JP2009234202A - Molded part and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molded part and its manufacturing method easily joining an insert part in a receiving hole with high strength. <P>SOLUTION: When inserting the insert part 28 into the receiving hole 26, a solder material 34 is sandwiched between an outer wall surface of the insert part 28 and an inner wall surface of the receiving hole 26. When heating the solder material 34, the solder material 34 melts. A metallic material 33 is exposed to the inner wall surface of the receiving hole 26. The solder material 34 sufficiently wets and expands between the outer wall surface of the insert part 28 and the inner wall surface of the receiving hole 26. Afterwards, the solder material 34 is solidified based on cooling. Thus, the solder material 34 can join the insert part 28 in the receiving hole 26 with high strength. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a molded part including, for example, an insert part.

  For example, an electronic device such as a mobile phone terminal includes a housing made of resin, for example. A resin boss is formed on the inner wall surface of the housing. The boss stands upright from the inner wall surface of the housing. A metal plating film is formed on the surface of the housing or the surface of the boss based on, for example, vapor deposition. Such a metal plating film realizes an electromagnetic shielding function and a high heat dissipation function in the casing. At the same time, the metal plating film improves the strength of the thin resin.

A metal insert nut is embedded in the boss. A female thread is cut on the inner wall surface of the insert nut. A male screw is screwed into the insert nut. Thus, for example, the printed circuit board is fixed to the housing. The shield ground is secured by the action of the insert nut.
JP-A-8-47942

  In embedding the insert nut in the boss, the insert nut is heated to a high temperature, for example. As a result, the resin boss is softened when the insert nut is press-fitted. So-called hot pressing is performed. However, when the housing or the boss is formed of, for example, a high heat resistant resin material, a metal material, a ceramic material, or a glass material, the boss is not softened. Therefore, hot pressing cannot be performed.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a molded part capable of easily joining an insert part with high strength in a receiving hole and a manufacturing method thereof.

  In order to achieve the above object, a method of manufacturing a molded part includes inserting an insert part into a receiving hole formed in the molded part, and exposing an outer wall surface of the insert part and the receiving hole exposing the metal material. It comprises a step of sandwiching a solder material between wall surfaces and a step of heating the solder material to melt the solder material.

  According to such a method for manufacturing a molded part, when the insert part is inserted into the receiving hole, the solder material is sandwiched between the outer wall surface of the insert part and the inner wall surface of the receiving hole. When the solder material is heated, the solder material melts. A metal material is exposed on the inner wall surface of the receiving hole. The solder material spreads sufficiently between the outer wall surface of the insert part and the inner wall surface of the receiving hole. Thereafter, the solder material is solidified based on the cooling. Thus, the solder material can join the insert part in the receiving hole with high strength.

  The solder material may be applied in advance to the outer wall surface of the insert part based on plating. On the other hand, the solder material may be arranged in advance in a groove formed on the outer wall surface of the insert part. The molded part is formed of at least one of a metal material, a thermoplastic resin material, a thermosetting resin material, a ceramic material, and a glass material. A low melting point solder is used as the solder material. It is sufficient that the solder material is heated at a relatively low temperature when melting the low melting point solder. Therefore, deformation and breakage of the main body due to heat are avoided as much as possible.

  To achieve the above object, a molded part includes a main body, a receiving hole formed in the main body to expose a metal material on the inner wall surface, an insert part received in the receiving hole, an inner wall surface of the receiving hole, and And a solder material sandwiched between outer wall surfaces of the insert part.

  In such a molded part, a solder material is sandwiched between the outer wall surface of the insert part and the inner wall surface of the receiving hole. A metal material is exposed on the inner wall surface of the receiving hole. As a result, the solder material can join the insert part in the receiving hole with high strength. In such a molded part, the main body is formed of at least one of a metal material, a thermoplastic resin material, a thermosetting resin material, a ceramic material, and a glass material. A low melting point solder is used as the solder material.

  In order to achieve the above object, the insert component includes a component main body that defines a screw hole, and a solder material that is disposed at least on the outer wall surface of the component main body. Such insert parts can greatly contribute to the realization of the aforementioned molded parts.

  The solder material may be formed from a plating film applied to the outer wall surface of the component main body based on plating. On the other hand, the solder material may be formed from an annular solder material disposed in a groove formed in the outer wall surface of the component main body. A low melting point solder is used as the solder material.

