JP2014136357A - Case for electronic equipment and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a case for electronic equipment capable of firmly integrating and improving appearance when a resin material is injection molded to an FRP plate consisting a thermoplastic resin as a parent material.SOLUTION: There is provided a case for electronic equipment 15 formed by making a prepreg thin plate 10 by coating a continuous fiber 11 with a thermoplastic resin 12, compression working the prepreg thin plate 10 with a press mold having convexoconcave on at least a part of surface to deform the continuous fiber 11 in the prepreg thin plate 10 to a rugged shape, removing the thermoplastic resin 12 by cutting work to expose the continuous fiber 11 positioning in a surface layer part of the deformed prepreg thin plate 10 to the surface layer part of the prepreg thin plate 10 with convex or concave, and laminating a resin material 14 containing a reinforced fiber 13 so that the continuous fiber 11 covers a surface of the exposed prepreg thin plate 10 with convex or concave.

Description

  The present application relates to a casing of an electronic device and a method for manufacturing the casing.

  In recent years, as small electronic devices such as mobile phones, smartphones, personal information devices (PDAs), notebook computers, car navigation devices have become thinner and smaller, the casings of these electronic devices are also thinner and lighter, In addition, a housing component having high rigidity is required.

In general, the following methods are known as methods for producing thin-walled and high-strength casing parts.
(1) Method of injection molding a fiber reinforced thermoplastic resin filled with glass fiber or carbon fiber (2) Method of pressing a rolled plate of aluminum alloy or magnesium alloy (3) Injection molding (die casting of aluminum alloy or magnesium alloy (4) Method of integrally forming a metal plate or a fiber reinforced resin (hereinafter referred to as FRP) plate by insert molding

Among these, when FRP plates are insert-molded, the FRP usually has a thermosetting resin matrix (base material), and thus it was not firmly bonded to the thermoplastic resin. For this reason, in order to integrate FRP with a thermoplastic resin, the following method has been performed.
(A) As shown in FIG. 1A, an FRP component 2 is joined to a thin plate substrate 1 made of a thermoplastic resin with a screw 3.
(B) As shown in FIG. 1B, the FRP component 2 is joined to the thin plate substrate 1 made of a thermoplastic resin using an adhesive 4.
(C) As shown in FIG. 1C, a macro in which a through hole 5 is provided in a thin plate base material 1 made of thermoplastic resin, and a molding resin 14 wraps around the back surface of the thin plate base material 1 through the through hole 5 during molding. A simple fitting structure is provided for joining. The mold resin 14 used in this method is a thermosetting FRP, and when it is hardened, it does not melt even when heat is applied.

  For this reason, a stepped shape as shown in FIG. 1 (c) occurs in the appearance of a precious thin product, or as shown in FIG. 1 (a), the screw 3 is formed on the surface of the thin plate substrate 1 made of thermoplastic resin. There were adverse effects such as exposure and damage to the appearance.

  As a method for solving this, the techniques disclosed in Patent Document 1 and Patent Document 2 are known. Each of these is a technique in which a low melting point polyamide resin serving as an adhesive is coated on the surface of the FRP base material so as to adhere and integrate with a higher melting point mold resin. By using these technologies, there is an advantage that a smarter product appearance without a step can be obtained and a stronger adhesion can be obtained.

JP 2004-269878 A

JP 2009-214371 A

  However, in the techniques disclosed in Patent Document 1 and Patent Document 2, there is a limitation that a mold resin other than a polyamide resin cannot be used due to the compatibility problem of the resin material used for the mold resin, and a resin having excellent heat resistance is used. could not. Further, the polyamide resin has problems such as a decrease in substrate rigidity due to water absorption.

  In one aspect, the present application is capable of injecting various resin materials onto a prepreg thin plate made of a thermoplastic resin as a matrix and integrally forming it, thereby realizing improved appearance, thin-walled weight and high reliability. It is an object of the present invention to provide a casing of an electronic device and a method for manufacturing the casing.

  According to one aspect of the embodiment, a prepreg thin plate in which continuous fibers are coated with a thermoplastic resin is provided, and the continuous fibers are exposed in a convex or concave form on at least one surface of the prepreg thin plate, There is provided a casing for an electronic device characterized in that a resin material containing reinforcing fibers is laminated so as to cover the surface of a prepreg thin plate exposed in a convex or concave form.

