JP2008218683A - Sealing structure for mounting substrate, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost and light-weight sealing structure for a mounting substrate which is to be paired and having high waterproofness without largely using rubber gaskets and screws, and to provide a method of manufacturing the same. <P>SOLUTION: The sealing structure 1 for the mounting substrate includes: a mounting substrate 4a where electronic components 3 are mounted on a printed circuit board 2; a thermoplastic resin case 5a wrapping the mounting substrate 4a, wherein the inner wall of the thermoplastic resin case 5a is thermally fused at least on part of the outer periphery of the mounting substrate 4a. Accordingly, the mounting substrate 4a is supported and fixed in the thermoplastic resin case 5a, thus solving the problem. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mounting substrate sealing structure and a method of manufacturing the mounting substrate sealing structure.

  Conventionally, as a sealing structure or a waterproof structure for electronic parts, a rubber packing having a certain thickness or more is sandwiched between fitting parts of a housing enclosing the electronic parts, and screws are frequently used to obtain a predetermined fitting force. Structure was used. However, since it is complicated to fit a rubber packing that is elastic and has no shape retention into a predetermined position of the housing without any gaps, there is a problem that manual operation is required and automation is difficult. . In addition, since manual work is a complicated work that is likely to cause inset errors, it is necessary to perform a waterproof test on all manufactured products in order to guarantee the waterproof function, resulting in an increase in processing costs. . Furthermore, in electronic devices that are required to be small and light, such as portable devices, the heavy use of screws leads to an increase in weight and volume, which makes it difficult to use the waterproof structure for such small and light electronic devices. there were.

  In order to solve the above problems, a sealing structure in which an electronic component is directly covered with a resin and sealed has been proposed. If such a sealing structure is used, it is not necessary to use a large amount of rubber packing or screws, and the operation is not complicated, so that automation is facilitated. Furthermore, it is possible to reduce the size and weight.

For example, in Patent Document 1, a capsule-shaped thermoplastic resin is covered on an IO chip on a circuit board, and then the thermoplastic resin is softened and melted to bond the IO chip and the thermoplastic resin. A stop structure is obtained. Moreover, in patent document 2, the sealing structure is obtained by covering and sealing the EL element produced on the transparent substrate with a moisture-proof film having a barrier layer and a sealant layer made of a predetermined thermoplastic adhesive resin. . More specifically, as a moisture-resistant film, polyethylene terephthalate (12 μm), biaxially stretched nylon (15 μm), aluminum foil (20 μm), an acid-modified product of polypropylene having a melt flow rate of 7 (g / 10 min), Dry lamination and extrusion lamination are sequentially performed on the EL element.
Japanese Patent Laid-Open No. 2-77137 (2nd page, upper right column, FIGS. 1 to 3) JP 2001-307871 A (Claim 1, paragraph 0043, FIGS. 1C to 1E)

  However, if a sealing structure in which an electronic component as described above is covered and sealed is used, the electronic component will be buried with a thermoplastic resin. There is a problem that it is difficult to do. Furthermore, unlike the case where the height of each member on the transparent substrate is constant like an EL element, the height of each electronic component varies in the mounting substrate in which the electronic component is mounted on the printed wiring board. For this reason, in order to embed the entire printed wiring board with resin, a considerable amount of resin is required, and there are problems in terms of cost and weight reduction.

  The present invention has been made in order to solve the above-described problems, and its purpose is to provide a mounting board that is easy to repair without using a lot of rubber packing and screws, is inexpensive, lightweight, and highly waterproof. It is to provide a sealing structure.

  Another object of the present invention is a method for manufacturing a mounting substrate sealing structure that can be automated without using a lot of rubber packing and screws, is easy to repair, is low in cost, is lightweight, and is highly waterproof. Is to provide.

  The mounting substrate sealing structure of the present invention for solving the above-described problem is a mounting substrate having a mounting substrate in which an electronic component is mounted on a printed wiring board, and a thermoplastic resin case enclosing the mounting substrate. In the sealing structure, the mounting substrate is supported and fixed inside the thermoplastic resin case by heat-sealing the inner wall of the thermoplastic resin case to at least a part of the outer periphery of the mounting substrate. It is characterized by that.

