Three-dimensional molded insulator and method for manufacturing the three-dimensional molded insulator

Abstract

Provided are a three-dimensional molded insulator that can reduce a dead space generated between a circuit board and the three-dimensional molded insulator and enable effective use of a space in which the circuit board is accommodated, and a method for manufacturing the three-dimensional molded insulator capable of manufacturing a three-dimensional molded insulator with high shape accuracy. 【Solution means】The three-dimensional molded insulator of the present invention is a three-dimensional molded insulator that covers a component to which a voltage is applied, and is formed into a shape having a recess including a bottom portion and a wall portion provided at an end of the bottom portion, and is used in a state where a component is inserted into the recess.

Description

Technical Field

[0001] The present invention relates to a three-dimensional molded insulator and a method for manufacturing the three-dimensional molded insulator.

Background Art

[0002] Inside an electronic device, a circuit board including a substrate and various voltage-applying components provided on the substrate is housed. Around such a circuit board, a predetermined insulation distance is ensured to prevent electrical short circuits.

[0003] For example, Patent Document 1 discloses a flame-retardant resin composition obtained by blending a polycarbonate resin, a phosphate ester compound, and a fibrous substance. Further, an insulating sheet formed by sheet-molding this flame-retardant resin composition is disclosed. The insulating sheet is useful in that it can be housed in a narrow gap inside an electronic device. By disposing the insulating sheet, for example, between conductors existing around a circuit board, it becomes possible to shorten the insulation space distance.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the height (thickness) of the voltage-applying components is not constant, the thickness of the circuit board varies partially accordingly. Since the conventional insulating sheet has a flat plate shape, it is arranged according to the tallest voltage-applying component. Then, there is a problem that a large dead space is generated between the substrate and the insulating sheet (around the voltage-applying components). This dead space is one of the factors hindering the miniaturization of electronic devices.

[0006] Moreover, not limited to circuit boards, shortening the insulating space distance around voltage-applying components can contribute to the miniaturization of electronic devices.

[0007] An object of the present invention is to provide a three-dimensional molded insulator capable of reducing the dead space generated around a voltage-applying component and enabling effective utilization of the space in which the voltage-applying component is accommodated, and a method for manufacturing a three-dimensional molded insulator capable of manufacturing a three-dimensional molded insulator with high shape accuracy.

Means for Solving the Problems

[0008] Such an object is achieved by the present invention described in the following (1) to (19) as described in the present invention. (1) A three-dimensional molded insulator (excluding those having an electromagnetic wave shielding layer) to be covered on a component to which a voltage is applied, A sheet made of a thermoplastic resin as the main material a recess including a bottom portion and a wall portion provided at an end of the bottom portion, and a flat portion connected to the concave portion is formed into a shape having is a sheet molded body , One surface of the concave portion is a surface concave in the first direction, The other surface of the concave portion is a surface protruding in the first direction, and is used in a state where the component is inserted into the recess, characterized by a three-dimensional molded insulator.

[0009] (2) The three-dimensional molded insulator according to (1) above, which is used by covering a circuit board including the component and a substrate on which the component is mounted. be able to The three-dimensional molded insulator according to (1) above.

[0010] (3) The three-dimensional molded insulator according to (2) above, which has a through hole penetrating the flat portion in the thickness direction.

[0011] (4) The three-dimensional molded insulator according to (3) above, wherein the thickness of the wall portion is 20% or more and 95% or less of the thickness of the flat portion.

[0012] (5) The three-dimensional molded insulator according to (3) or (4) above, wherein the thickness of the flat portion is 0.05 mm or more and 1.00 mm or less. (6) The three-dimensional molded insulator according to any one of (1) to (4) above, containing a flame retardant.

[0014] (7) The thermoplastic resin contains an aromatic polycarbonate resin, and the three-dimensional molded insulator according to the above Any one of (1) to (4) described. (8) The three-dimensional molded insulator according to any one of (1) to (4) above, which is used so that a gap is formed between the component and the concave portion. (9) The three-dimensional molded insulator according to any one of (1) to (4) above, wherein the constituent material is a polymer alloy formed by alloying an aromatic polycarbonate resin and a compatible resin. (10) The comparative tracking index CTI of the compatible resin is 50 V or more higher than the comparative tracking index CTI of the aromatic polycarbonate resin, and the three-dimensional molded insulator according to the above (9) described. (11) The compatible resin has a molar fraction of aromatic monomers in all monomer components of 90% or less, and the three-dimensional molded insulator according to the above (9) described. (12) The three-dimensional molded insulator according to (9) above, wherein the compatibilizing resin is a polyolefin resin. (13) The three-dimensional molded insulator according to (9) above, wherein the compatibilizing resin is a polyamide resin. (14) The three-dimensional molded insulator according to (9) above, wherein the compatibilizing resin is an aromatic polycarbonate resin containing a bisphenol isophorone carbonate unit. (15) The three-dimensional molded insulator according to (9) above, wherein the compatibilizing resin is an aliphatic polycarbonate resin.

[0015] (16) The comparative tracking index CTI, which is an index of tracking resistance measured in accordance with ASTM D3638, is 600 V or more, and the three-dimensional molded insulator according to any one of (1) to (4) above.

[0016] (17) The flame retardancy measured in accordance with the UL94 standard is V-0 or VTM-0 at a test piece thickness of 0.4 mm or more, and the three-dimensional molded insulator according to any one of (1) to (4) above.

[0017] (18)The manufacturing method of the three-dimensional molded insulator according to any one of (1) to (4) above, A method for manufacturing a three-dimensional molded insulator, characterized in that secondary processing including thermoforming is performed on a flat thermoplastic insulating sheet to form the concave portion.

[0018] (19) The thermoforming is vacuum forming or vacuum pressure forming. The manufacturing method of the three-dimensional molded insulator according to the above (18) is described.

Advantages of the Invention

[0019] According to the present invention, a three-dimensional molded insulator can be obtained that can reduce the dead space generated around the voltage-applying component and enable effective utilization of the space in which the voltage-applying component is accommodated. In addition, according to the present invention, a three-dimensional molded insulator with high shape accuracy can be manufactured.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Best Mode for Carrying Out the Invention

[0021] Hereinafter, the three-dimensional molded insulator and the method for manufacturing the three-dimensional molded insulator according to the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.

[0022] 1. Outline of the three-dimensional molded insulator FIG. 1 is a perspective view showing a three-dimensional molded insulator 1 according to an embodiment and a circuit board 9 on which the three-dimensional molded insulator 1 is placed. Note that FIG. 1 shows the state before the three-dimensional molded insulator 1 is placed on the circuit board 9. In each figure of the present application, the X-axis, Y-axis, and Z-axis are set as three axes orthogonal to each other, and each axis is indicated by an arrow. Further, the base end side of the arrow is referred to as the minus side of each axis, and the tip side is referred to as the plus side of each axis. Furthermore, the plus side of the Z-axis is also referred to as "up", and the minus side of the Z-axis is also referred to as "down".

[0023] As shown in FIG. 1, the three-dimensional molded insulator 1 is used, for example, in a state of being placed on the circuit board 9. The circuit board 9 includes a wiring board 90 having wirings (not shown), a power semiconductor element 91, a bus bar 92, a signal connector 93, and a fixing screw 94. Among these, the power semiconductor element 91, the bus bar 92, the signal connector 93, and the fixing screw 94 each protrude upward from the upper surface of the wiring board 90. In addition, the power semiconductor element 91 and the bus bar 92 are used in a state where a relatively high voltage is applied. The applied voltage is, for example, 50V or more, preferably 71V or more and 10kV or less. By covering the circuit board 9 with the three-dimensional molded insulator 1 from above, the insulation between the circuit board 9 and other objects (not shown) arranged above it can be enhanced. Thereby, the space distance required for insulation between the circuit board 9 and other objects can be reduced.

[0024] Further, as shown in FIG. 1, the three-dimensional molded insulator 1 has a shape with a recess 12, more specifically, it is three-dimensionally molded into a shape having a flat portion 11 and a recess 12. Three-dimensional molding means molding a sheet-like member into a shape having a recess deeper than the thickness of the member. When viewed in plan from above the Z-axis, the insulating sheet 1 has an outer size and outer shape that overlap with the wiring board 90. The flat portion 11 is a portion having a flat surface 110 parallel to the upper surface of the wiring board 90. The flat surface 110 is the lower surface of the flat portion 11 facing the upper surface of the wiring board 90. Note that for parallel, an angular deviation of 10 degrees or less is allowed. The recess 12 is a portion recessed upward from the flat surface 110. The position of the recess 12 in plan view is adjusted according to the positions of the power semiconductor element 91, the bus bar 92, and the signal connector 93 arranged on the wiring board 90.

[0025] When the three-dimensional molded insulator 1 is placed over the circuit board 9 from above, the power semiconductor element 91, the bus bar 92, and the signal connector 93 are inserted into the recess 12. As a result, the upper surfaces and side surfaces of these components protruding from the upper surface of the wiring board 90 can be covered with the three-dimensional molded insulator 1. As a result, only a minimum gap is generated between the circuit board 9 and the three-dimensional molded insulator 1, and the dead space can be reduced compared to the prior art. That is, the dead space around components to which a voltage is applied, such as the power semiconductor element 91, the bus bar 92, and the signal connector 93, can be reduced. Thereby, it becomes possible to effectively utilize the space in which the circuit board 9 is accommodated.

[0026] Therefore, by using the three-dimensional molded insulator 1, the miniaturization of the device on which the circuit board 9 is mounted can be achieved. Note that the posture (orientation with respect to vertically upward) when using the three-dimensional molded insulator 1 is not limited to the above. For example, when the upper surface of the wiring board 90 described above faces downward, the three-dimensional molded insulator 1 is placed over the wiring board 90 from below. In that case, the above-described recess 12 becomes a portion recessed downward from the flat surface 110.

