Processing method for package substrates

Abstract

To provide a method for processing a package substrate which can thin a sealing material of a package substrate including chips sealed with a sealing material such as a mold resin to desired finishing thickness.SOLUTION: A method for processing a package substrate 100 in which chips 102 stacked on a support substrate 101 is sealed with a sealing material 110 includes a holding step of holding the side of the support substrate 101 on a holding table 10, and a thinning step of thinning the sealing material 110 of the package substrate 100 held on the holding table 10 to finishing thickness. The package substrate 100 further has a column material 103 which is stacked on the support substrate 101 and is thicker than the finishing thickness. The thinning step irradiates the column material 103 with light by a thickness measuring device 30, and thins the sealing material 110 to the finishing thickness while measuring the thickness of the column material 103 by spectral interference waves generated by reflected light from a surface 108 of the column material 103 and reflected light from a rear face 109 thereof.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for processing a package substrate in which a chip is sealed with a molding resin or the like.

Background Art

[0002] WL-CSP (Wafer Level Chip Size Package) is a technology in which chips stacked on a wiring substrate in a wafer state are sealed with a molding resin or the like and divided into individual device packages using a cutting blade or the like. Since the size of the device package obtained by singulating the wafer becomes the size of the semiconductor device chip, it is widely adopted from the viewpoints of miniaturization and weight reduction (see, for example, Patent Document 1).

[0003] In addition, in WL-CSP, in addition to the above-described flip chip BGA (Ball Grid Array) process using a wiring substrate, after a chip is placed on a support substrate and sealed with a molding resin, the support substrate is removed and a redistribution layer is formed on the surface where the support substrate was adhered. A process called a fan-out type package (Fan Out Wafer Level Package: FO-WLP) has also been proposed. Further, in order to further improve productivity, development is also underway to use a wiring substrate of a panel larger than a wafer instead of a wafer (Panel Level Package: PLP).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Normally, package substrates sealed with molding resin are thinned to the final thickness, but in recent years, the required precision for the final thickness of package substrates has increased. To improve the precision of the final thickness, it is preferable to perform the thinning step while measuring the thickness of the package substrate. However, contact-type measuring instruments that contact the top surface of the holding table and the top surface of the package substrate with a measuring needle and determine the thickness of the package substrate from the difference have the problem that the thickness of the adhesive interposed between the support substrate and the chip is included, making it impossible to accurately measure the thickness of the package substrate. In addition, methods that irradiate the package substrate with measuring light and measure the thickness of the package substrate by the reflected light from the top and bottom surfaces of the package substrate have the problem that the thickness of the package substrate cannot be measured accurately because the filler contained in the molding resin scatters or absorbs the light. Furthermore, it is also possible to expose the top surface of the chip on the grinding surface and grind while measuring the thickness of the chip with a non-contact thickness measuring instrument, but this has the problem that it cannot be used when thinning to a final thickness where the chip is not exposed, and it cannot be used if the area where the chip is stacked is outside the measuring range of the thickness measuring instrument.

[0006] This invention has been made in view of the above problems, and its purpose is to provide a method for processing a package substrate that can thin the sealing material of a package substrate containing a chip sealed with a sealing material such as a molding resin to a desired finished thickness. [Means for solving the problem]

[0007] To solve the above-mentioned problems and achieve the objective, the present invention provides a method for processing a package substrate, which is a support substrate or wiring board A method for processing a package substrate, wherein chips stacked on top of a support substrate are sealed with a sealing material, and the sealing material of the package substrate is thinned to a finishing thickness, wherein the support substrate or wiring board The package substrate comprises a holding step of holding one side of a package substrate on a holding table, and a thinning step of thinning the sealing material of the package substrate held on the holding table to a finished thickness, wherein the package substrate is Applicable Support board or the wiring board Laminated on top of, and thicker than the finished thickness Furthermore, formed from the same material as the base material of the chip. The present invention further comprises a column member, and the thinning step is characterized by comprising a column member exposure step of grinding the package substrate until the column member is exposed, and a measurement step of thinning the sealing material to the finished thickness while measuring the thickness of the column member with a thickness measuring instrument after the column member exposure step has been performed.