  According to another aspect of the embodiment, a continuous fiber is coated with a thermoplastic resin to make a prepreg thin plate, and the prepreg thin plate is compressed from both sides by a press die having fine irregularities at least at one place on the press surface. The prepreg thin plate is deformed into a three-dimensional shape by fine unevenness, and the continuous fibers inside the prepreg thin plate are deformed into an uneven shape, and the thermoplastic resin located in the surface layer portion of the deformed portion of the prepreg thin plate is removed by cutting. Then, at least a part of the continuous fiber is exposed on the surface layer portion of the prepreg thin plate, and a resin material containing reinforcing fiber is laminated on the surface of the prepreg thin plate including the exposed portion of the continuous fiber to manufacture a casing of the electronic device. A method is provided.

(A) is a cross-sectional view showing a state in which an FRP component is joined to a thin plate base material made of a thermoplastic resin with a screw, and (b) is an FRP component made of an adhesive on a thin plate base material made of a thermoplastic resin. (C) is a macro mating structure in which a through hole is provided in a thin plate base material, and a mold resin wraps around the back surface of the thin plate base material through the through hole during molding. FIG. (A) is a cross-sectional view of a prepreg thin plate in which one layer of continuous fibers is coated with a thermoplastic resin, (b) is a cross-sectional view of a prepreg thin plate in which two layers of continuous fibers are coated with a thermoplastic resin, and (c) is a three-layered view. It is sectional drawing of the prepreg thin plate which coated the continuous fiber with the thermoplastic resin. (A) is a figure which shows the process of putting the prepreg thin plate shown in FIG. 2 (a) into a press die and pressing it, (b) is a die when the press die shown in (a) is closed. (C) is a partially enlarged cross-sectional view showing the state of the prepreg thin plate when pressed by a press die from the state of (b), and (d) is (a). The partial expanded sectional view of the D part vicinity of a metal mold | die when the press metal mold | die shown was closed, (e) is a state of the prepreg thin plate when a press mold is performed from the state of (d). (F) is a partially enlarged sectional view in the vicinity of the F portion when the press die shown in (a) is closed, and (g) is pressed by the press die from the state of (f). It is a partial expanded sectional view which shows the state of a prepreg thin plate when is performed. (A) is a partially enlarged cross-sectional view showing the deformation of continuous fibers formed by part B of the press die when the prepreg thin plate shown in FIG. 2 (b) is put into a press die and pressed. FIG. 2B is a partially enlarged cross-sectional view showing the deformation of the continuous fiber formed by the F portion of the press die when the prepreg thin plate shown in FIG. 2B is put into the press die and pressed. 2) A partially enlarged cross-sectional view showing deformation of a continuous fiber formed by another part of the press mold when the prepreg thin plate shown in FIG. When the prepreg thin plate is put into a press die and pressed into a bathtub shape, a partial enlarged cross-sectional view showing an example in which the deformation of the continuous fiber is provided on the outer surface of the prepreg thin plate by a slide die, (e) is before deformation Partial enlarged sectional view of continuous fiber, (f) Is a partially enlarged cross-sectional view of the continuous fibers after deformation by less. (A) is a perspective view which shows the process of the laser cutting which deletes a thermoplastic resin partially from the surface of the prepreg thin plate after a press, (b) to (d) is in the prepreg thin plate shown in FIG.4 (b). It is a partial expanded sectional view of the prepreg thin board which shows the example of a cutting when the deformation | transformation part of a continuous fiber is laser-cut. (A) is explanatory drawing which shows the process of laminating | stacking the resin material containing a reinforced fiber on one surface of a prepreg thin plate by insert molding by installing the prepreg thin plate from which surface layer resin was removed partially in a mold die, b) Partial enlargement explaining the behavior of the resin material containing reinforcing fibers in the mold when the resin material containing reinforcing fibers is injected into the mold dies on the prepreg thin plate from which the surface layer resin has been partially removed Sectional drawing, (c) is a partially enlarged sectional view for explaining the behavior of a resin material containing reinforcing fibers in a mold when a resin material containing reinforcing fibers is injected into a conventional prepreg thin plate. is there. It is explanatory drawing which shows the process of laminating | stacking the resin material containing a reinforced fiber by transfer molding to the prepreg thin plate from which surface layer resin was partially removed. It is explanatory drawing which shows the process of laminating | stacking the resin material containing a reinforced fiber by vacuum forming on the prepreg thin plate from which surface layer resin was partially removed. It is explanatory drawing which shows the process of laminating | stacking the resin material containing a reinforced fiber by blow molding on the prepreg thin board from which surface layer resin was partially removed. It is a perspective view which shows the housing | casing of the electronic device made by laminating | stacking the resin material containing a reinforced fiber on the prepreg thin plate from which surface layer resin was partially removed. (A) is the elements on larger scale of the X section of FIG. 10, (b) is the elements on larger scale of the Y section of FIG. 10, (c) is the elements on larger scale of the Z section of FIG.

