JP6007462B2 - FIXING STRUCTURE AND METHOD FOR PRODUCING THE FIXING STRUCTURE - Google Patents

Description

  The present invention relates to a fixing structure in which a flexible printed wiring board is fixed to a connected body such as a housing and a method for manufacturing the fixing structure.

2. Description of the Related Art Electronic devices such as mobile phones and hard disk devices generally have a fixing structure in which a flexible printed wiring board is fixed to a connected body (hereinafter referred to as a connected body) such as a housing.
Conventionally, such a fixing structure is generally formed by attaching a flexible printed wiring board to an object to be connected via an adhesive such as an adhesive tape (hereinafter referred to as an adhesive).
As a conventional technique showing a fixing structure in which a flexible printed wiring board is fixed to such a connected body via an adhesive, for example, there is Patent Document 1 below.

Japanese Unexamined Patent Application Publication No. 2009-144101

In recent years, with the progress of miniaturization and thinning of electronic devices, connected bodies and flexible printed wiring boards have also been miniaturized and thinned.
Therefore, in the conventional fixing structure as shown in the above-mentioned Patent Document 1, due to the narrowing of the area to which the adhesive is applied, sufficient adhesive force cannot be obtained, vibration, springback of the flexible printed wiring board itself, etc. As a result, the flexible printed wiring board is peeled off from the connected body, causing a problem that the connected body and the flexible printed wiring board are separated.
In order to solve such problems, conventionally, it is considered to form a fixing structure by forming a through hole in a flexible printed wiring board and fitting the through hole to a fitting convex portion provided in a connected body. It has been.
However, in such a fixing structure, after fitting the through hole to the cylindrical fitting convex portion, the tip of the fitting convex portion formed of resin is melted by heat (so-called resin caulking). Therefore, it is necessary to form a slip-off preventing piece for preventing the flexible printed wiring board from slipping out from the fitting convex portion.
Therefore, there is a time lag between fitting the through-hole to the fitting projection and forming the removal prevention piece, so flexible printing from the fitting projection due to vibration, spring back of the flexible printed wiring board itself, etc. There is a problem that the wiring board may come out (float) and the connected body and the flexible printed wiring board may be separated.

  Therefore, the present invention solves the above-mentioned problems, and in a fixing structure in which a flexible printed wiring board is fixed to a connected body such as a housing, the effect that the flexible printed wiring board comes out from the fitting convex portion of the connected body is effective. It is an object of the present invention to provide a fixing structure that can firmly fix a flexible printed wiring board to a connected body and a method for manufacturing the fixing structure.

The fixing structure of the present invention is a fixing structure in which a flexible printed wiring board is fixed to a body to be connected, and the body to be connected is provided with a fitting convex part having a slip-off preventing piece at the tip, and the flexible printed wiring The plate is provided with a through-hole having a cut-out portion on the outer periphery as a fitting recess, and the through-hole is provided in the fitting convex portion having a diameter larger than the diameter of the through-hole. The first feature is that the stripping prevention pieces are heat-welded to the flexible printed wiring board .

According to the first feature of the present invention, the fixing structure is a fixing structure in which a flexible printed wiring board is fixed to a body to be connected, and the body to be connected has a slip-off preventing piece at the tip. The fitting is provided with a convex portion, the flexible printed wiring board includes a through-hole having a cutout portion as an outer periphery as a concave portion for fitting, and the diameter of the removal preventing piece is larger than the diameter of the through-hole. When fitting the through hole to the fitting convex portion, the through hole is fitted to the fitting convex portion, and the removal preventing piece is thermally welded to the flexible printed wiring board . Starting from the cut portion, the flexible printed wiring board at the peripheral portion of the through hole and the peripheral portion of the cut portion can be temporarily bent along the outer surface of the prevention piece.
Therefore, even if the diameter of the removal preventing piece is larger than the diameter of the through hole, the through hole can be smoothly fitted to the fitting convex portion. Therefore, it is possible to prevent the flexible printed wiring board from being broken and to obtain a fixing structure with high manufacturing efficiency.
Further, in a state where the flexible printed wiring board is fixed to the connected body, it is possible to effectively prevent the flexible printed wiring board from coming out of the fitting convex portion.
Therefore, the flexible printed wiring board can be firmly fixed to the connected body. Accordingly, a fixed structure with high connection reliability can be obtained.

In addition , since the separation preventing piece is thermally welded to the flexible printed wiring board, the diameter of the separation preventing piece can be further increased, and a gap is provided between the separation preventing piece and the flexible printed wiring board. Can be prevented.
Therefore, it is possible to more effectively prevent the flexible printed wiring board from coming out of the fitting convex portion. Therefore, it is possible to obtain a fixing structure with higher connection reliability.

The fixing structure of the present invention is a fixing structure in which a flexible printed wiring board is fixed to a body to be connected, and the body to be connected is provided with a fitting convex portion having a slip-off preventing piece at the tip, The wiring board includes, as fitting recesses, a first through hole having a diameter equal to or larger than a diameter of the disconnection preventing piece, and a second through hole having a diameter smaller than the diameter of the disconnection preventing piece, The second through-hole is fitted to the fitting convex portion, and the removal preventing piece is thermally welded to the flexible printed wiring board. The first through-hole and the second through-hole Is connected through the notch part as a second feature.

According to the second aspect of the present invention, the fixing structure is a fixing structure in which a flexible printed wiring board is fixed to a body to be connected, and the body to be connected has a stripping prevention piece at the tip. The flexible printed wiring board is provided with a convex portion, and the flexible printed wiring board has a first through hole having a diameter equal to or larger than the diameter of the removal preventing piece as a fitting recessed portion, and a second diameter having a diameter smaller than the diameter of the removal preventing piece. Through-holes, the second through-holes are fitted to the fitting convex portions, and the first through-holes and the second through-holes are connected to each other through a notch portion. Therefore, the first through hole can be used as a fitting hole for fitting the through hole to the fitting convex portion, and the second through hole is used to fix the flexible printed wiring board to the housing. It can be a fixing hole.
More specifically, when the through hole is fitted to the fitting convex portion, the first through hole can be easily fitted to the fitting convex portion. Therefore, it can be set as the fixed structure with high manufacturing efficiency.
Further, after fitting the first through hole to the fitting convex portion, the fitting place of the fitting convex portion is slid (moved) from the first through hole to the second through hole through the notch portion. It is possible to effectively prevent the flexible printed wiring board from coming out of the fitting convex portion only by doing so. Therefore, it is possible to obtain a fixing structure with higher connection reliability .