[0027] 2. Circuit Board Prior to the description of the three-dimensional molded insulator 1, the circuit board 9 will be described in detail. The circuit board 9 is not particularly limited as long as it includes a substrate and components that protrude from the surface thereof and to which a voltage is applied.

[0028] As shown in FIG. 1, the circuit board 9 includes a wiring board 90, a power semiconductor device 91, a bus bar 92, a signal connector 93, and a fixing screw 94, as described above. FIG. 2 is a cross-sectional view taken along line A-A of the circuit board 9 shown in FIG. 1.

[0029] As shown in FIG. 2, the wiring board 90 has an insulating layer 901, a wiring layer 902, a through wiring 903, and a thermal via 904.

[0030] The power semiconductor device 91 is a semiconductor device that performs high-power switching and the like. Examples of the power semiconductor device 91 include an IGBT (Insulated Gate Bipolar Transistor) and a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor). Six power semiconductor devices 91 are illustrated in FIG. 1, each protruding upward from the upper surface of the wiring board 90. Each power semiconductor device 91 is in contact with the thermal via 904 to enable heat dissipation.

[0031] The bus bar 92 is a conductor that connects the circuit board 9 and a power source. The bus bar 92 is composed of, for example, a metal plate or bar. The bus bar 92 shown in FIG. 2 protrudes upward from the upper surface of the wiring board 90 and bends laterally (on the minus X-axis side) midway. The bus bar 92 is electrically connected to the wiring board 90 via the through wiring 903. Note that the bus bar 92 shown in FIG. 1 includes bus bars 921 and 922 in which the directions of the flowing currents are different from each other.

[0032] The signal connector 93 is a connector into which a signal line is inserted. The signal line is used, for example, for transmitting and receiving signals between the circuit board 9 and an external control device. The signal connector 93 protrudes upward from the upper surface of the wiring board 90.

[0033] The fixing screws 94 penetrate through the four corners of the wiring board 90 in the thickness direction. The fixing screws 94 fix the wiring board 90 to a housing (not shown) or the like. The heads of the fixing screws 94 protrude upward from the upper surface of the wiring board 90.

[0034] In the circuit board 9 as described above, voltages are applied to the power semiconductor element 91, the bus bar 92, and the signal connector 93. In particular, since high voltages are applied to the power semiconductor element 91 and the bus bar 92, insulation by the three-dimensional molded insulator 1 is effective.

[0035] Note that the components to which voltages are applied are not limited to the above, and any component can be used as long as it is a component to which a voltage is applied. Specific examples other than the above include batteries, capacitors, diodes, coils, resistors, relays, transformers, switches, connectors, terminals, etc.

[0036] Also, although voltages are not directly applied, components that are in contact with components to which direct voltages are applied may be inadvertently subjected to voltages, and thus are included in the "components to which voltages are applied". Specific examples of such components include heat sinks, heat spreaders, heat pipes, etc.

[0037] 3. Configuration of the three-dimensional molded insulator Next, the configuration of the three-dimensional molded insulator 1 will be described.

[0038] 3.1. Shape of the three-dimensional molded insulator As shown in FIG. 1, the three-dimensional molded insulator 1 has a plurality of recesses 12 in accordance with the components protruding from the upper surface of the wiring board 90 as described above. The recesses 12 are open at the bottom. The three-dimensional molded insulator 1 is used with the components inserted through this opening.

[0039] Such a recess 12 includes a recess 121 into which the power semiconductor element 91 is inserted, a recess 122 into which the bus bar 92 is inserted, and a recess 123 into which the signal connector 93 is inserted. The recesses 121, 122, and 123 are each formed in accordance with the outer size and outer shape of the inserted component. Therefore, the gap between each component and the recesses 121, 122, 123 can be minimized. Thereby, the dead space can be reduced. That is, since the areas of the recesses 121, 122, and 123 in plan view can be minimized, the area of the flat portion 11 can be maximized accordingly. As a result, the space above the flat portion 11 (the space around the component to which voltage is applied) can be effectively utilized as compared with the case of using a conventional flat insulating sheet.

[0040] Further, the recess 12 covers not only the upper surfaces of each component but also the side surfaces. Thereby, it is possible to suppress foreign matters such as dust from adhering to the side surfaces of each component and moisture from being adsorbed.

[0041] Furthermore, terminals or the like may be exposed on the side surfaces of each component. The recess 12 also effectively acts on insulating such terminals or the like. For example, by providing the recess 12, it becomes possible to shorten the required space distance L1 (the space distance required for insulation between components) for insulation between the bus bar 92 and the power semiconductor element 91 shown in FIG. 2. Thereby, the circuit board 9 can be miniaturized.

[0042] FIG. 3 is a cross-sectional view showing only the three-dimensional molded insulator 1 of FIG. 2. The recess 12 shown in FIG. 3 includes a bottom portion 12a and a wall portion 12b. The bottom portion 12a is a portion that covers the upper surfaces of the power semiconductor element 91 and the bus bar 92. The wall portion 12b is a portion that rises from the end of the bottom portion 12a and covers the side surfaces of the power semiconductor element 91 and the bus bar 92. Note that the shapes of the bottom portion 12a and the wall portion 12 are not limited to the shapes shown in FIG. 3. Also, the connection portion between the bottom portion 12a and the wall portion 12b may be rounded or chamfered.

[0043] Also, by forming the recess 12 with an appropriate size and shape, the separation distance S2 between the inner surface of the recess 12 and components such as the power semiconductor element 91 shown in FIG. 2 can be made sufficiently close. As a result, it becomes possible to more effectively reduce the dead space and effectively protect the side surfaces of each component.

[0044] The separation distance S2 is not particularly limited, but is preferably 10 mm or less, more preferably 7 mm or less, and even more preferably 5 mm or less. Thereby, the dead space can be sufficiently reduced and each component can be protected more effectively. Note that the three-dimensional molded insulator 1 has good tracking resistance as will be described later. Therefore, even when the separation distance S2 is within the above range, tracking is less likely to occur. On the other hand, considering the heat dissipation efficiency from the components, the stress on the components, etc., and the ease of assembly, etc., the separation distance S2 is preferably 0.5 mm or more, and more preferably 1 mm or more.

[0045] Also, although not shown, the separation distance between the ceiling surface of the recess 12 and components such as the power semiconductor element 91 is the same as the above separation distance S2.

[0046] On the other hand, by forming the recess 12 with an appropriate size and shape, the separation distance S1 between the flat surface 110 of the flat portion 11 and the wiring board 90 shown in FIG. 2 can be made sufficiently close. Also, as the separation distance S1 becomes closer, it becomes easier to suppress foreign matter such as dust from adhering to the upper surface of the wiring board 90 and moisture from being adsorbed. As a result, it also becomes easier to suppress surface discharge occurring between the bus bar 92 and the power semiconductor element 91 and subsequent tracking.

[0047] The separation distance S1 is not particularly limited, but is preferably 15 mm or less, more preferably 10 mm or less, and even more preferably 5 mm or less. Thereby, the dead space can be sufficiently reduced. Further, in the case of the example shown in FIG. 2, by setting the separation distance S1 within the above range, the probability that the three-dimensional molded insulator 1 is interposed between the power semiconductor element 91 and the bus bar 921 increases, and the three-dimensional molded insulator 1 can be sufficiently approximated to the wiring board 90 between them. Thereby, surface discharge and tracking generated between them can be suppressed, and the space distance L1 required between them can be sufficiently shortened.

[0048] The recess 12 includes recesses 121 into which the power semiconductor elements 91 are inserted one by one. Therefore, each power semiconductor element 91 can be individually protected. Further, the distance required for insulation between the power semiconductor elements 91 can be shortened. Note that two or more power semiconductor elements 91 (components) may be inserted into the recess 121.

[0049] The recess 12 includes recesses 122 into which the bus bars 921 and 922 are inserted one by one. Therefore, the bus bars 921 and 922 can be individually protected. Further, the distance required for insulation between the bus bars 921 and 922 can be shortened. Note that two or more bus bars 92 (components) may be inserted into the recess 122.

[0050] Further, in the circuit board 9 shown in FIG. 1, the bus bar 921 and the bus bar 922 are arranged side by side along the Y axis. In contrast, the bus bars 921 and 922 may be configured to partially overlap along the Z axis.

[0051] FIG. 4 is a cross-sectional view showing a modified example of the circuit board 9 of FIG. 2. In FIG. 4, bus bar 921 and bus bar 922 partially overlap along the Z axis. In this portion, the positive-side current and the negative-side current flow in close proximity. Therefore, the magnetic fluxes generated by the currents cancel each other out, and the inductance component can be reduced. Thus, with the configuration shown in FIG. 4, a circuit board 9 in which the inductance component in the bus bar 92 is reduced can be realized. As a result, the surge voltage in the circuit board 9 can be reduced.

[0052] Also, a three-dimensional molded insulator 1 is interposed between bus bar 921 and bus bar 922. Thereby, even if bus bars 921 and 922 are brought sufficiently close to each other, breakdown and the like can be prevented. As a result, the inductance component can be reduced more effectively.

[0053] Furthermore, in the example of FIG. 4, the side surface on the positive X-axis side of bus bar 921 and the side surfaces on the positive and negative Y-axis sides (not shown in FIG. 4) are covered by the inner surface of recess 122. Therefore, even if bus bars 921 and 922 are brought sufficiently close to each other, surface discharge can be effectively suppressed.

[0054] FIG. 5 is a top view showing a three-dimensional molded insulator 1 according to a modified example of the embodiment. FIG. 6 is a cross-sectional view of the bus bar 92 and the three-dimensional molded insulator 1 shown in FIG. 5.

