Resin mold structure, insert mold component, and insert member for insert mold component

Abstract

To provide a resin mold structure with which the bonding strength between an insert member constituting an insert mold component and a resin is enhanced.SOLUTION: A resin mold structure is formed by insert molding an insert member 100 with a resin 200. A first recess 110 and a second recess 120 are provided on a predetermined surface of the insert member 100. The first recess 110 and the second recess 120 communicate with each other. A resin 200 enters the first recess 110 and the second recess 120.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a resin molded structure, an insert molded part, and an insert member for an insert molded part. [Background technology]

[0002] 2. Description of the Related Art In electronic products and the like, a structure is used in which a recess is formed in part of an insert member made of metal, ceramic or the like by laser processing or the like, and then insert molding is performed to improve the bonding strength with the molding resin.

[0003] Patent Document 1 discloses a metal-resin composite molding in which a surface of an insert metal member is irradiated with laser light having a predetermined spot diameter to form multiple recesses on the surface, forming a roughened region with multiple wave-shaped extensions, and then a resin member is molded into the roughened region. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-56736 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the insert member used in the conventional insert molded parts, the recess is formed by irradiating the laser light in one direction, so the recess has a dead end shape. Therefore, the air in the recess cannot be sufficiently released to the outside during molding. Therefore, it is difficult to sufficiently fill the recess with resin. As a result, the function of the undercut of the recess is not fully exerted, and the resin that has entered the recess may not fully contribute to improving the joining strength.

[0006] The metal resin composite molded body described in Patent Document 1 does not solve the problem of the dead end of the recess, and there is thought to be room for improvement.

[0007] An object of the present disclosure is to increase the bonding strength between an insert member and a resin that constitutes an insert molded part. [Means for solving the problem]

[0008] The resin molded structure of the present disclosure is a structure formed by insert molding an insert member with resin, in which a first recess and a second recess are provided on a specific surface of the insert member, the first recess and the second recess are connected, and resin has entered the first recess and the second recess. Effect of the Invention

[0009] According to the present disclosure, it is possible to increase the bonding strength between the insert member and the resin that constitutes the insert molded component. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective view showing the insert molded part of the first embodiment. [Diagram 2] 2 is an enlarged schematic cross-sectional view showing a resin mold structure of the insert molded part of FIG. 1. [Diagram 3] FIG. 1 is an enlarged schematic cross-sectional view showing a resin mold structure of a conventional insert molded part. [Figure 4] FIG. 2 is an enlarged schematic cross-sectional view showing a desirable resin mold structure of Example 1. [Diagram 5] FIG. 11 is an enlarged schematic cross-sectional view showing a resin mold structure of the insert molded part of Example 2. [Figure 6] FIG. 11 is an enlarged schematic cross-sectional view showing a desirable resin mold structure of Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. The embodiment is an example for explaining the contents of the present disclosure, and has been omitted or simplified as appropriate for clarity of explanation. The present disclosure can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0012] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present disclosure is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings. EXAMPLES

[0013] FIG. 1 is a perspective view showing an insert molded part according to a first embodiment.

[0014] The insert molded part shown in this figure has a configuration in which an insert member 100 is insert molded into a resin 200. In the figure, the right side surface and the bottom surface of the insert member 100 are exposed to the outside. In this figure, the insert member 100 is in a quadrangular prism shape, and the overall shape of the insert molded part is also in a quadrangular prism shape. However, the overall shape of the insert member 100 and the insert molded part is not limited to a quadrangular prism shape, and may be a polygonal column shape other than a quadrangular prism shape, a cylindrical shape, an elliptical cylinder shape, or the like. In addition, the insert member 100 may have burrs, sagging, etc. formed during cutting, punching, etc. remaining thereon.

[0015] It should be noted that the insert member 100 does not need to have an exposed surface as shown in this figure, and the effect of the insert molded part of the present disclosure can be obtained regardless of the configuration of the insert molded part.

[0016] The insert member 100 is made of metal, ceramic, etc. As the metal, an alloy mainly composed of any of copper, nickel, iron, platinum, etc. is used. However, the type of alloy is not limited to these examples. As the ceramic, silica, alumina, etc. are used. However, the type of ceramic is not limited to these examples. Furthermore, as the resin, polyethylene, polypropylene, polyacrylonitrile, polycarbonate, polyamide, polyimide, polyacetal, etc. are used. However, the type of resin is not limited to these examples.

[0017] FIG. 2 is an enlarged schematic cross-sectional view showing a resin mold structure of the insert molded part of FIG.

[0018] In FIG. 2, the joint (boundary portion) between the insert member 100 and the resin 200 is shown.

[0019] A first recess 110 and a second recess 120 are formed on a flat surface (one flat face) of the insert member 100 that constitutes the joint. The first recess 110 and the second recess 120 are formed by laser irradiation from different directions. The first recess 110 and the second recess 120 intersect spatially and partially share a space. This space is covered by a bridge 130. In other words, the first recess 110 and the second recess 120 are in communication with each other.