[0008] The method for processing a package substrate according to the present invention is: Support substrate or A method for processing a package substrate, in which chips stacked on a wiring board are sealed with an sealing material, and the sealing material of the package substrate is thinned to the final thickness, The support substrate or The package substrate comprises a holding step of holding the side of the wiring board on a holding table, and a thinning step of thinning the sealing material of the package substrate held on the holding table to a finished thickness, wherein the package substrate is The support substrate or The wiring board is further laminated and has columnar material that is thicker than the finished thickness, The columnar material is arranged circumferentially and continuously or discontinuously around the entire circumference of the package substrate, or is formed to have the same shape and size as the chip in a plan view, and is arranged alongside the chip on the package substrate. The thinning step is characterized by comprising a column member exposure step, in which the package substrate is ground until the column member is exposed, and a measurement step, after the column member exposure step, in which the sealing material is thinned to the finished thickness while measuring the thickness of the column member with a thickness measuring instrument. The column material may be formed from the same material as the base material of the chip.

[0009] The thickness measuring instrument may measure the thickness of the column material by irradiating it with light and measuring the spectral interference wave generated by the reflected light from the front surface and the reflected light from the back surface of the column material.

[0010] The column material may be arranged on the outer periphery of the package substrate. [Effects of the Invention]

[0011] The present invention relates to a processing method for a package substrate in which a chip and a columnar material thicker than the finished thickness of the package substrate are laminated on a support substrate and sealed with a sealing material. In the columnar material exposure step, the columnar material is exposed, and in the measurement step, the thickness of the exposed columnar material is measured with a thickness measuring instrument and thinned down to the finished thickness. This allows grinding to be performed while measuring the thickness of the sealing material, excluding the thickness of the support substrate and the adhesive used to bond the support substrate and the package substrate. Therefore, even if the thickness of the support substrate and adhesive used varies from package substrate to package substrate, the sealing material of the package substrate, including the chip sealed with mold resin, can be thinned to the desired finished thickness.

[0012] Furthermore, even when chips and columnar materials are laminated on a wiring board, by performing a thinning step that similarly includes a columnar material exposure step and a measurement step, it is possible to grind while measuring the thickness of the sealing material excluding the thickness of the wiring board. This allows the sealing material of the package substrate, including the chip sealed with molded resin, to be thinned to the desired finish thickness, even if the thickness of the wiring board varies from the design value.

[0013] Furthermore, by installing columnar members on the outer perimeter, the difference in the proportion of sealing material within the package substrate can be reduced, thereby reducing warping of the package substrate. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a flowchart showing the processing procedure for the package substrate processing method according to the embodiment. [Figure 2] Figure 2 is a top view illustrating the lamination steps in Figure 1. [Figure 3] Figure 3 is a cross-sectional view illustrating the lamination steps in Figure 1. [Figure 4] Figure 4 is a cross-sectional view illustrating the sealing step in Figure 1. [Figure 5] Figure 5 is a cross-sectional view illustrating the holding step and thinning step in Figure 1. [Figure 6] Figure 6 is another cross-sectional view illustrating the holding step and thinning step of Figure 1. [Figure 7] FIG. 7 is a top view illustrating the thinning step of FIG. 1. [Figure 8] FIG. 8 is a cross-sectional view schematically showing the configuration of a package substrate processed by the method for processing a package substrate according to Embodiment 2. [Figure 9] FIG. 9 is a top view explaining an example of a modification of the method for processing a package substrate according to the embodiment. [Figure 10] FIG. 10 is a top view explaining another example of a modification of the method for processing a package substrate according to the embodiment. [Figure 11] FIG. 11 is a top view explaining another example of a modification of the method for processing a package substrate according to the embodiment. **[Mode for Carrying Out the Invention]**

[0015] The mode (embodiment) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the content described in the following embodiments. Further, the constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Also, various omissions, substitutions, or changes in the configuration can be made without departing from the gist of the present invention.

[0016] **[Embodiment 1]** A method for processing a package substrate according to Embodiment 1 of the present invention will be described based on the drawings. Figure 1 is a flowchart showing the processing steps of the method for processing a package substrate according to Embodiment 1. As shown in Figure 1, the method for processing a package substrate according to Embodiment 1 comprises a lamination step 1001, a sealing step 1002, a holding step 1003, and a thinning step 1004. The method for processing a package substrate according to Embodiment 1 is a method in which the sealing material 110 of a package substrate 100 (see Figure 4), which is obtained by lamination step 1001 and sealing step 1002 by sealing chips 102 (see Figures 2, 3, etc.) laminated on a support substrate 101 (see Figures 2, 3, etc.) with sealing material 110 (see Figure 4), is thinned to a finished thickness by holding step 1003 and thinning step 1004.