[0055] The three-dimensional molded insulator 1 shown in FIG. 5 is a modified example of the three-dimensional molded insulator 1 shown in FIG. 3, and is provided, for example, at a position away from the circuit board 9. Specifically, the bus bars 921 and 922 shown in FIG. 4 may protrude from the wiring board 90 and extend to the negative X-axis side. The three-dimensional molded insulator 1 shown in FIG. 5 is preferably used at the extension portions of the bus bars 921 and 922.

[0056] The bus bars 921 and 922 shown in Fig. 5 correspond to the above-mentioned extension parts. In the extension parts, the bus bars 921 and 922 overlap each other along the Z-axis. And at the overlapping part, the bottom 12a of the three-dimensional molded insulator 1 is arranged between the bus bar 921 and the bus bar 922. Also, as shown in Fig. 6, the wall part 12b of the three-dimensional molded insulator 1 shown in Fig. 5 rises from the end of the bottom 12a toward the positive Z-axis side. Thus, the side surface of the bus bar 922 is covered by the wall part 12b.

[0057] According to such a configuration, the dead space around the bus bar 922 can be reduced by the three-dimensional molded insulator 1 shown in Figs. 5 and 6. That is, by providing the wall part 12b, the insulation space distance on the side of the bus bar 922 can be reduced, so that it becomes possible to allow any member to be arranged on the side of the bus bar 922. Thereby, the space that was a dead space conventionally can be reduced.

[0058] Also, since the three-dimensional molded insulator 1 shown in Fig. 5 is used with the bus bar 922 inserted into the recess 12, the displacement between the bus bar 922 and the three-dimensional molded insulator 1 is suppressed. Therefore, even if vibration or the like is applied, the occurrence of the three-dimensional molded insulator 1 falling off or the like can be suppressed.

[0059] Also, the three-dimensional molded insulator 1 shown in Fig. 1 has a through hole 13 that penetrates the flat part 11 in the thickness direction. The through hole 13 is provided in accordance with the position of the fixing screw 94. By providing the through hole 13, even when the three-dimensional molded insulator 1 covers the circuit board 9, the rotation operation of the fixing screw 94 becomes possible. Therefore, with the three-dimensional molded insulator 1 covering the circuit board 9, it becomes possible to screw the circuit board 9 to a case or the like, and the assembly workability is improved. In this case, it is preferable that the inner diameter of the through hole 13 is equal to or larger than the outer diameter of the head of the fixing screw 94. Thereby, the rotation operation of the fixing screw 94 becomes easy.

[0060] When the fixing screw 94 is tightened against the circuit board 9, the head of the fixing screw 94 may be located above the three-dimensional molded insulator 1. Thereby, the three-dimensional molded insulator 1 can be fixed together with the circuit board 9 by the fixing screw 94. In this case, the inner diameter of the through hole 13 is preferably less than the outer diameter of the head of the fixing screw 94.

[0061] Further, the planar shape of the through hole 13 is not limited to a closed shape, and may be a shape with a part open to the outside.

[0062] The thickness t11 of the flat portion 11 of the three-dimensional molded insulator 1 is not particularly limited, but is preferably 0.05 mm or more and 1.00 mm or less, more preferably 0.10 mm or more and 0.90 mm or less, and even more preferably 0.20 mm or more and 0.80 mm or less. Thereby, a three-dimensional molded insulator 1 excellent in flame retardancy, tracking resistance, and insulation properties and relatively easy to manufacture can be obtained. If the thickness t11 of the flat portion 11 is less than the lower limit value, the flame retardancy, tracking resistance, and insulation properties may decrease. On the other hand, although the thickness t11 of the flat portion 11 may exceed the upper limit value, in that case, the three-dimensional molded insulator 1 may be too thick, resulting in a decrease in flexibility, difficulty in handling, a decrease in heat dissipation and shape accuracy, and an increase in manufacturing difficulty.

[0063] Also, the thickness t12b of the wall portion 12b is preferably 20% or more and 95% or less of the thickness t11 of the flat portion 11, more preferably 30% or more and 90% or less, and even more preferably 50% or more and 90% or less. If the thickness t12b of the wall portion 12b is within the above range, it has sufficient rigidity to support the shape of the concave portion 12, and the dead space on the side of the concave portion 12 can be further reduced.

[0064] If the thickness t12b of the wall portion 12b is less than the lower limit value, the rigidity of the wall portion 12b may become insufficient. On the other hand, if the thickness t12b of the wall portion 12b exceeds the upper limit value, the effect of reducing the dead space on the side of the concave portion 12 may be reduced.

[0065] Note that the outer shape of the three-dimensional molded insulator 1 shown in FIG. 1 overlaps the entire circuit board 9 as an example, but it may be smaller or larger than this.

[0066] Further, the recess 12 preferably covers the entire side surface of a component protruding from the upper surface of the wiring board 90, such as the recess 121, but may cover a part of the side surface of the component, such as the recesses 122 and 123.

[0067] Since the depth of the recess 12 is set according to the height of the component, it is not particularly limited, but it may be 0.5 mm or more and 100 mm or less, or may be 1 mm or more and 50 mm or less. Within such a range, a three-dimensional molded insulator 1 having excellent manufacturability and provided with a recess 12 into which various components can be inserted with almost no height limitation can be realized.

[0068] 3.2. Constituent Material of Three-Dimensional Molded Insulator Next, the constituent material of the three-dimensional molded insulator 1 will be described.

[0069] The three-dimensional molded insulator 1 contains, for example, a resin material. The proportion of the resin material in the constituent material of the three-dimensional molded insulator 1 is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. Thereby, a three-dimensional molded insulator 1 having excellent insulating properties and moldability and being easily weight-reduced can be obtained.

[0070] Examples of the resin material include various thermoplastic resins such as polyolefin resin, polyamide resin, polyester resin, aromatic polycarbonate resin, aliphatic polycarbonate resin, polyarylate resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polylactic acid, styrene copolymer, polyacetal resin, polyphenylene ether resin, polyphenylene sulfide resin, polymethyl methacrylate resin, cellulose ester resin, etc., and various thermosetting resins such as polyimide, polyurethane, epoxy resin, phenol resin, etc. The first resin and the second resin may be used in combination of one or more of these resins.

[0071] In addition, the three-dimensional molded insulator 1 is preferably made mainly of a thermoplastic resin. The main material means that it is the above ratio. A sheet made mainly of a thermoplastic resin can be plastically deformed by heat and has excellent secondary processability. For this reason, a three-dimensional molded insulator 1 that can be manufactured by thermoforming and has excellent manufacturing ease can be obtained.

[0072] Among these, polyolefin resin, polyamide resin, aromatic polycarbonate resin or aliphatic polycarbonate resin is preferably used as the thermoplastic resin.

[0073] In addition, a material with high tracking resistance is preferably used as the resin material. The tracking resistance refers to the resistance to the phenomenon in which a conductive path (tracking) is formed by discharge occurring on the surface of the insulator. Such tracking resistance can be quantified by, for example, the comparative tracking index CTI, which is an index of the tracking resistance measured in accordance with ASTM D3638.

[0074] The comparative tracking index CTI of the resin material is preferably 400 V or more, and more preferably 600 V or more. Thereby, a three-dimensional molded insulator 1 having particularly good tracking resistance can be obtained.

[0075] The glass transition temperature Tg of the resin material is preferably 125 °C or higher, more preferably 130 °C or higher and less than 200 °C. Thereby, heat resistance is imparted to the resin material, so that, for example, even when creeping discharge occurs in the three-dimensional molded insulator 1, coloring due to carbonization is easily suppressed. As a result, the occurrence of appearance defects and the deterioration of insulation properties due to carbonization in the three-dimensional molded insulator 1 can be suppressed. Note that the glass transition temperature Tg of the resin material is measured by the DSC (differential scanning calorimeter) method. The heating rate in the DSC method is 10 °C / min.

[0076] The melt volume rate (MVR) of the resin material at 300 °C and a load of 1.2 kg is 5 [cm 3 / 10 min] or more and 30 [cm 3 / 10 min] or less, preferably 8 [cm 3 / 10 min] or more and 20 [cm 3 / 10 min] or less. Thereby, the moldability in the secondary processing of the three-dimensional molded insulator 1, particularly the property of not causing defects such as distortion in vacuum molding, can be enhanced. Note that if the melt volume rate is less than the lower limit value, the fluidity may be insufficient and the moldability may decrease. On the other hand, if the melt volume rate exceeds the upper limit value, the impact resistance of the molded body may decrease. Note that the melt volume rate is measured according to the test method specified in JIS K 7210:2014.

[0077] 3.2.1. Polyolefin resin Examples of the polyolefin resin include high-density polyethylene resin, polypropylene resin, polybutene resin, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)methyl acrylate copolymer, ethylene-(meth)ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, maleic anhydride-modified polyethylene, carboxylic acid-modified polyethylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, and the like.

[0078] Polyolefin resins are excellent in chemical resistance to various chemicals. In addition, polyolefin resins have good tracking resistance based on the chain structure of hydrocarbons. Therefore, polyolefin resins contribute to the improvement of the chemical resistance and tracking resistance of the three-dimensional molded insulator 1.

[0079] Among these, polypropylene resins are preferably used. Polypropylene resins particularly improve the chemical resistance and tracking resistance of the three-dimensional molded insulator 1.

