesive body 23A can be reduced, and the subsequent handling of the adhesive body becomes easy.

Hereinafter, a description will be given of an embodiment in which the temporarily fixed substrate of the present invention is applied to an electronic component wafer. First, the electronic component is attached to the above-mentioned fixed surface of the temporarily fixed substrate, and temporarily fixed with a resin mold. For example, as shown in FIG. 9(a), an adhesive layer is provided on the fixing surface 1a on which the substrate 1 is temporarily fixed. As such an adhesive agent, a double-sided tape, a hot melt adhesive, etc. can be illustrated. In addition, various methods such as roll coating, spray coating, screen printing, and spin coating can be used as a method of providing the adhesive layer on the temporarily fixed substrate.

Next, a large number of electronic components 36 are placed on the temporarily fixed substrate 1, and the adhesive layer is cured to form the adhesive layer 34. This curing step is performed in accordance with the properties of the adhesive, but heating and ultraviolet irradiation can be exemplified.

Next, pour a liquid resin mold to harden the resin mold. Thereby, as shown in FIG. 9( a ), the electronic component 36 is fixed in the resin mold 35. However, 35b is a resin that fills the void 37 of the electronic component, and 35a is a resin that covers the electronic component. Examples of mold resins include epoxy resins, polyimide resins, polyurethane resins, and urethane resins.

Next, as indicated by an arrow mark A, the electronic component 36 and the resin mold 35 are separated from the temporarily fixed substrate 1 by irradiating light from the bottom surface 1b side of the temporarily fixed substrate 1 (see FIG. 9(b)). The wavelength of the light irradiated from the bottom surface of the temporarily fixed substrate may be appropriately changed according to the types of the electronic component and the resin mold, but may be, for example, 200 nm to 400 nm.

Hereinafter, each component of the present invention will be further described. The material for temporarily fixing the substrate is preferably ceramic in terms of mechanical strength and durability against chemicals, and particularly preferably alumina, aluminum nitride, YAG, sialon, and spinel.

In a suitable embodiment, the material constituting the temporarily fixed substrate is translucent alumina. At this time, it is preferable to add 100 ppm or more and 300 ppm or less of magnesium oxide powder to high-purity alumina powder with a purity of 99.9% or more (preferably 99.95% or more). As such a high-purity alumina powder, a high-purity alumina powder manufactured by Daming Chemical Industry Co., Ltd. can be exemplified. In addition, the purity of the magnesium oxide powder is preferably 99.9% or more, and the average particle size is preferably 50 μm or less.

In addition, in a suitable embodiment, as a sintering aid, 200 to 800 ppm of zirconia (ZrO ₂ ) and 10 to 30 ppm of yttrium trioxide (Y ₂ O ₃ ) are preferably added to the alumina powder.

The molding method for temporarily fixing the substrate is not particularly limited, and may be any method such as a doctor blade method, an extrusion method, and a casting method. It is particularly preferable to use the doctor blade method to manufacture the base substrate.

In a suitable embodiment, a slurry containing a ceramic powder, a dispersant, and a binder is produced, the slurry is shaped into a strip shape by a doctor blade method, the layer is laminated into a desired thickness shape, and a molded body is obtained by pressing.

Next, the formed body is dried, preferably sintered in the atmosphere, and then sintered in hydrogen. From the viewpoint of densification of the sintered body, the sintering temperature during firing is preferably 1700 to 1900°C, and more preferably 1750 to 1850°C. The surface of the sintered body is polished by diamond polishing or the like to adjust the thickness variation to a certain level or less to make both sides mirror-finished.

In this way, after a sufficiently dense sintered body is generated during firing, the thickness variation can be adjusted, the surface can be mirror-finished, and then an annealing process can be performed to accurately adjust the amount of bending. The annealing temperature is preferably 1700°C or less from the viewpoint of preventing deformation or abnormal grain growth, and the maximum temperature is more preferably 1600°C or less. On the other hand, in order to sufficiently advance the creep deformation of the sintered body, in order to adjust the amount of bending accurately, 1200°C or higher is preferable, and 1400°C or higher is more preferable. In addition, the annealing time is preferably 1 to 6 hours.