[0017] Figure 2 is a top view illustrating the lamination step 1001 of Figure 1. Figure 3 is a cross-sectional view illustrating the lamination step 1001 of Figure 1. As shown in Figures 2 and 3, the lamination step 1001 is a step in which a chip 102 and a column member 103 that is thicker than the finished thickness of the sealing material 110 of the package substrate 100 are laminated on a support substrate 101. In the lamination step 1001, a sheet-like adhesive 104 of uniform thickness is supplied to the upper surface of the support substrate 101, or the adhesive 104 is supplied and formed into a layer of uniform thickness, the chip 102 and the column member 103 are placed on the upper surface of the adhesive 104, and the chip 102 and the column member 103 are fixed to the upper surface of the support substrate 101 via the adhesive 104.

[0018] Here, the thickness 120 of the sealing material 110 of the package substrate 100 (see Figures 4 and 5) refers to the thickness of the portion of the adhesive 104 above the upper surface. In this embodiment, it specifically refers to the thickness from the lower surface of the sealing material 110, i.e., the upper surface of the adhesive 104, to the upper surface of the sealing material 110 that is supplied in the subsequent sealing step 1002 and thinned in the thinning step 1004. In other words, the thickness 120 of the sealing material 110 of the package substrate 100 does not include the thickness of the support substrate 101 and the adhesive 104. Furthermore, the finished thickness of the sealing material 110 of the package substrate 100 refers to the thickness 120 of the sealing material 110 of the package substrate 100 obtained when the processing of the package substrate manufacturing method is completed up to the thinning step 1004.

[0019] In this embodiment, the support substrate 101 is a wafer-shaped (disc-shaped) silicon plate or glass plate, but the present invention is not limited to this and may also be panel-shaped (rectangular). After the thinning step 1004 is performed, the support substrate 101 is peeled off from the package substrate 100, and a redistribution layer is formed on the surface of the package substrate 100 to which the support substrate 101 was adhered (Fan Out: FO method). The chip 102 is a semiconductor chip or device chip made of silicon, sapphire, silicon carbide (SiC), gallium arsenide, glass, etc. as the base material. The columnar material 103 is a solid material with a uniform material composition, which transmits a certain percentage of the light irradiated by the thickness measuring instrument 30 (see Figure 5), described later, and reflects it from both the front surface 108 (see Figure 5) and the back surface 109 (see Figure 5). The columnar material 103 is formed from a material with similar mechanical properties to the base material of the chip 102. The columnar material 103 is preferably formed from the same material as the base material of the chip 102. In this case, the warping of the package substrate 100 obtained after the subsequent sealing step 1002 can be reduced. For example, the columnar material 103 can be a dummy wafer or dummy chip formed from the same material as the base material of the chip 102 and shaped into a columnar form. The shape of the columnar material 103 in plan view is not particularly limited. For example, an adhesive made of epoxy resin can be used for the adhesive 104. The chip 102 has a device formed on the surface of a substrate such as Si, SiC, or GaAs, and the base material of the chip 102 refers to the substrate on which the device is laminated.

[0020] In the lamination step 1001, in this embodiment, as shown in Figure 2, it is preferable that the column members 103 are arranged on the outer periphery of the package substrate 100, i.e., on the outer periphery of the package substrate 100, on the outer side of the support substrate 101, i.e., on the outer periphery of the package substrate 100. Conventionally, there are usually no chips 102 on the outer periphery of the package substrate 100, and the proportion of sealing material 110 is higher there compared to the central part. As a result, shrinkage and expansion caused by the materials contained in the package substrate 100 do not occur uniformly across the surface of the package substrate 100, causing the package substrate 100 to warp. However, by installing the column members 103 on the outer periphery where there are no chips 102, the difference in the proportion of sealing material 110 and chips 102 or column members 103 across the entire surface of the package substrate 100 is reduced, and the distribution of materials contained in the package substrate 100 becomes more uniform. In particular, this prevents the package substrate 100 from warping due to sealing by the sealing material 110, and also makes it easier to measure the thickness of the column members 103 in the subsequent thinning step 1004. Furthermore, in the lamination step 1001, it is preferable to arrange the column members 103 along the circumferential direction, as shown in Figure 2. In this case, in the thinning step 1004, the thickness of the column members 103 can be measured appropriately by keeping the radial position of the thickness measuring instrument 30 constant. Note that the number of column members 103 arranged in the lamination step 1001 may be one or more.