  Hereinafter, embodiments of the present application will be described in detail based on specific examples with reference to the accompanying drawings.

  FIG. 2A is a cross-sectional view of a thin plate 10 of a fiber reinforced resin obtained by coating a single layer of continuous fiber 11 with a thermoplastic resin 12. Such a thin plate 10 of fiber reinforced resin is called a thermoplastic prepreg. The layer of the continuous fiber 11 to be coated with the thermoplastic resin 12 is not limited to one layer, and the number of layers can be increased according to the strength required for the thin plate 10 of fiber reinforced resin. FIG. 2 (b) shows a thin plate 10 of fiber reinforced resin in which two layers of continuous fibers 11 are coated with a thermoplastic resin 12, and FIG. 2 (c) shows three layers of continuous fibers 11 formed of a thermoplastic resin. 1 shows a thin plate 10 of fiber reinforced resin coated with 12. Hereinafter, the fiber-reinforced resin sheet 10 is referred to as a prepreg sheet 10.

  In the present application, the continuous fiber 11 incorporated in the prepreg thin plate 10 shown in FIGS. 2A to 2C and the like is deformed using a press die. This process will be described with reference to FIG. 3 in the case of using the prepreg thin plate 10 in which the single-layer continuous fiber 11 shown in FIG. 2A is coated with the thermoplastic resin 12.

  FIG. 3A shows a process of pressing the prepreg thin plate 10 shown in FIG. The press mold 20 includes a male mold 21 and a female mold 22, and the prepreg thin plate 10 is placed in a recess 24 of the female mold 22. The male die 21 of the press die 20 is provided with a convex portion 23 to be inserted into the concave portion 24. And the convex part 23 of the male die 21 and the B part, D part and F part of the concave part 24 of the female die 22 are concave parts 25 for deforming the continuous fibers 11 in the prepreg thin plate 10 into a three-dimensional shape. 26 and 27 are provided.

  FIG. 3B is a partially enlarged view of the vicinity of portion B of the press die 20 when the press die 20 shown in FIG. 3A is closed. In the state shown in FIG. 3B, no pressure is applied between the male die 21 and the female die 22 of the press die 20. When pressure is applied between the male mold 21 and the female mold 22, the thermoplastic resin 12 enters the recess 25, and the continuous fiber 11 also enters the recess 25 due to the movement of the thermoplastic resin 12. And if the depth of the recessed part 25 is enlarged, the continuous fiber 11 will fracture | rupture in the process which enters into the recessed part 25, and will be in the state shown in FIG.3 (c). Data on whether or not the dimensions and depth of the recesses and whether the continuous fiber breaks during pressing will be described later.

  FIG. 3D shows a partially enlarged view of the vicinity of the D portion of the press die 20 when the press die 20 shown in FIG. 3A is closed. In the state shown in FIG. 3D, no pressure is applied between the male die 21 and the female die 22 of the press die 20. When pressure is applied between the male mold 21 and the female mold 22, the thermoplastic resin 12 enters the recess 26, and the continuous fiber 11 also enters the recess 26 due to the movement of the thermoplastic resin 12. Since the depth of the concave portion 26 is not so large, the continuous fiber 11 is not broken in the process of entering the concave portion 26 and is in a depressed state (a state deformed into a three-dimensional shape) as shown in FIG. .

