Method for processing plate-like object and method for processing package substrate

Abstract

To provide a resin composition that is easily removed after forming a protective layer, and a new processing method using the resin composition.SOLUTION: A liquid UV curable heat release resin composition includes (meth) acrylate, a photopolymerization initiator, and a foaming agent that expands by heating. A plate-shaped material processing method includes a supply step of supplying the liquid UV curable heat release resin composition to the surface of the plate-shaped material, a curing step of irradiating the liquid UV curable heat release resin composition with ultraviolet rays to cure it to form a protective layer on the surface of the plate-shaped material, a cutting step of cutting the plate-shaped material on which the protective layer is formed, and a release step of heating the UV curable heat release resin composition to peel the protective layer from the plate-shaped material after performing the cutting step.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to an ultraviolet-curable resin composition and a processing method using the resin composition, and more particularly to a resin composition having a thermal peeling function. [Background technology]

[0002] 2. Description of the Related Art Conventionally, as disclosed in Patent Document 1, for example, in a package substrate having a recess, a technique for appropriately removing burrs formed in the recess has been known.

[0003] In Patent Document 1, a recess (cavity) that intersects with the planned division line is formed on the surface of the package substrate to be processed, and electrodes are formed in the recess after the package substrate is divided into individual chips. During the division process, burrs are formed along the inner side surface of the recess, and these burrs are removed with high-pressure cleaning water.

[0004] In this manner, by removing the burrs after dividing the package substrate, it is possible to prevent problems such as the burrs falling off during package mounting and causing mounting defects. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-181569 A Summary of the Invention [Problem to be solved by the invention]

[0006] As packages become smaller, the sizes of the electrodes and recesses formed on the package substrate are also becoming smaller, and are expected to continue to become smaller in the future.

[0007] Here, when the recesses become smaller, the gaps become smaller, making it more difficult to remove the burrs using high-pressure cleaning water.

[0008] In particular, in package substrates in which recesses are formed on the inside of the electrodes, there is a concern that when the electrode portion is cut with a cutting blade during the dividing process, burrs on the electrode may get into the recesses on the inside of the electrodes and may not be able to be sufficiently removed with high-pressure cleaning water, remaining as foreign matter.

[0009] In view of the above, the present invention proposes a novel resin composition suitable for forming a protective layer on the surface of a plate-like object to reduce the occurrence of burrs when a recess is cut with a cutting blade, and a novel processing method utilizing the resin composition.

[0010] In particular, in the case of a product in which recesses are formed, if the recesses are small, the resin composition that has entered the recesses may be difficult to remove, and may remain as foreign matter.

[0011] Furthermore, in addition to plate-like objects such as package substrates in which a recess is formed, in plate-like objects without a recess, when a protective layer is formed from a resin composition, the protective layer will be removed later. In this case too, it is necessary to ensure that no foreign matter remains.

[0012] Therefore, the present invention proposes a resin composition that is easily removed after the formation of a protective layer, and a novel processing method that utilizes the resin composition. [Means for solving the problem]

[0013] The problem to be solved by the present invention has been described above, and the means for solving this problem will now be described.

[0014] According to one aspect of the present invention, A liquid ultraviolet-curable heat-peelable resin composition, (Meth)acrylate, A photopolymerization initiator; and a foaming agent that expands when heated, to form a liquid ultraviolet-curable, heat-peelable resin composition.

[0015] According to another aspect of the present invention, The foaming agent has an outer shell made of a plastic resin and a low-boiling point hydrocarbon encapsulated in the outer shell.

[0016] According to another aspect of the present invention, A method for processing a plate-shaped object using the liquid ultraviolet-curable heat-peelable resin composition, comprising the steps of: A supplying step of supplying the liquid ultraviolet-curable heat-removable resin composition onto a surface of a plate-like object; a curing step of irradiating the liquid ultraviolet-curable heat-peelable resin composition with ultraviolet light to cure the composition and form a protective layer on the surface of the plate-shaped object; a cutting step of cutting the plate-shaped object on which the protective layer is formed; After carrying out the cutting step, the method for processing a plate-shaped article includes a peeling step of heating the ultraviolet-curable heat-peelable resin composition to peel off the protective layer from the plate-shaped article.