  As described above, according to the molded part and the manufacturing method thereof, the insert part can be easily joined with high strength in the receiving hole.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 schematically shows an external appearance of a specific example of an electronic apparatus, that is, a foldable mobile phone terminal 11. The mobile phone terminal 11 includes a transmitter 12 and a receiver 13. The transmitter 12 includes a main body, that is, a main body casing 14. A printed circuit board unit to be described later is incorporated in the main body casing 14. The printed circuit board unit includes a processing circuit such as a CPU (Central Processing Unit) and a memory. An input button 15 such as an on-hook button, an off-hook button, or a dial key is embedded in the front flat surface of the transmitter 12. Depending on the operation of the input button 15, the CPU executes various processes. The main housing 14 is formed from, for example, a reinforced resin material.

  The handset 13 includes a main body, that is, a display housing 16. A flat display panel such as a liquid crystal display (LCD) panel 17 is incorporated in the display housing 16. A display opening 18 is defined on the front flat surface of the display housing 16. The screen of the LCD panel 17 faces the display opening 18. Various texts and graphics are displayed on the screen of the LCD panel 17 in accordance with the processing operation of the CPU. The display housing 16 is formed from, for example, a reinforced resin material.

  The handset 13 can swing around the horizontal axis 19 by the action of a hinge with respect to the handset 12. The horizontal axis 19 is set at one end of the main body housing 14 in parallel with the front flat surface. When the handset 13 is swung around the horizontal axis 19 in the mobile phone terminal 11 in the opened state, the front flat surface of the display housing 16 is superimposed on the front flat surface of the main housing 14 inward. The mobile phone terminal 11 is closed. As a result, the closed state of the mobile phone terminal 11 is established.

  As shown in FIG. 2, a printed circuit board unit 21 is accommodated in the main body housing 14. The printed circuit board unit 21 includes a printed circuit board 22 made of resin, for example. A plurality of electronic components 23 such as a CPU chip and a memory are mounted on the surface of the printed circuit board 22. The printed circuit board 22 is fixed to the main housing 14 with a plurality of screws 24, for example. Each screw 24 is screwed into a cylindrical boss 25 rising from the bottom surface of the main body housing 14. The boss 25 is integrated with the bottom plate of the main body casing 14 based on integral molding.

  As shown in FIG. 3, the boss 25 includes, for example, a cylindrical receiving hole or boss hole 26. The boss hole 26 defines a large diameter space 26a having a first inner diameter and a small diameter space 26b having a second inner diameter smaller than the first inner diameter. One end of the small diameter space 26b is connected to the other end of the large diameter space 26a. One end of the large diameter space 26 a is adjacent to the upper end of the boss 25. The other end of the small diameter space 26 b is adjacent to the lower end of the boss 25. An annular step surface 27 is formed on the inner wall surface of the boss 25 between the large diameter space 26a and the small diameter space 26b. The step surface 27 extends, for example, parallel to the bottom surface of the main housing 14.

  A metal insert part, that is, an insert nut 28 is received in the large-diameter space 26 a of the boss 25. The insert nut 28 includes a cylindrical component body 29, for example. The outer diameter of the component main body 29 is formed slightly smaller than the first inner diameter of the large-diameter space 26a. Here, for example, the outer diameter of the component main body 29 may be set to be smaller by about 0.2 mm than the first inner diameter of the large-diameter space 26a. The bottom surface of the component main body 29 is received by the step surface 27. A groove 31 is formed on the outer peripheral surface of the component main body 29. The groove 31 extends around the axis of the insert nut 28. A knurl 32 is formed on the outer wall surface of the component main body 29 outside the groove 31. The component body 29 is made of a metal material such as brass, aluminum, or zinc.

  A metal plating film 33 is formed with a uniform film thickness on the bottom surface of the main body casing 14 and the inner and outer wall surfaces and top surface of the boss 25. The metal plating film 33 is formed based on a plating process. The metal plating film 33 is formed of a metal material such as gold, silver, nickel, tin, or copper, or a metal alloy thereof. Thus, the boss 25 exposes the metal plating film 33, that is, the metal material on the inner wall surface. Such a metal plating film 33 functions as an electromagnetic shield. For example, a noise component generated by the electronic component 23 is blocked by the metal plating film 33. As a result, components such as a radio circuit and an antenna in the mobile phone terminal 11 can operate normally. At the same time, the metal plating film 33 can release, for example, heat transferred from the printed circuit board 22 into the air over a wide area.