[0080] 3.2.2. Polyamide Resins Examples of polyamide resins include polycaproamide (polyamide 6), polytetramethylene adipamide (polyamide 46), polyhexamethylene adipamide (polyamide 66), polyhexamethylene sebacamide (polyamide 610), polyhexamethylene dodecamide (polyamide 612), polyundecamethylene adipamide (polyamide 116), polyundecanamide (polyamide 11), polydodecanamide (polyamide 12), polytrimethylhexamethylene terephthalamide (polyamide TMHT), polyhexamethylene terephthalamide (polyamide 6T), polyhexamethylene isophthalamide (polyamide 6I), polyhexamethylene terephthal / isophthalamide (polyamide 6T / 6I), polybis(4-aminocyclohexyl)methane dodecamide (polyamide PACM12), polybis(3-methyl-4-aminocyclohexyl)methane dodecamide (polyamide dimethyl PACM12), polymetaxylylene adipamide (polyamide MXD6), polynonamethylene terephthalamide (polyamide 9T), polydecamethylene terephthalamide (polyamide 10T), polyundecamethylene terephthalamide (polyamide 11T), polyundecamethylene hexahydroterephthalamide (polyamide 11T(H)), and copolymers or mixtures thereof may also be used.

[0081] The polyamide resin can be obtained, for example, by polymerizing or copolymerizing a nylon salt composed of a diamine and a dicarboxylic acid as a raw material by known methods such as melt polymerization, solution polymerization, and solid-phase polymerization. By using the polyamide resin as the first resin and the second resin, the tracking resistance of the three-dimensional molded insulator 1 can be further enhanced.

[0082] As the diamine, an aliphatic diamine may be used, but an alicyclic diamine or an aromatic diamine is preferably used, and an alicyclic diamine is more preferably used. By using these, a polyamide resin having a cyclic structure such as an aromatic ring structure or an alicyclic structure can be prepared. Such a polyamide resin contributes to improving the heat resistance of the three-dimensional molded insulator 1. In addition, in particular, the alicyclic diamine contributes to improving the tracking resistance of the three-dimensional molded insulator 1.

[0083] Examples of the alicyclic diamine include 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 1,3-cyclohexanedimethylamine, 1,4-cyclohexanedimethylamine, bis(4-aminocyclohexyl)methane, bis(4-aminocyclohexyl)propane, bis(3-methyl-4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)propane, 5-amino-2,2,4-trimethyl-1-cyclopentanemethylamine, 5-amino-1,3,3-trimethylcyclohexanemethylamine (isophoronediamine), bis(aminopropyl)piperazine, bis(aminoethyl)piperazine, norbornanedimethylamine, tricyclodecanedimethylamine, etc. One or more of these are used.

[0084] Examples of the aromatic diamine include m-xylylenediamine, p-xylylenediamine, etc.

[0085] The dicarboxylic acid may be an alicyclic dicarboxylic acid or an aromatic dicarboxylic acid, but an aliphatic dicarboxylic acid is preferably used. Thereby, a polyamide resin having a chain structure of hydrocarbon can be prepared. Such a polyamide resin contributes to improving the tracking resistance of the three-dimensional molded insulator 1.

[0086] Examples of the dicarboxylic acid include aliphatic dicarboxylic acids such as adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, eicosanedioic acid; alicyclic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, dicyclohexanemethane-4,4'-dicarboxylic acid, norbornanedicarboxylic acid; aromatic dicarboxylic acids such as isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, etc. One or more of these are used.

[0087] As the polyamide resin, polyamide 6T, polyamide PACM12, polyamide dimethyl PACM12, polyamide MXD6, polyamide 9T, polyamide 10T, polyamide 11T, or polyamide 11T(H) is preferably used, and polyamide PACM12 or polyamide dimethyl PACM12 is more preferably used. Since these have both a cyclic structure such as an aromatic ring structure or an alicyclic structure and a structure derived from an aliphatic monomer, they contribute to improving both the heat resistance and the tracking resistance of the three-dimensional molded insulator 1. Polyamide PACM12 contains a structural unit represented by the following formula (2).

[0088]

Chemical formula

[0089] The above polyamide PACM12 is synthesized from bis(4-aminocyclohexyl)methane (PACM) and dodecanedioic acid as raw materials. The polyamide dimethyl PACM12 contains a structural unit represented by the following formula (3).

[0090]

Chemical formula

[0091] The above polyamide dimethyl PACM12 is synthesized from bis(3-methyl-4-aminocyclohexyl)methane (MACM) and dodecanedioic acid as raw materials.

[0092] 3.2.3. Aliphatic polycarbonate resin Examples of the aliphatic polycarbonate resin include those containing aliphatic carbonate units having 2 to 12 carbon atoms. Specifically, for example, polyethylene carbonate, polypropylene carbonate, polytrimethylene carbonate, polytetramethylene carbonate, polypentamethylene carbonate, polyhexamethylene carbonate, polyheptamethylene carbonate, polyoctamethylene carbonate, polynonamethylene carbonate, polydecamethylene carbonate, polyoxydiethylene carbonate, poly-3,6-dioxyoctane carbonate, poly-3,6,9-trioxoundecane carbonate, polyoxydipropylene carbonate, polycyclopentene carbonate, polycyclohexene carbonate, etc.

[0093] Further, the aliphatic polycarbonate resin may be a resin containing an aliphatic carbonate unit containing a diol residue represented by the following formula (4).

[0094]

Chemical formula

[0095] (In formula (4), R 5 ~R 8is independently a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group.)

[0096] The aliphatic polycarbonate resin preferably contains 30 mol% or more and 100 mol% or less, more preferably 50 mol% or more and 90 mol% or less, of an aliphatic carbonate unit containing a diol residue represented by the above formula (4) in all structural units.)

[0097] The diol residue represented by the above formula (4) has a structure in which two tetrahydrofuran rings are fused. By including such a structure in the structural unit, the glass transition temperature Tg of the aliphatic polycarbonate resin can be increased. As a result, the three-dimensional molded insulator 1 having excellent heat resistance and tracking resistance can be obtained.)

[0098] Examples of the diol constituting the diol residue represented by the above formula (4) include isosorbide, isomannide, isoidide, etc. These diols derived from carbohydrates are useful in that they can also be obtained from natural biomass.)

[0099] 3.2.4. Aromatic polycarbonate resin The aromatic polycarbonate resin can be obtained by a phosgene method in which various dihydroxydiaryl compounds are reacted with phosgene, a transesterification method in which a dihydroxydiaryl compound is reacted with a carbonate ester such as diphenyl carbonate, a ring-opening polymerization method of a cyclic carbonate compound, an interfacial polycondensation method, etc. Such an aromatic polycarbonate resin imparts excellent heat resistance and flame retardancy derived from the aromatic ring structure to the three-dimensional molded insulator 1.)

[0100] Examples of the dihydroxy diaryl compound include, in addition to bisphenol A, bis(hydroxyaryl)alkanes such as bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)octane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxyphenyl-3-methylphenyl)propane, and 1,1-bis(4-hydroxy-3-tert-butylphenyl)propane; bis(hydroxyaryl)cycloalkanes such as 1,1-bis(4-hydroxyphenyl)cyclopentane and 1,1-bis(4-hydroxyphenyl)cyclohexane; dihydroxy diaryl ethers such as 4,4'-dihydroxy diphenyl ether and 4,4'-dihydroxy-3,3'-dimethyl diphenyl ether; dihydroxy diaryl sulfides such as 4,4'-dihydroxy diphenyl sulfide and 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfide; dihydroxy diaryl sulfoxides such as 4,4'-dihydroxy diphenyl sulfoxide and 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfoxide; dihydroxy diaryl sulfones such as 4,4'-dihydroxy diphenyl sulfone and 4,4'-dihydroxy-3,3'-dimethyl diphenyl sulfone. These may be used alone or in combination of two or more.

[0101] Examples of the aromatic polycarbonate resin include, in particular, those having a structural unit represented by the following formula (1).

[0102] [Chemical formula] (In formula (1), R 1 and R 2 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a halogen atom. m and n each independently represent an integer of 0 to 4. X represents a direct bond, O, S, SO, SO2, CR 3 R 4(R 3 and R 4 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and they may be the same as or different from each other.), an alkylene group having 2 to 10 carbon atoms, a polydimethylsiloxane group, or C(CF3)2.)

[0103] The aromatic polycarbonate resin having the structural unit represented by the above formula (1) imparts particularly excellent heat resistance and flame retardancy to the three-dimensional molded insulator 1.

[0104] Among all the structural units constituting the aromatic polycarbonate resin, the proportion of the structural unit represented by the above formula (1) is preferably 55 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more.

[0105] Also, from the viewpoints of availability, cost, etc., R 1 and R 2 are each preferably a hydrogen atom, and X is CR 3 R 4 and R 3 and R 4 are each preferably a methyl group or a hydrogen atom.

[0106] The aromatic polycarbonate resin is preferably a polycarbonate resin having a structural unit derived from bisphenol A (2,2-bis(4-hydroxyphenyl)propane). Thereby, the flame retardancy and heat resistance of the three-dimensional molded insulator 1 can be further enhanced.

[0107] The viscosity average molecular weight (M) of the aromatic polycarbonate resin is not particularly limited, but is preferably 5000 or more and 100000 or less, more preferably 12000 or more and 35000 or less, even more preferably 15000 or more and 30000 or less, and particularly preferably 18000 or more and 28000 or less.

[0108] The viscosity-average molecular weight (M) is calculated from the viscosity (η) of the methylene chloride solution of the resin using the equation η = kM α where k and α are constants specific to the polymer. For the measurement of viscosity, an Ubbelohde viscometer is used and the measurement is carried out at 20°C.

[0109] Also, the aromatic polycarbonate resin may be a blend of a resin with a high viscosity-average molecular weight (high-viscosity resin) and a resin with a low viscosity-average molecular weight (low-viscosity resin). Thereby, a three-dimensional molded insulator 1 excellent in moldability can be obtained without impairing the heat resistance and flame retardancy of the aromatic polycarbonate resin.