  FIG. 3 (f) shows a partially enlarged view of the vicinity of the F portion of the press die 20 when the press die 20 shown in FIG. 3 (a) is closed. In the state shown in FIG. 3 (f), no pressure is applied between the male die 21 and the female die 22 of the press die 20. When pressure is applied between the male mold 21 and the female mold 22, the thermoplastic resin 12 enters the recess 27, and the continuous fiber 11 also enters the recess 27 due to the movement of the thermoplastic resin 12. Since the depth of the concave portion 27 is not so large, the continuous fiber 11 is not broken in the process of entering the concave portion 27 and is in a depressed state as shown in FIG.

  FIG. 4A shows the prepreg thin plate 10 corresponding to the portion B of the press die 20 after the prepreg thin plate 10 shown in FIG. 2B is placed in the press die 20 and pressed. is there. In the prepreg thin plate 10 shown in this embodiment, the first-layer continuous fibers 11 are broken and deformed, but the second-layer continuous fibers 11 are not deformed. Only the first-layer continuous fibers 11 can be deformed in this way depending on the size of the recesses provided in the press die 20.

  FIG. 4B shows the prepreg thin plate 10 at a portion corresponding to the F portion of the press die 20 after the prepreg thin plate 10 shown in FIG. 2B is put in the press die 20 and pressed. is there. Although the prepreg thin plate 10 shown in this embodiment is deformed so that the first-layer continuous fibers 11 are convex upward, the second-layer continuous fibers 11 are not deformed. Only the first-layer continuous fibers 11 can be deformed in this way depending on the size of the recesses provided in the press die 20.

  FIG. 4C shows the prepreg thin plate 10 corresponding to the F portion of the press die 20 after the prepreg thin plate 10 shown in FIG. 2B is placed in the press die 20 and pressed. It is. The prepreg thin plate 10 shown in this embodiment is deformed so that the first-layer continuous fibers 11 have a convex dome shape on the upper side, but the second-layer continuous fibers 11 are not deformed. Depending on the size of the recess provided in the press die 20, only the first-layer continuous fiber 11 can be deformed into a dome shape.

  4 (d) shows the prepreg thin plate 10 shown in FIG. 2 (b) formed into a bathtub shape by the shape of the press die 20 and a prepreg by a slide die (not shown) provided in the press die 20. This is an example in which a deformed portion of the continuous fiber 11 is provided on the outer surface of the thin plate 10. As described above, the portion where the continuous fiber 11 is deformed by the press mold 20 can be provided on either the upper or lower side of the prepreg thin plate 10. When the prepreg thin plate 10 is formed in a bathtub shape, the outer surface of the prepreg thin plate 10 is provided. Can also be provided.

  FIG. 4 (e) shows a state before deformation of the continuous fiber 11 incorporated in the prepreg thin plate 10. The continuous fiber 11 includes warp and weft. The continuous fiber 11 is knitted by the warp and weft so that there is almost no gap between the yarns. FIG. 4 (f) shows the warp and weft states of the continuous fiber 11 after the continuous fiber 11 is deformed by the press die 20. When the continuous fiber 11 is deformed by the press die 20, a gap S is formed between the yarns as shown in FIG. Therefore, if the thermoplastic resin 12 on the surface layer where the continuous fiber 11 is deformed is removed to expose the continuous fiber 11, a resin material containing reinforcing fibers is laminated thereon, and the resin material becomes a gap between the continuous fibers 11. Since it enters, the bond between the continuous fiber 11 and the resin material including the reinforcing fiber is strengthened.

  As described above, the prepreg thin plate 10 is processed into the outer shape of the casing in advance, and at the same time, a fine uneven shape is imparted to the continuous fibers 11 where the mold resin is laminated later. As a result, the area of the joint portion between the mold resin and the continuous fiber 11 is increased, and the bonding force due to the anchor effect is improved.