Moreover, the anti-piece exit, since which had been thermally welded to the full lexical Bull printed wiring board, it is possible to further increase the diameter of the prevention piece missing, between the prevention piece and the flexible printed wiring board missing A gap can be prevented from being generated.
Therefore, it is possible to more effectively prevent the flexible printed wiring board from coming out of the fitting convex portion. Therefore, it is possible to obtain a fixing structure with higher connection reliability.

In addition to the first or second feature of the present invention described above, the fixing structure of the present invention is provided with an adhesive between the connected body and the flexible printed wiring board and in the vicinity of the through hole. The third feature is that they are interposed.

According to the third feature of the present invention, in addition to the function and effect of the first or second feature of the present invention, between the connected body and the flexible printed wiring board and the through hole Since the adhesive is interposed in the vicinity region, the flexible printed wiring board can be more securely fixed to the connected body. Therefore, it is possible to more effectively prevent the flexible printed wiring board from coming out of the fitting convex portion. Therefore, it is possible to obtain a fixing structure with higher connection reliability.

Moreover, the manufacturing method of the fixing structure of the present invention is the manufacturing method of the fixing structure according to claim 1, wherein the connecting body is formed by forming a connecting body having a fitting convex portion having a disconnection preventing piece at the tip. A flexible printed wiring board forming step for forming a flexible printed wiring board having a through hole having a cut-out portion provided on the outer periphery as a recess for fitting, and a preparation for the connected body after the connecting body forming step A fitting step of fitting a through-hole provided in the flexible printed wiring board to the convex portion for fitting; and a step of heat-welding the stripping prevention piece to the flexible printed wiring board after the fitting step; wherein is the the benzalkonium be formed larger than the diameters of the through hole of the for prevention piece in the connected body forming step the fourth feature.

According to the fourth aspect of the present invention, the manufacturing method of the fixing structure is the manufacturing method of the fixing structure according to claim 1, wherein the connected structure includes a fitting convex portion having a disconnection preventing piece at the tip. A to-be-connected body forming step for forming a body, a flexible printed wiring board forming step for forming a flexible printed wiring board having a through-hole provided with a notch on the outer periphery as a recess for fitting, and the to- be-connected body forming step. Later, a fitting step of fitting a through hole provided in the flexible printed wiring board to a fitting convex portion provided in the connected body , and after the fitting step, the disconnection prevention piece is heated to the flexible printed wiring board. at least a step of welding, the and a benzalkonium be formed larger than the diameters of the through hole of the for prevention piece in the connected body forming step, the fixing structure with the fitting step In the formed state, it is possible to prevent the flexible printed wiring board comes out of the fitting protrusion effectively.
Therefore, a flexible printed wiring board can be firmly fixed to a to-be-connected body, and a fixed structure with high connection reliability can be manufactured.

In addition , since a step for thermally welding the removal preventing piece to the flexible printed wiring board is provided after the fitting step, the diameter of the removal preventing piece can be further increased, and the removal preventing piece and the flexible printed wiring It is possible to prevent a gap from being generated between the plates.

I I can be more firmly fixed a flexible printed circuit board to be connected body, it is possible to manufacture a highly fixing structure further connection reliability.

According to the fixing structure of the present invention, a fixing structure with high connection reliability can be obtained. Moreover, it can be set as the fixed structure with high manufacturing efficiency.
Further, according to the method for manufacturing a fixing structure of the present invention, a fixing structure with high connection reliability can be manufactured. Moreover, it can be set as the manufacturing method of the fixed structure with high manufacturing efficiency.

It is a top view which shows the fixing structure which concerns on embodiment of this invention. It is sectional drawing of the principal part in the AA line direction of FIG. It is a top view which shows the principal part of the flexible printed wiring board which concerns on embodiment of this invention, (a) is a figure which shows the state before fixing a flexible printed wiring board to a housing | casing, (b) is a flexible printed wiring board. It is a figure which shows the state fixed to the housing | casing. It is sectional drawing which simplifies and shows the manufacturing method of the housing | casing which comprises the fixing structure which concerns on embodiment of this invention. It is sectional drawing which simplifies and shows the manufacturing method of the flexible printed wiring board which comprises the fixing structure which concerns on embodiment of this invention. It is sectional drawing which simplifies and shows the process of fitting the flexible printed wiring board which concerns on embodiment of this invention to the housing | casing which concerns on embodiment of this invention. It is sectional drawing which shows the principal part of the modification of the fixing structure which concerns on embodiment of this invention. It is a top view which shows the principal part of the modification of the fixing structure which concerns on embodiment of this invention. It is sectional drawing of the principal part which shows the conventional fixing structure.

  With reference to the following drawings, the fixing structure 1 and the manufacturing method of the fixing structure 1 according to the embodiment of the present invention will be described for the understanding of the present invention. However, the following description is an embodiment of the present invention, and does not limit the contents described in the claims.

First, a fixing structure 1 according to an embodiment of the present invention will be described with reference to FIGS.
The fixing structure 1 according to the embodiment of the present invention is a fixing structure in which a flexible printed wiring board is fixed to a connected body such as a housing.
As shown in FIGS. 1 and 2, the fixing structure 1 includes a housing 10 as a connected body and a flexible printed wiring board 20.