[0021] Figure 4 is a cross-sectional view illustrating the sealing step 1002 of Figure 1. As shown in Figure 4, the sealing step 1002 is a step in which the chips 102 and column members 103 laminated on the support substrate 101 in the lamination step 1001 are sealed with a sealing material 110 to obtain a package substrate 100. The sealing material 110 is a so-called molding resin composed of, for example, epoxy resin, silicone resin, urethane resin, unsaturated polyester resin, acrylic urethane resin, or polyimide resin. The sealing material 110 may also contain a filler. The filler included in the sealing material 110 may be one or more of the inorganic fillers such as fused silica, crystalline silica, alumina, calcium carbonate, calcium silicate, barium sulfate, talc, clay, magnesium oxide, aluminum oxide, beryllium oxide, iron oxide, titanium oxide, aluminum nitride, silicon nitride, boron nitride, mica, glass, quartz, and mica. The sealing material 110 may scatter or absorb light due to the filler.

[0022] Figure 5 is a cross-sectional view illustrating the holding step 1003 and thinning step 1004 of Figure 1. Figure 6 is another cross-sectional view illustrating the holding step 1003 and thinning step 1004 of Figure 1. Figure 7 is a top view illustrating the thinning step 1004 of Figure 1. A thinning apparatus 1, which is an example of an apparatus for performing the holding step 1003 and thinning step 1004, comprises a holding table 10, a thinning unit 20, a thickness measuring instrument 30, and a control unit 40, as shown in Figure 5. In this embodiment, the thinning apparatus 1 is a grinding apparatus that grinds the sealing material 110 of the package substrate 100 with the thinning unit 20, but the present invention is not limited thereto, and may be a processing apparatus that thins the sealing material 110 of the package substrate 100 by other processing methods.

[0023] The holding table 10 holds the package substrate 100 from the side of the support substrate 101. In this embodiment, the holding table 10 is a so-called chuck table having, for example, a disc-shaped frame with a recess formed therein and a disc-shaped suction part fitted into the recess. The upper surface of the suction part of the holding table 10 is formed parallel to the horizontal plane and is a holding surface 11 that holds the package substrate 100, which is placed with the support substrate 101 facing downwards, by suction from the side of the support substrate 101 when negative pressure is introduced from a suction source (not shown) connected to the suction part. The holding table 10 is rotatable around an axis perpendicular to the holding surface 11 and parallel to the vertical direction by a rotation drive source (not shown).

[0024] The thinning unit 20 thins the sealing material 110 of the package substrate 100 held on the holding table 10 to the final thickness. In this embodiment, the thinning unit 20 is a grinding unit that thins the sealing material 110 of the package substrate 100 by grinding it, but the present invention is not limited to this, and may be a processing unit that thins the sealing material 110 of the package substrate 100 by other processing methods.

[0025] In this embodiment, the thinning unit 20 comprises a spindle 21, a grinding wheel 23 in which grinding wheels 22 are arranged in an annular shape, and a grinding feed unit 24. In the thinning unit 20, the grinding wheel 23 mounted on the lower end of the spindle 21 is subjected to rotational motion around an axis parallel to the vertical direction by the rotational motion of the spindle 21. The grinding feed unit 24 moves the spindle 21 and the grinding wheel 23 mounted on the spindle 21 along the grinding feed direction parallel to the vertical direction. The thinning unit 20 rotates the grinding wheel 23 with the spindle 21 and presses the sealing material 110 side of the package substrate 100 held on the rotating holding table 10 along the grinding feed direction with the grinding feed unit 24, thereby grinding and thinning the sealing material 110 of the package substrate 100 with the grinding wheel 22 of the grinding wheel 23, and forming the processed surface (grinded surface) of the sealing material 110 of the package substrate 100 parallel to the horizontal direction.

[0026] In this embodiment, the thinning apparatus 1 has the rotation axis of the holding table 10 and the rotation axes of the spindle 21 and grinding wheel 23 of the thinning unit 20 arranged to be horizontally offset from each other. When the thinning unit 20 grinds and thins the sealing material 110 of the package substrate 100 held on the holding table 10, a portion of the package substrate 100 held on the holding table 10 is exposed upwards.