In addition, the glass constituting the temporarily fixed substrate may be silicate-based glass or borosilicate-based glass.

The temporarily fixed substrate of the present invention has an outer peripheral flat plate portion; and a concave deformed portion surrounded by the outer peripheral flat plate portion, and the fixing surface is a flat surface on the outer peripheral flat portion. Here, the width F of the outer peripheral flat plate portion (refer to Fig. 5(b), (c)) is preferably 4% or more of the width R of the substrate 21 to be temporarily fixed, thereby improving the effect of suppressing the bending of the adhesive body . From this viewpoint, the width F of the outer peripheral flat plate portion is more preferably 8% or more of the width R of the temporarily fixed substrate 21, and particularly preferably 10% or more.

In addition, the width F of the outer peripheral flat plate portion is preferably 60% or less of the width R of the substrate 21 to be temporarily fixed, so that the amount of suppression of the bending of the adhesive body can be increased. From this viewpoint, the width F of the outer peripheral flat plate portion is preferably 40% or less of the width R of the temporarily fixed substrate 21, and particularly preferably 30% or less.

Furthermore, the width R of the temporarily fixed substrate is the length of the line that the plane crosses the temporarily fixed substrate. In addition, the width F of the outer peripheral flat plate portion is the total value of the lengths of the line segments that cross the outer peripheral flat portion among the line segments whose plane crosses the temporarily fixed substrate. For example, as shown in the top view of Figure 5(c), the width of the two outer peripheral flat plate portions in the width direction of the temporarily fixed substrate is F/2, and the width of the outer peripheral flat plate portion becomes (F/2+F/2) =F.

In addition, depending on the direction across the line segment of the temporarily fixed substrate, the width R of the temporarily fixed substrate and the width F of the outer peripheral flat portion may change. For example, in the example shown in FIG. 8, the planar shape of the temporarily fixed substrate 31 is rectangular, and the thickness of the temporarily fixed substrate 31 (the interval between the main surface 31a and the opposite main surface) is fixed. An outer peripheral flat plate portion 31c is provided on the peripheral edge of the temporarily fixed substrate 31, and a concave deformable portion 31d is provided inside the outer peripheral flat plate portion 31c. The outer peripheral flat plate portion 31c has a flat plate shape, and the main surface 31a of the outer peripheral flat plate portion 31 constitutes a flat surface 31e. The concave deformed portion 31d deforms downward from the imaginary surface and is recessed. In this example, the planar shape of the concave deformed portion 31d is a rectangle. For example, when the planar shape of the temporarily fixed substrate is a rectangle, the vertical width R2 is different from the horizontal width R1, and the outer peripheral flat portion width F2 (F2/2+F2/2) in the vertical direction may be different from the horizontal width R1. The width F1 (F1/2+F1/2) of the peripheral flat part is different. At this time, the vertical direction and the horizontal direction (the width of the outer peripheral flat plate portion/the width of the temporarily fixed substrate (F1/R1, F2/R2), respectively, are preferably 4-60%.

In the temporary fixing of the substrate before bonding, the bending amount W of the concave deformation portion is preferably 0.1 mm or more, so that the bending amount of the adhesive body can be suppressed. From this point of view, the bending amount W of the concave deformed portion is more preferably 0.3 mm or more, and particularly preferably 0.6 mm or more.

In addition, with regard to the shape of the concave deformed portion, the profile of the cross section can be made into an arc shape, a parabola shape, a cone shape, or a dish shape. However, in order to effectively suppress the amount of bending, the profile of the cross-section of the concave deformed portion is preferably parabolic. In addition, by relaxing the boundary portion between the outer peripheral flat portion and the curved portion (making the radius of curvature R larger), it is possible to suppress the occurrence of cracks when bonding to the silicon substrate.

In addition, for the temporary fixing of the substrate before bonding, the bending amount of the concave deformed portion is preferably 2.5 mm or less, which can suppress handling problems in the bonding device and easily prevent damage during bonding. From this point of view, the amount of curvature of the concave deformed portion is preferably 2.0 mm or less, and more preferably 1.0 mm or less.

