JP5990969B2 - Work stripping apparatus and stripping method - Google Patents

Description

  The present invention relates to a workpiece peeling apparatus and a peeling method, and more particularly to an apparatus and a peeling method for peeling a substrate bonded by a thermal foam sheet.

  A multilayer substrate is widely used as a mounting substrate for electronic circuits (see, for example, Patent Document 1). A multilayer board is a printed wiring board formed by alternately laminating insulating layers and wiring layers. By having wiring layers not only on the front and back surfaces of the board but also on the inner layer, the wiring density is increased, and as a result High-density mounting is possible.

  In recent years, with the reduction in height of electronic devices, multilayer boards are also required to be thin. However, if the multilayer substrate is made thinner, handling becomes difficult, and it is difficult to withstand stress during processing due to insufficient strength. Therefore, in the manufacture of a thin multilayer substrate, a method is employed in which a base material is attached to a support substrate having sufficient strength and processed after ensuring the strength.

  The multilayer substrate that has been subjected to the predetermined processing is peeled off from the support substrate. However, in order to facilitate peeling, a thermal foam sheet is preferably used for bonding the support substrate and the multilayer substrate (see Patent Document 2). Conventionally, when a multilayer substrate is peeled off from a support substrate, a work made of the multilayer substrate formed on the support substrate is set in a thermostatic bath, and then heated to 200 ° C. or more, which is the foaming temperature of the thermal foam sheet. The two were separated.

JP 2007-188986 A JP 2009-40930 A

  However, it is difficult to control the inside of the bath to a uniform temperature in the thermostatic bath, which causes temperature unevenness in the substrate surface, and the thermally foamed sheet does not foam uniformly, and the multilayer substrate that is the adherend is uniform. May not be peeled off. Further, warpage occurred in the multilayer substrate after peeling due to the difference in linear expansion coefficient between the front and back surfaces of the multilayer substrate.

  The present invention has been made to solve such problems, and the object of the present invention is to provide an in-plane thermal foam sheet when peeling a multilayer substrate attached via a thermal foam sheet from a support substrate. It is an object of the present invention to provide a workpiece peeling apparatus and a peeling method capable of uniformly heating and preventing warpage of a multilayer substrate after peeling.

  In order to solve the above-described problem, a workpiece peeling apparatus according to the present invention heat-treats a workpiece including a first substrate and a second substrate bonded to each other via a thermally foamed sheet, thereby causing the second substrate to move from the first substrate. A suction plate for sucking and holding the workpiece, a heating table for heating the workpiece, and a heating table having a suction means for sucking the workpiece. The first main surface on the first substrate side is sucked and held and conveyed onto the heating table, and the workpiece is placed on the heating table while the suction surface of the suction plate is in contact with the workpiece. The second main surface of the second substrate side is heated and heated on the heating table, whereby the adhesive force of the thermal foam sheet is reduced or disappears, and is also adsorbed from the heating table side. The workpiece lift adsorbed and held a that characterized by peeling the second substrate from the workpiece.

  The workpiece peeling method according to the present invention is a method of peeling the second substrate from the first substrate by heat-treating a workpiece including the first and second substrates bonded to each other via a thermal foam sheet. A step of sucking and holding the main surface of the work on the first substrate side by a suction plate, transporting the work onto the heating table, and bringing the suction surface by the suction plate to the main surface of the work While heating the work on the heating table in a contacted state, reducing or extinguishing the adhesive force of the thermal foam sheet, while adsorbing and holding both surfaces of the work heated on the heating table And a step of lifting the suction plate and peeling the second substrate from the workpiece.

  When the first substrate attached via the thermal foam sheet is peeled from the second substrate, the thermal foam sheet can be uniformly foamed and separated from the second substrate side in the plane. In addition, since the plane is regulated by the suction plate at the time of heating and immediately after cooling, the occurrence of warpage due to cooling can be suppressed.

  It is preferable that the apparatus further includes a cooling table for cooling the work, and the suction plate transports and places the work, which is heated on the heating table and the second substrate is peeled, to the cooling table. The work from which the second substrate has been peeled is transported and placed on a cooling table and cooled on the cooling table, so that it can be cooled on the cooling table even after being separated from the suction plate. Accordingly, warpage of the first substrate after peeling can be prevented.