[0017] According to another aspect of the present invention, A method for processing a package substrate using a liquid ultraviolet-curable heat-peelable resin composition, comprising: the package substrate has a surface on which a plurality of division lines and electrodes crossing the division lines are formed, and recesses opening on the surface and crossing the division lines are formed in the electrodes; a supplying step of supplying the ultraviolet-curable heat-removable resin composition in liquid form onto a surface of the package substrate; a filling step of filling the concave portion with the liquid ultraviolet-curable heat-peelable resin composition by disposing the package substrate in a vacuum atmosphere after the supplying step; a curing step of curing the liquid ultraviolet-curable heat-removable resin composition by irradiating the ultraviolet ray thereto after the filling step; a cutting step of cutting the package substrate together with the ultraviolet-curable heat-peelable resin composition along the intended division line with a cutting blade after the curing step is performed; After the cutting step, the method for processing a package substrate includes a removing step of heating the ultraviolet-curable, heat-peelable resin composition to remove the ultraviolet-curable, heat-peelable resin composition from the package substrate. Effect of the Invention

[0018] According to one aspect of the present invention, by using a liquid resin composition, the recesses of a plate-like object having recesses formed on the surface can be easily filled, and the recesses can be filled with the resin composition by curing the resin composition by irradiating it with ultraviolet light while the resin composition is filled in the recesses. This prevents burrs generated by cutting the electrode portion around the recesses from extending into the space of the recesses. Furthermore, by including a foaming agent, the resin composition can be expanded by heating after processing, and the resin composition can be easily peeled off from the recesses and the surface.

[0019] Moreover, according to one aspect of the present invention, the resin composition can be used to form a protective layer on the surface of a plate-like object regardless of whether or not the surface has a recess, making it possible to realize a protective layer that is easily peeled off. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a diagram showing a package substrate as an example of a plate-like object to be processed; [Diagram 2] 1A is a diagram for explaining the supply of a resin composition, and FIG. 1B is a diagram for explaining the state of the surface of a package substrate to which the resin composition has been supplied. [Diagram 3] 1 is a flowchart showing the procedure of one embodiment of a processing method according to the present invention. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] 5A to 5C are diagrams illustrating a cutting step. [Figure 7] 4A to 4C are diagrams illustrating cut grooves formed in a package substrate covered with a resin composition. [Figure 8] FIG.

[0021] FIG. 1 shows a package substrate 1 as an example of a plate-like workpiece.

[0022] The package substrate 1 has a plurality of first planned division lines 21 extending in a first direction F1 on the surface 11a of the substrate 11 and second planned division lines 22 extending in a second direction F2 perpendicular to the first planned division lines 21, which are set in a grid pattern.

[0023] A semiconductor device chip (not shown) is mounted on the back surface 11 b of the substrate 11 in a mounting area 15 defined by the first dividing lines 21 and the second dividing lines 22 , and is sealed with a synthetic resin 16 .

[0024] On the front surface 11a side of the substrate 11, division lines 21, 22 are set between the mounting areas 15, and electrodes 30 are disposed so as to cross the division lines 21, 22.

[0025] Each electrode 30 has a groove-like recess 32 formed in the longitudinal direction of the electrode 30, and when cutting is performed along the intended division lines 21, 22, each electrode 30 and each recess 32 is divided into two.

[0026] 2(A) and (B), in the present invention, the recesses 32 of each electrode 30 are filled with a resin composition 5 to fill the spaces, thereby preventing burrs from extending into the spaces when the electrode 30 is cut. Note that the present invention can also be applied to a plate-like object in which recesses are formed in places other than the electrodes 30.

[0027] As shown in Figures 2(A) and (B), the resin composition 5 is a liquid ultraviolet-curable, heat-peelable resin composition, and contains (meth)acrylate, a photopolymerization initiator, and a foaming agent that expands when heated.