The housing 10 is made of resin and forms a main body of an electronic device such as a mobile phone.
In the present embodiment, as shown in FIGS. 1 and 2, a pair of fitting convex portions 11 for fixing the flexible printed wiring board 20 is provided at opposing positions in the short direction of the housing 10. is there.
Further, in the present embodiment, as shown in FIG. 2, a rivet-like fitting convex portion 11 is formed by a shaft 11a and a slip-off preventing piece 11b formed at the tip of the shaft 11a.
More specifically, as shown in FIGS. 1 to 3, the shape of the shaft 11a is formed in a cylindrical shape. Moreover, the shape of the piece 11b for preventing slipping is formed in a shape in which both the upper surface and the lower surface are circular and have side surfaces that widen toward the lower surface from the upper surface.
The diameter B (diameter) of the shaft 11a shown in FIG. 2 is desirably about 0.3 mm to 3 mm, more preferably 0.5 mm to 1.5 mm. This is because if it is less than 0.3 mm, molding becomes difficult, and if it exceeds 3 mm, it cannot be made compact.
2 is preferably equal to the total thickness E of the flexible printed wiring board 20 or less than or equal to the total thickness E of the flexible printed wiring board 20 + 0.7 mm. This is because if the height C is less than the total thickness E of the flexible printed wiring board 20, a through hole T (described later) of the flexible printed wiring board 20 cannot be fitted to the shaft 11a portion. This is because when the total thickness E + 0.7 mm is exceeded, there is too much space between the stripping prevention piece 11b and the flexible printed wiring board 20, and the flexible printed wiring board 20 is wobbled.
Further, the diameter F (diameter) of the removal preventing piece 11b needs to be larger (longer) than the diameter G (diameter) of a through hole T (described later) of the flexible printed wiring board 20. More specifically, the diameter F (diameter) of the removal preventing piece 11b is about 110% to 500%, more preferably 150% to 400%, relative to the diameter G (diameter) of the through hole T. desirable. This is because if it is less than 110%, the flexible printed wiring board 20 cannot be fixed by the stripping prevention piece 11b, and if it exceeds 500%, it cannot be made compact.
Here, the “diameter F of the slip prevention piece 11b” is the largest diameter in the slip prevention piece 11b having a shape in which both the upper surface and the lower surface are circular and have side surfaces spreading from the upper surface toward the lower surface. It means the (long) part, that is, the diameter (diameter) of the lower surface.
The height H of the removal preventing piece 11b is preferably about 0.3 mm to 3 mm, more preferably 0.5 mm to 2 mm. This is because if it is less than 0.3 mm, the slip-off preventing piece 11b is deformed and pulled out when stress is applied, and if it exceeds 3 mm, it cannot be made compact.
As will be described later, the fitting convex portion 11 having the removal preventing piece 11b is formed by injecting a resin into a mold first, thereby forming a housing including the rod-shaped member 11c. After the body 10 is formed, it can be formed by thermally melting the tip of the rod-shaped member 11c.
As the resin forming the housing 10, polycarbonate, ABS, polystyrene, or the like can be used.

The flexible printed wiring board 20 is a flexible printed wiring board disposed inside an electronic device (not shown) while being fixed to the housing 10.
More specifically, as shown in FIG. 2, the through hole T is fitted to the fitting convex portion 11 provided in the case 10, thereby fixing the case 10 to form the fixing structure 1. It is a flexible printed wiring board.
The flexible printed wiring board 20 is a so-called single-sided flexible printed wiring board having a conductive layer 22 on one side of a base material layer 21, and includes a base material layer 21, a conductive layer 22, and an insulating layer 23.

The base material layer 21 is an insulating resin layer made of an insulating resin that constitutes the base of the flexible printed wiring board 20 and is formed of an insulating resin film.
As the insulating resin film, a film made of a resin material having excellent flexibility is used. For example, any resin film may be used as long as it is normally used as a resin film for forming a flexible printed wiring board such as a polyimide film or a polyester film.
In particular, those having high heat resistance in addition to flexibility are desirable. For example, polyamide resin films, polyimide resin films such as polyimide and polyamideimide, and polyethylene naphthalate can be preferably used.
The heat-resistant resin may be any resin as long as it is normally used as a heat-resistant resin for forming a flexible printed wiring board, such as a polyimide resin or an epoxy resin.

The conductive layer 22 is a layer made of a conductive metal, and is a layer for forming the wiring 22a of the flexible printed wiring board 20 and the like.
The wiring 22a can be formed using a known forming method such as coating the surface of the base material layer 21 with a conductive metal such as copper by plating and etching.
In the present embodiment, as shown in a simplified manner in FIG. 1, the flexible printed wiring board 20 includes a conductive layer covering region D including the conductive layer 22 and a conductive layer non-covering region N not including the conductive layer 22. It is set as the structure provided with.
Further, as shown in a simplified manner in FIG. 1, the conductive layer covering region D is electrically connected to the wiring region D1 including the wiring 22a and the wiring 22a, and to other printed wiring boards and the like. And a terminal region D2 including a terminal (not shown).
Although not shown, various electronic components are mounted at predetermined positions in the conductive layer covering region D.

The insulating layer 23 is an insulating resin layer made of an insulating resin for covering the base material layer 21 and the wiring 22 a to ensure the insulation of the flexible printed wiring board 20.
As the insulating resin, a polyimide film with an adhesive, a photosensitive resist, a liquid resist, or the like that is usually used for forming an insulating layer of a flexible printed wiring board can be used.
The total thickness E of the flexible printed wiring board 20 shown in FIG. 2 is preferably about 30 μm to 500 μm, more preferably 50 μm to 250 μm. This is because if the thickness is less than 30 μm, the wiring is easily disconnected or insulation cannot be secured, and if it exceeds 500 μm, the flexibility is lost.