  According to the present invention, the inner wall of the thermoplastic resin case is thermally fused to at least a part of the outer periphery of the mounting substrate, so that the mounting substrate is supported and fixed inside the thermoplastic resin case. Is supported and fixed to the thermoplastic resin case, and there is a space between the upper and lower surfaces of the mounting substrate and the thermoplastic resin case. As a result, rubber packing and screws are frequently used. Therefore, it is possible to provide a mounting substrate sealing structure that is easy to repair, inexpensive, lightweight, and highly waterproof.

  In a preferable aspect of the mounting substrate sealing structure of the present invention, one end of a flexible printed wiring board for connecting to an external terminal of the thermoplastic resin case is connected to the mounting substrate, and the flexible printed wiring The other end of the plate is led out to the outside of the thermoplastic resin case from a portion where the outer periphery of the mounting substrate and the inner wall of the thermoplastic resin case are heat-sealed.

  According to the present invention, one end of the flexible printed wiring board for connecting to an external terminal of the thermoplastic resin case is connected to the mounting board, and the other end of the flexible printed wiring board is connected to the outer periphery of the mounting board and heat. Since the inner wall of the plastic resin case is led out of the thermoplastic resin case to the outside, the flexible printed wiring board with one end connected to the mounting board is connected to the outer circumference of the mounting board and thermoplastic The portion where the inner wall of the resin case is heat-sealed is led out to the outside of the thermoplastic resin case, and as a result, the external interface of the mounting board can be constituted by a flexible printed wiring board.

  In a preferable aspect of the mounting substrate sealing structure of the present invention, the inner wall of the thermoplastic resin case is also thermally fused to the electronic component.

  According to the present invention, since the inner wall of the thermoplastic resin case is also heat-sealed to the electronic component, the height of the thermoplastic resin case can be easily made substantially the same as the maximum height of the mounting substrate. It is possible to reduce the thickness of the mounting substrate sealing structure without impairing the above.

  The manufacturing method of the mounting substrate sealing structure of the present invention for solving the above problems, a thermoplastic resin case in which an internal space is formed by joining the opening of the upper case and the opening of the lower case, A mounting board sealing structure having a mounting board in which an electronic component is mounted on a printed wiring board, which is installed in an internal space of the thermoplastic resin case, wherein the mounting is performed in the lower case A fitting step is formed by aligning the opening of the upper case with the opening of the lower case, and an arrangement step of arranging the substrate, and at least a part of the outer periphery of the mounting substrate contacts the inner wall of the fitting portion A fitting step of forming a contact portion, and locally heating the fitting portion to melt and join the opening of the lower case and the opening of the upper case, and the fitting at the contact portion Inner wall and the mounting base Having a heat-sealing step of heat sealing the outer periphery of, and wherein the.

  According to the present invention, the placement step of placing the mounting substrate in the lower case, and the fitting portion is formed by aligning the opening of the upper case with the opening of the lower case, and the mounting substrate is formed on the inner wall of the fitting portion. At the contact portion, the fitting step of forming the contact portion by contacting at least a part of the outer periphery, and melting and joining the opening portion of the lower case and the opening portion of the upper case by locally heating the fitting portion A heat-seal process for heat-sealing the inner wall of the fitting part and the outer periphery of the mounting substrate, so that the joint of the lower case opening and the upper case opening is obtained by locally heating the fitting part. In addition, the inner wall of the fitting portion, which is the inner wall in the vicinity of the contact surface between the opening of the lower case and the opening of the upper case, and the outer periphery of the mounting substrate can be heat-sealed. Part of the mounting board is supported and fixed to the thermoplastic resin case Since there is a space between the upper and lower surfaces and the thermoplastic resin case, the result is that work can be automated without using too many rubber packings and screws, making repairs easy, low cost, and light weight. And the manufacturing method of the sealing structure of the mounting board | substrate with high waterproofness can be provided.

  In a preferred embodiment of the method for producing a sealing structure of a mounting board according to the present invention, one end side of a flexible printed wiring board for connecting to an external terminal of the thermoplastic resin case is connected to the mounting board. In forming the fitting portion in the fitting step, the other end side of the flexible printed wiring board is pulled out from between the opening of the lower case and the opening of the upper case, and the heat fusion step The other end of the flexible printed wiring board is led out of the thermoplastic resin case by heat-sealing the lower case, the upper case, and the flexible printed wiring board.

