Temporary fixed substrate

Abstract

To provide a temporarily fixed substrate with which a semiconductor package can be obtained at a higher yield than usual while a peeling defect is suppressed.SOLUTION: A temporarily fixed substrate which has a plurality of electronic components bonded to one principal surface and temporarily fixed by resin molding comprises a beveled region at ends over the outer peripheries on the one principal surface and the other principal surface, and the beveled region comprises a first beveled part and a second beveled part differing in inclination angle to the one principal surface, and has a width which is 1% or less of the radius of the temporarily fixed substrate.SELECTED DRAWING: Figure 2

Description

【Technical Field】 【0001】 The present invention relates to a temporary fixing substrate used in the manufacturing process of semiconductor packages. 【Background Art】 【0002】 As a semiconductor package manufacturing technology, FOWLP (Fan-out Wafer Level Package) technology is known. The FOWLP technology generally includes a process of resin molding on a temporary fixing substrate where a semiconductor chip is temporarily fixed with an adhesive, a process of grinding the resin molding to expose the electrode ends of the semiconductor chip, a process of forming a thin film rewiring layer (multilayer wiring) and solder balls on the surface where the electrode ends are exposed, and a process of singulating individual packages and peeling them from the temporary fixing substrate, to obtain a semiconductor package with a lower profile than conventional ones. 【0003】 As a temporary fixing substrate for a chip in such FOWLP technology, an aspect of using a translucent ceramic substrate is already known (see, for example, Patent Document 1 and Patent Document 2). The translucent ceramic substrate has all the requirements for a temporary fixing substrate, such as high flatness necessary for electrode end exposure, high rigidity and reverse curvature shape necessary for warp suppression during multilayer wiring formation, translucency that allows laser light for curing the adhesive to pass through, and chemical resistance for cleaning and reusing after use. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent No. 6430081 【Patent Document 2】 Japanese Patent No. 6420023 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 However, conventional temporary fixing substrates had a problem where delamination defects occurred, such as the resin portion peeling off at the outer edge, resulting in a decrease in yield. 【0006】 Furthermore, conventional temporary fixing substrates had the problem of reduced yield due to chipping (breakage) at the outer edge. 【0007】 This invention has been made in view of the above problems, and aims to provide a temporary fixing substrate that suppresses peeling defects and enables the acquisition of semiconductor packages with a higher yield than conventional substrates. 【0008】 Furthermore, a second objective of the present invention is to suppress the occurrence of chipping on the outer periphery of the temporary fixed substrate. [Means for solving the problem] 【0009】 To solve the above problems, in a first aspect of the present invention, a predetermined object to be fixed is temporarily fixed on one main surface. , separated after temporary fixation ru, Made of translucent alumina A temporary fixing substrate is provided with a chamfered area at the end extending over the entire outer circumference of one main surface and the other main surface, wherein the chamfered area comprises a first chamfered portion and a second chamfered portion having different inclination angles with respect to the one main surface, and the width of the chamfered area is 1% or less of the radius of the temporary fixing substrate. 【0010】 A second aspect of the present invention is a temporary fixing substrate according to the first aspect, characterized in that the arithmetic mean roughness of the chamfered region on at least one main surface side is 0.1 μm to 10 μm and is greater than the arithmetic mean roughness of the one main surface. 【0011】 A third aspect of the present invention is a temporary fixing substrate according to the second aspect, characterized in that the arithmetic mean roughness of the one main surface and the other main surface is 100 nm or less. 【0012】 A fourth aspect of the present invention is a temporary fixing substrate according to any of the first to third aspects, characterized in that the arithmetic mean roughness of the side edge is smaller than the arithmetic mean roughness of the chamfered region. 【0013】 A fifth aspect of the present invention is a temporary fixing substrate according to the fourth aspect, characterized in that the arithmetic mean roughness of the side edge is greater than the arithmetic mean roughness of the one main surface and is 5 μm or less. 【0014】 A sixth aspect of the present invention is a temporary fixing substrate according to the fifth aspect, characterized in that the arithmetic mean roughness of the side edge is 2 μm or less. 【0015】 A seventh aspect of the present invention is a temporary fixing substrate according to any of the first to third aspects, characterized in that the inclination angle θ1 of the first chamfered portion with respect to the one main surface is 5° to 55°, the inclination angle θ2 of the second chamfered portion with respect to the one main surface is 35° to 85°, and θ1 < θ2. 