Moreover, in this embodiment, as shown in FIG. 1, the through-hole T which penetrates in the thickness direction of the flexible printed wiring board 20 is provided in the conductive layer non-coating area | region N in the flexible printed wiring board 20 which consists of an already described structure. As a configuration.
More specifically, in the conductive layer non-covering region N, a circular through-hole T is formed at the upper corner of the flexible printed wiring board 20 and at a position facing the short side of the flexible printed wiring board 20. It is set as the structure provided in pairs.
As shown in FIGS. 2 and 3, the through hole T is a fitting recess that fits into the fitting protrusion 11 provided in the housing 10.
2 and 3, the diameter G (diameter) of the through hole T is larger by about 0.03 mm to 0.3 mm than the diameter B (diameter) of the shaft 11a, and more preferably 0.05 mm to 0.15 mm. It is desirable to enlarge it. This is because if it is less than 0.03 mm, the insertion into the fitting convex portion 11 becomes difficult, and if it exceeds 0.3 mm, play increases.

Furthermore, in this embodiment, as shown to Fig.3 (a), it is set as the structure provided with the two notch parts K in the outer periphery of the through-hole T. As shown in FIG.
More specifically, as shown in FIG. 3, the flexible printed wiring board 20 is formed in a U shape in the thickness direction at two opposing positions (left and right directions) on the outer periphery of the circular through hole T in plan view. The cut portion K is formed by punching. Furthermore, it is set as the structure which provides the notch part K so that the U-shaped opening end may contact | connect the outer periphery of the through-hole T. FIG. Moreover, in this embodiment, it is set as the structure which makes the shape and magnitude | size of a pair of notch part K the same.
Note that the length J of the notch K shown in FIG. 3A is preferably about 25% to 250%, more preferably 50% to 200% with respect to the diameter G (diameter) of the through hole T. . This is because if it is less than 25%, the insertion becomes difficult, and if it exceeds 250%, the flexible printed wiring board is likely to come off from the removal preventing piece 11b.
In the present embodiment, as will be described later, the cut portion K is formed at the same time as the through hole T by punching the flexible printed wiring board 20 in the thickness direction using a mold in the step of forming the through hole T. It is.

The fixing structure 1 according to the embodiment of the present invention having such a configuration has the following effects.
The diameter F of the prevention piece 11b is made larger than the diameter G of the through hole T, and a length J of about 25% to 250% with respect to the diameter G (diameter) of the through hole T is formed on the outer periphery of the through hole T. When the through hole T is fitted to the fitting convex portion 11 (when the flexible printed wiring board 20 is fixed to the housing 10), the cut portion K is the starting point. As described above, the flexible printed wiring board 20 at the peripheral portion of the through hole T and the peripheral portion of the cut portion K can be temporarily bent along the outer surface of the removal preventing piece 11b. Therefore, even if the diameter F of the removal preventing piece 11b is larger than the diameter G of the through hole T, the through hole T can be smoothly and reliably fitted to the fitting convex portion 11. Therefore, the fixing structure 1 with high manufacturing efficiency can be obtained. Further, after fitting the through hole T to the fitting convex portion 11, the flexible printed wiring board 20 is effectively prevented from coming out of the fitting convex portion 11 by vibration, spring back of the flexible printed wiring board 20 itself, or the like. be able to. Therefore, the flexible printed wiring board 20 can be firmly fixed to the housing 10. Therefore, the fixing structure 1 with high connection reliability can be obtained.
Further, by setting the height C of the shaft 11a to be equal to the total thickness E of the flexible printed wiring board 20 or less than about the total thickness E + 0.7 mm of the flexible printed wiring board 20, the separation preventing piece 11b and the flexible print It is possible to effectively prevent a gap from being formed between the wiring board 20 and the wiring board 20. Therefore, the flexible printed wiring board 20 can be more firmly fixed to the housing 10 simply by fitting the flexible printed wiring board 20 to the housing 10. Therefore, the fixing structure 1 with higher connection reliability can be obtained.
Further, the shape of the removal preventing piece 11b is such that the upper surface and the lower surface are both circular and have side surfaces that widen from the upper surface toward the lower surface, so that the through hole T is formed along the side surface of the removal preventing piece 11b. It can be fitted efficiently. Therefore, it can be set as the fixing structure 1 with high manufacturing efficiency.
In addition, the through hole T is formed in a circular shape, and the shape of the cut portion K is U-shaped, and the cut portion K is provided so that the U-shaped opening end is in contact with the outer periphery of the through hole T. As shown in FIG. 3A, stress concentration points where stress applied to the flexible printed wiring board 20 concentrates are not formed on the outer periphery of the through hole T and the outer periphery of the cut portion K. Therefore, when the through hole T is fitted to the fitting convex portion 11, the stress applied to the peripheral portion of the through hole T and the peripheral portion of the cut portion K can be effectively dispersed. Therefore, it is possible to effectively prevent the flexible printed wiring board 20 from being broken.
In addition, a pair of fitting projections 11 are provided at opposing positions in the short direction of the housing 10, and a pair of through holes T are provided at opposing positions in the short direction of the flexible printed wiring board 20. Alignment between the fitting convex portion 11 and the through-hole T is easy, and the flexible printed wiring board 20 can be firmly fixed to the housing 10 simply by fitting the flexible printed wiring board 20 to the housing 10. it can. Therefore, it is possible to obtain the fixing structure 1 with high manufacturing efficiency and high connection reliability.