  According to the present invention, one end side of the flexible printed wiring board for connecting with the external terminal of the thermoplastic resin case is connected to the mounting substrate, and the flexible printed circuit board is formed when the fitting portion is formed in the fitting process. The other end side of the wiring board is pulled out from between the opening of the lower case and the opening of the upper case, and in the heat fusion process, the lower case, the upper case, and the flexible printed wiring board are thermally fused. Since the other end side of the flexible printed wiring board is led out of the thermoplastic resin case, the flexible printed wiring board whose one end side is connected to the mounting board is heated by the lower case, the upper case, and the flexible printed wiring board. The fused part is led out of the thermoplastic resin case, and as a result, the external interface of the mounting board is It can be configured by preparative wiring board.

  In a preferred aspect of the method for manufacturing the mounting substrate sealing structure of the present invention, the electronic component and the lower case and / or the upper case come into contact with each other when the fitting portion is formed in the fitting step. A component contact portion is formed, and the electronic component contact portion is also locally heated together with the local heating of the fitting portion in the heat-sealing step to heat the electronic component and the inner wall of the lower case and / or the upper case. Fuse.

  According to this invention, when the fitting part is formed in the fitting process, the electronic component and the lower case and / or the upper case come into contact with each other to form the electronic component contact part, and the fitting part is locally disposed in the heat fusion process. The electronic component contact part is also locally heated with heating, and the electronic component and the inner wall of the lower case and / or the upper case are heat-sealed. Therefore, it is easy to make the height of the thermoplastic resin case substantially the same as the maximum height of the mounting board. As a result, the mounting substrate sealing structure can be thinned without impairing repairability.

  According to the mounting substrate sealing structure of the present invention, it is possible to provide a mounting substrate sealing structure that is easy to repair without using many rubber packings and screws, and that is inexpensive, lightweight, and highly waterproof. . In particular, by using a thermoplastic resin case, a waterproof structure can be provided without using a lot of rubber packing or screws. In addition, it is possible to provide a waterproof structure in which electronic parts can be replaced or soldered by peeling the thermoplastic resin case even after the sealing structure is formed. Further, since it is not necessary to embed an electronic component with a resin, it is possible to provide a low-cost and lightweight waterproof structure with a small amount of resin used. Furthermore, since a complicated operation for fitting the rubber packing into the housing without any gap is not required, the operation can be easily automated.

  According to the method for manufacturing a mounting substrate sealing structure of the present invention, it is possible to automate the operation without using a large amount of rubber packing and screws, and it is easy to repair, and is inexpensive, lightweight, and highly waterproof. A method for manufacturing a sealing structure can be provided. In particular, by using a thermoplastic resin case, a waterproof structure can be provided without using a lot of rubber packing or screws. In addition, it is possible to provide a waterproof structure in which electronic parts can be replaced or soldered by peeling the thermoplastic resin case even after the sealing structure is formed. Further, since it is not necessary to embed an electronic component with a resin, it is possible to provide a low-cost and lightweight waterproof structure with a small amount of resin used. Furthermore, since a complicated operation for fitting the rubber packing into the housing without any gap is not required, the operation can be easily automated.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. However, it is needless to say that the present invention is not limited to the following embodiments and can be variously modified within the scope of the gist thereof.

[First Embodiment]
FIG. 1 is a schematic cross-sectional view showing a first embodiment of the mounting substrate sealing structure of the present invention.

  The mounting substrate sealing structure 1 includes a mounting substrate 4a in which an electronic component 3 is mounted on a printed wiring board 2, and a thermoplastic resin case 5a that encloses the mounting substrate 4a. The mounting substrate 4a is supported and fixed inside the thermoplastic resin case 5a by heat-sealing the inner wall of the thermoplastic resin case 5a at least partially. More specifically, as shown in FIG. 1, the heat constituting the inner wall of the thermoplastic resin case 5a at the portion where the outer periphery of the printed wiring board 2 of the mounting substrate 4a is in contact with the inner wall of the thermoplastic resin case 5a. By forming the adhesive portion 6 by the plastic resin wrapping around the upper and lower surfaces of the printed wiring board 2, the mounting substrate 4a is supported and fixed inside the thermoplastic resin case 5a.