[0028] The blending ratio of each component is not particularly limited, but the foaming agent that expands upon heating can be, for example, 5% by weight to 45% by weight based on the total amount of (meth)acrylate. If the amount of foaming agent is too small, the peelability described below will be poor, and conversely, if the amount of foaming agent is too large, curing will be insufficient or the viscosity will be too high, making it difficult to apply uniformly or fill recesses.

[0029] (Meth)acrylate refers to acrylate, which is an acrylic acid compound, or methacrylate, which is a methacrylic acid compound, and (meth)acrylate refers to either (meth)acrylate having a urethane bond or (meth)acrylate not having a urethane bond, or a mixture thereof.

[0030] The (meth)acrylate having a urethane bond (urethane group) refers to one having a urethane group in the molecule. Examples include Light Acrylate IAA, AT-600, UA-306H, UA-306T, UA-306I, UA-510H, UF-8001G, DAUA-167, UF-07DF (all manufactured by Kyoeisha Chemical Co., Ltd.), R-1235, R-1220, RST-201, RST-402, R-1301, R-1304, R-1214, R- 1302XT, GX-8801A, R-1603, R-1150D, DOCR-102, DOCR-206 (all manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), UX-3204, UX-4101, UXT-6100, UX-6101, UX-7101, UX-8101, UX-0937, UXF-4001-M35, UXF-4002, DPHA-40H, UX-5000, UX-510 2D-M20, UX-5103D, UX-5005, UX-3204, UX-4101, UX-6101, UX-7101, UX-8101, UX-0937, UXF-4001-M35, UXF-4002, UXT-6100, DPHA-40H, UX-5000, UX-5102D-M20, UX-5103, UX-5005 (all manufactured by Nippon Kayaku Co., Ltd.), etc.

[0031] The (meth)acrylate having no urethane bond refers to one having no (urethane group) in the molecule. Examples include tetrahydrofurfuryl acrylate, isobornyl acrylate, phenyl glycidyl ether acrylate, 1,9-nonanediol diacrylate, etc.

[0032] The photopolymerization initiator is used to initiate photopolymerization (ultraviolet light) of the resin composition, and examples thereof include 1-hydroxycyclohexyl phenyl ketone (e.g., Irgacure (registered trademark) 184 manufactured by BASF, etc.), α-hydroxyalkylphenone (e.g., Omnirad (registered trademark) 184 manufactured by IGM Resins BV, etc.), etc.

[0033] The foaming agent that expands by heating is composed of an outer shell made of a plastic resin and a low-boiling point hydrocarbon encapsulated in the outer shell. Examples of such foaming agents include Kureha Microsphere (registered trademark) (manufactured by Kureha Corporation) and Advancell (registered trademark) EM (manufactured by Sekisui Chemical Co., Ltd.).

[0034] Next, an embodiment of the method for processing a plate-like object according to the present invention will be described. Fig. 3 is a flow chart showing the procedure of one embodiment of the processing method. Each step will be described in order below.

[0035] <Supply step> As shown in FIGS. 2(A) and 2(B), this is a step in which a liquid resin composition 5 is supplied onto the surface 11a of the substrate 11 of the package substrate 1.

[0036] 2(A), a liquid resin composition 5 is dropped from a supply nozzle 6 onto the surface 11a of the substrate 11 so that the resin composition 5 spreads over the entire surface 11a. After dropping, the resin composition 5 may be spread and applied over the entire surface 11a by a coating device (not shown). Alternatively, the resin composition may be supplied only to recesses rather than to the entire surface, so that the recesses are filled with the resin composition.

[0037] <Filling step> After the supplying step is performed, as shown in FIG. 4, the package substrate 1 is placed in a vacuum atmosphere, thereby filling the liquid resin composition 5 into the recess 32 (FIG. 2(B)).

[0038] 4, the package substrate 1 is set in a vacuum chamber 8 connected to a vacuum source 9b via a valve 9a, and a vacuum is drawn for a predetermined time to create a vacuum atmosphere in the vacuum chamber 8. At this time, as shown in FIG. 2(B), the gas remaining in the recess 32 is extracted, and the resin composition 5 is filled into the recess 32 without any gaps.