That is, as shown in FIG. 9A, the conventional fixing structure 2 in which the flexible printed wiring board 70 is fixed to a connected body such as the housing 60 has an adhesive 50 such as an adhesive tape attached to the housing 60. In general, it is formed by attaching the flexible printed wiring board 70.
However, in the fixing structure 2 having such a configuration, with the recent progress of downsizing and thinning of electronic devices, the area to which the adhesive is applied is narrowed, so that sufficient adhesive force cannot be obtained. As a result of peeling of the flexible printed wiring board 70 from the housing 60 due to vibration, spring back of the flexible printed wiring board 70 itself, etc., there arises a problem that the housing 60 and the flexible printed wiring board 70 are separated. ing. Such a problem is more conspicuous when the flexible printed wiring board 70 is fixed over the bent portion of the housing 60.
Further, for such a problem, as shown in FIG. 9B, the through hole T is formed in the flexible printed wiring board 90 and the through hole T is formed in the fitting convex portion 81 provided in the housing 80. It is considered that the fixing structure 3 is formed by fitting.
However, in such a fixing structure 3, as shown in FIG. 9B, after the through hole T is fitted to the columnar fitting convex portion 81, the heat tool 30 is used to form the resin. It is necessary to form the slip-off preventing piece 81b by melting the tip of the fitting convex portion 81.
Therefore, there is a time lag between fitting the through hole T to the fitting convex portion 81 and forming the removal preventing piece 81b, so that the fitting convexity is caused by vibration or spring back of the flexible printed wiring board 90 itself. There is a problem that the flexible printed wiring board 90 may come out (float) from the portion 81 and the casing 80 and the flexible printed wiring board 90 may be separated.
The casing 60 and the casing 80 are formed of the same member as the casing 10 according to the present embodiment described above, and the flexible printed wiring boards 70 and 90 are flexible according to the embodiments of the present invention described above. Since it is formed of the same member as the printed wiring board 20, detailed description thereof will be omitted.

Therefore, it can be set as the fixed structure 1 with high connection reliability by setting it as the structure of the fixed structure 1 which concerns on embodiment of this invention.
Moreover, it can be set as the fixing structure 1 with high manufacturing efficiency.

  Next, with reference to FIGS. 4-6, the manufacturing method of the fixing structure 1 which concerns on embodiment of this invention is demonstrated.

  The manufacturing method of the fixing structure 1 according to the embodiment of the present invention includes a connected body forming step for forming the housing 10, a flexible printed wiring board forming step for forming the flexible printed wiring board 20, and a fitting provided in the housing 10. A fitting step of fitting the through-hole T provided in the flexible printed wiring board 20 to the fitting convex portion 11.

First, with reference to FIG. 4, the connected body forming step will be described.
With reference to Fig.4 (a), the housing | casing 10 provided with the rod-shaped member 11c shown to Fig.4 (a) is formed by injecting resin to the metal mold | die which is not illustrated and shape | molding.
Thereafter, referring to FIG. 4 (b), the tip of the rod-shaped member 11c made of resin is melted by the heat tool 30, so that a rivet-like fitting convex portion having a shaft 11a and a slip-off preventing piece 11b is provided. 11 is formed.
At this time, it is necessary to form the diameter F of the prevention piece 11b larger than the diameter G of the through hole T. Moreover, it is necessary to form so that the height C of the axis | shaft 11a may become the same as the total thickness E of the flexible printed wiring board 20, or below the total thickness E + 0.7mm of the flexible printed wiring board 20. Further, it is necessary to form the shape of the removal preventing piece 11b into a shape in which both the upper surface and the lower surface are circular and have side surfaces spreading toward the lower surface from the upper surface.
The housing | casing 10 which concerns on embodiment of this invention is formed of the above process.

Next, a flexible printed wiring board forming process will be described with reference to FIG.
First, referring to FIG. 5A, a base material layer 21 made of an insulating resin material is prepared by a base material layer preparation step.
Next, the conductive layer 22 is formed on the base material layer 21 by a conductive layer forming step. More specifically, the conductive layer 22 is formed by covering the surface of the base material layer 21 with copper by plating.
Thereafter, referring to FIG. 5B, in a wiring formation step, the pattern mask 40 is covered on the surface of the conductive layer 22 (a region where the wiring 22a is formed later) and etching is performed.
Thereby, as shown in FIG.5 (c), the wiring 22a is formed in a predetermined position. Although not shown, a terminal is also formed in the same process as this process.
Thereafter, referring to FIG. 5D, the insulating layer 23 is formed by covering the surface of the base material layer 21 and the wiring 22a with an insulating resin in the insulating layer forming step.
Thereafter, referring to FIG. 5 (e), in the through hole forming step, the wiring board is punched out in the thickness direction using a mold, so that a pair of cut portions K ( (Not shown) at the same time.
At this time, it is necessary to make the diameter G of the through hole T smaller than the diameter F of the prevention piece 11b. Further, it is necessary to form the cut portion K (not shown) to have a length of about 25% to 250% with respect to the diameter G (diameter) of the through hole T. Further, it is necessary to form the through-hole T in a circular shape, and further to make the cut-out portion K into a U-shape, and to form the cut-out portion K so that the U-shaped opening end is in contact with the outer periphery of the through-hole T. .
The flexible printed wiring board 20 which concerns on embodiment of this invention is formed of the above process.

Next, the fitting process will be described with reference to FIG. In addition, this fitting process is performed after the to-be-connected body formation process and flexible printed wiring board formation process which were already described.
First, as shown in a simplified manner in FIG. 6 (a), after positioning the fitting convex portion 11 provided with the removal preventing piece 11b and the through hole T, the flexible printed wiring board is disposed above the housing 10. 20 is arranged.
Thereafter, referring to FIG. 6B, the through-hole T provided in the flexible printed wiring board 20 is fitted into the fitting convex portion 11 provided in the housing 10 which is a connected body. At this time, since the cut portion K is provided on the outer periphery of the through hole T, as shown in FIG. 6B, the peripheral portion of the through hole T and the cut portion K start from the cut portion K (not shown). The flexible printed wiring board 20 at the peripheral edge can be temporarily bent along the outer surface of the stripping prevention piece 11b.
And the fixing structure 1 which concerns on embodiment of this invention is formed as shown in FIG.6 (c) by further fitting the through-hole T with which the flexible printed wiring board 20 is equipped with the convex part 11 for fitting.