  A solder material 34 is sandwiched between the outer wall surface of the component main body 29 and the inner wall surface of the boss 25. The solder material 34 is filled in the groove 31. Such a solder material 34 is formed of a low melting point solder such as a tin-indium 52 alloy solder or a tin-bismuth 58 alloy solder. The tin-indium 52 alloy solder has a melting point of about 118 degrees Celsius, for example. Tin-bismuth 58 alloy solder has a melting point of, for example, about 138 degrees Celsius. The main body housing 14, the boss 25, the insert nut 28, and the solder material 34 constitute a molded part according to the present invention.

  The top surface of the boss 25 receives the back surface of the printed circuit board 22. A through hole 35 penetrating from the front surface to the back surface is formed in the printed board 22. The through hole 35 receives the screw shaft 24 a of the screw 24. The screw head 24 b of the screw 24 is received on the surface of the printed circuit board 22. Referring also to FIG. 4, the threaded shaft 24a is male threaded. On the other hand, a screw hole 36 is formed in the component main body 29 of the insert nut 28. The screw hole 36 penetrates the component main body 29 from the upper end to the lower end. An internal thread is cut on the inner wall surface of the component main body 29. Thus, the screw 24 is screwed into the component main body 29. No solder material is disposed on the inner wall surface of the component main body 29.

  In such a mobile phone terminal 11, a metal insert nut 28 is embedded in the boss 25. A metal plating film 33 is formed on the inner wall surface of the boss 25. The solder material 34 is uniformly sandwiched between the outer wall surface of the component main body 29 of the insert nut 28 and the inner wall surface of the boss 25. The solder material 34 can join the insert nut 28 to the boss 25 with high strength. In addition, the outer diameter of the component main body 29 of the insert nut 28 is set slightly smaller than the inner diameter of the boss 25. Therefore, as will be described later, the insert nut 28 can be easily inserted into the boss hole 26 when the insert nut 28 is embedded.

  Next, a method for manufacturing a molded part according to the present invention will be described. First, the insert nut 28 is prepared. FIG. 5 schematically shows the structure of the insert nut 28 according to the first embodiment of the present invention. In this insert nut 28, a solder material 34 is applied in advance to the outer wall surface of the component main body 29. The solder material 34 is formed based on plating, for example. The solder material 34 has a thickness of about 20 μm, for example. The solder material 34 is not formed on the inner wall surface of the component main body 29. The insert nut 28 is disposed on a parts feeder heated to, for example, 100 degrees Celsius. Thus, the solder material 34 is heated in advance. On the other hand, in the main body casing 14, a metal plating film 33 is formed in advance on the inner wall surface and the outer wall surface of the boss 25.

  As shown in FIG. 6, the insert nut 28 is held by a suction jig 37. The insert nut 28 is inserted into the large diameter space 26 a of the boss hole 26. The bottom surface of the component main body 29 is received by the step surface 27. At this time, a heater (not shown) incorporated in the suction jig 37 heats the component main body 29. The temperature of the heater is set to 350 degrees Celsius, for example. The heating time is set to 5 seconds, for example. The solder material 34 is heated to, for example, about 150 degrees Celsius. As a result, the solder material 34 melts. The solder material 34 wets and spreads between the outer wall surface of the component main body 29 and the inner wall surface of the boss 25. Thereafter, the suction jig 37 is pulled away from the insert nut 28. The solder material 34 is solidified based on the cooling. Thus, the insert nut 28 is embedded in the boss 25.

  According to such a manufacturing method, the solder material 34 is applied to the outer wall surface of the insert nut 28 in advance. Since the outer diameter of the component main body 29 is set slightly smaller than the inner diameter of the boss hole 26, the insert nut 28 is easily inserted into the large-diameter space 26 a of the boss hole 26. Since low melting point solder is used for the solder material 34, it is sufficient that the insert nut 28 is heated at a relatively low temperature when the solder material 34 is melted. Deformation and breakage of the main body casing 14 and the boss 25 based on heat are avoided as much as possible. In addition, since the metal plating film 33 is formed on the inner wall surface of the boss 25, the solder material 34 can spread evenly between the outer wall surface of the component main body 29 and the inner wall surface of the boss 25. Thus, the solder material 34 can join the insert nut 28 in the boss hole 26 with high strength.

  Prior to the insertion of the insert nut 28, a flux liquid may be applied to the solder material 34 on the outer wall surface of the component main body 29. For the flux, for example, a flux liquid mainly composed of an organic acid is used. Organic acids include, for example, pine sprout resin and stearic acid. These organic acids are diluted with a solvent in the production of the flux liquid. The wettability of the solder material 34 is improved by the action of the flux liquid. As a result, the solder material 34 can spread evenly between the outer wall surface of the component main body 29 and the inner wall surface of the boss 25. The outer wall surface of the component body 29 and the inner wall surface of the boss 25 are joined with higher strength.