[0110] The difference between the viscosity-average molecular weight of the high-viscosity resin and the viscosity-average molecular weight of the low-viscosity resin is not particularly limited, but is preferably 3000 or more and 20000 or less, and more preferably 5000 or more and 10000 or less. Thereby, a three-dimensional molded insulator 1 with particularly good moldability can be obtained.

[0111] When the blending amount of the high-viscosity resin is M1 and the blending amount of the low-viscosity resin is M2, the blending ratio M1 / M2 is preferably 0.5 or more and 8.0 or less, more preferably 0.8 or more and 6.0 or less, and even more preferably 0.9 or more and 5.0 or less in terms of mass ratio. Thereby, a three-dimensional molded insulator 1 with particularly good moldability can be obtained.

[0112] The glass transition temperature Tg of the aromatic polycarbonate resin is preferably 130°C or more and less than 160°C, and more preferably 140°C or more and 155°C or less. If the glass transition temperature Tg of the aromatic polycarbonate resin is within the above range, the heat resistance and flame retardancy of the three-dimensional molded insulator 1 can be sufficiently enhanced. The glass transition temperature Tg of the aromatic polycarbonate resin is measured by the DSC (differential scanning calorimeter) method. The heating rate in the DSC method is 10°C / min.

[0113] The content rate of the aromatic polycarbonate resin in the three-dimensional molded insulator 1 is not particularly limited, but is preferably 70% by mass or more, and more preferably 80% by mass or more.

[0114] The melt volume rate (MVR) of the aromatic polycarbonate resin at 300 °C and a load of 1.2 kg is 5 [cm 3 / 10 min] or more and 20 [cm 3 / 10 min] or less, preferably 8 [cm 3 / 10 min] or more and 15 [cm 3 / 10 min] or less. Thereby, the moldability in the secondary processing of the three-dimensional molded insulator 1, particularly the property of not causing defects such as distortion in vacuum molding, can be enhanced. When the melt volume rate is lower than the lower limit value, the fluidity may be insufficient and the moldability may decrease. On the other hand, when the melt volume rate exceeds the upper limit value, the impact resistance of the molded body may decrease. The melt volume rate is measured according to the test method specified in JIS K 7210:2014.

[0115] The aromatic polycarbonate resin may be a resin containing a carbonate unit (bisphenol isophorone carbonate unit) represented by the following formula (5). Such an aromatic polycarbonate resin has higher heat resistance than the aromatic polycarbonate resin containing the carbonate unit represented by the above formula (1). Hereinafter, the polycarbonate resin containing the bisphenol isophorone carbonate unit may be referred to as a "heat-resistant polycarbonate resin".

[0116]

Chemical formula

[0117] In formula (5), R a and R b are each independently an alkyl group having 1 to 12 carbon atoms, R g is an alkyl group having 1 to 12 carbon atoms, p and q are each independently 0 to 4, and t is 0 to 10.

[0118] In addition, each R a and R b at least one of which is preferably arranged at the meta-position with respect to the cyclohexylidene crosslinking group.

[0119] Also, R a and R b are each independently an alkyl group having 1 to 4 carbon atoms, R g is an alkyl group having 1 to 4 carbon atoms, p and q are each 0 or 1, and t may be 0 to 5.

[0120] Furthermore, R a , R b , and R g are each a methyl group, p and q are each 0 or 1, t is 0 or 3, and preferably 0.

[0121] Specific examples of such a heat-resistant polycarbonate resin include a resin containing a carbonate unit (bisphenol A carbonate unit) derived from bisphenol A (2,2-bis(4-hydroxyphenyl)propane) and a carbonate unit (bisphenol isophorone carbonate unit) represented by the formula (5). In this case, in the bisphenol isophorone carbonate unit, p and q are each 0, each R g is a methyl group, and t is preferably 3. In this case, the bisphenol isophorone carbonate unit is a carbonate unit containing a structure derived from bisphenol TMC (1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane) in particular.

[0122] Such a bisphenol isophorone carbonate unit contains both an aromatic ring structure and an alicyclic ring structure. Therefore, the bisphenol isophorone carbonate unit particularly contributes to improving both the heat resistance (flame retardancy) and the tracking resistance of the three-dimensional molded insulator 1.

[0123] Of all the structural units constituting the heat-resistant polycarbonate resin, the proportion of the bisphenol isophorone carbonate unit is preferably 30% by mass or more, more preferably 35% by mass or more and 60% by mass or less, and even more preferably 40% by mass or more and 50% by mass or less. This contributes to improving both the heat resistance (flame retardancy) and tracking resistance of the three-dimensional molded insulator 1. In addition, the moldability of the heat-resistant polycarbonate resin can be enhanced.

[0124] In addition, when the proportion of the bisphenol isophorone carbonate unit is less than the lower limit value, at least one of the heat resistance (flame retardancy) and tracking resistance of the three-dimensional molded insulator 1 may decrease. On the other hand, when the proportion of the bisphenol isophorone carbonate unit exceeds the upper limit value, the moldability of the heat-resistant polycarbonate resin may decrease, and the dimensional accuracy of the three-dimensional molded insulator 1 may decrease.

[0125] The glass transition temperature Tg of the heat-resistant polycarbonate resin is preferably 160°C or higher and 230°C or lower, and more preferably 165°C or higher and 220°C or lower. If the glass transition temperature Tg of the heat-resistant polycarbonate resin is within the above range, the heat resistance of the three-dimensional molded insulator 1 can be particularly enhanced. Thereby, for example, even when creeping discharge occurs in the three-dimensional molded insulator 1, coloring due to carbonization can be particularly suppressed, so that the occurrence of appearance defects and the decrease in insulation properties accompanying carbonization can be particularly suppressed.

[0126] In addition, when the glass transition temperature Tg is lower than the lower limit value, there is a risk that appearance defects and carbonization accompanying creeping discharge are likely to occur. On the other hand, when the glass transition temperature Tg exceeds the upper limit value, the molding temperature of the heat-resistant polycarbonate resin becomes too high, and molding defects are likely to occur. Further, when the heat-resistant polycarbonate resin and the compatible resin are alloyed, depending on the heat resistance of the compatible resin, there is a risk of causing thermal deterioration of the compatible resin.

[0127] 3.2.5. Polymer Alloy The constituent material of the three-dimensional molded insulator 1 may contain a polymer alloy formed by alloying an aromatic polycarbonate resin and a compatible resin. The polymer alloy refers to a single-phase material or a stable multi-phase material formed by mixing a plurality of types of polymers, and preferably refers to a single-phase material. In this specification, "alloying" means that kneading or the like is performed on a raw material containing a plurality of types of polymers to prepare such a single-phase or multi-phase material. In particular, by alloying an aromatic polycarbonate resin and a compatible resin, a three-dimensional molded insulator 1 having both the heat resistance derived from the aromatic polycarbonate resin and another property derived from the compatible resin can be obtained.

[0128] As the compatible resin, the above-described polyolefin resin, polyamide resin, aliphatic polycarbonate resin, aromatic polycarbonate resin (heat-resistant polycarbonate resin) containing a carbonate unit represented by the above formula (5), etc. are preferably used. In this case, as the aromatic polycarbonate resin alloyed with these compatible resins, a resin having a structural unit represented by the above formula (1) is preferably used. In such a combination, the tracking resistance (comparative tracking index CTI) of the compatible resin is higher than that of the aromatic polycarbonate resin having the structural unit represented by the above formula (1). Thereby, a three-dimensional molded insulator 1 having both heat resistance and tracking resistance can be obtained.

[0129] The ratio of the compatible resin in the polymer alloy is not particularly limited, but is preferably 5% by mass or more and 80% by mass or less, more preferably 10% by mass or more and 75% by mass or less, still more preferably 20% by mass or more and 70% by mass or less, and particularly preferably 40% by mass or more and 65% by mass or less. According to such a configuration, a polymer alloy having well-balanced properties such as heat resistance and flame retardancy of the aromatic polycarbonate resin having the structural unit represented by the above formula (1) and the properties of the compatible resin can be realized.

[0130] The comparative tracking index CTI of the compatible resin is preferably 400 V or higher, more preferably 600 V or higher. Thereby, the three-dimensional molded insulator 1 having particularly excellent tracking resistance can be obtained.

[0131] Further, the comparative tracking index CTI of the compatible resin is preferably 50 V or higher, more preferably 100 V or higher, than the comparative tracking index CTI of the aromatic polycarbonate resin. Thereby, the three-dimensional molded insulator 1 in which flame retardancy and tracking resistance are better balanced can be obtained.

[0132] The glass transition temperature Tg of the compatible resin is preferably 125°C or higher, more preferably 130°C or higher and 230°C or lower. Thereby, heat resistance is imparted to the compatible resin, so that, for example, even when creeping discharge occurs in the three-dimensional molded insulator 1, it is easier to suppress coloring due to carbonization. As a result, the occurrence of appearance defects and the decrease in insulation properties due to carbonization in the three-dimensional molded insulator 1 can be suppressed.

[0133] Further, in the compatible resin, the molar fraction of the aromatic monomer in all monomer components is preferably 90% or less, more preferably 70% or less, still more preferably 50% or less. Such a compatible resin has a relatively high ratio of the structure derived from the aliphatic monomer. Therefore, good tracking resistance can be imparted to the three-dimensional molded insulator 1. Thereby, the three-dimensional molded insulator 1 having better performance in both flame retardancy and tracking resistance can be obtained. Also, for example, even when creeping discharge occurs in the three-dimensional molded insulator 1, it is easier to suppress coloring due to carbonization. As a result, the occurrence of appearance defects and the decrease in insulation properties due to carbonization in the three-dimensional molded insulator 1 can be suppressed. Note that the aromatic monomer refers to a monomer (aromatic compound) containing an aromatic ring structure.