【0017】 This invention 8 The embodiment is a temporary fixing substrate according to any of the first to third embodiments, characterized in that the predetermined object to be fixed is a plurality of electronic components or semiconductor substrates. [Effects of the Invention] 【0018】 The first to the first of the present invention 8 According to this embodiment, it is possible to effectively suppress the occurrence of delamination between the temporary fixing substrate and the object to be fixed, the adhesive layer, or other resins during the process of temporarily fixing an object to be fixed, such as an electronic component, to the temporary fixing substrate. 【0019】 In particular, according to the fifth and sixth embodiments, the occurrence of chipping at the side edges of the temporary fixed substrate can be effectively suppressed. [Brief explanation of the drawing] 【0020】 [Figure 1]It is a plan view of one main surface (front surface) 1a of the temporary fixing substrate 1 according to the first embodiment. [Figure 2] It is an enlarged cross-sectional view near the side end portion 1e of the temporary fixing substrate 1 showing the state of the chamfered region 2. [Figure 3] It is a schematic cross-sectional view showing step by step the state during the manufacturing process of a semiconductor package by the FOWLP technology using the temporary fixing substrate 1. [Figure 4] It is a flowchart schematically showing the manufacturing process of the temporary fixing substrate 1. [Figure 5] It is a diagram schematically showing the state of chamfering the temporary fixing substrate 1 using the chamfering device 100. [Figure 6] It is an enlarged schematic view of part A of FIG. 5 showing the state of performing chamfering. [Figure 7] It is a schematic cross-sectional view showing the main part of the lapping and polishing device 200 for performing lapping and polishing on the temporary fixing substrate 1. [Figure 8] It is a perspective view of the main part of the lapping and polishing device 200 with the upper surface plate 202 omitted. [Figure 9] It is a diagram schematically showing the state of polishing the side end portion 1e of the temporary fixing substrate 1 on which the chamfered region 2 is not formed in the lapping and polishing device 200. 【Embodiments for Carrying Out the Invention】 【0021】 <First Embodiment> <Temporary Fixing Substrate> FIG. 1 is a plan view of one main surface (front surface) 1a of the temporary fixing substrate 1 according to the first embodiment of the present invention. The temporary fixing substrate 1 is a substrate to which a semiconductor chip is temporarily fixed in manufacturing a semiconductor package by the FOWLP (Fan - out Wafer Level Package) technology. 【0022】 The temporary fixing substrate 1 is a translucent ceramic substrate with a diameter of several hundred mm (e.g., 300 mm), a thickness of several hundred μm to several mm (e.g., 1 mm), an in-plane thickness difference of several μm or less (e.g., within 3 μm), and a warp of several hundred μm or less (e.g., 200 μm). In this embodiment, a translucent ceramic is defined as a ceramic with a forward total light transmittance of 20% or more across the entire wavelength range of 200 nm to 1500 nm. Examples of such translucent ceramics include alumina, silicon nitride, aluminum nitride, and silicon oxide. For example, a suitable example of the temporary fixing substrate 1 is one with alumina as the main component and a forward total light transmittance of 70% or more at a wavelength of 1500 nm. When alumina is the main component, it is preferable to use high-purity alumina powder of 99.9% or more (preferably 99.95% or more) as the raw material, and it is preferable to add magnesium oxide and zirconia (ZrO2) and yttria (Y2O3) as sintering aids to the alumina powder. 【0023】 The surface 1a, which is the placement surface of the semiconductor chip, and the other main surface (back surface) 1b are both pre-polished to become flat polished surfaces with low surface roughness. More specifically, the surface 1a and back surface 1b achieve an in-plane thickness difference of a few micrometers or less and an arithmetic mean roughness Ra of 100 nm or less (preferably 20 nm or less). More specifically, both the surface 1a and back surface 1b are surfaces that have been lapped. There is no particular limit on the lower limit of the arithmetic mean roughness Ra of the surface 1a and back surface 1b, but 1 nm is sufficient for practical purposes. 【0024】 However, the temporary fixing substrate 1 according to this embodiment has a chamfered area 2 at the edge along the entire outer circumference of the surface 1a. Although not shown in the figures, the chamfered area 2 is also provided on the back surface 1b. Therefore, strictly speaking, the arithmetic mean roughness Ra of the surface 1a and back surface 1b, which is 100 nm or less as described above, is achieved in the area excluding the chamfered area 2. Hereafter, the surface 1a and back surface 1b excluding the chamfered area 2 will also be referred to as the flat surface 1a and the flat back surface 1b, respectively. 