  In order to remove the thermoplastic resin 12 on the surface layer of the part where the continuous fiber 11 is deformed, a method of cutting with a grinder or the like, or a method of laser cutting using laser light from the laser device 30 as shown in FIG. There is. Since the laser device 30 can be moved according to the position of the concave portion provided in the press die 20, it is possible to accurately remove the thermoplastic resin 12 on the surface layer of the portion where the continuous fiber 11 is deformed. .

  If this laser device 30 is used, it is possible to delete the thermoplastic resin 12 on the surface layer where the continuous fiber 11 is deformed into various shapes. FIG. 5B shows an embodiment in which all of the thermoplastic resin 12 located above the portion T of the prepreg thin plate 10 shown in FIG. 4B deformed into a convex shape of the continuous fiber 11 is removed. FIG. 5C shows a predetermined state by partially removing the thermoplastic resin 12 located above the portion T of the prepreg thin plate 10 shown in FIG. An example in which a pattern is formed is shown. Further, FIG. 5 (d) shows a partial removal of the thermoplastic resin 12 located at the top of the top surface of the convex portion T of the continuous fiber 11 in the prepreg thin plate 10 shown in FIG. 4 (b). An embodiment in which the wall portion W is formed around the exposed portion while being exposed is shown.

  FIG. 6A shows that the prepreg thin plate 10 from which the thermoplastic resin 12 on the surface layer of the deformed portion of the continuous fiber 11 is partially removed is placed in the mold 40 and the reinforced fiber is injected by the injection molding machine 50. The insert molding which injects the resin material containing is demonstrated. The mold die 40 includes a male die 41, a female die 42, a convex portion 43 provided with a resin flow path 45, a concave portion 44 for setting the prepreg thin plate 10, and a resin material containing reinforcing fibers inside the prepreg thin plate 10. There is a cavity 46 for laminating. The cavity 46 is provided corresponding to a flat part, a boss part, and a rib part formed inside the prepreg thin plate 10.

  FIG. 6B shows the reinforcement in the mold 40 when the mold resin 14 containing the reinforcing fibers 13 is injected into the mold prep 40 to the prepreg thin plate 10 from which the thermoplastic resin 12 in the surface layer has been partially removed. The behavior of the mold resin 14 including the fibers 13 will be described. When the mold resin 14 including the reinforcing fiber 13 flowing into the cavity 46 in the mold 40 reaches the deformed portion of the continuous fiber 11, the mold resin 14 is entangled with the deformed portion of the continuous fiber 11 and firmly bonded as described above.

  That is, when the prepreg thin plate 10 and the mold resin 14 are joined, the mold resin 14 impregnates the gap S (see FIG. 4F) between the continuous fibers 11 from which the surface layer resin (thermoplastic resin 12) has been removed. At the same time, the reinforcing fibers 13 in the mold resin 14 enter the gaps S between the continuous fibers 11 to obtain strong adhesion. If a resin having high heat resistance is used for the matrix of the prepreg thin plate 10, an anchor effect can be imparted by allowing a part to remain on the surface of the prepreg thin plate 10. For this reason, the combination of the prepreg thin plate 10 and the mold resin 14 is not limited as in the prior art.

  On the other hand, as shown in FIG. 6C, the prepreg thin plate 10 in which the continuous fiber 11 is only exposed by removing a part of the thermoplastic resin 12 has a gap S between the exposed continuous fibers 11. There is no. Therefore, even when the mold resin 14 including the reinforcing fibers 13 is injected into the mold 40, the mold resin 14 including the reinforcing fibers 13 is not firmly bonded to the continuous fibers 11. As a result, the mold resin 14 including the reinforcing fibers 13 is easily peeled off from the prepreg thin plate 10.

  There is a method of laminating the mold resin 14 including the reinforcing fibers 13 on the prepreg thin plate 10 from which the thermoplastic resin 12 on the surface layer of the deformed portion of the continuous fiber 11 is partially removed, in addition to the above-described insert molding. For example, transfer molding, vacuum molding, blow molding, or the like can be performed instead of insert molding.