  FIG. 7 schematically shows the structure of the insert nut 28a according to the second embodiment of the present invention. In this insert nut 28 a, an annular solder material 34 is disposed in the groove 31. For example, the solder material 34 may extend over the entire circumference of the groove 31 or may be partially interrupted. The low melting point solder used for the solder material 34 has a relatively high ductility. Therefore, for example, as shown in FIG. 8, the annular solder material 34 can be relatively easily fitted into the groove 31 from the lower end of the component main body 29. Then, the solder material 34 should just be accommodated in the groove | channel 31 based on crushing, for example. Like reference numerals are attached to the structure or components equivalent to those of the aforementioned insert nut 28.

  In embedding the insert nut 28a, the insert nut 28a is heated in advance as described above. Based on the suction jig 37, the component main body 29 is inserted into the large-diameter space 26 a of the boss hole 26. The solder material 34 melts as the heater of the suction jig 37 is heated. The solder material 34 wets and spreads between the groove 31 and the outer wall surface of the component main body 29 and the inner wall surface of the boss 25. The insert nut 28 a is embedded in the boss 25 based on the solidification of the solder material 34. According to such an insert nut 28a, the same operation effect as the above-mentioned insert nut 28 is realized.

  In addition, in the insert nut 28a, thread solder containing a flux liquid may be used for the solder material 34. The thread solder is formed in a cylindrical shape, for example. A hollow space formed in the longitudinal direction in the thread solder is filled with a flux liquid. Such a solder material 34 may be wound around the groove 31 in accordance with the rotation of the insert nut 28a as shown in FIG. 9, for example. At this time, a pair of pressing rollers 38 may be pressed against the outer wall surface of the component main body 29. In winding, the insert nut 28a may be heated to a predetermined temperature. As a result, the solder material 34 can be easily wound in the groove 31.

  FIG. 10 schematically shows the structure of an insert nut 28b according to a third embodiment of the present invention. In this insert nut 28 b, a plurality of grooves 39 are formed on the outer wall surface of the component body 29 along the axis of the component body 29. The groove 39 extends to the upper end and the lower end of the component main body 29. Adjacent grooves 39 extend parallel to each other. The grooves 39 may be arranged at equal intervals around the axis of the insert nut 28b. A solder material 34 is disposed in the groove 39. As the solder material 34, thread solder may be used. As described above, the flux solder is filled in the hollow space of the thread solder. In addition, the same reference numerals are assigned to configurations and structures equivalent to those of the insert nuts 28 and 28a described above.

  In embedding the insert nut 28b, the insert nut 28b is heated in advance as described above. The insert nut 28 b is inserted into the large-diameter space 26 a of the boss hole 26 based on the suction jig 37. The solder material 34 melts as the heater of the suction jig 37 is heated. The solder material 34 wets and spreads between the groove 39 and the outer wall surface of the component main body 29 and the inner wall surface of the boss 25. Thereafter, the solder material 34 is cooled. The solder material 34 is solidified. The insert nut 28 b is joined in the boss 25 based on the solidification of the solder material 34. According to such an insert nut 28b, the same operation effect as the above-mentioned insert nut 28, 28a is realized.

  In the mobile phone terminal 11 as described above, the main body casing 14 is made of a thermoplastic resin such as a polyamide resin containing glass fiber, a polyphenylene sulfide (PPS) resin containing glass fiber, a polybutylene terephthalate (PBT) resin, or a liquid crystal resin. You may form from thermosetting resins, such as an epoxy resin and an imide resin, LCD glass, metal alloy materials, such as aluminum, titanium, and iron, and nonmetallic materials, such as a ceramic. At this time, when the main body casing 14 is formed of a material other than a metal material, a metal plating film may be formed on the surface of the main body casing 14 as described above. In addition, the molded part may be established by other electronic devices such as a notebook personal computer, a desktop computer, and an information processing terminal (PDA).

(Additional remark 1) The process of inserting an insert part into the receiving hole formed in a molded part, and sandwiching the solder material between the outer wall surface of the insert part and the inner wall surface of the receiving hole exposing the metal material,
And a step of melting the solder material by heating the solder material.

  (Additional remark 2) The manufacturing method of the molded component of Additional remark 1 WHEREIN: The said solder material is previously apply | coated to the outer wall surface of the said insert component based on plating.