【0025】 FIG. 2 is an enlarged cross-sectional view near the side end portion 1e of the temporary fixing substrate 1 showing the state of the chamfered region 2. 【0026】 In the case shown in FIG. 2, an example is illustrated where the chamfered region 2 has a two-stage configuration including a first chamfered portion 2a inclined at an inclination angle θ1 with respect to the flat surface 1a and a second chamfered portion 2b inclined at an inclination angle θ2 (> θ1) with respect to the flat surface 1a. The second chamfered portion 2b is provided in a range of a predetermined width b (< a) from the side end portion 1e. Similarly, on the flat back surface 1b side, a chamfered region 2 having a two-stage configuration of the first chamfered portion 2a and the second chamfered portion 2b is provided. Note that the second chamfered portion 2b may be omitted and the chamfered region 2 may have a single-stage configuration consisting only of the first chamfered portion 2a. 【0027】 The inclination angle θ1 is preferably 5° to 55° (for example, 30°). Further, when the chamfered region 2 has a two-stage configuration, the inclination angle θ2 is preferably 35° to 85° (for example, 60°). However, θ1 < θ2. 【0028】 By providing the chamfered region 2 satisfying the above range of the inclination angle, in the temporary fixing substrate 1, the occurrence of chipping is preferably suppressed. That is, in the case of the temporary fixing substrate 1 not provided with the chamfered region 2, chipping in which the corners where the surface 1a and the back surface 1b are perpendicular to the side end portion 1e are chipped is likely to occur. However, in the case of the temporary fixing substrate 1 according to the present embodiment, since it does not have such a perpendicular corner by providing the chamfered region 2, and the angles formed by the chamfered region 2 with the surface 1a and the back surface 1b and the angle formed by the chamfered region 2 with the side end portion 1e are all obtuse angles, chipping is extremely unlikely to occur. 【0029】 That is, the provision of the chamfered region 2 has an effect of suppressing the occurrence of defects due to the occurrence of chipping and increasing the manufacturing yield of the temporary fixing substrate 1. In particular, making the chamfered region 2 have a two-stage configuration of the first chamfered portion 2a and the second chamfered portion 2b is effective in suppressing such chipping because such obtuse angles are provided in two stages. 【0030】 <Semiconductor package manufacturing process and the effect of chamfering> In the manner described above, of the chamfered areas 2 provided on the temporary fixed substrate 1, at least the chamfered area 2 provided on the surface (one main surface) 1a side is made a rough surface with a surface roughness greater than that of the flat surface 1a. Specifically, the arithmetic mean roughness Ra of the chamfered area 2 is 0.1 μm to 10 μm. This is intended to ensure the manufacturing yield of the semiconductor package. This point will be explained below. 【0031】 Figure 3 is a schematic cross-sectional view showing the intermediate steps of the semiconductor package fabrication process using FOWLP technology with a temporary fixed substrate 1. However, for simplicity of illustration in Figure 3, the chamfered area 2 is shown with diagonal lines only on the surface 1a side. 【0032】 In the semiconductor package manufacturing process, first, as shown in Figure 3(a), a layer (adhesive layer) 3α made of adhesive is formed on the temporary fixing substrate 1. Examples of adhesives include double-sided tape and hot-melt adhesives, and various known methods such as roll coating, spray coating, screen printing, and spin coating can be applied to its formation. 【0033】 Next, as shown in Figure 3(b), multiple semiconductor chips 4 are placed on the adhesive layer 3α. The semiconductor chips 4 are placed in the area inside the chamfered region 2. Subsequently, the adhesive layer 3α is cured to form an adhesive layer 3. The curing method is selected from heating, ultraviolet irradiation, etc., depending on the material of the adhesive used in the adhesive layer 3α. As a result, the semiconductor chips 4 are bonded and fixed to the temporary fixing substrate 1. 【0034】 Once the semiconductor chips 4 are fixed to the temporary fixing substrate 1 in this manner, molding resin is poured over the entire upper surface of the temporary fixing substrate 1, that is, over the gaps 5 between the semiconductor chips 4 and the entire upper surface of the semiconductor chips 4. As the molding resin hardens, a resin mold 6 is formed, as shown in Figure 3(c). Examples of molding resins include epoxy resins, polyimide resins, polyurethane resins, and urethane resins. 【0035】 Subsequently, the resin mold 6 is ground until the electrode ends of the semiconductor chip 4 are exposed, and then a redistribution layer and solder balls are formed on the ground surface. Finally, the chips are separated into individual packages, and the temporary fixed substrate 1 is separated by laser lift-off. 【0036】 The chamfered area 2 provided on the outer periphery of the temporary fixing substrate 1 has the effect of suppressing the occurrence of defects (peeling defects) in which the resin (adhesive layer 3 and resin mold 6) peels off from the temporary fixing substrate 1 during the semiconductor package manufacturing process described above, up until individualization and laser lift-off are performed. 