[0020] Here, the flat surface refers to, for example, one of the planes constituting the quadrangular prism in the case of the quadrangular prism-shaped insert member 100 in Fig. 1. Such a plane is surrounded by several ridges (four ridges in the case of a quadrangular prism). Furthermore, when the insert member 100 is cylindrical, the circular bottom surface is of course a flat surface. The side surface of a cylinder is also a convex surface with no ridges, and when viewed partially, the side surface can be said to be a nearly flat surface.

[0021] In summary, in this specification, a "flat surface" refers to a surface that does not include edges or vertices macroscopically, and includes convex and concave surfaces.

[0022] In addition, since the insert member 100 may have burrs, sagging, etc. formed during cutting, punching, etc., burrs, sagging, etc. may be present on the actual flat surface, or on either the ridge line or the apex.

[0023] The first recess 110 and the second recess 120 are filled with a resin 200 .

[0024] Also, a first burr 111 is formed on the periphery of the first opening, which is the entrance part of the first recess 110. Meanwhile, a second burr 121 is formed on the periphery of the second opening, which is the entrance part of the second recess 120. Furthermore, a third burr 122 is formed on the inner wall of the first recess 110. Note that a "burr" is also called a "protrusion."

[0025] The laser is first irradiated from a direction in which the first recess 110 is formed. At this time, the first burr 111 is formed. Next, the laser is irradiated from a direction in which the second recess 120 is formed. At this time, the second burr 121 is formed. The laser for forming the second recess 120 also hits the inner wall surface of the existing first recess 110. As a result, the third burr 122 is formed. In summary, the third burr 122 is formed by forming the second recess 120 after forming the first recess 110.

[0026] When the insert member 100 is irradiated with a laser, the temperature of the irradiated portion rises instantaneously, and part of the insert member 100 melts and evaporates to form a recess. At the same time, the melted and evaporated insert member 100 is instantaneously cooled by the air or nearby insert members 100 and adheres to the insert member 100, forming a burr.

[0027] Since the first recess 110 and the second recess 120 are connected, when the resin is filled, the resin can easily enter and the air in the recess can easily be discharged. In other words, the volume of the dead end of the recess is small, and most of the air in the recess can easily be pushed out by the resin. This promotes filling with the resin.

[0028] The bonding strength between the insert member 100 and the resin 200 can be improved because the first recess 110 and the second recess 120 are easily filled with resin, the resin is bonded at the portion where the first recess 110 and the second recess 120 communicate with each other (in other words, the bridge 130 becomes an undercut), and the first burr 111, the second burr 121, and the third burr 122 increase the contact area with the resin 200. Note that the bridge 130 has a larger volume as an undercut than a burr, and therefore contributes greatly to improving the bonding strength.

[0029] In this figure, only one set of the first recess 110 and the second recess 120 is shown, but in reality, these sets are arranged vertically and horizontally. These sets may be arranged regularly or irregularly. The interval between these sets is not particularly limited, and if necessary, they may be arranged closely enough that the openings of adjacent sets overlap.

[0030] In addition, in this embodiment, the number of recesses in one set is two, but the resin mold structure of the present disclosure is not limited to this, and the number of recesses in one set may be three or more. In other words, the resin mold structure may be configured such that one or more other recesses are provided to communicate with at least one of the first recess 110 and the second recess 120. If the number of communicating recesses is large, the shape of the resin inside the recess becomes complex, the number of burrs increases, and the directions of the burrs become diverse, making it easier for the resin to be filled, and the joining strength can be further improved.

[0031] The spot diameter of the laser is preferably about 10 μm to 100 μm. Also, it is preferable to irradiate the laser in a pulsed manner.

[0032] When the above-mentioned sets of recesses are arranged regularly, for example, first, a pulsed laser is irradiated at the same angle to the surface while moving the laser device, thereby forming a plurality of first recesses 110. Next, the angle is changed, and a pulsed laser is irradiated at the changed angle while moving the laser device, thereby forming a plurality of second recesses 120.

[0033] In this embodiment, the recesses are formed by a laser, but the resin mold structure of the present disclosure is not limited to this, and the recesses may be formed by drilling or punching.

[0034] (Comparative Example) FIG. 3 is an enlarged schematic cross-sectional view showing a resin mold structure of a conventional insert molded part as a comparative example.

[0035] As shown in this figure, in the resin mold structure of a conventional insert molded part, one recess 310 is formed at one location on the surface of the insert member 100. In this case, one recess 310 is formed by irradiating the surface with a laser once from a direction perpendicular to the surface. As a result, a burr 311 is formed at the opening, which is the entrance portion of the recess 310.

[0036] In the resin mold structure of this comparative example, when the resin 200 is filled, air tends to remain in the recess 310, making it difficult for the resin 200 to enter. For this reason, the bonding strength between the insert member 100 and the resin 200 may not be sufficiently high.

[0037] Next, a desirable configuration of the first embodiment will be described.

[0038] FIG. 4 is an enlarged schematic cross-sectional view showing a desirable resin mold structure of the first embodiment.