The manufacturing method of the fixing structure 1 according to the embodiment of the present invention having such a configuration has the following effects.
The diameter F of the prevention piece 11b is made larger than the diameter G of the through hole T, and the outer periphery of the through hole T has a length of about 25% to 250% with respect to the diameter G (diameter) of the through hole T. When the through-hole T is fitted to the fitting convex portion 11 (when the flexible printed wiring board 20 is fixed to the housing 10), the configuration in which the cut portion K is provided is shown in FIG. As shown, the flexible printed wiring board 20 at the peripheral portion of the through-hole T and the peripheral portion of the cut portion K is temporarily bent along the outer surface of the removal preventing piece 11b starting from the cut portion K (not shown). Can do. Therefore, even if the diameter F of the removal preventing piece 11b is larger than the diameter G of the through hole T, the through hole T can be smoothly fitted to the fitting convex portion 11. Therefore, it can be set as the manufacturing method of the fixing structure 1 with high manufacturing efficiency. Further, after fitting the through hole T to the fitting convex portion 11, the flexible printed wiring board 20 is effectively prevented from coming out of the fitting convex portion 11 by vibration, spring back of the flexible printed wiring board 20 itself, or the like. be able to. Therefore, the flexible printed wiring board 20 can be firmly fixed to the housing 10. Therefore, the fixing structure 1 with high connection reliability can be manufactured.
Further, by setting the height C of the shaft 11a to be equal to the total thickness E of the flexible printed wiring board 20 or less than about the total thickness E + 0.7 mm of the flexible printed wiring board 20, the separation preventing piece 11b and the flexible print It is possible to effectively prevent a gap from being formed between the wiring board 20 and the wiring board 20. Therefore, the flexible printed wiring board 20 can be more firmly fixed to the housing 10 simply by fitting the flexible printed wiring board 20 to the housing 10. Therefore, the fixing structure 1 with higher connection reliability can be manufactured.
Also, the shape of the drop prevention piece 11b is such that the upper surface and the lower surface are both circular and have side surfaces that widen from the upper surface toward the lower surface, as shown in FIG. 6B, the drop prevention piece 11b. The through-hole T can be efficiently fitted along the side surface of the. Therefore, it can be set as the manufacturing method of the fixing structure 1 with high manufacturing efficiency.
In addition, the through hole T is formed in a circular shape, and the shape of the cut portion K is U-shaped, and the cut portion K is provided so that the U-shaped opening end is in contact with the outer periphery of the through hole T. As shown in FIG. 3A, stress concentration points where stress applied to the flexible printed wiring board is concentrated are not formed on the outer periphery of the through hole T and the outer periphery of the cut portion K. Therefore, when the through hole T is fitted to the fitting convex portion 11, the stress applied to the flexible printed wiring board 20 at the peripheral portion of the through hole T and the peripheral portion of the cut portion K can be effectively dispersed. Therefore, it can be set as the manufacturing method of the fixed structure 1 which can prevent effectively that a fracture | rupture arises in the flexible printed wiring board 20. FIG.
Further, the housing 10 having the rod-shaped member 11c is molded by injecting resin into the mold, and the fitting convex portion 11 having the removal preventing piece 11b is formed by thermally melting the tip of the rod-shaped member 11c. By doing, the fitting convex part 11 can be formed easily. Therefore, the housing | casing 10 can be manufactured efficiently. Moreover, the through-hole T and the notch part K can be formed efficiently by setting it as the structure which forms the through-hole T and the notch part K by punching the flexible printed wiring board 20 in the thickness direction using a metal mold | die. Therefore, it can be set as the manufacturing method of the fixing structure 1 with high manufacturing efficiency.

  Next, modified examples 1 to 3 of the fixing structure 1 according to the embodiment of the present invention described above will be described with reference to FIG.

Although not shown in detail, the first modification is obtained by modifying the configuration of the fitting convex portion 11 with respect to the fixing structure 1 according to the embodiment of the present invention described above. Moreover, this modification 2 adds the adhesive agent 50 with respect to the fixing structure 1 which concerns on embodiment of this invention mentioned above. Further, the deformability 3 is obtained by modifying the configuration of the fitting convex portion 11 and adding an adhesive 50 to the fixing structure 1 according to the embodiment of the present invention.
Therefore, the same member and the same function as those of the fixing structure 1 according to the embodiment of the present invention described above are denoted by the same reference numerals and the same alphabet, and detailed description thereof will be omitted below.

First, referring to FIG. 7 (a), the fixing structure 4 according to the first modification is different from the fixing structure 1 according to the embodiment of the present invention described above in that a piece 11 for preventing slipping is provided on the flexible printed wiring board 20. It is set as the structure heat-welded.
In addition to the manufacturing method of the fixing structure 1 according to the embodiment of the present invention described above, the fixing structure 4 is provided with the flexible printed wiring board 20 by using a heat tool (not shown) after the fitting process. It can manufacture by performing the process heat-welded to.
With such a configuration, the flexible printed wiring board 20 can be fixed to the casing 10 without causing a further gap between the casing 10 and the flexible printed wiring board 20. In addition, the diameter of the removal preventing piece 11 can be made larger (longer).
Therefore, the flexible printed wiring board 20 can be more firmly fixed to the housing 10. Therefore, the fixing structure 4 with higher connection reliability can be obtained.

Next, referring to FIG. 7B, the fixing structure 5 according to the second modification is different from the fixing structure 1 according to the embodiment of the present invention described above between the housing 10 and the flexible printed wiring board 20. The adhesive 50 is interposed between and in the vicinity of the through hole T.
The fixing structure 5 is fitted with the adhesive 50 interposed between the housing 10 and the flexible printed wiring board 20 in addition to the manufacturing method of the fixing structure 1 according to the embodiment of the present invention described above. It can manufacture by performing a process.
Here, the “region in the vicinity of the through hole T” means a region surrounded by a range of about 20 mm from the outer periphery of the through hole T to the outside.
With such a configuration, the flexible printed wiring board 20 can be more reliably fixed to the housing 10.
Therefore, it is possible to effectively prevent the flexible printed wiring board 20 from coming out of the fitting convex portion 11, and the fixing structure 5 with higher connection reliability can be obtained.