【0037】 In the case of conventional temporary fixing substrates, during the semiconductor package manufacturing process described above, air can enter from the outside between the temporary fixing substrate and the resin near the outer edge of the temporary fixing substrate, causing air bubbles to form, which can lead to delamination between the temporary fixing substrate and the resin. 【0038】 However, when using the temporary fixing substrate 1 according to this embodiment, the adhesive and mold resin penetrate the chamfered area 2, which is a rough surface with a surface roughness sufficiently greater than that of the surface 1a, provided on the outer periphery of the surface 1a, thereby creating an anchoring effect between the resin and the chamfered area 2. This anchoring effect suppresses the formation of air bubbles and the peeling of the resin on the outer periphery of the temporary fixing substrate 1. The presence or absence of air bubbles can be confirmed by visually inspecting the temporary fixing substrate 1 from the back surface 1b or by observing it with a stereomicroscope. In this embodiment, peeling of the resin is considered to have occurred not only when a separation between the resin and the temporary fixing substrate 1 is confirmed as a result of visual inspection of the temporary fixing substrate 1 from the side edge 1e, but also when an air bubble with a size of 3 mm or more in the longitudinal or transverse direction is confirmed as a result of visual inspection or observation with a stereomicroscope from the back surface 1b. 【0039】 When a chamfered area 2 satisfying an arithmetic mean roughness Ra of 0.1 μm to 10 μm is provided on the temporary fixed substrate 1, the occurrence rate of delamination defects (delamination defect rate) counted per substrate is suppressed to 3% or less. Preferably, the arithmetic mean roughness Ra of the chamfered area 2 is 0.5 μm to 2 μm. 【0040】 Furthermore, from the standpoint of suppressing delamination, the width a of the chamfered area 2 only needs to be at most 1% of the radius r of the temporary fixed substrate 1, and it is not necessary to provide the chamfered area 2 further inward beyond this point. For example, in the case of a temporary fixed substrate 1 with a diameter of 300 mm (r=150 mm), a width of approximately 0.2 mm to 0.5 mm is preferable. The width b of the second chamfered area 2b is preferably approximately 0.01 mm to 0.11 mm. The presence of the chamfered area 2 does not hinder laser lift-off. 【0041】 <Manufacturing process for temporary fixed substrates> Next, the manufacturing process of the temporary fixing substrate 1 having a chamfered area 2 will be described. Figure 4 is a schematic flowchart showing the manufacturing process of the temporary fixing substrate 1. The temporary fixing substrate 1 is manufactured through a molded body manufacturing process (step S1), a firing process (step S2), a chamfering process (step S3), and a polishing process (step S4). 【0042】 In manufacturing the temporary fixing substrate 1, first, a molded body mainly composed of translucent ceramic powder is prepared (step S1). For example, a slurry is produced by kneading the above-mentioned alumina or other translucent ceramic raw material powder, ceramic powder such as magnesium oxide or sintering aid, and organic materials such as binders and solvents in a ball mill or the like, and this slurry is formed into a tape. Multiple rectangular sheets of a predetermined size obtained by shearing (cutting) the obtained tape are stacked and pressed, and the resulting stacked body is die-cut into a circular shape. This gives a disc-shaped molded body. Alternatively, the molded body may be obtained by the doctor blade method, extrusion method, gel casting method, etc. 【0043】 Next, the formed molded body is fired (step S2). This removes the organic components, and a sintered ceramic body (temporarily fixed substrate 1 before chamfering and polishing) is obtained. 【0044】 For firing, it is preferable to perform a preliminary firing in an atmospheric furnace followed by the main firing in a hydrogen furnace. The sintering temperature during the main firing is preferably 1700°C to 1900°C, and more preferably 1750°C to 1850°C, from the viewpoint of densifying the sintered body. 【0045】 Furthermore, after the main firing, the resulting sintered body may be further annealed in a hydrogen furnace for the purpose of adjusting (correcting) warping. From the viewpoint of preventing deformation and abnormal grain growth while promoting the discharge of sintering aids, the annealing treatment is preferably performed at a temperature within ±100°C of the maximum temperature during the main firing, and more preferably at 1900°C or lower. The annealing time is preferably 1 to 6 hours. 【0046】 Once the sintered body (temporary fixing substrate 1 before chamfering and polishing) is obtained, the entire outer circumference of both the front and back surfaces (both main surfaces) of the sintered body is then chamfered (step S3). For convenience, in the following explanation, the temporary fixing substrate 1 before chamfering and the temporary fixing substrate 1 before polishing will also be simply referred to as temporary fixing substrate 1. 