At this time, if the thickness variation (so-called TTV) of the entire temporarily fixed substrate is large, the thickness variation of the bonding layer occurs during bonding with the silicon substrate or electronic component wafer, which may cause the deformation after bonding, so the thickness variation is 10um or less is better. In addition, when high-precision wiring formation is performed on the next silicon substrate or electronic component, the thickness variation is preferably 5um or less, and more preferably 3um or less.

In addition, the amount of bending of the concave deformed portion is measured as follows. That is, the fixed surface (flat surface) of the outer peripheral flat plate portion is extended to the concave deformed portion to obtain the virtual surface L. Then, the depth of the deepest part among the concave deformed portions viewed from the virtual plane L is defined as the amount of curvature W. In addition, the specific measuring device can use a laser length measuring machine to measure the shape of a substrate set on a flat table.

The respective planar shapes and planar dimensions of the temporarily fixed substrate and the silicon substrate are not particularly limited. The so-called temporarily fixed substrate and silicon substrate, etc., mean that they may have the same planar shape and planar size as each other, or may have different planar shapes and planar sizes. Specifically, for example, the temporarily fixed substrate, the silicon substrate, etc., may have a disc shape, a rectangular shape, an oval shape, an ellipse shape, a triangular shape, or a polygonal shape. Among them, when the substrate is temporarily fixed to the silicon substrate, etc., a circular plate shape or a regular polygonal shape is preferred, and a circular plate shape is more preferred. At this time, thermal shrinkage occurs equally in all directions with the point symmetry axis as the center.

Furthermore, when the temporarily fixed substrate, silicon substrate, etc. are in the shape of a circular plate, the diameter (width) is preferably 100 to 300 mm. When an orientation plane or notch is formed on the silicon substrate, the same orientation plane or notch can also be formed on the temporarily fixed substrate, which facilitates positioning during bonding and can reduce misalignment in bonding. In addition, when the substrate is temporarily fixed and the silicon substrate is square or rectangular, the length of one side is preferably 100-1000 mm. At this time, the corners are preferably R or C-shaped, from the viewpoint of suppressing the amount of bending after bonding.

Temporarily fix the thickness of the substrate, for example, 0.2~5.0mm is preferred, and 0.5~2.0mm is more preferred. By making this to be 0.2 mm or more, it becomes easy to suppress bending after the bonding, and it becomes easy to prevent damage to the temporarily fixed substrate. In addition, by making it 5.0 mm or less, the weight of the substrate can be suppressed, and it can be easily transported.

When bonding the temporarily fixed substrate and the silicon substrate or the like using a thermosetting resin, the temporarily fixed substrate and the silicon substrate or the like are superposed and pressurized and fixed by heating to harden the thermosetting adhesive to obtain an adhesive body.

As an adhesive for temporarily fixing a substrate and a silicon substrate, etc., other than thermosetting resins, UV (ultraviolet curing type) adhesives, double-sided tapes, hot-melt adhesives, etc. can be exemplified. In addition, various methods such as roll coating, spray coating, screen printing, and spin coating can be used as a method of providing an adhesive on the temporarily fixed substrate.

In addition, it is preferable to form a peeling layer between the adhesive layer and the temporarily fixed substrate. As such a peeling layer, a laser peeling type in which the peeling layer is carbonized and peeled by irradiation of laser light can also be used. A UV peeling type that is deactivated by UV light irradiation and loses adhesion and peels off. A heat-peeling type in which the components in the layer are peeled by foaming by heating.

Various electronic component structures can be fabricated on the silicon substrate of the present invention. For example, in the production of CCD or CMOS, after bonding the silicon substrate to the temporary fixed substrate, the silicon substrate is thinned, and then the wiring layer is formed by performing a thin film formation step and a pattern formation step. At this time, when the bending of the adhesive body that temporarily fixes the substrate and the silicon substrate is large, it is difficult to pattern the fine wiring structure with high accuracy in the patterning step, so the present invention is particularly useful.

In addition, electronic component wafers can be arranged on the silicon substrate to electrically connect each electronic component wafer with the wiring layer. Then, after separating the silicon substrate from the temporarily fixed substrate, by cutting the silicon substrate, each electronic component wafer can be separated.