  The inner wall of the thermoplastic resin case 5a is thermally fused to at least a part of the outer periphery of the mounting substrate 4a. More specifically, the inner wall of the thermoplastic resin case 5a is heated to at least a part of the outer periphery of the printed wiring board 2. Since the mounting substrate 4a is supported and fixed inside the thermoplastic resin case 5a by being fused, at least a part of the outer periphery of the mounting substrate 4a is supported and fixed to the thermoplastic resin case 5a and the mounting substrate 4a. There will be a space 7 between the upper and lower surfaces of the resin and the thermoplastic resin case 5a. As a result, repair is easy without using a lot of rubber packing and screws, and it is inexpensive, lightweight, and waterproof. It is possible to provide a high mounting substrate sealing structure.

  The mounting board 4 a is obtained by attaching the electronic component 3 on the printed wiring board 2. A conventionally well-known thing can be used for the printed wiring board 2, The thing of a glass epoxy type or a ceramic type material can be mentioned. In addition, various electronic components 3 such as capacitors, resistors, and ICs may be appropriately selected according to the function of the mounting board. The height of the electronic component 3 is usually different depending on the type of the electronic component 3, but the mounting substrate sealing structure of the present invention is thermoplastic depending on the height of the electronic component 3 disposed on the printed wiring board 2. Since the height of the resin case 5a can be adjusted as appropriate, it is possible to cope with mounting boards of various shapes.

  The thermoplastic resin case 5a is not limited as long as it is made of a thermoplastic resin. Usually, the thermoplastic resin case 5a is required to be waterproof and protected for the mounting substrate 4a, and thus is preferably a thermoplastic resin having a predetermined mechanical strength. From this point, examples of the material of the thermoplastic resin case 5a include an acrylic resin. On the other hand, a part of the thermoplastic resin case 5 a melts and goes up and down on the printed wiring board 2 to form the bonding portion 6. For this reason, the thermoplastic resin case 5a is preferably a thermoplastic resin that softens and melts when heated to a predetermined temperature. From these points, it is preferable to use a thermoplastic resin having a softening point of around 120 ° C., more specifically 120 ± 30 ° C. The softening point of the thermoplastic resin can be measured by, for example, a ball and ring method.

  As described above, the thermoplastic resin case 5a may be made of a thermoplastic resin, and may contain an additive such as an antioxidant or a filler as necessary. However, when a filler is contained, it is preferable not to contain a conductive filler. That is, in the case where a thermoplastic resin containing a filler is used from the viewpoint of ensuring the mechanical strength of the thermoplastic resin case 5a, it is preferable not to use conductive fillers. This is because the adhesive portion 6 formed by melting the thermoplastic resin case 5a is in contact with the printed wiring board 2 at the top and bottom, so that conductivity is imparted to the adhesive portion 6 This is because leakage may occur between the printed wiring board 2 and malfunction of the mounting board 4a. Note that if the end portion of the printed wiring board 2 that is in contact with the adhesive portion 6 is secured as an insulating region, the leakage and the malfunction of the mounting board 4a are less likely to occur. Therefore, addition and filling of a conductive filler to the thermoplastic resin It will be easier to do. However, in this case, since the entire mounting substrate 4a tends to be large due to the necessity of securing an insulating region at the end of the printed wiring board 2, the mounting substrate sealing structure 1 tends to be large, and the size can be reduced. There are disadvantages. For the same reason, it is also preferable not to provide a conductive layer such as an aluminum foil for electromagnetic wave shielding on the inner wall of the thermoplastic resin case 5a.

  The inner wall of the thermoplastic resin case 5a is heat-sealed with at least a part of the outer periphery of the mounting substrate 4a. More specifically, the inner wall of the thermoplastic resin case 5 a is heat-sealed with at least a part of the outer periphery of the printed wiring board 2. As a result, the mounting substrate 4a is supported and fixed inside the thermoplastic resin case 5a. In FIG. 1, a part of the outer periphery of the mounting substrate 4a is heat-sealed with the thermoplastic resin case 5a. However, the entire outer periphery of the mounting substrate 4a may be heat-sealed with the thermoplastic resin case 5a. . More specifically, the entire outer periphery of the printed wiring board 2 may be heat-sealed with the thermoplastic resin case 5a.