【0047】 Figure 5 is a schematic diagram showing how the temporary fixed substrate 1 is chamfered using a chamfering device (beveling machine) 100. The chamfering device 100 comprises a table 101, a table rotation mechanism 102, a grinding wheel holding and moving mechanism 103, and a grinding wheel 104. Figure 6 is an enlarged schematic diagram of part A of Figure 5, showing the chamfering process. 【0048】 The table 101 is configured such that a temporary fixed substrate 1 to be chamfered can be placed horizontally on its upper surface, and the table can rotate in a horizontal plane along with the placed temporary fixed substrate 1 when the table rotation mechanism 102 is operated. 【0049】 The grinding wheel holding and moving mechanism 103 is capable of holding a disc-shaped grinding wheel 104 in a horizontal position at its lower end, and is capable of rotational movement and forward / backward movement in the horizontal plane while holding the grinding wheel 104. 【0050】 The grinding wheel 104 is disc-shaped, and as shown in Figure 6, its outer edge has a blade portion 104a that is an isosceles triangle in cross-section. The grit of the grinding wheel 104 (blade portion 104a) is selected so that the arithmetic mean roughness Ra of the chamfered region 2 that is ultimately formed is in the range of 0.1 μm to 10 μm as described above. 【0051】 When chamfering, first, the temporary fixing base plate 1 is placed on the upper surface of the table 101. Meanwhile, the grinding wheel 104 is attached to the grinding wheel holding and moving mechanism 103. At that time, the temporary fixing base plate 1 and the grinding wheel 104 are aligned so that their respective center heights in the thickness direction (position in the vertical direction) coincide. 【0052】 Then, with the table 101 on which the temporary fixing substrate 1 is placed rotated horizontally by the table rotation mechanism 102 as shown by arrows AR1 (AR1a, AR1b), the grinding wheel holding and moving mechanism 103 rotates the grinding wheel 104 horizontally in the opposite direction to the table 101 as shown by arrows AR2 (AR2a, AR2b), and translates it toward the side end 1e of the temporary fixing substrate 1 as shown by arrows AR3 (AR3a, AR3b). 【0053】 As the grinding wheel 104 rotates and translates, the cutting edge 104a of the grinding wheel 104 approaches the side edge 1e of the temporary fixed substrate 1, and eventually comes into contact with the two upper and lower edge portions 1ea and 1eb of the side edge 1e of the temporary fixed substrate 1. As the rotation and translation of the grinding wheel 104 continues after this contact, the side edge 1e of the temporary fixed substrate 1 is gradually shaved away from the edge portions 1ea and 1eb, and finally a chamfered region 2 is formed. 【0054】 When the chamfering area 2 is configured in two stages, two types of grinding wheels 104 with different angles of the blade portion 104a are used sequentially. Alternatively, a single grinding wheel 104 may be equipped with multiple blade portions 104a with different angles, and these may be used sequentially to create a two-stage configuration for the chamfering area 2. 【0055】 In addition, since semiconductor chips 4 are not usually mounted on the back surface 1b of the temporary fixed substrate 1 using the above process, roughening of the chamfered area 2 formed on the back surface 1b side is not essential from the standpoint of suppressing resin peeling. However, there is no particular disadvantage to the chamfered area 2 on the back surface 1b side being roughened along with the front surface 1a side during chamfering by the chamfering device 100. Rather, it can be said that it is preferable from the standpoint of symmetry of the shape of the side edge 1e if the front surface 1a side and the back surface 1b side are chamfered similarly with the same grit blade portion 104a. 【0056】 Finally, the front and back surfaces (both main surfaces) of the temporarily fixed substrate 1 after chamfering are polished (step S4). 【0057】 Figure 7 is a schematic cross-sectional view showing the main parts of a lapping apparatus 200 for lapping a temporary fixed substrate 1. The lapping apparatus 200 comprises a lower platen 201, an upper platen 202, and a plurality of carriers 203. Figure 8 is a perspective view of the main parts of the lapping apparatus 200 with the upper platen 202 omitted. 【0058】 The lower platen 201 and the upper platen 202 are rotatable in the horizontal plane coaxially and in opposite directions, as indicated by arrows AR4 and AR5. Examples of materials for the lower platen 201 and the upper platen 202 include copper, resin copper, and tin. Alternatively, a polishing pad may be attached to a metal platen. Examples of polishing pads include hard urethane pads, non-woven fabric pads, and suede pads. 【0059】 Each carrier 203 is equipped with a circular through-hole 203h into which the temporary fixed substrate 1 to be polished is fitted, and is capable of rotating around between the annular guide 204 and the central axis 205 as the lower platen 201 and upper platen 202 rotate. 