  The cooling table preferably has a water cooling structure. According to this structure, the 1st board | substrate after peeling can be cooled efficiently, and, thereby, the curvature after peeling can be prevented reliably.

  The suction plate preferably transports the workpiece onto the heating table while holding the workpiece on the cooling table. According to this configuration, a cooling table used for cooling after separation can be used as a preparation table. Also, since the temperature of the cooling table is relatively stable due to water cooling, by placing the work on the cooling table first, the temperature of the work at the start of the process can be made constant, the heating temperature and The heating time can be made constant.

  The heating table preferably sucks the workpiece with a suction force weaker than that of the suction plate. According to this configuration, the first substrate and the second substrate can be reliably separated by the suction force from both the upper and lower sides while preventing the suction by the suction plate from deviating.

  Preferably, the first substrate is a multilayer substrate, and the second substrate is a metal support substrate. The thin multilayer substrate is processed while mounted on a metal support substrate, and after the processing is peeled off from the support substrate, the workpiece peeling device according to the present invention is used to prevent the multilayer substrate from warping. On the other hand, the thermally foamed sheet can be uniformly heated in the plane to be separated by foaming.

  The multilayer substrate is formed by alternately laminating insulating layers and wiring layers, and the insulating layer comprises at least a core substrate in which a core material is impregnated with a resin and a resin layer laminated on the core substrate. It is preferable to include one build-up layer. Since such a multilayer substrate has different linear expansion coefficients on the front and back surfaces, the substrate warps during heating. However, by using the workpiece peeling apparatus according to the present invention, it is possible to uniformly heat and thermally foam the thermally foamed sheet in the plane while preventing warping of the multilayer substrate.

  According to the present invention, when the work including the first and second substrates bonded to each other via the thermal foam sheet is heat-treated to peel the second substrate from the first substrate, the thermal foam sheet is in-plane. It is possible to provide a workpiece peeling apparatus and a peeling method capable of uniformly heating and preventing warping of the substrate after peeling.

FIG. 1 is a schematic cross-sectional view showing the structure of a workpiece that is a processing target of a workpiece peeling apparatus according to a preferred embodiment of the present invention. FIG. 2 is a schematic diagram showing a configuration of a workpiece peeling apparatus according to a preferred embodiment of the present invention. FIG. 3 is a schematic diagram for explaining a peeling process of the workpiece 1. FIG. 4 is a schematic diagram for explaining the peeling process of the workpiece 1. FIG. 5 is a flowchart showing a peeling process of the workpiece 1.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic cross-sectional view showing the structure of a workpiece that is a processing target of the workpiece peeling apparatus according to the present embodiment.

  As shown in FIG. 1, the workpiece 1 is obtained by attaching a multilayer substrate 3 on a support substrate 2. A thermal foam sheet 7 is used for bonding the support substrate 2 and the multilayer substrate 3. The material of the support substrate 2 is not particularly limited, but a metal plate such as nickel or stainless steel can be used. The thickness of the support substrate 2 is not particularly limited as long as necessary mechanical strength is ensured, but may be set to about 50 to 2000 μm, for example.

  The multilayer board 3 is a printed wiring board formed by alternately laminating insulating layers 4 and wiring layers 5. The multilayer substrate 3 is provided with through-hole electrodes 6 that penetrate the insulating layer 4 and electrically connect the upper and lower wiring layers. Chip components such as chip capacitors and semiconductor IC chips may be surface-mounted on the multilayer substrate 3. A semiconductor IC chip may be embedded in the multilayer substrate 3.

  The multilayer substrate 3 according to the present embodiment is a substrate manufactured by a so-called buildup method, and includes a core substrate 4a and a buildup layer 4b. The core substrate 4a is obtained by forming a conductor layer on the front and back surfaces of a core material (glass epoxy substrate) formed by, for example, impregnating a glass cloth with an epoxy resin. The build-up layer 4b can be formed by patterning the conductive layer after laminating a laminated sheet of an uncured or semi-cured thermosetting resin layer and the conductive layer on the core substrate 4a. .