[0027] The thickness measuring instrument 30 is positioned vertically opposite the area of ​​the package substrate 100 that is exposed above the holding table 10. The thickness measuring instrument 30 is connected to a radial movement unit (not shown) and is mounted to move freely along the radial direction of the holding table 10 by the radial movement unit. The thickness measuring instrument 30 is positioned on the circumference where the column members 103 within the package substrate 100 are arranged by the radial movement unit (not shown). As the column members 103 within the package substrate 100 rotate and move due to the rotation of the holding table 10, the thickness measuring instrument 30 irradiates the column members 103 with light as it passes directly beneath it, and measures the thickness of the column members 103 by spectral interference waves generated by the reflected light from the surface 108 of the column members 103 and the reflected light from the back surface 109 of the column members 103. In this embodiment, the thickness measuring device 30 is provided on the outer periphery of the holding table 10 and measures the thickness of the outer periphery of the sealing material 110 of the package substrate 100 held on the holding table 10. However, the present invention is not limited to this, and a mechanism may be provided in which a moving mechanism 31 (shown in Figure 6) moves the measuring unit that irradiates the aforementioned light and receives the reflected light in the radial direction of the holding table 10 and the package substrate 100, and measures the thickness of the sealing material 110 of the package substrate 100 by moving it radially with the moving mechanism 31. When measuring the thickness of the sealing material 110 of the package substrate 100 with the moving mechanism 31, multiple columnar members 103 are formed in the radial direction of the package substrate 100, not just the outer periphery, and the thickness of the sealing material 110 of the package substrate 100 is measured at the top of the columnar members 103. This makes it possible to measure the overall thickness distribution of the sealing material 110 of the package substrate 100 with higher accuracy, rather than just the outer periphery, thus improving the accuracy of the finished thickness.

[0028] The control unit 40 controls the operation of each component of the thinning device 1 to cause the thinning device 1 to perform the holding step 1003 and the thinning step 1004. In this embodiment, the control unit 40 includes a computer system. The computer system included in the control unit 40 is a computer having an arithmetic processing unit with a microprocessor such as a CPU (Central Processing Unit), a storage device with memory such as ROM (Read Only Memory) or RAM (Random Access Memory), and an input / output interface device. The arithmetic processing unit of the control unit 40 performs arithmetic processing according to a computer program stored in the storage device of the control unit 40 and outputs control signals for controlling the thinning device 1 to each component of the thinning device 1 via the input / output interface device of the control unit 40.

[0029] The holding step 1003 is the step of holding the support substrate 101 side of the package substrate 100 on the holding table 10 of the thinning device 1, as shown in Figure 5. The thinning step 1004 is performed after the holding step 1003 and is the step of thinning the sealing material 110 of the package substrate 100 held on the holding table 10 to the finished thickness. In this embodiment, as shown in Figure 5, the thinning step 1004 is performed by grinding the sealing material 110 of the package substrate 100 held on the holding table 10 to the finished thickness using a grinding wheel 22 arranged on a grinding wheel 23. However, the present invention is not limited to this, and the sealing material 110 of the package substrate 100 may also be thinned by other processing methods, such as using a cutting device equipped with a spindle rotated by a motor, a mount fixed to the tip of the spindle, and a cutting tool fixed to the mount to cut and thin the sealing material 110 with a cutting tool.

[0030] As shown in Figure 1, the thinning step 1004 includes a column member exposure step 1004-1 and a measurement step 1004-2. The column member exposure step 1004-1 is a step in which the package substrate 100 is ground until the column member 103 is exposed. In the column member exposure step 1004-1, since the column member 103 is thicker than the finished thickness of the sealing material 110 of the package substrate 100, in the thinning step 1004, as the sealing material 110 of the package substrate 100 is ground and thinned in the column member exposure step 1004-1, as shown in Figure 7, the surface 108 of the column member 103 is exposed on the processed surface of the sealing material 110 of the package substrate 100 before the sealing material 110 of the package substrate 100 is thinned to the finished thickness. Therefore, in the thinning step 1004, the control unit 40 first thins the sealing material 110 of the package substrate 100 held on the holding table 10 using the thinning unit 20, exposing the surface 108 of the column member 103 on the processed surface of the sealing material 110 of the package substrate 100.