[0039] <Curing step> After the filling step, as shown in FIG. 5, the liquid resin composition 5 is irradiated with ultraviolet light to harden it.

[0040] 5, ultraviolet light is irradiated from a light source 14 constituted by an ultraviolet lamp or the like onto the front surface side of the package substrate 1 for a predetermined period of time to cure the resin composition 5. As the resin composition 5 cures, a protective layer 50 is formed on the front surface side of the package substrate 1. The thickness of the protective layer 50 is preferably set to, for example, about 200 μm, which is a sufficient thickness so that the protective layer 50 does not peel off during the cutting step.

[0041] <Cutting step> After the curing step is performed, as shown in FIG. 6, the package substrate is cut together with the resin composition 5 (protective layer 50) by a cutting blade 60 along the intended division lines 21 and 22 (FIG. 1).

[0042] 6, a cutting jig 64 is placed on a holding table 62, and the package substrate 1 is held by suction on the cutting jig 64. The cutting jig 64 has an escape groove 64a formed along the planned division lines 21, 22 (FIG. 1) of the package substrate 1, and when the cutting blade 60 cuts into the package substrate 1, the cutting blade 60 fits into the escape groove 64a.

[0043] The holding table 62 is connected to a suction source 62b via a valve 62a, and by generating a negative pressure on the holding surface of the cutting jig 64, the package substrate 1 is held by suction.

[0044] During cutting, the cutting blade 60 is positioned at a predetermined cutting height and rotated at high speed, and cutting water is supplied from a nozzle (not shown) to the cutting blade 60 and the package substrate 1 while the holding table 62 is moved in the processing feed direction, thereby performing cutting along the planned division lines 21 extending in the first direction F1. Next, the holding table 62 is rotated 90 degrees, and cutting is performed along the planned division lines 22 (FIG. 1) extending in the second direction F2, thereby dividing the package substrate 1 into a plurality of chips 1C (FIG. 8).

[0045] As shown in Fig. 6, the package substrate 1 is cut together with the resin composition 5 by the cutting blade 60, and thus a cutting groove 25 is formed along the intended division line 21 as shown in Fig. 7. During this cutting, since the resin composition 5 that has filled the recess 32 without any gaps has hardened, it is possible to prevent burrs from extending toward the space that existed in the recess 32.

[0046] <Removal Step> After the cutting step, the resin composition 5 is heated to remove it from the package substrate 1, as shown in FIG.

[0047] In the example of FIG. 8, the package substrate 1 is set under the heater 80, and the resin composition 5 formed on the surface of the package substrate 1 is heated by the heater 80 for a predetermined time. When the temperature of the resin composition 5 rises, the foaming agent contained in the resin composition 5 expands. That is, the shell made of the plastic resin of the foaming agent softens, and the encapsulated low-boiling point hydrocarbon turns into gas, resulting in a foamed state, and the resin composition 5 expands as a whole, making it easy to peel off from the inner wall surface of the recess 32 and the surface of each chip 1C, thereby achieving high peelability. In addition to heating using the heater 80, heating may be performed using other heating means such as a lamp, an oven, or a hot plate.

[0048] 8 shows a state in which the resin composition 5 has expanded and warped as a whole, and the resin composition 5 in this state can be easily removed by washing it off with a cleaning solution using a cleaning device (not shown). In addition, the enlarged portion of FIG. 8 shows an image in which the resin composition 5 expands and swells within the recess 32, pressing against the inner wall surface, and the bulge cannot be suppressed and rises upward, and further, the resin composition 5 warps as a whole, causing a gap between the inner wall surfaces of the recess 32 and making it easy to peel off. Note that the resin composition 5 may be removed by air blowing in addition to being washed off by washing.

[0049] By using the liquid resin composition 5 of the present invention as described above, the recess 32 can be easily filled in a plate-like object such as a package substrate 1 having a surface on which a recess 32 is formed as shown in Figs. 2(A)(B), and the recess 32 can be filled with the resin composition 5 by curing the resin composition 5 by irradiating it with ultraviolet light while the resin composition 5 is filled in the recess 32. This makes it possible to prevent burrs generated by contacting the electrodes 30 around the recess 32 from extending into the space of the recess 32. Furthermore, by including a foaming agent as shown in Fig. 8, the resin composition 5 can be expanded by heating after processing, and the resin composition 5 can be easily peeled off from the recess 32 and the surface 11a.