  In order to cope with a reduction in the height of the electronic device, the multilayer substrate 3 according to the present embodiment is very thin, for example, has a thickness of 1 mm or less. In order to make the multilayer substrate 3 thinner, it is necessary to make the core substrate 4a thinner. However, if the core substrate 4a is thinned, the substrate strength for practical use cannot be ensured, and it becomes difficult to form the through-hole electrode 6 and the buildup layer 4b. Further, in an aggregate substrate that acquires a large number of substrates from one large substrate, the area in the plane direction is larger than the thickness of the aggregate substrate, the substrate strength is greatly insufficient, and handling in manufacturing becomes very difficult. Therefore, in manufacturing the thin multilayer substrate 3, a method is adopted in which the core substrate 4 a is attached to the support substrate 2 to be reinforced and processing is performed, and the support substrate 2 is removed after the multilayer substrate 3 is completed.

  As described above, the multilayer substrate 3 and the support substrate 2 are bonded to each other via the thermal foam sheet 7. Although not particularly limited, the thermal foam sheet 7 is a heat-peelable pressure-sensitive adhesive sheet including a heat-expandable pressure-sensitive adhesive layer having heat-expandable microspheres. Specific examples include trade names “Riva Alpha” and “River Clean” manufactured by Nitto Denko Corporation. Since the adhesive strength of the thermally foamed sheet decreases or disappears by heating, the adherend can be easily peeled off. Hereinafter, a method for peeling the support substrate from the multilayer substrate of the workpiece 1 will be described in detail.

  FIG. 2 is a schematic diagram showing a configuration of a workpiece peeling apparatus according to a preferred embodiment of the present invention.

  As shown in FIG. 2, the workpiece peeling apparatus 10 includes a suction plate 11 that sucks and holds the workpiece 1, a heating table 12 that heats the workpiece 1, and a cooling table 13 that cools the workpiece 1.

  The suction plate 11 has a suction surface 11a that comes into contact with the main surface of the work 1, and the suction surface 11a is provided with a large number of small air holes 11b. The vent hole 11b is connected to the vacuum device 11c. By bringing the work 1 into contact with the suction surface 11 a and sucking it from the vent hole 11 b, the entire surface of the work 1 is sucked and held by the suction plate 11. Although not particularly limited, the diameter of the vent hole 11b is preferably 0.8 to 1.0 mm.

  The suction surface 11 a of the suction plate 11 is preferably wider than the main surface of the workpiece 1. According to this configuration, the entire surface of the work 1 can be brought into contact with the suction surface 11a. Therefore, the in-plane surface of the workpiece 1 can be uniformly corrected in a thermal peeling process described later, and thus the warpage of the workpiece 1 can be reliably suppressed.

  The suction plate 11 is driven by the transport mechanism 14 and moves between the cooling table 13 and the heating table 12. Although not particularly limited, the transport mechanism 14 includes a cylinder mechanism that drives in the vertical direction and the horizontal direction. The cylinder output is adjusted by a regulator, and the speed is adjusted by a speed controller.

  The heating table 12 has a heating means. The temperature of the heating table 12 should just be heated to the temperature which can make the thermal foam sheet of the workpiece | work 1 into a peeling state, and is 300 degrees C or less normally. Although not particularly limited, it is preferable to use a cartridge heater as the heat source. The temperature of the heating table 12 is controlled by a temperature adjustment function.

  Further, the heating table 12 has a suction means for the workpiece 1. The heating table 12 has a suction surface 12a that comes into contact with the main surface of the work 1, and the suction surface 12a is provided with a large number of small air holes 12b. The vent hole 12b is connected to the vacuum device 12c.

  When the workpiece 1 is placed, the workpiece 1 is heated by the heat from the heating table 12. Furthermore, the main surface (second main surface) of the work 1 on the support substrate 2 side is adsorbed by the suction force from the heating table 12. At this time, the heating table 12 is preferably sucked with a suction force slightly weaker than that of the suction plate 11. The support plate 2 is peeled from the work 1 by raising the suction plate 11 while holding both surfaces of the work 1 by suction and pulling the work 1 up and down. Since the multilayer substrate 3 of the workpiece 1 is separated from the interface with the thermal foam sheet 7 when the thermal foam sheet 7 reaches a predetermined separation temperature, the support substrate 2 and the multilayer substrate 3 can be easily separated.