Next, referring to FIG. 7 (c), the fixing structure 6 according to the third modification is different from the fixing structure 1 according to the above-described embodiment of the present invention in that the separation preventing piece 11 is connected to the flexible printed wiring board 20. The adhesive 50 is interposed between the housing 10 and the flexible printed wiring board 20 and in the vicinity of the through hole T.
In addition to the manufacturing method of the fixing structure 1 according to the embodiment of the present invention described above, the fixing structure 6 is fitted with the adhesive 50 interposed between the housing 10 and the flexible printed wiring board 20. It can manufacture by performing a process and also performing the process of heat-welding the piece 11 for prevention of slipping out to the flexible printed wiring board 20 using the heat tool which is not shown in figure after that.
With such a configuration, the flexible printed wiring board 20 can be fixed to the casing 10 without causing a further gap between the casing 10 and the flexible printed wiring board 20. Further, the diameter of the removal preventing piece 11 can be further increased. Furthermore, the flexible printed wiring board 20 can be more securely fixed to the housing 10.
Therefore, the flexible printed wiring board 20 can be more firmly fixed to the housing 10, and the fixing structure 6 with higher connection reliability can be obtained.

  Next, with reference to FIG. 8, the fixing structure 7 according to the modified example 4 of the fixing structure 1 according to the embodiment of the present invention described above will be described.

Although not shown in detail, the fourth modification is obtained by modifying the configuration of the through hole and the cut portion with respect to the fixing structure 1 according to the embodiment of the present invention described above.
Accordingly, the same members and the same functions as those of the fixing structure 1 according to the embodiment of the present invention described above are denoted by the same reference numerals and the same alphabets, and the following detailed description is omitted.

With reference to FIG. 8 (a), the present modification 4 has a first through hole T1 having a diameter larger than the diameter F of the prevention piece 11b and a diameter smaller than the diameter of the prevention piece 11b. A through-hole T including the second through-hole T2 is provided, and the first through-hole T1 and the second through-hole T2 are connected via a notch K1.
More specifically, a circular first through-hole T1 having a diameter P larger than the diameter F of the removal preventing piece 11b, and a circular second having a diameter Q smaller than the diameter F of the removal preventing piece 11b. A through-hole T composed of the through-hole T2 is provided, and the first through-hole T1 and the second through-hole T2 are connected to each other at a central portion via a notch K1.
Further, the vertical length R of the cut portion K1 is configured to be shorter than the diameter B of the shaft 11a.
Further, the diameter Q of the second through hole T2 is configured to be larger than the diameter B of the shaft 11a.
The vertical length R of the notch K1 is desirably about 50% or less, more preferably 33% or less with respect to the diameter B of the shaft 11a. If it exceeds 50%, the fitting location of the fitting convex portion 11 slides (moves) from the second through hole T2 back to the first through hole T1 due to vibration, spring back of the flexible printed wiring board 20 itself, and the like. Because it will end up.
The lateral length V of the cut portion K1 is desirably about 1.5 mm to 30 mm, more preferably 2 mm to 15 mm. If it is less than 1.5 mm, the fitting place of the fitting convex portion 11 slides (moves) from the second through hole T2 to the first through hole T1 due to vibration, spring back of the flexible printed wiring board 20 itself, or the like. This is because if it exceeds 30 mm, it is difficult to slide (move) the fitting place of the fitting convex portion 11 from the first through hole T1 to the second through hole T2.
Further, the diameter P of the first through hole T1 is desirably about 0.03 mm to 0.2 mm, more preferably 0.05 mm to 0.15 mm larger than the diameter F of the removal preventing piece 11b. This is because if it is less than 0.03 mm, insertion becomes difficult, and if it exceeds 0.2 mm, play increases.
In addition, the diameter Q of the second through hole T2 is desirably about 0.03 mm to 0.2 mm, more preferably 0.05 mm to 0.15 mm larger than the diameter B of the shaft 11a. If it is less than 0.03 mm, it is difficult to slide (move) the fitting place of the fitting convex portion 11 from the first through hole T1 to the second through hole T2. This is because play increases.
In the present modification, the notch K1 is formed simultaneously with the through hole T by punching the flexible printed wiring board 20 in the thickness direction using a mold in the step of forming the through hole T.
Although not shown, also in this modification, the region where the through hole T and the cut portion K1 are provided in the flexible printed wiring board 20 is combined with the base material layer 21 and the insulating layer 23 each made of an insulating resin layer. The structure is formed as follows.

By adopting such a configuration, as shown in a simplified manner in FIG. 8, the first through hole T1 can be a fitting hole for fitting the through hole to the fitting convex portion 11, and The second through hole T <b> 2 can be a fixing hole for fixing the flexible printed wiring board 20 to the housing 10.
More specifically, as shown in FIG. 8A, when the through hole T is first fitted into the fitting convex portion 11, the first P having a diameter P larger than the diameter F of the removal preventing piece 11b. The flexible printed wiring board 20 can be fitted to the fitting convex portion 11 through the through hole T1.
Therefore, when the flexible printed wiring board 20 is fitted to the fitting convex portion 11, the flexible printed wiring board 20 is not bent. Therefore, the through hole can be fitted to the fitting convex portion 11 more easily, and the flexible printed wiring board 20 can be more reliably prevented from being broken. Therefore, the fixing structure 7 with high manufacturing efficiency can be obtained.
Thereafter, as shown in FIG. 8 (b), the fitting convex portion 11 passes from the first through hole to the second through hole T2 having a diameter Q smaller than the diameter F of the removal preventing piece 11b through the cut portion K1. The flexible printed wiring board 20 can be fixed by the second through hole T2 and the removal preventing piece 11b simply by sliding (moving) the fitting place.
Accordingly, it is possible to more effectively prevent the flexible printed wiring board 20 from coming out of the fitting convex portion 11. Therefore, the fixing structure 7 with higher connection reliability can be obtained. That is, the flexible printed wiring board 20 can be easily fitted to the housing 10 and can be firmly fixed to the housing 10.