[0031] In the thinning step 1004, after exposing the surface 108 of the column member 103 to the workpiece surface of the sealing material 110 of the package substrate 100, in the measurement step 1004-2, the control unit 40 continues to thin the sealing material 110 of the package substrate 100 with the thinning unit 20, while positioning the thickness measuring instrument 30 on the circumference where the exposed column member 103 is located using a radial movement unit (not shown). As the column member 103 inside the package substrate 100 rotates and moves with the rotation of the holding table 10, passing directly below the thickness measuring instrument 30, the thickness measuring instrument 30 irradiates the column member 103 with light, and measures the thickness of the column member 103 by spectral interference waves generated by the reflected light from the surface 108 of the column member 103 and the reflected light from the back surface 109 of the column member 103. The measurement step 1004-2 is a step in which, after the column member exposure step 1004-1 has been performed, the thickness of the column member 103 is measured with the thickness measuring instrument 30 while the sealing material 110 is thinned to the finished thickness.

[0032] When the sealing material 110 of the package substrate 100 is being thinned in the measurement step 1004-2 of the thinning step 1004, the thickness of the column member 103 measured by the thickness measuring instrument 30 is equal to the thickness 120 of the sealing material 110 of the package substrate 100. Therefore, the control unit 40 can measure the thickness 120 of the sealing material 110 of the package substrate 100 by measuring the thickness of the column member 103, and monitor the thickness 120 of the sealing material 110 of the package substrate 100 in real time. Therefore, in the measurement step 1004-2 of the thinning step 1004, the control unit 40 thins the sealing material 110 of the package substrate 100 with the thinning unit 20 until the thickness of the column member 103 measured by the thickness measuring instrument 30 becomes the finished thickness of the sealing material 110 of the package substrate 100. When the thickness of the column member 103 measured by the thickness measuring instrument 30 reaches the finished thickness of the sealing material 110 of the package substrate 100, the thinning unit 20 stops thinning the sealing material 110 of the package substrate 100. In this way, in the measurement step 1004-2 of the thinning step 1004, the thickness measuring instrument 30 irradiates the column member 103 with light, and the thickness of the column member 103 is measured and monitored by the spectral interference wave generated by the reflected light from the surface 108 and the reflected light from the back surface 109 of the column member 103, while thinning the sealing material 110 to the finished thickness.

[0033] In this way, by performing the thinning step 1004, the encapsulant 110 of the package substrate 100 can be thinned to a desired finished thickness. Furthermore, after performing the thinning step 1004, the support substrate 101 is peeled off and removed from the package substrate 100, and a redistribution layer is formed on the surface of the package substrate 100 to which the support substrate 101 was adhered, thereby obtaining a package substrate 100 containing the chip 102 and the encapsulant 110 of the desired finished thickness. In this embodiment, a wafer-shaped (disc-shaped) support substrate 101 is used to obtain a wafer-level package substrate 100, but the present invention is not limited to this, and a panel-shaped (rectangular-shaped) support substrate 101 may be used to obtain a panel-level package substrate 100.

[0034] In the package substrate processing method according to Embodiment 1 having the above configuration, the measurement result of the thickness 120 of the sealing material 110 of the package substrate 100 does not include the thickness of the adhesive 104 or the support substrate 101. Therefore, even if the thickness of the adhesive 104 or the support substrate 101 varies from the design value, the thickness 120 of the sealing material 110 will not be affected and will not vary. Even if the adhesive 104 is controlled to be the same thickness each time, some variation will occur from one package substrate 100 to the other. Also, even if the support substrate 101 is from the same lot and of the same thickness, individual differences will inevitably occur. Therefore, the present invention improves the accuracy of the finished thickness by measuring the thickness 120 of the sealing material 110 while excluding the thickness of the adhesive 104 and the support substrate 101. Furthermore, in the package substrate processing method according to Embodiment 1, the light irradiated to measure the thickness 120 of the sealing material 110 of the package substrate 100 passes through the inside of the column member 103 and not through the inside of the sealing material 110. Therefore, the measurement result of the thickness 120 of the sealing material 110 of the package substrate 100 is not affected by fillers or the like contained in the sealing material 110. Thus, the package substrate processing method according to Embodiment 1 allows the sealing material 110 of the package substrate 100, including a chip 102 sealed with a sealing material 110 such as molded resin, to be thinned while measuring and monitoring the thickness of the column member 103, without being affected by the thickness of the adhesive 104 or fillers or the like contained in the sealing material 110. This provides the effect of being able to thin the sealing material 110 of the package substrate 100, including a chip 102 sealed with a sealing material 110 such as molded resin, to a desired finished thickness.