  FIG. 7 shows a step of laminating a resin material containing reinforcing fibers by transfer molding on the prepreg thin plate 10 from which the surface layer resin has been partially removed. In the transfer molding, the prepreg thin plate 10 with exposed fibers is placed in the concave portion 54 of the female mold 52 and the molten resin is put into the mold through the resin flow path 55 in the state where the male mold 51 is attached, as in the injection molding. 56 is transferred to the cavity and cured. Reference numeral 53 denotes a convex portion of the male mold 51. Compared to injection molding, transfer molding is not as easy as burr treatment is essential, but it can mold a reinforced layer or additional parts using a thermosetting resin.

  FIG. 8 shows a vacuum forming machine 60 for laminating a resin material containing reinforcing fibers by vacuum forming on the prepreg thin plate 10 from which the surface layer resin has been partially removed. In vacuum forming (pressure air forming), the prepreg thin plate 10 in which fibers are exposed is first fitted into a recess 63 in a forming table 62 provided with an exhaust passage 61. A resin sheet 64 made of a resin material containing reinforcing fibers is placed thereon. A cover 65 is airtightly attached to the molding table 62 on the molding table 62. The cover 65 has an internal space 66, and a heater 67 is installed in the internal space 66 so as to face the seat 64. When the resin sheet 64 is heated by the heater 67 and the resin sheet 64 is softened, the exhaust passage 61 is connected to decompression means (not shown), and the resin sheet 64 is pressed against and integrated with the prepreg thin plate 10 by air pressure or suction. A decorative part and a thinner additional part can be formed mainly by forming a coating layer on the inner and outer surfaces of the casing or by partially transferring the coating layer.

  Furthermore, FIG. 9 shows a blow molding machine 70 for laminating a resin material containing reinforcing fibers by blow molding on the prepreg thin plate 10 from which the surface layer resin has been partially removed. The blow molding machine 70 includes an upper mold 71 and a lower mold 72, and the prepreg thin plate 10 finished in a hollow shape is fitted into an internal space 73 between the upper mold 71 and the lower mold 72. Then, a resin sheet is inserted as a parison 74 into the hollow prepreg thin plate 10, and high-pressure hot air is blown from the blowing port 75 to blow the parison 74. By blowing, the parison 74 swells and is pressed against the inner peripheral surface of the prepreg thin plate 10 to be integrated. In blow molding, a seamless coating layer is formed on the hollow part.

  FIG. 10 shows a casing 15 of an electronic device made by laminating a resin material containing reinforcing fibers on a prepreg thin plate 10 from which a surface layer resin has been partially removed. A casing 15 of the electronic device has a bathtub shape, and a boss 16 and a rib 17 are formed inside. 11A is a partially enlarged cross-sectional view of the X portion of FIG. 10, FIG. 10B is a partially enlarged cross-sectional view of the Y portion of FIG. 10, and FIG. 10C is a partially enlarged view of the Z portion of FIG. A cross-sectional view is shown. From these figures, it can be seen that the mold resin 14 including the reinforcing fiber 13 is firmly bonded to the deformed portion of the continuous fiber 11.

  Here, a specific implementation example of the embodiment described above will be described. Carbon fiber (CF) can be used for the continuous fiber 11, and for example, a plain woven CF cloth with t = 0.2 mm is used. As the thermoplastic resin 12, a polyetherimide (PEI) film with t = 0.25 mm can be used as a matrix resin. Then, when the two-layer continuous fiber (carbon fiber sheet) 11 shown in FIG. 2B is coated with the three-layer thermoplastic resin 12 to produce the prepreg thin plate 10, a size of 70 mm × 100 mm, t = 0.6 mm. Prepreg thin plate 10 was obtained.

  A small press machine was used as the press die 20, and the processing conditions were a heating temperature of 280 ° C. and a gauge pressure of 15 MPa. Further, the casing 15 of the bathtub-shaped electronic device shown in FIG. 10 has a bottom surface of 50 × 90 mm and the height of the side wall is 5 mm. The boss 16 provided inside was 1 mm in diameter and 1 mm in height, and the rib 17 was 1 mm in width, 40 mm in length and 2 mm in height.