  (Additional remark 3) The manufacturing method of the molded component of Additional remark 1 WHEREIN: The said solder material is previously arrange | positioned in the groove | channel formed in the outer wall surface of the said insert component, The manufacturing method of the molded component characterized by the above-mentioned.

  (Supplementary Note 4) In the method of manufacturing a molded part according to any one of Supplementary Notes 1 to 3, the molded part is at least one of a metal material, a thermoplastic resin material, a thermosetting resin material, a ceramic material, and a glass material. A method of manufacturing a molded part, characterized in that the molded part is formed from the above.

  (Additional remark 5) The manufacturing method of the molded component in any one of Additional remarks 1-4 WHEREIN: A low melting-point solder is used for the said solder material.

(Appendix 6)
A receiving hole formed in the main body and exposing the metal material on the inner wall surface;
An insert part received in the receiving hole;
A molded part comprising: a solder material sandwiched between an inner wall surface of the receiving hole and an outer wall surface of the insert part.

  (Additional remark 7) The molded part of Additional remark 6 WHEREIN: The said main body is formed from at least any one of a metal material, a thermoplastic resin material, a thermosetting resin material, a ceramic material, and a glass material, It is characterized by the above-mentioned. Molded parts to do.

  (Additional remark 8) The molded component according to Additional remark 6 or 7, wherein a low melting point solder is used as the solder material.

(Supplementary note 9)
An insert component comprising: a solder material disposed at least on an outer wall surface of the component main body.

  (Additional remark 10) The insert component of Additional remark 9 WHEREIN: The said solder material is formed from the plating film apply | coated to the outer wall surface of the said component main body based on plating, The insert component characterized by the above-mentioned.

  (Additional remark 11) The insert component of Additional remark 9 WHEREIN: The said solder material is formed from the cyclic | annular solder material arrange | positioned in the groove | channel formed in the outer wall surface of the said component main body.

  (Additional remark 12) The insert component of Additional remark 9 WHEREIN: A low melting-point solder is used for the said solder material, The insert component characterized by the above-mentioned.

It is a perspective view which shows roughly the external appearance of one specific example, ie, a mobile telephone terminal, of an electronic device. It is a partial exploded perspective view of a mobile phone terminal. FIG. 3 is a partial enlarged cross-sectional view taken along line 3-3 in FIG. 2. It is a partial expanded sectional view which shows roughly the structure of insert components. It is an expansion perspective view showing roughly the structure of the insert part concerning a 1st embodiment of the present invention. It is a partial expanded sectional view which shows roughly the process in which insert components are inserted in a receiving hole. It is an expansion perspective view which shows roughly the structure of the insert component which concerns on 2nd Embodiment of this invention. It is an expansion perspective view which shows roughly the process of fitting a solder material in the groove | channel formed in the component main body of insert components. It is an expanded sectional view which shows roughly the process of winding a solder material in the groove | channel formed in the component main body of insert components. It is an expansion perspective view which shows roughly the structure of the insert component which concerns on 3rd Embodiment of this invention.

Explanation of symbols

  14 body (body housing), 26 receiving hole (boss hole), 28 insert part (insert nut), 29 part body, 31 groove, 33 metal material (metal plating film), 34 solder material, 39 groove.

Claims (7)

Inserting the insert part into the receiving hole formed in the molded part, and sandwiching the solder material between the outer wall surface of the insert part and the inner wall surface of the receiving hole exposing the metal material;
And a step of melting the solder material by heating the solder material.   2. The method for manufacturing a molded part according to claim 1, wherein the solder material is applied in advance to an outer wall surface of the insert part based on plating.   2. The method of manufacturing a molded part according to claim 1, wherein the solder material is disposed in advance in a groove formed on an outer wall surface of the insert part.   4. The method of manufacturing a molded part according to claim 1, wherein the molded part is formed from at least one of a metal material, a thermoplastic resin material, a thermosetting resin material, a ceramic material, and a glass material. A method for producing a molded part, characterized in that:   5. The method of manufacturing a molded part according to claim 1, wherein a low melting point solder is used as the solder material. The body,
A receiving hole formed in the main body and exposing the metal material on the inner wall surface;
An insert part received in the receiving hole;
A molded part comprising: a solder material sandwiched between an inner wall surface of the receiving hole and an outer wall surface of the insert part. A component body that defines a screw hole;
An insert component comprising: a solder material disposed at least on an outer wall surface of the component main body.

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