  FIG. 2 is a schematic cross-sectional view showing, in an enlarged manner, a heat fusion portion between the inner wall of the thermoplastic resin case and the outer periphery of the mounting substrate. More specifically, FIG. 1 is a schematic cross-sectional view showing the vicinity of the bonding portion 6 in an enlarged manner. The thickness T of the thermoplastic resin case 5a shown in the figure is usually 0.2 mm or more and 2 mm or less. When the thickness of the thermoplastic resin case 5a is within the above range, the mechanical strength of the thermoplastic resin case 5a can be easily secured. Further, the length L of the bonding portion 6 bonded to the upper and lower sides of the printed wiring board 2 is usually 0.5 mm or more and 5 mm or less. If the length of the bonding portion 6 is within the above range, the support and fixing of the printed wiring board 2 to the thermoplastic resin case 5a tends to be strong.

  The manufacturing method of the mounting substrate sealing structure 1 usually includes forming a thermoplastic resin case from a lower case and an upper case each having openings of substantially the same shape, and mounting the substrate between the lower case and the upper case. After inserting the lower case and the upper case, the lower case and the upper case are melted and joined together by melting the lower case and the upper case together. This is performed by heat-sealing the inner wall of the substrate and the outer periphery of the mounting substrate.

  As described above, the thermoplastic resin case is usually formed of a lower case and an upper case. Therefore, a method for manufacturing the lower case and the upper case will be described below.

  FIG. 3 is a schematic cross-sectional view showing a method for manufacturing a lower case and an upper case of a thermoplastic resin. More specifically, the lower case 8 or the upper case 9 is manufactured through the steps of FIGS. 3A, 3B, 3C, and 3D. Each step will be described below.

  As shown in FIG. 3 (a), a predetermined amount of thermoplastic resin 15 is placed on the lower mold 13 disposed on the removable heater 14, and the upper mold 11 having the stopper 12 is mounted. And placed above the lower mold 13. Here, as the thermoplastic resin, additive, filler, and the like used as the thermoplastic resin 15, the above-described materials may be used.

  Then, as shown in FIG. 3B, while the heater 14 is heated to melt the thermoplastic resin 15, the upper mold 11 is moved downward to move the upper mold 11 and the lower mold. The mold 13 is fitted. At the time of fitting, the upper mold 11 is provided with a stopper 12 so that the lower mold 13 and the upper mold 11 do not come closer than a predetermined distance. In addition, since a gap is provided between the upper mold 11 on the side where the stopper 12 is not attached and the lower mold 13, the upper mold 11 and the lower mold 13 are fitted together. Excess thermoplastic resin 15 in this process is protruded from this gap.

  Further, as shown in FIG. 3C, the heater 14 is removed from the lower mold 13 to cool the molded thermoplastic resin 15. Then, excess thermoplastic resin 15 protruding from the gap is cut with a cutter 16.

  Finally, as shown in FIG. 3D, the upper mold 11 is moved upward, and the upper mold 11 is removed from the lower mold 13 to form the thermoplastic resin 15. The lower case 8 or the upper case 9 can be obtained.

  Using the lower case 8 and the upper case 9 obtained as described above, the mounting substrate sealing structure 1 is manufactured. Such a manufacturing method will be described below.

  FIG. 4 is a schematic cross-sectional view showing a method of manufacturing a mounting substrate sealing structure. More specifically, the thermoplastic resin case 5b in which the internal space is formed by joining the opening of the upper case 9 and the opening of the lower case 8 is installed in the internal space of the thermoplastic resin case 5b. FIG. 5 is a schematic cross-sectional view for explaining a manufacturing method of a mounting substrate sealing structure including a mounting substrate 4a on which an electronic component is mounted on a printed wiring board. And the sealing structure 1 of a mounting substrate is manufactured through FIG. 4 (a), (b), (c), (d).

  As shown in FIG. 4A, the lower case 8 is installed on a receiving jig 18 around which a slide heater 17 is provided. As shown in the figure, the receiving jig 18 is processed to a size that can be fixed while accommodating the lower case 8.