[0134] Note that the polymer alloy may contain a resin other than the above components. That is, the polymer alloy may be formed by alloying three or more resins.

[0135] An example of a method for preparing a polymer alloy will be described. First, the raw materials are preliminarily mixed and then melted and kneaded using a batch kneader, a twin-screw extruder, or the like. By doing so, a mechanical stirring operation is applied to the raw materials, and a kneaded product containing the polymer alloy is obtained. The kneading and melting conditions are appropriately set according to the types and compounding ratios of the raw materials. As an example, the temperature is 200 to 250 °C, the screw rotation speed is 300 to 1000 rpm, and the kneading time is about 3 to 20 minutes. Next, the kneaded product is pelletized if necessary.

[0136] In addition, a compatibilizer may be added to the raw materials as necessary. By adding a compatibilizer, the compatibility of the resins to be alloyed can be further enhanced.

[0137] The addition amount of the compatibilizer is preferably 2 parts by mass or more and 30 parts by mass or less, and more preferably 5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the resin.

[0138] 3.2.6. Additives The three-dimensional molded insulator 1 may contain any additive. Examples of the additive include a flame retardant, a coloring material, a stabilizer, a lubricant, a processing aid, an antistatic agent, an antioxidant, a neutralizing agent, an ultraviolet absorber, a dispersant, a thickener, a mold release agent, a filler, a fluidity improver, a plasticizer, an antibacterial agent, and the like. Note that one type of additive may be contained, or two or more types may be contained in any combination.

[0139] Among these, the flame retardant enhances the flame retardancy of the three-dimensional molded insulator 1. Examples of the flame retardant include halogen-based flame retardants, inorganic phosphorus-based flame retardants such as red phosphorus and ammonium polyphosphate, organic phosphorus-based flame retardants such as triaryl phosphate compounds, metal hydroxide-based compounds, antimony oxide-based compounds, nitrogen-containing compounds, and the like. Also, two or more of these may be combined and used as the flame retardant.

[0140] Among these, as the flame retardant, a phosphorus-based flame retardant or a nitrogen-containing compound is preferably used, and a nitrogen-containing compound is more preferably used. By including a nitrogen-containing compound in the flame retardant, the flame retardancy of the three-dimensional molded insulator 1 can be further enhanced. In addition, since the nitrogen-containing compound does not contain a halogen atom, a so-called halogen-free and fluorine-free three-dimensional molded insulator 1 can be realized.

[0141] Examples of the nitrogen-containing compound include compounds having a triazine skeleton. Examples of the compound having a triazine skeleton include melamine; melamine derivatives such as butyl melamine, trimethylol melamine, hexamethylol melamine, hexamethoxymethyl melamine, and melamine phosphate; cyanuric acid; cyanuric acid derivatives such as methyl cyanurate, diethyl cyanurate, trimethyl cyanurate, and triethyl cyanurate; isocyanuric acid; isocyanuric acid derivatives such as methyl isocyanurate, N,N'-diethyl isocyanurate, tris methyl isocyanurate, tris ethyl isocyanurate, bis(2-carboxyethyl) isocyanurate, 1,3,5-tris(2-carboxyethyl) isocyanurate, and tris(2,3-epoxypropyl) isocyanurate; melamine cyanurate; melamine isocyanurate and the like. These compounds can be used alone or in combination of two or more.

[0142] Among these, as the compound having a triazine skeleton, one or more melamine-based compounds selected from the group consisting of melamine, melamine cyanurate, melamine isocyanurate, and their derivatives are preferably used, and melamine cyanurate is more preferably used. Thereby, the flame retardancy of the three-dimensional molded insulator 1 can be particularly enhanced.

[0143] The addition amount of the flame retardant is preferably 0.1 part by mass or more and 30 parts by mass or less, more preferably 1 part by mass or more and 20 parts by mass or less, and still more preferably 3 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the resin. By setting the addition amount of the flame retardant within the above range, the effect of enhancing the flame retardancy can be sufficiently exhibited, and side effects such as a decrease in mechanical properties due to an excess of the flame retardant can be suppressed.

[0144] The flame retardant is, for example, in a particulate form. In this case, the average particle diameter of the flame retardant is preferably 0.01 μm or more and 10 μm or less, more preferably 0.05 μm or more and 5 μm or less, and still more preferably 0.2 μm or more and 2 μm or less. When the average particle diameter of the flame retardant is within the above range, the dispersibility of the flame retardant becomes particularly good, so that the flame retardancy of the three-dimensional molded insulator 1 can be particularly enhanced. The average particle diameter of the flame retardant is the particle diameter when the cumulative from the small-diameter side in the volume-based particle size distribution is 50% using a laser diffraction particle size distribution measuring device.

[0145] Also, the total addition amount of the additives is preferably 0.1 part by mass or more and 10 parts by mass or less, more preferably 0.3 part by mass or more and 5 parts by mass or less, and still more preferably 0.5 part by mass or more and 3 parts by mass or less, based on 100 parts by mass of the resin.

[0146] 3.3. Multilayer Structure Next, the three-dimensional molded insulator 1 according to the modified example will be described. FIG. 7 is a cross-sectional view showing the three-dimensional molded insulator 1 according to the modified example.

[0147] Hereinafter, the three-dimensional molded insulator 1 according to the modified example will be described. In the following description, the description will focus on the differences from the three-dimensional molded insulator 1 shown in FIG. 1, and the description of the same matters will be omitted.

[0148] The three-dimensional molded insulator 1 shown in FIG. 7 is the same as the three-dimensional molded insulator 1 shown in FIG. 1 except that it has a multilayer structure.

[0149] The three-dimensional molded insulator 1 shown in FIG. 7 has a first layer 101, an intermediate layer 103, and a second layer 102 that are laminated in order from below. The intermediate layer 103 preferably has a lower surface (first surface) and an upper surface (second surface) that are in a front-back relationship with each other, and contains an aromatic polycarbonate resin and a flame retardant. The first layer 101 is laminated on the lower surface (first surface) of the intermediate layer 103 and contains a first resin. The second layer 102 is laminated on the upper surface (second surface) of the intermediate layer 103 and contains a second resin. And it is preferable that the first resin and the second resin are materials having higher tracking resistance than the aromatic polycarbonate resin contained in the intermediate layer 103.

[0150] According to such a configuration, since the aromatic polycarbonate resin is a polycarbonate resin containing an aromatic ring structure in the main chain and the ratio of the aromatic ring structure is high, good heat resistance is imparted to the intermediate layer 103. Further, the intermediate layer 103 contains a flame retardant. By the action of these, the intermediate layer 103 has good flame retardancy.

[0151] Further, the intermediate layer 103 is sandwiched between the first layer 101 and the second layer 102. Therefore, when surface discharge occurs along the three-dimensional molded insulator 1, the intermediate layer 103 is prevented from being directly exposed to arc discharge or the like. By using a material having higher tracking resistance than the aromatic polycarbonate resin as the resin contained in the first layer 101 and the second layer 102, good tracking resistance is imparted to the three-dimensional molded insulator 1. Therefore, a three-dimensional molded insulator 1 excellent in both flame retardancy and tracking resistance can be obtained.

[0152] Further, according to such a configuration, as one of the effects of the multilayer structure, improvement in pinhole resistance is achieved. By improving the pinhole resistance, the insulation, flame retardancy, and tracking resistance of the three-dimensional molded insulator 1 can be further enhanced.

[0153] The comparative tracking index CTI of each of the first resin and the second resin is preferably 400 V or more, and more preferably 600 V or more. Thereby, first resins and second resins with particularly good tracking resistance can be obtained.

[0154] In addition, the comparative tracking index CTI of each of the first resin and the second resin is preferably 50 V or more higher than the comparative tracking index CTI of the aromatic polycarbonate resin, and more preferably 100 V or more higher. Thereby, the three-dimensional molded insulator 1 that better combines flame retardancy and tracking resistance can be obtained.

[0155] The glass transition temperature Tg of each of the first resin and the second resin is preferably 125°C or higher, and more preferably 130°C or higher and lower than 200°C. Thereby, heat resistance is imparted to the first resin and the second resin. Therefore, for example, even when surface discharge occurs in the first layer 101 and the second layer 102, it becomes easier to suppress coloring due to carbonization. As a result, the occurrence of appearance defects and the decrease in insulation properties due to carbonization in the first layer 101 and the second layer 102 can be suppressed. The glass transition temperature Tg of each of the first resin and the second resin is measured by the DSC (differential scanning calorimeter) method. The heating rate in the DSC method is 10°C / min.

[0156] The melt volume rate (MVR) of each of the first resin and the second resin at 300°C and a load of 1.2 kg is 5 [cm 3 / 10 min] or more and 30 [cm 3 / 10 min] or less, preferably 8 [cm 3 / 10 min] or more and 20 [cm 3 / 10 min] or less. Thereby, the moldability in the secondary processing of the three-dimensional molded insulator 1, particularly the property of not causing defects such as distortion in vacuum molding, can be enhanced. When the melt volume rate is below the lower limit value, the fluidity may be insufficient and the moldability may decrease. On the other hand, when the melt volume rate exceeds the upper limit value, the impact resistance of the molded body may decrease. The melt volume rate is measured according to the test method specified in JIS K 7210:2014.

[0157] Further, in the first resin and the second resin, the molar fraction of the aromatic monomer in all the monomer components is preferably 90% or less, more preferably 70% or less, and even more preferably 50% or less. In such first and second resins, the ratio of the structure derived from the aliphatic monomer is relatively high. Therefore, good tracking resistance can be imparted to the first resin and the second resin. As a result, first and second resins having better performance in both flame retardancy and tracking resistance can be obtained. Also, for example, even when surface discharge occurs in the three-dimensional molded insulator 1, coloring due to carbonization is less likely to occur. As a result, the occurrence of appearance defects and a decrease in insulation properties due to carbonization in the three-dimensional molded insulator 1 can be suppressed. Note that the aromatic monomer refers to a monomer (aromatic compound) containing an aromatic ring structure.