【0060】 In the lapping polishing apparatus 200, a plurality of carriers 203, each fitted with a temporary fixed substrate 1 to be polished, are sandwiched between a lower platen 201 and an upper platen 202. While dripping slurry SL between the lower platen 201 and the upper platen 202, the lower platen 201 and the upper platen 202 are rotated in opposite directions as indicated by arrows AR4 and AR5. As a result, both main surfaces of the temporary fixed substrate 1 are polished simultaneously, and a flat surface 1a and a flat back surface 1b with an arithmetic mean roughness Ra of 100 nm or less (preferably 20 nm or less) can be obtained. Examples of slurry SL include water-based or oil-based diamond slurry. 【0061】 Although the chamfered area 2 is polished to some extent during the lapping process, the surface roughness of the chamfered area 2, which has been roughened beforehand, remains almost unchanged from before polishing. 【0062】 By going through the above steps, a temporary fixing substrate 1 according to this embodiment, having a chamfered region 2, is obtained. 【0063】 As described above, according to this embodiment, by providing a chamfered area on the entire outer circumference of both main surfaces of the temporary fixing substrate used for temporary fixing of semiconductor chips in the semiconductor package manufacturing process using FOWLP technology, the occurrence of chipping at the corners of the temporary fixing substrate can be suitably suppressed. In addition, by making the chamfered area provided on the outer circumference of the main surface to which the semiconductor chip is temporarily fixed a rough surface with a greater surface roughness than the main surface, the delamination between the temporary fixing substrate and the resin during the above process can be suitably suppressed. 【0064】 <Second Embodiment> In the first embodiment described above, the chamfering area 2 is made rough in the chamfering device 100, and then both main surfaces of the temporary fixing substrate 1 are lapped in the lapping device 200 to form a flat surface 1a on which the semiconductor chip 4 is temporarily fixed. 【0065】 In the lapping process performed by the lapping device 200, the side edge 1e is also polished to some extent due to the nature of the method. That is, the surface roughness of the side edge 1e decreases with lapping. Therefore, the surface roughness (arithmetic mean roughness Ra) of the side edge 1e, in addition to the flat surface 1a and the flat back surface 1b, is also smaller than the surface roughness (arithmetic mean roughness Ra) of the chamfered region 2. Reducing the surface roughness of the side edge 1e by performing lapping has the effect of suppressing the occurrence of chipping within the surface of the side edge 1e. Moreover, this effect can be obtained even in temporary fixed substrates 1 in which the chamfered region 2 is formed, in other words, even in temporary fixed substrates 1 in which the chamfering process is omitted. 【0066】 Figure 9 is a schematic diagram showing the polishing process of the side edge 1e of the temporary fixed substrate 1, where the chamfered area 2 is not formed, using the lapping polishing apparatus 200. 【0067】 As described above, in the lapping apparatus, slurry SL is dripped between the carrier 203 and the carrier 203, and the lower platen 201 and upper platen 202, which sandwich the temporary fixed substrate 1. As shown in Figure 9, this slurry SL also gets into the space between the side edge 1e of the temporary fixed substrate 1 and the carrier 203. This entering slurry SL polishes the side edge 1e of the temporary fixed substrate 1. This is also true when the temporary fixed substrate 1 is provided with a chamfered area 2. 【0068】 When the arithmetic mean roughness Ra of the side edge 1e is 5 μm or less, the chipping occurrence rate (chipping defect rate) counted per substrate is suppressed to less than 3.0%. When the arithmetic mean roughness Ra of the side edge 1e is 2 μm or less, the chipping defect rate is suppressed to less than 1.0%. 【0069】 Furthermore, in the case of a temporary fixed substrate 1 having a chamfered area 2 as in the first embodiment, if the arithmetic mean roughness Ra of the side edge 1e is 2 μm or less, the chipping defect rate can be suppressed to 0.5% or less. 【0070】 There is no particular limit to the lower limit of the arithmetic mean roughness Ra of the side edge 1e, but in practice, anything above 0.01 μm is sufficient. However, since lapping primarily targets the main surface of the temporary fixed substrate 1, the polishing of the side edge 1e progresses more slowly than that of the main surface. Therefore, the arithmetic mean roughness Ra of the side edge 1e is usually larger than that of the flat surface 1a and the flat back surface 1b. 【0071】 As described above, according to this embodiment, by setting the arithmetic mean roughness Ra of the side edge of the temporary fixing substrate used for temporary fixing of semiconductor chips in the semiconductor package manufacturing process using FOWLP technology to 5 μm or less, the occurrence of chipping at the side edge can be suitably suppressed. 