  Next, as shown in FIG. 4B, an arrangement step of arranging the mounting substrate 4a in the lower case 8 is performed. Next, as shown in the figure, the upper case 9 sucked by the suction jig 19 disposed above the lower case 8 is moved downward.

  Then, as shown in FIG. 4C, the fitting portion 20 is formed by aligning the opening of the upper case 9 with the opening of the lower case 8, and the outer periphery of the mounting substrate 4 a is formed on the inner wall of the fitting portion 20. A fitting process is performed in which at least a portion is brought into contact with each other to form a contact portion. As shown in the figure, the fitting portion 20 indicates a portion of the lower case 8 and the upper case 9 that exists in the vicinity of the contact surface between the opening of the lower case 8 and the opening of the upper case 9. And a contact part points out the part which the inner wall of the lower case 8 and / or the upper case 9 in the fitting part 20 and the outer periphery of the mounting substrate 4a contact.

  Further, as shown in FIG. 4C, the sliding heater 17 is moved inward to bring the sliding heater 17 into contact with the outer walls of the lower case 8 and the upper case 9 in the fitting portion 20. Then, the fitting portion 20 is locally heated to melt and bond the opening of the lower case 8 and the opening of the upper case 9, and at the contact portion, the inner wall of the fitting portion 20 and the outer periphery of the mounting substrate 4 a (more Specifically, a heat fusion process is performed in which the outer periphery of the printed wiring board is thermally fused. What is necessary is just to set suitably the heating temperature in the case of the heat sealing | fusion by the heater 17 considering the softening point and melting | fusing point of each thermoplastic resin used for the lower case 8 and the upper case 9, and the heat resistance of a printed wiring board.

  Finally, as shown in FIG. 4D, the sliding heater 17 is returned to the original position, and the fitting portion 20 is cooled. Thereby, the thermoplastic resin case 5b is completed. Thereafter, the suction jig 19 may be moved upward to take out the obtained mounting substrate sealing structure 1.

  By using such a manufacturing method having an arrangement step, a fitting step, and a heat fusion step, the opening of the lower case and the opening of the upper case can be joined by locally heating the fitting portion. In addition, thermal fusion between the inner wall of the thermoplastic resin case, which is the inner wall near the contact surface between the opening of the lower case and the opening of the upper case, and the outer periphery of the mounting board (more specifically, the outer periphery of the printed wiring board) Since at least a part of the outer periphery of the mounting substrate is supported and fixed to the thermoplastic resin case, there is a space between the upper and lower surfaces of the mounting substrate and the thermoplastic resin case. As a result, it is possible to automate the work without using a large amount of rubber packing and screws, and to provide a method for manufacturing a mounting substrate sealing structure that is easy to repair, inexpensive, lightweight, and highly waterproof.

[Second Embodiment]
In the first embodiment, the mechanical strength of the thermoplastic resin case is taken into consideration. However, in the second embodiment, the kind of thermoplastic resin to be molded and the additive are appropriately selected to provide heat with elasticity. A plastic resin case is used. Thereby, in the sealing structure of a mounting substrate, the effect which absorbs a drop impact can also be show | played and drop impact resistance can be improved. The mounting substrate sealing structure and the manufacturing method thereof described in the first embodiment may be the same as those described in the first embodiment except that a thermoplastic resin case having elasticity is used. For this reason, description here is abbreviate | omitted in order to avoid duplication of description.

[Third Embodiment]
FIG. 5: is typical sectional drawing which shows 3rd Embodiment of the sealing structure of the mounting board | substrate of this invention.

  The mounting substrate sealing structure 30 is configured such that one end side of the flexible printed wiring board 21 for connecting to an external terminal of the thermoplastic resin case 5c is connected to the mounting substrate 4b, and the other end side of the flexible printed wiring board 21 is connected to the other end side. The outer periphery of the mounting substrate 4b and the inner wall of the thermoplastic resin case 5c are led out to the outside of the thermoplastic resin case 5c from the heat-sealed portion. More specifically, one end of the flexible printed wiring board 21 is connected to the connector 22 of the mounting board 4b, and the other end of the flexible printed wiring board 21 is in contact with the outer periphery of the printed wiring board of the mounting board 4b. The lead is led out from the plastic resin case 5c. The printed wiring board and the flexible printed wiring board 21 are integrally heat-sealed to the thermoplastic resin case 5c in the vicinity of the outer periphery of the mounting board 4b. Except for using the flexible printed wiring board 21 and the connector 22, the mounting substrate sealing structure described in the first embodiment may be used. For this reason, description here is abbreviate | omitted in order to avoid duplication of description.