[0158] The content of the first resin in the first layer 101 and the content of the second resin in the second layer 102 are preferably 70% by mass or more, and more preferably 80% by mass or more. Examples of the first resin and the second resin include the resin materials described above.

[0159] Here, the tracking resistance and the glass transition temperature Tg of the resin (compound) that can be used for the three-dimensional molded insulator 1 according to the present embodiment are exemplified. Table 1 below lists the CTI values representing the tracking resistance and the glass transition temperature Tg of various resins that can be used as the above-described resin materials (including the first resin and the second resin), and the above-described aromatic polycarbonate resin. Also, the viscosity average molecular weight of the aromatic polycarbonate resin is described.

[0160]

Table 1

[0161] As shown in Table 1, aromatic polycarbonate resins tend to have slightly lower tracking resistance than other resins. For this reason, using aromatic polycarbonate resins in combination with these resins is useful from the perspective of achieving both the characteristics of both resins.

[0162] Examples of the method for manufacturing the three-dimensional molded insulator 1 shown in FIG. 7 include a coextrusion method, a dry lamination method, an extrusion lamination method, a hot melt method, and the like.

[0163] 3.4. Characteristics of the three-dimensional molded insulator Next, the characteristics of the three-dimensional molded insulator 1 according to the embodiment will be described.

[0164] 3.4.1. Tracking resistance The tracking resistance of the three-dimensional molded insulator 1 according to the embodiment can be quantified by the comparative tracking index CTI, which is an index of the tracking resistance measured in accordance with ASTM D3638.

[0165] The comparative tracking index CTI (CTI value) of the three-dimensional molded insulator 1 according to the embodiment is preferably 600 V or more. If the CTI value is within the above range, the pollution severity level PLC representing the tracking resistance is 0, which is the highest rank. Therefore, it can be said that the three-dimensional molded insulator 1 with a CTI value within the above range has particularly good tracking resistance.

[0166] In the measurement method defined in IEC60112, third edition, the CTI value is measured using a 0.1 mass% ammonium chloride aqueous solution and platinum electrodes. More specifically, this ammonium chloride aqueous solution is dropped in a specified number of drops (50 drops), and the voltage at which all of the test pieces (n = 5) are not destroyed is obtained and taken as the CTI value.

[0167] Note that, as the test piece, a three-dimensional molded insulator 1 with a thickness of 3 mm or more is used. The test piece may be a stack of multiple three-dimensional molded insulators 1.

[0168] In addition, the measurement methods for the comparative tracking index CTI of the first resin and the second resin, and the comparative tracking index CTI of the aromatic polycarbonate resin are the same as described above. In this case, as the test piece, a sheet with a thickness of 3 mm or more obtained by extrusion molding these resins is used.

[0169] 3.4.2. Flame retardancy The flame retardancy of the three-dimensional molded insulator 1 according to the embodiment can be quantified by the rank of flame retardancy determined in accordance with the UL94 standard (the rank determined by the UL94V test or the UL94VTM test).

[0170] For the three-dimensional molded insulator 1 according to the embodiment, it is preferable that the determination rank by the UL94V test is V-0 at a test piece thickness of 0.4 mm or more, or the determination rank by the UL94VTM test is VTM-0 at a test piece thickness of 0.4 mm or more.

[0171] Since the three-dimensional molded insulator 1 satisfying such a determination rank satisfies the highest rank in each test, it can be said that the flame retardancy is particularly good.

[0172] In the UL94V test, a vertical combustion test is performed using a test piece having a size of 125 ± 5 mm × 13.0 ± 0.5 mm and a thickness of 0.4 mm or more and less than 13 mm.

[0173] The UL94VTM test is performed when the test piece is too thin to perform the UL94V test. In the UL94VTM test, a vertical combustion test is performed using a test piece having a size of 200 mm × 50 mm and a thickness of 0.4 mm or more and 0.25 mm or less.

[0174] 3.4.3. Dielectric breakdown voltage The dielectric breakdown voltage of the three-dimensional molded insulator 1 according to the embodiment is the dielectric breakdown voltage measured in accordance with the measurement method (alternating current test) of the dielectric breakdown strength defined in JIS C 2318:2020.

[0175] The breakdown voltage of the three-dimensional molded insulator 1 according to the embodiment is preferably 5 kV or more, more preferably 7 kV or more and 60 kV or less, and even more preferably 10 kV or more and 50 kV or less. The three-dimensional molded insulator 1 satisfying such a breakdown voltage contributes to ensuring sufficient insulation even when the insulation space distance is short. Note that the breakdown voltage may exceed the upper limit value, but in consideration of suppressing individual differences, it is preferably below the upper limit value.

[0176] 4. Method for manufacturing a three-dimensional molded insulator Next, a method for manufacturing the three-dimensional molded insulator 1 (method for manufacturing the three-dimensional molded insulator according to the embodiment) will be described.

[0177] First, using a raw material containing the above resin material, a thermoplastic insulating sheet having a flat shape is produced by a method such as a calendering method, an extrusion method, a press method, or a casting method. In the case of a thermoplastic insulating sheet having a multilayer structure, it is produced by the method described above.

[0178] Next, secondary processing including thermoforming is performed on the thermoplastic insulating sheet. Thereby, the recess 12 is formed. Thermoforming includes vacuum forming, pressure air forming, vacuum-pressure air forming, etc. According to such thermoforming, a three-dimensional molded insulator 1 with little variation in thickness due to shape and high shape accuracy can be obtained. Further, according to vacuum forming and vacuum-pressure air forming, particularly high shape accuracy can be obtained.

[0179] The heating temperature during thermoforming is not particularly limited, but is preferably 130°C or more and 260°C or less, and more preferably 140°C or more and 240°C or less. Thereby, a three-dimensional molded insulator 1 with particularly little variation in thickness and particularly high shape accuracy can be obtained.

[0180] Also, another secondary processing may be added before or after the thermoforming. Examples of another secondary processing include bending processing and punching processing.

[0181] 5. Method for using a three-dimensional molded insulator Next, an example of use of the three-dimensional molded insulator 1 will be described.

[0182] FIG. 8 is a cross-sectional view showing a control device 8 in which the three-dimensional molded insulator 1 and the circuit board 9 according to the embodiment are housed in a case 80.

[0183] The control device 8 shown in FIG. 8 includes a circuit board 9, a three-dimensional molded insulator 1, and a case 80 that houses these components inside. Note that the device including the circuit board 9 is not limited to the control device 8 and may be any device having any function.

[0184] The case 80 has a bottomed box-shaped housing 81 with an open upper surface, a lid portion 82 that closes the opening of the housing 81, and a heat dissipation sheet 85.

[0185] The housing 81 has a bottom portion that extends along the X-Y plane and a wall portion that rises upward from the outer end of the bottom portion. The circuit board 9 is housed inside the housing 81. The circuit board 9 is fixed to the housing 81 by fixing screws 94 (not shown in FIG. 8). Further, the circuit board 9 is fixed in a state of being in contact with the heat dissipation sheet 85.

[0186] The lid portion 82 only needs to close the opening of the housing 81, but it is preferably sealed in a liquid-tight or airtight manner. Thereby, the circuit board 9 can be stably protected from the external environment.

[0187] Examples of the constituent materials of the housing 81 and the lid portion 82 include metal materials, ceramic materials, resin materials, etc. Also, a composite material using two or more of these may be used. Among these, a metal material is preferably used. Since the metal material is excellent in thermal conductivity and mechanical properties, it is useful as the constituent material of the housing 81 and the lid portion 82. Also, since the metal material is often excellent in conductivity and magnetic permeability, it becomes possible to use the housing 81 and the lid portion 82 as an electromagnetic shield or a magnetic field shield.

[0188] In addition, when using a metal material, there is a concern about a short circuit between the circuit board 9 and the metal material. In particular, since a short circuit is likely to occur between the component protruding from the upper surface of the wiring board 90 and the lid portion 82, conventionally, it has been necessary to secure a necessary space distance between them.

[0189] On the other hand, by using the three-dimensional molded insulator 1, this space distance can be shortened. For example, as shown in FIG. 8, the separation distances S3 between the power semiconductor element 91 and the lid portion 82, and S4 between the bus bar 92 and the lid portion 82 can be shortened respectively. As a result, the thickness reduction and size reduction of the control device 8 become possible.

[0190] The separation distances S3 and S4 vary depending on the voltage applied to the component, etc., but as an example, it is preferably 10 mm or less, and more preferably 5 mm or less. As a result, further thickness reduction and size reduction of the control device 8 become possible.

[0191] In addition, by using the three-dimensional molded insulator 1, a sufficient space SP can be secured between the flat portion 11 of the three-dimensional molded insulator 1 and the lid portion 82. Since insulation is ensured with the power semiconductor element 91, the bus bar 92, etc., even when used for accommodating another object, for example, the occurrence of a short circuit, etc., can be suppressed.

[0192] FIG. 9 is a cross-sectional view showing a modified example of the control device 8 in FIG. 8. The case 80 shown in FIG. 9 is the same as the case 80 shown in FIG. 8 except that a partition wall 83 is added. The partition wall 83 is installed inside the housing 81 and separates the internal space of the housing 81 vertically. The circuit board 9 and the three-dimensional molded insulator 1 are accommodated in the space below the partition wall 83. Another circuit board 7 different from the circuit board 9 is accommodated in the space above the partition wall 83. The circuit board 7 includes a wiring board 71 and a semiconductor element 72. By accommodating such a circuit board 7 in the same space as the circuit board 9, it is possible to achieve a high functionality of the control device 8 while minimizing the height of the case 80.