【0072】 (modified version) In the above-described embodiment, the temporary fixing substrate having a chamfered area is used as a substrate to which multiple semiconductor chips are temporarily fixed when manufacturing a semiconductor package using FOWLP technology. However, the use of such a temporary fixing substrate is not limited to this, and it may also be used for the temporary fixing of electronic components other than semiconductor chips. That is, in cases where multiple electronic components are bonded to the temporary fixing substrate with an adhesive and then a resin mold is formed, the temporary fixing substrate according to the above embodiment may be used to suppress delamination between the resin and the temporary fixing substrate. 【0073】 Alternatively, various semiconductor substrates may be temporarily fixed to a temporary fixing substrate having a chamfered area using an adhesive, and after the semiconductor substrates have been temporarily fixed, a desired treatment may be performed, and then the temporary fixing substrate may be peeled off in the same manner as in the embodiment described above. Examples of semiconductor substrates include silicon substrates, compound semiconductor substrates, or epitaxial substrates and other composite substrates, multilayer substrates, and multilayer substrates that use these as base substrates. In this case as well, the same effects and advantages as in the embodiment described above can be obtained. [Examples] 【0074】 (Confirmation of the effect of roughening the chamfered area) Five types of temporary fixing substrates 1 (conditions 1 to 5) were fabricated, each consisting of 200 substrates with different combinations of arithmetic mean roughness Ra of the flat surface 1a and the chamfered area 2. The chamfered area 2 had a two-stage configuration, with inclination angles θ1 and θ2 set to 30° and 60°, respectively. For each temporary fixing substrate 1, the semiconductor chip 4 was temporarily fixed using a resin mold 6, following the process illustrated in Figure 3. 【0075】 Furthermore, a temporary fixed substrate was fabricated in the same manner as under conditions 1, 4, and 5, except that chamfered region 2 was not formed (condition 6). 【0076】 For all obtained samples (laminated structures of temporary fixing substrate 1, semiconductor chip 4, and resin), the presence or absence of delamination between the temporary fixing substrate 1 and the resin was visually confirmed, and the delamination defect rate for each example was determined. Specifically, the temporary fixing substrate 1 was visually inspected from the side edge 1e and the back surface 1b. If separation between the resin mold 6 and the temporary fixing substrate 1 was confirmed at the side edge 1e, or if, upon observation from the back surface 1b, air bubbles with a minimum size of 3 mm or more were present in at least one of the radial or circumferential directions of the temporary fixing substrate 1, it was determined that delamination had occurred. 【0077】 Table 1 lists the arithmetic mean roughness Ra values ​​of the flat surface 1a and chamfered area 2, and the evaluation results of the peeling defect rate for each example and comparative example. 【0078】 [Table 1] 【0079】 Regarding the evaluation of the delamination defect rate, temporary fixed substrate 1, which was manufactured under conditions where the delamination defect rate was 3% or less, was judged to have good suppression of resin delamination. Specifically, conditions 1 to 5 fell into this category. In Table 1, a circle ("〇") is marked in the "Delamination Defect Rate" column for conditions 1 to 5. 【0080】 On the other hand, for temporary fixed substrate 1, which was manufactured under conditions where the delamination defect rate exceeded 3%, it was determined that the suppression of resin delamination was insufficient. Specifically, only condition 6 fell into this category. Specifically, the delamination defect rate for condition 6 was 4.5%. In Table 1, the "Delamination Defect Rate" column for condition 6 is marked with an "×" (cross). 【0081】 The above results indicate that having a chamfered region 2, which is a sufficiently rough surface compared to surface 1a and has an arithmetic mean roughness Ra in the range of 0.1 μm to 10 μm, is effective in suppressing delamination between the temporary fixed substrate 1 and the resin. 【0082】 (Confirmation of the effect of polishing the side edges) Five types of temporary fixing substrates 1 (conditions 3-1 to 3-5) were fabricated, each with 200 pieces, while the chamfered region 2 was formed in the same manner as in condition 3, and the arithmetic mean roughness Ra of the side edge 1e was varied. The arithmetic mean roughness Ra was measured using a laser microscope. In addition, three types of temporary fixing substrates 1 (conditions 4-1 to 4-3) were fabricated, each with 200 pieces, while the chamfered region 2 was formed in the same manner as in condition 4, and the arithmetic mean roughness Ra of the side edge 1e was varied. Furthermore, two types of temporary fixing substrates 1 (conditions 6-1 to 6-2) were fabricated, each with 200 pieces, without forming the chamfered region 2, and with the arithmetic mean roughness Ra of the side edge 1e being varied, similar to condition 6. 【0083】 The side edges 1e of each temporary fixing substrate 1 were observed using a stereomicroscope to check for the presence or absence of chipping. If a chip measuring 5 mm or more in the circumferential direction and 1 mm or more in the radial direction was found on the temporary fixing substrate 1, it was determined that chipping had occurred. 