  As a result, the flexible printed wiring board 21 whose one end is connected to the mounting substrate 4b is moved from the portion where the outer periphery of the mounting substrate 4b and the inner wall of the thermoplastic resin case 5c are thermally fused to the outside of the thermoplastic resin case 5c. As a result, the external interface of the mounting substrate 4b can be configured by the flexible printed wiring board 21.

  The manufacturing of the mounting substrate sealing structure 30 is the same as that in the first embodiment except that one end of the flexible printed wiring board 21 for connection to an external terminal is connected to the mounting substrate 4b. This can be done using the described manufacturing method. Therefore, differences from the manufacturing method described in the first embodiment will be described below.

  First, when forming the fitting portion in the fitting step, the other end side of the flexible printed wiring board is pulled out from between the opening of the lower case and the opening of the upper case. In the heat-sealing step, the lower case, the upper case, and the flexible printed wiring board are heat-sealed to lead the other end of the flexible printed wiring board to the outside of the thermoplastic resin case.

  Thereby, the flexible printed wiring board whose one end side is connected to the mounting substrate is led out of the thermoplastic resin case from the portion where the lower case, the upper case, and the flexible printed wiring board are thermally fused, and as a result, The external interface of the mounting board can be configured with a flexible printed wiring board.

[Fourth Embodiment]
FIG. 6 is a schematic sectional view showing a fourth embodiment of the mounting substrate sealing structure of the present invention.

  In the mounting substrate sealing structure 40, the inner wall of the thermoplastic resin case 5d is also heat-sealed to the electronic components 23a and 23b. More specifically, the top surface of the electronic component 23a having the highest height among the electronic components mounted on the top surface of the printed wiring board is heat-sealed so as to sink into the top surface of the inner wall of the thermoplastic resin case 5d. Of the electronic components mounted on the lower surface of the printed circuit board, the lower surface of the electronic component 23b having the highest height is heat-sealed so as to sink into the lower surface of the inner wall of the thermoplastic resin case 5d. Except for performing heat fusion between the electronic component and the thermoplastic resin case, the mounting substrate sealing structure described in the first embodiment may be used. For this reason, description here is abbreviate | omitted in order to avoid duplication of description.

  This makes it easy to make the height of the thermoplastic resin case 5d substantially the same as the maximum height of the mounting substrate, and as a result, it is possible to reduce the thickness of the sealing structure of the mounting substrate without impairing repairability.

  The manufacturing of the mounting substrate sealing structure 40 can be performed using the manufacturing method described in the first embodiment, except that the inner wall of the thermoplastic resin case is also thermally fused to the electronic component. Therefore, differences from the manufacturing method described in the first embodiment will be described below.

  First, when forming the fitting portion in the fitting step, the electronic component and the lower case and / or the upper case come into contact with each other to form the electronic component contact portion. By providing such an electronic component contact portion, when the thermoplastic resin case is heat-sealed to the electronic component, the electronic component is likely to sink into the thermoplastic resin case. More specifically, as shown in FIG. 6, when the mounting substrate sealing structure 40 is completed, the height of the thermoplastic resin case 5d and the length from the upper surface of the electronic component 23a to the lower surface of the electronic component 23b are obtained. It is preferable that the maximum height of the mounting substrate represented by is substantially the same.

  And an electronic component contact part is also heated locally with the local heating of the fitting part in a heat-fusion process, and an electronic component and the inner wall of a lower case and / or an upper case are heat-seal | fused. FIG. 7 shows a heat-sealing process in the method for manufacturing the mounting substrate sealing structure according to the fourth embodiment. As shown in the figure, in the heat fusion process, the fitting portion is locally heated to form the thermoplastic resin case 5d, and the vertical slide heater 24 is pressed against the electronic component contact portion to perform local heating. Then, the lower case and the upper case corresponding to the electronic component contact portion are melted so that the electronic components 23a and 23b are embedded in the thermoplastic resin case 5d.