[0193] Note that, on the lower surface of the lid portion 82 shown in FIG. 9, another flat insulating sheet 2 is provided. This flat insulating sheet 2 has a flat shape. By providing such a flat insulating sheet 2, it is possible to shorten the necessary space distance between the circuit board 7 and the lid portion 82. As a result, the height of the case 80 can be further reduced.

[0194] As described above, by using the three-dimensional molded insulator 1 and the flat insulating sheet 2 in combination, it is possible to achieve both high functionality and miniaturization of the control device 8.

[0195] 6. Effects of the Embodiment The three-dimensional molded insulator 1 according to the embodiment is a three-dimensional molded insulator that covers a component to which a voltage is applied. Such a three-dimensional molded insulator 1 is molded into a shape having a recess 12. The recess 12 includes a bottom portion 12a and a wall portion 12b provided at an end of the bottom portion 12a. Then, the three-dimensional molded insulator 1 is used with a component inserted into the recess 12.

[0196] According to such a configuration, by providing the recess 12 in accordance with the component to which a voltage is applied, the dead space generated around the component can be reduced. As a result, effective use of the space in which the component is accommodated becomes possible. As a result, miniaturization of the device on which the component is mounted can be achieved.

[0197] Further, it may be used by covering a circuit board 9 including a component and a wiring board 90 (substrate) on which the component is mounted. In this case, the three-dimensional molded insulator 1 is preferably molded into a shape having a recess 12 and a flat portion 11 connected to the recess 12.

[0198] According to such a configuration, by providing the recess 12 in accordance with the component mounted on the wiring board 90, the dead space generated between the circuit board 9 and the three-dimensional molded insulator 1 (around the component) can be reduced. As a result, effective use of the space in which the circuit board 9 is accommodated becomes possible. As a result, miniaturization of the device on which the circuit board 9 is mounted can be achieved.

[0199] In addition, the three-dimensional molded insulator 1 according to the embodiment has a through hole 13 that penetrates the flat portion 11 in the thickness direction.

[0200] According to such a configuration, when fixing screws 94 or the like are provided in accordance with the through hole 13, even when the three-dimensional molded insulator 1 is placed over the circuit board 9, the rotational operation of the fixing screw 94 becomes possible. Therefore, with the three-dimensional molded insulator 1 placed over the circuit board 9, it becomes possible to screw the circuit board 9 to a case or the like, improving the assembly workability.

[0201] Also, the thickness t12b of the wall portion 12b is preferably 20% or more and 95% or less of the thickness t11 of the flat portion 11.

[0202] According to such a configuration, the wall portion 12b has sufficient rigidity to support the shape of the concave portion 12 and can contribute to further reduction of the dead space on the side of the concave portion 12.

[0203] Also, the thickness t11 of the flat portion 11 is preferably 0.05 mm or more and 1.00 mm or less.

[0204] According to such a configuration, a three-dimensional molded insulator 1 that is excellent in flame retardancy, tracking resistance, and insulation properties and is relatively easy to manufacture can be obtained.

[0205] In addition, the three-dimensional molded insulator 1 according to the embodiment may contain a flame retardant. According to such a configuration, a three-dimensional molded insulator 1 excellent in flame retardancy can be obtained.

[0206] Also, it is preferable that the three-dimensional molded insulator 1 according to the embodiment has a thermoplastic resin as the main material.

[0207] A sheet made of a thermoplastic resin as the main material can be plastically deformed by heat and is excellent in secondary processability. Therefore, a three-dimensional molded insulator 1 that can be manufactured by thermoforming and is excellent in manufacturing ease can be obtained.

[0208] Further, the thermoplastic resin may contain an aromatic polycarbonate resin. According to such a configuration, the three-dimensional molded insulator 1 having excellent heat resistance and flame retardancy derived from the aromatic ring structure can be obtained.

[0209] Also, for the three-dimensional molded insulator 1 according to the above embodiment, the comparative tracking index CTI, which is an index of tracking resistance measured in accordance with ASTM D3638, is preferably 600 V or more.

[0210] According to such a configuration, the three-dimensional molded insulator 1 having particularly good tracking resistance can be obtained.

[0211] Also, for the three-dimensional molded insulator 1 according to the above embodiment, the flame retardancy rank determined in accordance with the UL94 standard is preferably V-0 or VTM-0 when the test piece thickness is 0.4 mm or more. According to such a configuration, the three-dimensional molded insulator 1 having particularly good flame retardancy can be obtained.

[0212] Also, the method for manufacturing the three-dimensional molded insulator according to the above embodiment is a method for manufacturing the three-dimensional molded insulator 1, in which secondary processing including thermoforming is performed on a flat thermoplastic insulating sheet to form the concave portion 12. According to such a configuration, a three-dimensional molded insulator with high shape accuracy can be manufactured.

[0213] Also, the thermoforming is preferably vacuum forming or vacuum-pressure forming. According to such a configuration, a three-dimensional molded insulator with particularly high shape accuracy can be manufactured.

[0214] As described above, the three-dimensional molded insulator and the method for manufacturing the three-dimensional molded insulator of the present invention have been described, but the present invention is not limited to the above embodiment.

[0215] For example, additives different from the additives described in the above embodiment may be added to the three-dimensional molded insulator of the present invention.

[0216] In addition, the three-dimensional molded insulator of the present invention may be one in which a layer having an arbitrary function, such as an adhesive layer, an adhesive layer, a protective layer, a release layer, etc., is added to the layer configuration described in the above embodiment.

[0217] Furthermore, the method for manufacturing the three-dimensional molded insulator of the present invention may be one in which a process for an arbitrary purpose is added to the above embodiment.

Explanation of Reference Numerals

[0218] 1 Three-dimensional molded insulator 2 Flat insulating sheet 7 Circuit board 8 Control device 9 Circuit board 11 Flat part 12 Concave part 13 Through hole 71 Wiring board 72 Semiconductor element 80 Case 81 Housing 82 Lid part 83 Partition wall 85 Heat dissipation sheet 90 Wiring board 91 Power semiconductor element 92 Bus bar 93 Signal connector 94 Fixing screw 101 First layer 102 Second layer 103 Intermediate layer 110 Flat surface 121 Concave part 122 Concave part 123 Concave part 901 Insulating layer 902 Wiring layer 903 Through wiring 904 Thermal via 921 Bus bar 922 Bus bar L1 Spatial distance S1 Separation distance S2 Separation distance S3 Separation distance S4 Separation distance SP Space

Claims

1. A three-dimensional molded insulator that covers a component to which a voltage is applied (excluding those having an electromagnetic wave shielding layer), wherein a sheet made of a thermoplastic resin as a main material is formed into a shape having a recess including a bottom portion and a wall portion provided at an end of the bottom portion, and a flat portion connected to the recess, one surface of the recess is a surface recessed in a first direction, the other surface of the recess is a surface protruding in the first direction, and the three-dimensional molded insulator is used in a state where the component is inserted into the recess.

2. The three-dimensional molded insulator according to claim 1, which is used by covering a circuit board including the component and a substrate on which the component is mounted.

3. The three-dimensional molded insulator according to claim 2, which has a through hole penetrating the flat portion in a thickness direction.

4. The three-dimensional molded insulator according to claim 3, wherein the thickness of the wall portion is 20% or more and 95% or less of the thickness of the flat portion.

5. The three-dimensional molded insulator according to claim 3 or 4, wherein the thickness of the flat portion is 0.05 mm or more and 1.00 mm or less.

6. The three-dimensional molded insulator according to any one of claims 1 to 4, which contains a flame retardant.

7. The three-dimensional molded insulator according to any one of claims 1 to 4, wherein the thermoplastic resin contains an aromatic polycarbonate resin.

8. The three-dimensional molded insulator according to any one of claims 1 to 4, which is used so that a gap is formed between the component and the recess.

9. The three-dimensional molded insulator according to any one of claims 1 to 4, wherein the constituent material is a polymer alloy formed by alloying an aromatic polycarbonate resin and a compatible resin.

10. The three-dimensional molded insulator according to claim 9, wherein the comparative tracking index CTI of the compatible resin is 50 V or more higher than the comparative tracking index CTI of the aromatic polycarbonate resin.

11. The three-dimensional molded insulator according to claim 9, wherein the compatible resin has a molar fraction of aromatic monomers in all monomer components of 90% or less.

12. The three-dimensional molded insulator according to claim 9, wherein the compatible resin is a polyolefin resin.

13. The three-dimensional molded insulator according to claim 9, wherein the compatible resin is a polyamide resin.

14. The three-dimensional molded insulator according to claim 9, wherein the compatible resin is an aromatic polycarbonate resin containing bisphenol isophorone carbonate units.

15. The three-dimensional molded insulator according to claim 9, wherein the compatible resin is an aliphatic polycarbonate resin.

16.

16. The three-dimensional molded insulator according to any one of claims 1 to 4, wherein the comparative tracking index CTI, which is an index of tracking resistance measured in accordance with ASTM D3638, is 600 V or more.

17.

17. The three-dimensional molded insulator according to any one of claims 1 to 4, wherein the flame retardancy measured in accordance with the UL94 standard is V-0 or VTM-0 when the test piece thickness is 0.4 mm or more.

18.

18. A method for manufacturing a three-dimensional molded insulator according to any one of claims 1 to 4, characterized in that secondary processing including thermoforming is performed on a thermoplastic insulating sheet having a flat shape to form the concave portion.

19.

19. The method for manufacturing a three-dimensional molded insulator according to claim 18, wherein the thermoforming is vacuum forming or vacuum pressure forming.

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