In the embodiment of the present invention, the configuration of the flexible printed wiring board 20 is a so-called single-sided flexible printed wiring board. However, the configuration is not necessarily limited to such a configuration. A so-called double-sided flexible printed wiring board including the layer 22 may be used. By setting it as such a structure, it can be set as the flexible printed wiring board 20 in which higher density wiring can be achieved.
Further, the configuration (shape, size, number, forming position, forming method, etc.) of the fitting convex portion 11, the through hole T, and the cut portion K is not limited to the configuration of the present embodiment, and can be appropriately changed. Specifically, in the present embodiment, the horizontal section of the shaft 11a, the removal preventing piece 11b, and the through-hole T is all circular, but the configuration is not necessarily limited to such a configuration. The shape of the horizontal section of the prevention piece 11b and the through hole T may be a shape other than a circle such as a triangle, a quadrangle, or a polygon. In this case, “the diameter of the shaft 11a, the diameter of the removal preventing piece 11b, and the diameter of the through hole T” means the length of the insertion in the longest direction. However, in the through-hole T, it is necessary to have a shape that can be aligned with the fitting convex portion 11 (a shape that can take the center point). Further, it is desirable that the shape of the through hole T and the cut portion K is a shape in which stress concentration points are not formed on the outer periphery of the through hole T and the outer periphery of the cut portion K.
Further, the shape of the housing 10 is not limited to the configuration of the present embodiment, and can be appropriately changed as long as the fitting protrusion 11 is provided inside.
In the present embodiment and the modification, the through hole T (the first through hole T1 and the second through hole T2) is provided in the conductive layer non-covering region N. However, the configuration is not necessarily limited thereto. Instead, a configuration in which the through hole T is provided in the conductive layer covering region D (a configuration in which the through hole T is provided by punching the conductive layer 22 in the thickness direction) may be employed. However, in this case, it is necessary that the conductive layer 22 facing the through hole T is not electrically connected to the wiring 22a.
Moreover, in this embodiment and the modification, the area | region in which the through-hole T and the notch | incision part K (K1) in the flexible printed wiring board 20 are provided is each made into the base material layer 21 and insulating layer 23 which consist of an insulating resin layer. Although it is configured to be formed in combination, it is not necessarily limited to such a configuration. For example, it is good also as a structure formed only combining the base material layer 21, or the base material layer 21, the conductive layer 22, and the insulating layer 23. However, in any case, the total thickness E of the flexible printed wiring board 20 is desirably about 30 μm to 500 μm, more preferably 50 μm to 250 μm. This is because if the thickness is less than 30 μm, the wiring is easily disconnected or insulation cannot be secured, and if it exceeds 500 μm, the flexibility is lost.
Further, the formation position of the conductive layer coating region D and the conductive layer non-covering region N, the number of wirings 22a, the formation position, and the like are not limited to those of the present embodiment, and can be changed as appropriate.
In the fourth modification, the diameter P of the first through hole T1 is set to be larger than the diameter F of the removal preventing piece 11b. However, the present invention is not necessarily limited to such a configuration. The diameter P of T1 may be configured to have the same length as the diameter F of the prevention piece 11b.

  According to the present invention, since a fixing structure that constitutes an electronic device such as a mobile phone can be a fixing structure with high connection reliability, industrial applicability in the field of electronic devices such as a mobile phone is high.

DESCRIPTION OF SYMBOLS 1 Fixing structure 2 Fixing structure 3 Fixing structure 4 Fixing structure 5 Fixing structure 6 Fixing structure 7 Fixing structure 10 Housing | casing 11 Protruding part 11a Shaft 11b Drop prevention piece 11c Bar-shaped member 20 Flexible printed wiring board 21 Base material layer 22 Conductivity Layer 22a Wiring 23 Insulating layer 30 Heat tool 40 Pattern mask 50 Adhesive 60 Housing 70 Flexible printed wiring board 71 Base material layer 73 Insulating layer 80 Housing 81 Projection for fitting 81b Stripping prevention piece 90 Flexible printed wiring board 91 Base Material layer 93 Insulating layer B Diameter C Height D Conductive layer lamination area D1 Wiring area D2 Terminal area E Total thickness F Diameter G Diameter J Length K Cut section K1 Cut section N Conductive layer uncovered area P Diameter Q Diameter R Length T through hole T1 first through hole T2 second through hole V length

Claims (4)

A fixing structure in which a flexible printed wiring board is fixed to a connected body, wherein the connected body includes a protrusion for fitting having a disconnection preventing piece at a tip, and the flexible printed wiring board has an outer periphery as a recessed portion for fitting. a through hole is provided with a notch portion, the diameter of the escape prevention piece into the fitting convex portion that is in the greater condition than the diameter of the through hole, with are fitted to the through hole, wherein A fixing structure characterized in that a slip-off preventing piece is thermally welded to the flexible printed wiring board . It is a fixed structure in which a flexible printed wiring board is fixed to a connected body, the connected body includes a fitting convex portion having a slip-off preventing piece at a tip, and the flexible printed wiring board is used as a fitting concave portion, A first through hole having a diameter equal to or larger than a diameter of the removal prevention piece; and a second through hole having a diameter smaller than the diameter of the removal prevention piece, and the fitting convex portion includes the second through hole. The through-holes are fitted together, and the removal preventing pieces are thermally welded to the flexible printed wiring board, and the first through-holes and the second through-holes are connected via a notch. Fixed structure characterized by being allowed to. The fixing structure according to claim 1 , wherein an adhesive is interposed between the connected body and the flexible printed wiring board and in a region near the through hole . It is a manufacturing method of the fixed structure according to claim 1, and a to-be-connected body forming step for forming a to-be-connected body having a fitting convex portion having a disconnection preventing piece at the tip, and a recess for fitting is cut into the outer periphery. A flexible printed wiring board forming step for forming a flexible printed wiring board having a through hole provided with a portion, and a fitting convex portion provided in the connected body after the connecting body forming step, to the flexible printed wiring board A fitting step for fitting the through-holes provided, and a step of thermally welding the piece for preventing detachment to the flexible printed wiring board after the fitting step, and for preventing the detachment in the connected body forming step. A method of manufacturing a fixed structure, wherein the diameter of the piece is formed larger than the diameter of the through hole.

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