In addition, the present invention can be used well in the so-called FOWLP technology. In FOWLP technology, the electronic component wafer is temporarily placed on a support substrate (temporarily fixed substrate), and after sealing with a resin mold, wiring is formed on the surface of the resin mold, and then the electronic component wafer and mold resin are removed from the support substrate (temporarily fixed The substrate) can be peeled off to realize a thin structure. After separating the resin mold and the sealed electronic component wafer from the temporarily fixed substrate, the resin mold is cut to separate the electronic component wafers. In this case, when resin sealing and wiring formation of the electronic component chip are performed on the temporarily fixed substrate, although the bending of the adhesive body caused by the thermal expansion difference of each component may become a problem, it is improved by using the present invention. .

In addition, when the area of the electronic component to be temporarily fixed to the substrate is enlarged, the bending of the substrate due to the thermal expansion difference between the temporarily fixed substrate and the electronic component wafer becomes a problem, but this can be improved by using the present invention. In particular, the electronic component wafer occupies more than 60% of the area of the temporarily fixed substrate, this tendency will be significant, so the present invention is very useful.

When temporarily fixing the substrate to form the outer peripheral flat part and the concave deformed part, prepare a jig with a flat part suitable for the outer peripheral flat part and a protrusion suitable for the concave deformed part, and heat the substrate temporarily to temporarily fix the substrate. Pay to make plastic deformation. Alternatively, the flat plate is housed in a metal mold having the same flat portion and protrusion, and the metal mold is pressed while heating to form the outer peripheral flat plate portion and the concave deformed portion.

When thinning the silicon substrate by processing, a grinder can be used. That is, the temporarily fixed substrate side of the adhesive body of the temporarily fixed substrate and the silicon substrate is fixed using a vacuum chuck or the like, and the silicon substrate side is processed with grinding abrasive grains to have a desired thickness. [Example]

(Examples 1 to 7) A slurry in which the following components were mixed was prepared. (Raw material powder) ‧Alpha-alumina powder with a purity of 99.99% 100 parts by mass‧MgO (magnesium oxide) 250ppm ‧ZrO ₂ (zirconia) 400ppm ‧Y ₂ O ₃ (yttrium trioxide) 15ppm (dispersant) ‧2 -Ethylhexanol 45 parts by mass (binder) ‧PVB resin 4 parts by mass (dispersant) ‧Polymer surfactant 3 parts by mass (plasticizer) ‧DOP 0.1 mass part

This slurry was formed into a thin ribbon shape with a thickness of 0.7 mm converted to firing using a doctor blade method, and cut to a size converted to a size of ψ 300 mm after firing. After the obtained powder compact was sintered in the atmosphere at 1240°C (preliminary firing), the substrate was placed on a molybdenum plate and kept at 1800°C for 2.5 hours in an atmosphere of hydrogen 3: nitrogen 1. Firing. After that, grinding with a grinder, polishing with diamond abrasive grains, and polishing with a CMP solution are sequentially performed to obtain a temporarily fixed substrate material 20 with a thickness of 0.6 mm (FIG. 5(a)).

Next, the material 20 is sandwiched with a jig of a predetermined shape, and it is deformed by heat treatment at a temperature of 1600° C. to obtain a temporarily fixed substrate 21 (see Figs. 5(b) and (c)).

The obtained temporarily fixed substrate and the silicon substrate of the same diameter were bonded with thermosetting resin, and the presence or absence of cracks at this time and the amount of bending after bonding were measured. However, the peeling layer uses a heat peeling type adhesive. Next, the silicon substrate was ground to a thickness of 0.1 mm, and the amount of bending of the bonded body after grinding was measured.

However, by changing the molding conditions or the shape of the jig, the diameter (width) of the temporarily fixed substrate, the width of the outer peripheral flat portion, and the amount of bending W were changed as shown in Table 1.

Then, for each example, the presence or absence of cracks during bonding (visual observation), the amount of bending of the bonding body after bonding, and the amount of bending of the bonding body after grinding the silicon substrate were measured. The measurement results are shown in Table 1.