[0039] In this figure, the portions corresponding to the tip of the second recess 120 and the third burr 122 in Figure 2 are hatched. The boundary indicated by the dotted line corresponds to the inner wall surface of the first recess 110 in a state in which the tip of the second recess 120 and the third burr 122 are not formed in the first recess 110. In other words, the tip of the second recess 120 is a portion of the second recess 120 that is deeper than the inner wall surface of the first recess 110.

[0040] As mentioned above, in laser processing, the insert material that was in the recess before the recess was formed melts, evaporates, and moves due to laser irradiation, becoming a burr. Therefore, there is a correlation between the volume of the recess and the volume of the burr.

[0041] It is desirable to adjust the conditions of the laser processing so that the volume of the third burr 122 is 50% or more of the volume of the tip of the second recess 120. In this case, even if the volume of the third burr 122 becomes 100% of the volume of the tip of the second recess 120, the third burr 122 is disposed in a dispersed manner, and therefore the first recess 110 is not likely to be blocked. This allows the resin 200 to enter the space in the three-dimensional structure formed by the tip of the second recess 120 and the third burr 122, and the joining strength can be further increased. EXAMPLES

[0042] FIG. 5 is an enlarged schematic cross-sectional view showing a resin mold structure of the insert molded part of the second embodiment.

[0043] This figure shows a joint (boundary portion) between the ridge or apex of the insert member 100 and the resin 200. In the following explanation, explanation of the same configuration as in FIG. 2 will be omitted.

[0044] At the ridge of the insert member 100 constituting the joint, two flat surfaces intersect, and at the apex, three flat surfaces intersect. As shown in FIG. 5, a first recess 110 is formed on one surface, and a second recess 120 is formed on the other surface. The first recess 110 and the second recess 120 are formed by laser irradiation from different directions. The first recess 110 and the second recess 120 are connected to each other. The bridge 130 includes the ridge or the apex of the insert member 100.

[0045] The apex is configured such that, in addition to the two flat surfaces shown in the figure, another flat surface (not shown) intersects with the apex. In this case, another recess is provided on the other flat surface. The other recess is connected to at least one of the first recess 110 and the second recess 120.

[0046] In this specification, "two intersecting flat surfaces" refers to a state in which two surfaces that do not include a ridgeline or a vertex intersect to form a ridgeline when viewed macroscopically, and "three intersecting flat surfaces" refers to a state in which three surfaces that do not include a ridgeline or a vertex intersect to form a ridgeline and a vertex when viewed macroscopically.

[0047] In this embodiment as well, similarly to the first embodiment, the bonding strength between the insert member 100 and the resin 200 can be improved.

[0048] FIG. 6 is an enlarged schematic cross-sectional view showing a desirable resin mold structure of the second embodiment.

[0049] In this drawing, the portions corresponding to the tip end of the second recess 120 and the third burr 122 in FIG. 5 are hatched.

[0050] FIG. 6 also shows that there is a correlation between the volume of the recessed portion and the volume of the burrs, similarly to FIG. 4 of the first embodiment.

[0051] In this embodiment as well, it is desirable to adjust the conditions of the laser processing so that the volume of the third burr 122 is 50% or more of the volume of the tip of the second recess 120. [Explanation of symbols]

[0052] 100: insert member, 110: first recess, 111: first burr, 120: second recess, 121: second burr, 122: third burr, 130: bridge, 200: resin.

Claims

1. The structure is formed by insert molding an insert member with resin, A first recess and a second recess are provided on a predetermined surface of the insert member, The first recess and the second recess communicate with each other, A resin mold structure, wherein the resin has entered the first recess and the second recess.

2. The resin mold structure according to claim 1 , wherein a protrusion is formed on an inner wall of the first recess.

3. The resin mold structure according to claim 1 , wherein a protrusion is formed on the periphery of the opening of the first recess and the second recess.

4. 3. The resin mold structure according to claim 2, wherein a volume of the protrusion formed on the inner wall of the first recess is 50% or more of a volume of the tip of the second recess.

5. The resin mold structure according to claim 1 , wherein the predetermined surface of the insert member is provided with one or more other recesses that communicate with at least one of the first recess and the second recess.

6. The predetermined surface of the insert member is formed of a single flat surface, The resin mold structure according to claim 1 , wherein the first recess and the second recess are provided in the one flat surface.

7. the predetermined surface of the insert member includes two flat surfaces; the first recess is provided in one of the two flat surfaces; The resin mold structure according to claim 1 , wherein the second recess is provided in the other of the two flat surfaces.

8. the predetermined surface of the insert member further includes another flat surface; the other flat surface is provided with another recess; The resin mold structure according to claim 7 , wherein the other recess is in communication with at least one of the first recess and the second recess.

9. An insert member; A resin, The insert member has a structure formed by insert molding with the resin, A first recess and a second recess are provided on a predetermined surface of the insert member, The first recess and the second recess communicate with each other, The resin has entered the first recess and the second recess.

10. A first recess and a second recess are provided on the predetermined surface, The first recess and the second recess communicate with each other, An insert member for an insert molded part, in which resin enters the first recess and the second recess by insert molding.

Images