  The shape of the recess processed into the male mold or female mold of the press mold was a circular hole with a circular cross section or a square hole with a rectangular cross section. By changing the diameter and depth of the circular hole and the length and depth of the square hole, the continuous fiber could be deformed without breaking, or it could be broken and deformed. The data of the size of a circular hole and a square hole, and the presence or absence of the fracture | rupture of continuous fiber are shown below. There is no limitation on the size of the unevenness provided in the male die or female die of the press die, but if the unevenness is about 0.5 mm to 1 mm in height, glass is used even if the continuous fiber 11 is carbon fiber. Even fibers are not broken.

(1) Circular hole 10 mm in diameter 0.5 mm in depth: no break in continuous fiber 10 mm in diameter 1.0 mm in depth: no break in continuous fiber 10 mm in diameter 1.5 mm in depth: with break in continuous fiber 1 mm in diameter Depth 0.5 mm: No break in continuous fiber Diameter 1 mm and depth 1.0 mm: Break in continuous fiber (2) Square hole 2 mm x 5 mm, depth 0.5 mm: No break in continuous fiber 2 mm x 5 mm deep Length 1.0 mm: No break in continuous fiber 2 mm x 5 mm and depth 1.5 mm: Break in continuous fiber 0.5 mm x 5 mm and depth 0.5 mm: No break in continuous fiber 0.5 mm x 5 mm and depth 1.0 mm: There is a break in continuous fibers

  As the laser device 30, a laser processing machine was used, the irradiation energy was 40 J, and the thermoplastic resin was removed by repeating scanning in the direction parallel to the FRP plate surface. In insert molding, polyphenylene sulfide (glass fiber 30%) was used as a molding resin in an injection molding machine, a resin temperature was 280 ° C., a mold temperature was 130 ° C., and an injection speed was 20 mm / s.

When the tensile test was performed on the formed boss part and rib part using the universal testing machine in the casing of the electronic device manufactured as described above and the casing of the electronic device having the conventional configuration, the following adhesive strength was obtained. It was confirmed.
(1) In a prepreg thin plate in which continuous fibers were simply coated with a thermoplastic resin, it was 10 kgf / cm.
(2) In the prepreg thin plate in which the continuous fibers were removed by coating the continuous fibers with the thermoplastic resin and removing the thermoplastic resin on the surface layer without performing the pressing process, it was 70 kgf / cm.
(3) In the sample in which continuous fibers were coated with a thermoplastic resin, pressed to form irregularities on the continuous fibers, and the surface resin with fine irregularities was removed, the sample was 120 kgf / cm2, and the FRP plate was broken.

  Thus, according to the present application, after compressing the prepreg thin plate with a press die, the thermoplastic resin on the surface layer where the continuous fibers of the prepreg thin plate are deformed by cutting such as laser cutting is removed, and the continuous fiber layer is removed. The housing of the electronic device is manufactured by insert molding in the exposed state. The casing of the electronic device manufactured by this process is a lightweight and thin casing of an electronic device excellent in design, in which the prepreg thin plate and the mold resin are firmly integrated.

  The present application has been described in detail with particular reference to preferred embodiments thereof. For easy understanding of the present application, specific forms of the present application are appended below.

(Supplementary note 1) A prepreg thin plate with continuous fibers coated with a thermoplastic resin is used as a matrix
The continuous fiber is exposed in a convex or concave form on at least one surface of the prepreg thin plate,
A housing for an electronic device, wherein a resin material containing reinforcing fibers is laminated so as to cover a surface of the prepreg thin plate in which the continuous fibers are exposed in a convex or concave shape.
(Additional remark 2) The convex form of the said continuous fiber is a form where the said continuous fiber was fractured | ruptured and bent, The housing | casing of the electronic device of Additional remark 1 characterized by the above-mentioned.
(Additional remark 3) The convex form of the said continuous fiber is a form in which the said continuous fiber rose to the trapezoid shape, The housing | casing of the electronic device of Additional remark 1 characterized by the above-mentioned.
(Additional remark 4) The convex form of the said continuous fiber is a form which the said continuous fiber raised in the dome shape, The housing | casing of the electronic device of Additional remark 1 characterized by the above-mentioned.
(Supplementary note 5) The electronic device casing according to any one of Supplementary notes 1 to 4, wherein the prepreg thin plate is formed by coating the thermoplastic resin on a plurality of continuous fibers. .