Table 1 Example 1 2 3 4 5 6 7 Temporarily fix the width of the substrate R (mm) 300 300 300 300 300 300 200 Width of outer peripheral flat part F/2 (mm) 5 25 90 5 25 90 15 R/F(%) 3.3 17 60 3.3 17 60 15 Bending amount of concave deformation part (mm) -0.5 -0.5 -0.5 -0.8 -0.8 -0.8 -0.8 Cracks during subsequent no no no no no no no The bending amount of the adhesive body shortly thereafter (mm) +1.3 +1.1 +1.2 +0.7 +0.6 +0.9 +0.1 Bending amount of silicon substrate after grinding (mm) +1.0 +0.9 +0.8 +0.5 +0.4 +0.5 +0.1

(Comparative Examples 1~3) The same experiment as in Example 1 was performed. However, in this example, the shape of the jig during heat treatment was adjusted, and the outer peripheral flat plate was not provided on the temporarily fixed substrate. In addition, by changing the molding conditions or the shape of the jig, the diameter ψ and the bending amount W of the temporarily fixed substrate were variously changed as shown in Table 2. The width of the outer peripheral flat portion is 0 mm.

Then, for each example, the presence or absence of cracks during bonding (visual observation), the amount of bending of the bonding body after bonding, and the amount of bending of the bonding body after grinding the silicon substrate were measured. The measurement results are shown in Table 2.

Table 2 Example 1 2 3 Temporarily fix the width of the substrate R (mm) 300 300 300 Width of outer peripheral flat part F/2 (mm) 0 0 0 R/F(%) 0 0 0 Bending amount of concave deformation part (mm) -0.5 -0.8 -0.8 Cracks during subsequent no no no The bending amount of the adhesive body shortly thereafter (mm) +1.9 +1.8 +0.8 Bending amount of silicon substrate after grinding (mm) +1.2 +1.0 +0.3

When the temporarily fixed substrate of the comparative example without the outer peripheral flat portion was used, the bending amount of the adhesive body was relatively large, and the bending amount of the silicon substrate after polishing also became large.

When the temporarily fixed substrate of the present invention is used, even if the amount of bending of the temporarily fixed substrate is the same as that of the comparative example, the amount of bending of the adhesive body becomes smaller. In addition, by setting the ratio of the width of the outer peripheral flat plate portion to 4 to 60%, the effect of the present invention becomes more remarkable.

In addition, each of the temporarily fixed substrates of Examples 1 to 7 was manufactured, and the electronic component wafer was bonded and sealed with a resin mold. Otherwise, in the same manner as in Examples 1 to 7, the electronic component wafer and the resin mold were separated from the temporarily fixed substrate. Then, the resin mold was cut to obtain each electronic component wafer. The presence or absence of cracks during bonding (visual observation) and the amount of bending of the bonding body after bonding were respectively measured, and the same results as in Examples 1 to 7 were obtained.

1: Temporarily fix the substrate 1a: fixed surface 13: Fixture 15: Fixture 15a: flat surface 20: Temporarily fix the substrate material 20a, 20b: main surface 21a, 21b: main surface 21: Temporarily fix the substrate 21A: Temporarily fix the substrate 21c: peripheral flat part 21d: concave deformed part 21e: flat surface 22: Silicon substrate 22B: Silicon layer 22A: Silicon substrate 23: follow body 23A: then body 34: Next layer 35: Resin mold 35b: Resin filling the void 37 of the electronic component 36: Electronic components 37: gap L: imaginary face W: bending amount R: wide