  This makes it easy to make the height of the thermoplastic resin case substantially the same as the maximum height of the mounting substrate, and as a result, it is possible to reduce the thickness of the mounting substrate sealing structure without impairing repairability.

It is typical sectional drawing which shows 1st Embodiment of the sealing structure of the mounting board | substrate of this invention. It is typical sectional drawing which expanded and showed the heat sealing | fusion part of the inner wall of a thermoplastic resin case, and the outer periphery of a mounting substrate. It is typical sectional drawing which shows the manufacturing method of the lower case and upper case of a thermoplastic resin. It is typical sectional drawing which shows the manufacturing method of the sealing structure of a mounting board | substrate. It is typical sectional drawing which shows 3rd Embodiment of the sealing structure of the mounting board | substrate of this invention. It is typical sectional drawing which shows 4th Embodiment of the sealing structure of the mounting board | substrate of this invention. The heat sealing | fusion process of the manufacturing method of the sealing structure of the mounting substrate concerning 4th Embodiment is shown.

Explanation of symbols

1, 30, 40 Mounting board sealing structure 2 Printed wiring boards 3, 23a, 23b Electronic components 4a, 4b Mounting boards 5a, 5b, 5c, 5d Thermoplastic resin case 6 Adhesive portion 7 Space 8 Lower case 9 Upper case 11 Upper die 12 Stopper 13 Lower die 14 Heater 15 Thermoplastic resin 16 Cutter 17 Sliding heater 18 Receiving jig 19 Adsorption jig 20 Fitting portion 21 Flexible printed wiring board 22 Connector 24 Vertical sliding heater

Claims (6)

A mounting board sealing structure comprising: a mounting board on which an electronic component is mounted on a printed wiring board; and a thermoplastic resin case enclosing the mounting board.
The mounting substrate is characterized in that the mounting substrate is supported and fixed inside the thermoplastic resin case by heat-sealing the inner wall of the thermoplastic resin case to at least a part of the outer periphery of the mounting substrate. Sealing structure. One end side of the flexible printed wiring board for connecting with an external terminal of the thermoplastic resin case is connected to the mounting substrate,
The other end side of the flexible printed wiring board is led out to the outside of the thermoplastic resin case from a portion where the outer periphery of the mounting substrate and the inner wall of the thermoplastic resin case are heat-sealed.
The sealing structure of the mounting substrate according to claim 1.   3. The mounting substrate sealing structure according to claim 1, wherein an inner wall of the thermoplastic resin case is also thermally fused to the electronic component. A thermoplastic resin case in which an internal space is formed by joining the opening of the upper case and the opening of the lower case, and an electronic component installed on the printed wiring board installed in the internal space of the thermoplastic resin case A mounting substrate mounted, and a manufacturing method of a mounting substrate sealing structure comprising:
An arrangement step of arranging the mounting substrate in the lower case;
A fitting part is formed by aligning the opening part of the upper case with the opening part of the lower case, and at least a part of the outer periphery of the mounting substrate is brought into contact with the inner wall of the fitting part to form a contact part. Joint process,
The fitting portion is locally heated to melt and bond the opening of the lower case and the opening of the upper case, and heat the inner wall of the fitting portion and the outer periphery of the mounting substrate at the contact portion. A heat-sealing process for fusing,
A method for manufacturing a mounting substrate sealing structure, comprising: One end side of a flexible printed wiring board for performing connection with an external terminal of the thermoplastic resin case is connected to the mounting substrate,
In forming the fitting portion in the fitting step, the other end side of the flexible printed wiring board is pulled out from between the opening of the lower case and the opening of the upper case,
In the heat sealing step, the other end of the flexible printed wiring board is led out of the thermoplastic resin case by heat-sealing the lower case, the upper case, and the flexible printed wiring board. The manufacturing method of the sealing structure of the mounting substrate of Claim 4. In forming the fitting portion in the fitting step, the electronic component and the lower case and / or the upper case come into contact to form an electronic component contact portion,
5. The electronic component contact portion is also locally heated together with the local heating of the fitting portion in the heat fusion step, and the electronic component and the lower case and / or the inner wall of the upper case are thermally fused. Or the manufacturing method of the sealing structure of the mounting board | substrate of 5.

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