[0050] In the above embodiment, the package substrate 1 is described as an example, but regardless of whether or not a recess is present, by supplying a resin composition to the surface of a plate-like object to form a protective layer, the protective layer can be easily peeled off and removed after necessary processing, and the resin composition can be prevented from remaining as a foreign matter. This protective layer is formed, for example, for the purpose of protecting a device formed on the surface of a semiconductor wafer.

[0051] In this case, the processing method includes a supplying step of supplying a liquid resin composition onto the surface of the plate-like object, a curing step of irradiating the liquid resin composition with ultraviolet light to harden it and form a protective layer on the surface of the plate-like object, a cutting step of cutting the plate-like object on which the protective layer has been formed, and a peeling step of heating the resin composition to peel the protective layer from the plate-like object after the cutting step is performed, and in this case, the filling step by vacuum suction described above is omitted.

[0052] 1 Package substrate 1C chip 5 Resin composition 6 Supply Nozzle 8. Vacuum Chamber 9a Valve 9b Vacuum source 11 Substrate 11a surface 11b Back side 14 Light source 15 Mounting area 16 Synthetic Resins 21 Division line 22 Division line 25 Cutting groove 30 electrodes 32 Recess 50 protective layer 60 Cutting Blade 62 Holding Table 64 Cutting jig 80 Heater F1 direction F2 direction

Claims

1. A method for processing a plate-shaped object using a liquid ultraviolet-curable heat-peelable resin composition containing a (meth)acrylate, a photopolymerization initiator, and a foaming agent that expands upon heating, comprising: a supplying step of supplying the liquid ultraviolet-curable heat-removable resin composition onto a surface of a plate-shaped object on which a recess is to be formed; a filling step of filling the concave portion with the liquid ultraviolet-curable heat-peelable resin composition by disposing the plate-like object in a vacuum atmosphere after the supplying step; a curing step of irradiating the liquid ultraviolet-curable heat-peelable resin composition with ultraviolet light to cure the composition and form a protective layer on the surface of the plate-like object; a cutting step of cutting the plate-shaped object on which the protective layer is formed; After carrying out the cutting step, the method for processing a plate-shaped article includes a peeling step of heating the ultraviolet-curable heat-peelable resin composition to peel off the protective layer from the plate-shaped article.

2. A method for processing a plate-like object as described in claim 1, characterized in that the foaming agent has an outer shell made of a plastic resin and a low-boiling point hydrocarbon encapsulated in the outer shell.

3. A method for processing a package substrate using a liquid ultraviolet-curable heat-peelable resin composition containing a (meth)acrylate, a photopolymerization initiator, and a foaming agent that expands upon heating, comprising: the package substrate has a surface on which a plurality of division lines and electrodes crossing the division lines are formed, and recesses opening on the surface and crossing the division lines are formed in the electrodes; a supplying step of supplying the ultraviolet-curable heat-removable resin composition in liquid form onto the surface of the package substrate; a filling step of filling the concave portion with the liquid ultraviolet-curable heat-peelable resin composition by disposing the package substrate in a vacuum atmosphere after the supplying step; a curing step of curing the liquid ultraviolet-curable heat-removable resin composition by irradiating the ultraviolet ray thereto after the filling step; a cutting step of cutting the package substrate together with the ultraviolet-curable heat-peelable resin composition along the intended division line with a cutting blade after the curing step is performed; After carrying out the cutting step, a removing step is performed in which the ultraviolet-curable, heat-peelable resin composition is heated to remove the ultraviolet-curable, heat-peelable resin composition from the package substrate.

4. The method for processing a package substrate as described in claim 3, characterized in that the foaming agent has an outer shell made of a plastic resin and a low-boiling point hydrocarbon encapsulated in the outer shell.

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