(Appendix 6) A prepreg sheet is made by coating continuous fibers with a thermoplastic resin.
Compress the prepreg thin plate from both sides with a press die having fine irregularities at least at one place on the press surface,
During the compression, the prepreg thin plate is deformed into a three-dimensional shape by the fine unevenness, and the continuous fibers in the prepreg thin plate are deformed into an uneven shape,
Removing the thermoplastic resin located in the surface layer portion of the deformed portion of the prepreg thin plate by cutting, exposing at least a part of the continuous fiber to the surface layer portion of the prepreg thin plate,
A method of manufacturing a casing of an electronic device by laminating a resin material containing reinforcing fibers on the surface of the prepreg thin plate including the exposed portion of the continuous fibers.
(Additional remark 7) The convex form of the said continuous fiber is a form which the said continuous fiber was fractured | ruptured and bent, The manufacturing method of the housing | casing of the electronic device of Additional remark 6 characterized by the above-mentioned.
(Additional remark 8) The convex form of the said continuous fiber is a form in which the said continuous fiber rose in the trapezoid shape, The manufacturing method of the housing | casing of the electronic device of Claim 6 characterized by the above-mentioned.
(Additional remark 9) The convex form of the said continuous fiber is a form which the said continuous fiber raised in the dome shape, The manufacturing method of the housing | casing of the electronic device of Additional remark 6 characterized by the above-mentioned.
(Additional remark 10) The manufacturing method of the housing | casing of the electronic device of Additional remark 8 or 9 characterized by removing all the said thermoplastic resins located in the upper surface of the said convex continuous fiber by the said cutting process.

(Additional remark 11) The said thermoplastic resin located on the upper surface of the convex-shaped continuous fiber which rose to the trapezoid shape by said cutting is partially removed, and a predetermined pattern is formed. The manufacturing method of the housing | casing of the electronic device of description.
(Additional remark 12) The said cutting is laser cutting, The manufacturing method of the housing | casing of the electronic device in any one of Additional remark 6-11 characterized by the above-mentioned.
(Supplementary note 13) Any one of Supplementary notes 6 to 11, wherein the step of laminating the resin material containing the reinforced fiber on the fiber reinforced resin is performed by a mold accommodating the prepreg thin plate and an injection molding machine. A method for manufacturing a casing of the electronic device according to claim 1.

10 Fiber reinforced resin sheet (prepreg sheet)
11 Continuous Fiber 12 Thermoplastic Resin 13 Reinforcing Fiber 14 Resin Material (Mold Resin)
20 Press Die 25-27 Recess 30 Laser Device 40 Mold Die 50 Injection Molding Machine

Claims (5)

A prepreg thin plate in which continuous fibers are coated with a thermoplastic resin is used as a matrix.
The continuous fiber is exposed in a convex or concave form on at least one surface of the prepreg thin plate,
A housing for an electronic device, wherein a resin material containing reinforcing fibers is laminated so as to cover a surface of the prepreg thin plate in which the continuous fibers are exposed in a convex or concave shape.   The casing of the electronic device according to claim 1, wherein the convex form of the continuous fiber is a form in which the continuous fiber is broken and bent. A continuous fiber is coated with a thermoplastic resin to make a prepreg sheet,
Compress the prepreg thin plate from both sides with a press die having fine irregularities in at least one place on the press surface,
During the compression, the prepreg thin plate is deformed into a three-dimensional shape by the fine unevenness, and the continuous fibers in the prepreg thin plate are deformed into an uneven shape,
Removing the thermoplastic resin located in the surface layer portion of the deformed portion of the prepreg thin plate by cutting, exposing at least a part of the continuous fiber to the surface layer portion of the prepreg thin plate,
A method of manufacturing a casing of an electronic device by laminating a resin material containing reinforcing fibers on the surface of the prepreg thin plate including the exposed portion of the continuous fibers.   The method for manufacturing a casing of an electronic device according to claim 3, wherein the cutting is laser cutting.   5. The electronic apparatus according to claim 3, wherein the step of laminating the resin material containing the reinforcing fiber on the prepreg thin plate is performed by a mold that accommodates the prepreg thin plate and an injection molding machine. Manufacturing method of the housing.

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