[0035] Furthermore, in the package substrate processing method according to Embodiment 1, since the columnar material 103 is arranged on the outer periphery of the chip 102, the difference in the ratio of sealing material 110 to chip 102 or columnar material 103 across the entire surface of the package substrate 100 is reduced. This prevents the package substrate 100 from warping due to sealing, such as areas with a higher proportion of sealing material 110 shrinking or expanding more, and also makes it easier to measure the thickness of the columnar material 103. Moreover, if the base material (substrate) of the chip 102 and the columnar material 103 are formed from the same material, the distribution of material within the package substrate 100 becomes more uniform in the areas with chip 102 and the areas with columnar material 103, thus preventing the package substrate 100 from warping.

[0036] [Embodiment 2] The method for processing a package substrate according to Embodiment 2 will be described with reference to the drawings. Figure 8 is a schematic cross-sectional view showing the configuration of a package substrate 100-2 processed by the method for processing a package substrate according to Embodiment 2. Note that in Figure 8, the same reference numerals are used for the same parts as in Embodiment 1, and their description is omitted.

[0037] The method for processing a package substrate according to Embodiment 2 is the same as Embodiment 1, except that the package substrate 100-2 includes a wiring board 121 instead of a support substrate 101. In the method for processing a package substrate according to Embodiment 2, the wiring board 121 is held on the holding table 10 in the holding step 1003, and then ground in the thinning step 1004. However, in the conventional technique, a contact-type thickness measuring instrument is brought into contact with the upper surface of the sealing material 110, and another contact-type thickness measuring instrument is brought into contact with the holding surface of the holding table 10, and the difference is considered to be the total thickness including the wiring board 121 and the sealing material 110, and the grinding thickness is controlled. However, this has the problem that even if the wiring board 121 is from the same lot, the thickness will vary slightly, so when the thickness of the wiring board 121 varies, the thickness of the sealing material 110 will also vary.

[0038] Therefore, in the second embodiment, the packaging substrate processing method involves exposing the column member 103 in the column member exposure step 1004-1, similar to the first embodiment, and controlling the grinding thickness according to the thickness of the column member 103 in the measurement step 1004-2. This allows the thickness 120 of the sealing material 110 to be controlled regardless of the thickness variation of the wiring board 121. In the second embodiment, the wiring board 121 is used, and the wiring board 121 is also included in the subsequent chip formation, so the packaging substrate 100-2 includes the wiring board 121, the chip 102, and the sealing material 110.

[0039] [Variation] The processing methods for package substrates according to Modifications 1, 2, and 3 of the present invention will be described based on the drawings. Figures 9, 10, and 11 are top views illustrating Modifications 1, 2, and 3, which are examples of modifications of the processing method for package substrates according to Embodiments 1 and 2, respectively. Figures 9, 10, and 11 are all top views illustrating the lamination step 1001 of Modifications 1, 2, and 3. In Figures 9, 10, and 11, the same reference numerals are used for the same parts as in Embodiments 1 and 2, and their descriptions are omitted.

[0040] Modifications 1, 2, and 3 all involve changing the shape or position of the column members 103 placed on the support substrate 101 in the lamination step 1001, as described in Embodiments 1 and 2 above.

[0041] Modification 1, as shown in Figure 9, is a modification in which the column members 103 are changed to annular in a plan view, as in Embodiments 1 and 2. As a result, in Modification 1, the column members 103 are continuously arranged in the circumferential direction on the package substrate 100, and there are more measurement points where the thickness of the column members 103 can be measured by the thickness measuring instrument 30. Therefore, compared to Embodiments 1 and 2, the thickness of the column members 103 can be measured continuously and at a higher frequency by the thickness measuring instrument 30 in the thinning step 1004, allowing for more accurate monitoring of the thickness 120 of the sealing material 110 of the package substrate 100.