【0084】 Table 2 lists the arithmetic mean roughness Ra values ​​of the chamfered area 2 and side edge 1e, and the evaluation results of the chipping defect rate for each embodiment. 【0085】 [Table 2] 【0086】 Regarding the evaluation of the chipping defect rate, if the chipping defect rate was 0.5% or less, it was judged that the occurrence of chipping was suppressed very well. Specifically, conditions 3-1, 3-3, 4-2, and 4-3 fell into this category. In Table 2, the "Chipping Defect Rate" column for these conditions is marked with a double circle ("◎"). 【0087】 Furthermore, if the chipping defect rate was greater than 0.5% but less than or equal to 1.0%, it was determined that the occurrence of chipping was generally well suppressed. Specifically, condition 6-2 fell into this category. In Table 2, the "Chipping Defect Rate" column for the relevant condition is marked with a circle ("〇"). 【0088】 Furthermore, if the chipping defect rate was greater than 1.0% but less than 3.0%, it was determined that the occurrence of chipping was suppressed to a certain extent. Specifically, conditions 3-2, 3-4, and 4-1 fell into this category. In Table 2, a "△" (triangle mark) is placed in the "Chipping Defect Rate" column for these conditions. 【0089】 On the other hand, if the obtained chipping defect rate was greater than 3%, it was determined that the chipping suppression was insufficient. Specifically, conditions 3-5 and 6-1 fell into this category. In Table 2, these conditions are marked with an "×" (cross) in the "Chipping Defect Rate" column. For example, the chipping defect rate for condition 6-1 was 4.0%. 【0090】 The above results indicate that having a side edge 1e with an arithmetic mean roughness Ra of 5 μm or less has a certain degree of effect in suppressing chipping at the side edge 1e, specifically that the chipping occurrence rate is suppressed to less than 3%. Furthermore, it is shown that when the arithmetic mean roughness Ra of the side edge 1e is 2 μm or less, the chipping occurrence rate is suppressed to less than 1%, and in addition, when the temporary fixed substrate 1 further includes a chamfered region 2, the chipping occurrence rate is suppressed to less than 0.5%. [Explanation of symbols] 【0091】 1. Temporary fixed substrate 1a One main surface (front surface) of the temporary fixed substrate 1b The other main surface (back surface) of the temporary fixed substrate 1e (Side edge of the temporary fixing substrate) 2 Chamfered area 3 Adhesive layer 4 Semiconductor chips 5 Gap 6. Resin mold SL Slurry 100 Chamfering device 101 Table 102 Table Rotation Mechanism 103 Grinding wheel holding and moving mechanism 104 Sharpening Stones 104a (Sharpening stone) blade 200 Lapping and polishing equipment 201 Lower surface plate 202 Upper surface plate 203 Carriers 203h Through hole

Claims

[Claim 1] A temporary fixing substrate made of translucent alumina, on which a predetermined object to be fixed is temporarily fixed to one main surface and then separated after the temporary fixing, The ends of the outer circumference of each of the aforementioned main surfaces are provided with chamfered areas, The chamfered region comprises a first chamfered portion and a second chamfered portion, each having different inclination angles with respect to the one main surface. The width of the chamfered area is 1% or less of the radius of the temporary fixing substrate. A temporary fixing substrate characterized by the following features. [Claim 2] A temporary fixing substrate according to claim 1, The arithmetic mean roughness of the chamfered area on at least one main surface is 0.1 μm to 10 μm, and is greater than the arithmetic mean roughness of the one main surface. A temporary fixing substrate characterized by the following features. [Claim 3] A temporary fixing substrate according to claim 2, The arithmetic mean roughness of the one main surface and the other main surface is 100 nm or less. A temporary fixing substrate characterized by the following features. [Claim 4] A temporary fixing substrate according to any one of claims 1 to 3, The arithmetic mean roughness of the side edge is less than the arithmetic mean roughness of the chamfered area. A temporary fixing substrate characterized by the following features. [Claim 5] A temporary fixing substrate according to claim 4, The arithmetic mean roughness of the side edge is greater than the arithmetic mean roughness of the one main surface, and is 5 μm or less. A temporary fixing substrate characterized by the following features. [Claim 6] A temporary fixing substrate according to claim 5, The arithmetic mean roughness of the aforementioned side end is 2 μm or less. A temporary fixing substrate characterized by the following features. [Claim 7] A temporary fixing substrate according to any one of claims 1 to 3, The inclination angle θ1 of the first chamfered portion with respect to the one main surface is 5° to 55°, The inclination angle θ2 of the second chamfered portion with respect to the one main surface is 35° to 85°. θ1 < θ2, A temporary fixing substrate characterized by the following features. [Claim 8] A temporary fixing substrate according to any one of claims 1 to 3, The predetermined object to be fixed is a plurality of electronic components or semiconductor substrates. A temporary fixing substrate characterized by the following features.

Images