  The cooling table 13 has a water cooling mechanism 13a and is forcibly cooled by cooling water supplied from the outside. Room temperature water may be used as the cooling water. Although the cooling table 13 is mainly used for cooling the workpiece 1 after the peeling process, in the present embodiment, the suction plate 11 is also used as a work table when the workpiece 1 before the peeling process is handled. Taking out the cooled workpiece 1 and setting the workpiece 1 on the cooling table 13 may be performed manually or automatically by a mechanical operation. The temperature of the cooling table 13 may be controlled by the temperature adjustment function, but may not be controlled. In addition, the cooling table 13 according to the present embodiment does not have a suction function, but a suction function similar to that of the heating table 12 may be provided.

  3 and 4 are schematic diagrams for explaining the peeling process of the workpiece 1. FIG. 5 is a flowchart showing the peeling process of the workpiece 1.

  As shown in FIGS. 3-5, in the peeling process of the workpiece | work 1, the workpiece | work 1 is first set on the cooling table 13 (FIG. 3 (a), step S11). At this time, the workpiece 1 is set with the main surface (first main surface) on the multilayer substrate 3 side facing upward. Further, the suction plate 11 is in a retracted position above the cooling table 13. The heating table 12 is maintained at a predetermined temperature at which the thermally foamed sheet can be peeled, but the suction operation is stopped.

  Next, the suction plate 11 is lowered to hold the work 1 by suction (FIG. 3B, step S12). And the adsorption | suction plate 11 is raised, the workpiece | work 1 is lifted and it moves to the upper direction of the heating table 12 as it is (FIG.3 (c), step S13).

  Next, the suction plate 11 is lowered to bring the workpiece 1 into contact with the heating table 12 (FIG. 3 (d), step S14). At this time, the suction plate 11 may maintain the suction holding state of the workpiece 1 or may be temporarily released, but the contact state between the workpiece 1 and the suction plate 11 is maintained. When the workpiece 1 comes into contact with the heating table 12, the workpiece 1 is heated, and the adhesiveness of the thermally foamed sheet is reduced or disappears.

  Next, the support substrate 2 is peeled from the work 1 by lifting the work plate 1 by lifting the work plate 1 while holding the work 1 from both sides of the suction plate 11 and the heating table 12 (FIG. 4A). Step S15). At this time, it is preferable to make the suction force on the heating table 12 side stronger than the suction plate 11 side. The workpiece 1 can be separated from the interface with the thermal foam sheet by the raising operation of the suction plate 11.

  Next, the work 1 is moved to the cooling table 13 side while being sucked and held by the suction plate 11 (FIG. 4B, step S16), the suction plate 11 is lowered and the work 1 is placed on the cooling table 13. (FIG. 4C, step S17). Further, the suction state of the suction plate 11 is released, and the suction plate 11 is raised and separated from the work 1 (FIG. 4 (d), step S18). The workpiece 1 is taken out after being cooled on the cooling table 13 for a certain time, and a series of peeling steps is completed.

  As described above, the workpiece peeling apparatus 10 according to the present embodiment heats the workpiece 1 in a state where the workpiece 1 is sandwiched between the suction plate 11 and the heating table 12 to make the workpiece 1 peelable, and handles both sides of the workpiece 1. Since the suction plate 11 is raised while the support substrate is peeled from the work 1, the warping of the work 1 after peeling can be regulated by the suction plate 11. Moreover, the workpiece | work 1 can be efficiently cooled by mounting the workpiece | work 1 after peeling on the water-cooling type cooling table 13, and the curvature of the workpiece | work 1 can be suppressed.

  In this embodiment, since the cooling table 13 is used as a work table when handling the workpiece 1, a dedicated work table can be omitted, and the efficiency of the equipment can be improved. Moreover, since the temperature of the cooling table is relatively stable by being cooled with water, the temperature of the work 1 at the start of the process can be made constant by placing the work on the cooling table first, and the heating table Variations in heating temperature and heating time due to can be suppressed.