[0042] Modification 2, as shown in Figure 10, is a modification in which, in embodiments 1 and 2, the column members 103 are changed to four pieces that are approximately 1 / 4 arc-shaped in plan view. As a result, in modification 2, the column members 103 are arranged almost all around the circumferential circumference of the package substrate 100, albeit discontinuously. This increases the number of measurement points where the thickness of the column members 103 can be measured by the thickness measuring instrument 30. Therefore, compared to embodiments 1 and 2, the thickness of the column members 103 can be measured at a higher frequency, albeit discontinuously, using the thickness measuring instrument 30, allowing for more accurate and continuous monitoring of the thickness 120 of the sealing material 110 of the package substrate 100.

[0043] Modification 3, as shown in Figure 11, is a modification in which, in embodiments 1 and 2, the column members 103 are changed to four pieces of the same shape and size as the chips 102 in a plan view, and the column members 103 are arranged side by side with the chips 102. In modification 3, in the package substrate 100, the column members 103 are arranged in the minimum amount necessary to suitably maintain the balance between the chips 102 and the column members 103 across the entire surface of the package substrate 100, thus further minimizing the impact on the thinning of the sealing material 110 of the package substrate 100 compared to embodiments 1 and 2.

[0044] It should be noted that the present invention is not limited to the embodiments and modifications described above. That is, it can be implemented with various modifications without departing from the core principles of the present invention. [Explanation of symbols]

[0045] 10 Retention Table 30 Thickness measuring instrument 100,100-2 Package substrate 101 Support substrate 102 chips 103 Pillar material 108 Surface 109 Back side 110 Sealing material 120 thickness 121 Wiring board

Claims

1. A method for processing a package substrate, in which chips stacked on a support substrate or wiring substrate are sealed with an sealing material, the sealing material of the package substrate is thinned to a finishing thickness, A holding step of holding the side of the support board or the wiring board in a holding table, The system includes a thinning step of thinning the sealing material of the package substrate held on the holding table to the finished thickness, The package substrate is laminated on the support substrate or the wiring substrate and further comprises columnar members that are thicker than the finished thickness and made of the same material as the base material of the chip. The thinning step is, A column member exposure step in which the package substrate is ground until the column member is exposed, After the column member exposure step is performed, a measurement step is performed in which the sealing material is thinned to the finished thickness while measuring the thickness of the column member with a thickness measuring instrument, A method for processing a package substrate, characterized by having [a certain feature].

2. A method for processing a package substrate, in which chips stacked on a support substrate or wiring substrate are sealed with an sealing material, the sealing material of the package substrate is thinned to a finishing thickness, A holding step of holding the side of the support board or the wiring board in a holding table, The system includes a thinning step of thinning the sealing material of the package substrate held on the holding table to the finished thickness, The package substrate is laminated on the support substrate or the wiring substrate and further has columnar members that are thicker than the finished thickness. The column members are arranged around the entire circumference of the package substrate, either continuously or discontinuously in the circumferential direction. The thinning step is, A column member exposure step in which the package substrate is ground until the column member is exposed, After the column member exposure step is performed, a measurement step is performed in which the sealing material is thinned to the finished thickness while measuring the thickness of the column member with a thickness measuring instrument, A method for processing a package substrate, characterized by having [a certain feature].

3. A method for processing a package substrate, in which chips stacked on a support substrate or wiring substrate are sealed with an sealing material, the sealing material of the package substrate is thinned to a finishing thickness, A holding step of holding the side of the support board or the wiring board in a holding table, The system includes a thinning step of thinning the sealing material of the package substrate held on the holding table to the finished thickness, The package substrate is laminated on the support substrate or the wiring substrate and further has columnar members that are thicker than the finished thickness. The column material is formed to have the same shape and size as the chip in a plan view, and is arranged alongside the chip on the package substrate. The thinning step is, A column member exposure step in which the package substrate is ground until the column member is exposed, After the column member exposure step is performed, a measurement step is performed in which the sealing material is thinned to the finished thickness while measuring the thickness of the column member with a thickness measuring instrument, A method for processing a package substrate, characterized by having [a certain feature].

4. The method for processing a package substrate according to claim 2 or 3, characterized in that the column material is formed from the same material as the base material of the chip.

5. The method for processing a package substrate according to any one of claims 1 to 4, characterized in that the thickness measuring instrument irradiates the column material with light and measures the thickness of the column material by spectral interference waves generated by the reflected light from the surface and the reflected light from the back surface of the column material.

6. The method for processing a package substrate according to any one of claims 1 to 5, characterized in that the column material is arranged on the outer periphery of the package substrate.

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