[figure 1] (a) refers to the silicon base sheet 2 and temporarily fixed substrate 1 before bonding; (b) indicates the adhesive body that joins the substrate 2 and the temporarily fixed substrate 1; (c) shows the state where the silicon layer 2A of the adhesive body is thinned. [figure 2] (a) shows the state where the wiring 6 is provided on the silicon layer 2A; (b) shows the state where the silicon substrate is separated from the temporarily fixed substrate 1. [image 3] (a) is a schematic diagram showing the silicon substrate 12 and the curved temporary fixed substrate 11 (before joining); (b) shows the state where the silicon substrate 12 and the temporary fixed substrate 11 are joined; (c) shows the adhesive 14. [Figure 4] (a) shows the state where the silicon layer 14A of the bonding body is thinned; (b) shows the bonding body of the silicon layer 14A and the temporarily fixed substrate 11A; (c) shows the state where the silicon layer 12B is separated from the temporarily fixed substrate 11A . [Figure 5] (a) is the material 20 before processing; (b) shows the temporarily fixed substrate 21 related to the embodiment of the present invention; (c) is a plan view of the temporarily fixed substrate 21. [Figure 6] (a) is a schematic diagram showing the silicon substrate 22 and the temporarily fixed substrate 21 (before joining); (b) is a state where the silicon substrate 22 and the temporarily fixed substrate 21 are joined; (c) is a bonding body 23. [Figure 7] (a) shows the state where the silicon substrate 22B of the bonding body is thinned; (b) shows the bonding body of the silicon substrate 22B and the temporarily fixed substrate 21A; (c) shows the state where the silicon substrate 22B is separated from the temporarily fixed substrate 21 . [Figure 8] FIG. 8 is a schematic diagram showing a rectangular temporarily fixed substrate 31 viewed in plan. [Figure 9] (a) shows the state where the electronic component wafer 36 is temporarily fixed with the resin mold 35; (b) shows the state where the electronic component 36 and the resin mold 35 are separated from the temporarily fixed substrate 1 by light irradiation.

F/2: The width of the peripheral flat part

L: imaginary face

R: wide

W: bending amount

t21: Temporarily fix the thickness of the substrate

20: Temporarily fix the substrate material

20a, 20b: main surface

21: Temporarily fix the substrate

21a, 21b: main surface

21c: peripheral flat part

21d: concave deformed part

21e: flat surface

Claims (13)

A temporarily fixed substrate, which is a temporary fixed substrate composed of ceramic or glass, and includes: a fixing surface for bonding at least one of a silicon substrate and an electronic component wafer; and a bottom surface on the opposite side of the fixing surface, characterized in that :have: The outer peripheral flat plate portion; and the concave deformed portion surrounded by the outer peripheral flat plate portion, and the fixed surface is a flat surface on the outer peripheral flat portion. The temporarily fixed substrate as described in the first item of the scope of patent application, wherein the ceramic is transparent alumina. In the temporarily fixed substrate as described in item 1 or 2 of the scope of patent application, the width of the outer peripheral flat portion is 4-60% of the width of the temporarily fixed substrate. The temporarily fixed substrate according to any one of items 1 to 3 in the scope of patent application, wherein the bending amount of the concave deformed portion is 0.1~2.5mm. A temporary fixing method, characterized in that: having the fixing surface for temporarily fixing the substrate as described in any one of the first to the fourth of the scope of patent application, and then at least one of the silicon substrate and the electronic component wafer is bonded step. The temporary fixing method as described in item 5 of the scope of patent application, which has the steps of processing the silicon substrate of the adhesive body to thin the silicon substrate to form a silicon layer; and The step of separating the silicon layer from the temporarily fixed substrate. As the method described in item 5 or 6 of the scope of patent application, it has the step of arranging an electronic component structure on the silicon layer. The method described in claim 5 includes a step of attaching the electronic component wafer to the fixed surface of the temporarily fixed substrate, and then covering the electronic component wafer with a resin mold. A manufacturing method of an electronic component, characterized in that it has: The step of attaching the above-mentioned silicon substrate to the above-mentioned fixing surface of the temporary fixing substrate described in any one of items 1 to 4 of the scope of patent application to obtain an adhesive body; The step of arranging electronic component wafers in or on the silicon layer; and The step of separating the silicon layer and the electronic component wafer from the temporarily fixed substrate. The method described in item 9 of the scope of patent application includes a step of dividing the silicon layer after separating the silicon layer from the temporarily fixed substrate. The method described in item 9 or 10 of the scope of patent application includes the steps of arranging wiring in the silicon layer and connecting the wiring to the wafer with the electronic component. A manufacturing method of an electronic component, characterized in that it has: The step of applying the above electronic component wafer to the above-mentioned fixed surface of the temporarily fixed substrate described in any one of items 1 to 4 of the scope of patent application to obtain an adhesive body; and The step of separating the electronic component wafer from the temporarily fixed substrate. The method described in claim 12 includes a step of attaching the electronic component wafer to the fixed surface of the temporarily fixed substrate, and then covering the electronic component wafer with a resin mold.

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