  The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention, and these are also included in the scope of the present invention. Needless to say.

  For example, in the above-described embodiment, the work in which the multilayer substrate is bonded onto the support substrate by the thermal foam sheet is given as an example. However, the present invention is not limited to such a work, and the thermal foam sheet is used. The present invention can be used in various cases for separating two bonded substrates.

  Moreover, in the said embodiment, although the cooling table 13 of a water cooling structure is used, it is also possible to use the cooling table 13 without a water cooling structure. For example, a method of air cooling with a fan or the like is also possible. Although the thermal separation is performed after the work is sucked and held on the cooling table 13, the work may be sucked and held at a place other than the cooling table 13.

DESCRIPTION OF SYMBOLS 1 Work 2 Support substrate 3 Multilayer substrate 4 Insulating layer 4a Core substrate 4b Build-up layer 5 Wiring layer 6 Through-hole electrode 7 Thermal foam sheet 10 Work stripping device 11 Suction plate 11a Suction surface 11b Vent hole 11c Vacuum device 12 Heating table 12a Suction Surface 12b Ventilation hole 12c Vacuum device 13 Cooling table 13a Water cooling mechanism 14 Transport mechanism

Claims (10)

A workpiece peeling device for heat-treating a workpiece including a first substrate and a second substrate bonded to each other via a thermal foam sheet and peeling the second substrate from the first substrate,
A suction plate for sucking and holding the workpiece;
A heating table having a heating means for heating the work and a suction means for sucking the work;
The suction plate is
The first main surface of the workpiece on the first substrate side is sucked and held and conveyed onto the heating table, and the workpiece is placed on the heating table while the suction surface of the suction plate is in contact. Heating the second main surface of the workpiece on the second substrate side,
The adhesive force of the thermal foam sheet decreases or disappears by being heated on the heating table, and the workpiece that is also adsorbed from the heating table side is suction-held and lifted to lift the second from the workpiece. A workpiece peeling apparatus characterized by peeling a substrate. A cooling table for cooling the workpiece;
2. The workpiece peeling apparatus according to claim 1, wherein the suction plate conveys and places the workpiece, which is heated on the heating table and peeled off the second substrate, to the cooling table.   The workpiece peeling apparatus according to claim 2, wherein the cooling table has a water cooling structure.   4. The workpiece peeling apparatus according to claim 2, wherein the suction plate sucks and holds the workpiece on the cooling table and conveys the workpiece onto the heating table.   5. The workpiece peeling device according to claim 1, wherein the heating table sucks the workpiece with a suction force weaker than that of the suction plate.   The workpiece peeling apparatus according to any one of claims 1 to 5, wherein the first substrate is a multilayer substrate, and the second substrate is a metal support substrate. The multilayer substrate is formed by alternately laminating insulating layers and wiring layers,
The workpiece peeling apparatus according to claim 6 , wherein the insulating layer includes a core substrate in which a core material is impregnated with a resin and at least one buildup layer formed of a resin layer laminated on the core substrate. A workpiece peeling method for peeling the second substrate from the first substrate by heat-treating a workpiece including the first and second substrates bonded to each other via a thermal foam sheet,
A step of sucking and holding the main surface of the workpiece on the first substrate side by a suction plate;
Wherein transporting the workpieces on a pressurized heat table, said heated while said workpiece in a state where the suction surface by the suction plate is brought into contact with the main surface of the workpiece on the heating table, the adhesive strength of the heat-foamable sheet Reducing or extinguishing,
And a step of lifting the suction plate while sucking and holding both surfaces of the workpiece heated on the heating table and peeling the second substrate from the workpiece.   The work peeling method according to claim 8, further comprising a step of transporting and placing the work on which the second substrate has been peeled off on a cooling table and cooling the work on the cooling table.   The workpiece peeling method according to claim 9, wherein in the step of sucking and holding the workpiece by a suction plate, the workpiece is sucked and held on the cooling table and conveyed onto the heating table.

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