JP2006005200A - Insulating film for printed circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible insulating film which is interposed between a printed circuit board received in a metal case and the inner wall surface of the metal case, does not require the formation of notches in the printed circuit board, and uses a relatively small amount of a material for each insulating film. <P>SOLUTION: Side plates 12, 12 are inwardly folded back at fold back lines L2 nearly orthogonal to bending lines L1 to form folded back parts 13 at both ends of respective bending lines L1 of the side plates 12, 12. Engagements 15 capable of engaging the corners of the printed circuit board 2 are provided in the folded back parts 13. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention ensures insulation between the printed circuit board and the metal case when the printed circuit board on which the electronic component is mounted is stored in the metal case, and prints the printed circuit board before storing the printed circuit board in the metal case. The present invention relates to an insulating film capable of temporarily fixing a substrate.

  A flexible insulating film interposed between a printed circuit board accommodated in a metal case and an inner wall surface of the metal case is known from, for example, Patent Document 1. The insulating film is continuous with the bottom plate portion facing the bottom surface of the printed circuit board fixed to the metal case, and the bottom plate portion on both sides of the bottom plate portion with the fold line interposed therebetween. A pair of side plate portions that rises along both parallel side surfaces of the printed circuit board by bending, and a plurality of folded portions that extend from the upper edge of each side plate portion with a fold line substantially parallel to the fold line. In the state where the end of the folded portion is in pressure contact with both sides of the printed board parallel to each other by the folding of the folded line to the inside of the side plate, the side plate is connected to both sides of the printed board and the metal case. The printed circuit board and the insulating film are fixed by engaging the notches formed on both side surfaces of the printed circuit board which are located between the wall surface and the folded portion. It is configured to.

The insulating film having such a structure can be formed by die cutting, and when the printed circuit board is housed in the metal case through the insulating film, the inner bottom surface and both inner side surfaces of the metal case are formed of the insulating film. There are advantages that the printed circuit board is completely covered with the bottom plate and the both side plates to ensure the insulation of the printed circuit board with respect to the metal case, and the relative positional relationship between the printed circuit board and the insulating film can be fixed.
JP 2002-164675 A

  However, in the insulating film described in Patent Document 1, notched portions that engage with the folded portions of the insulating film are formed on both side surfaces of the printed circuit board in order to determine the relative position between the printed circuit board and the insulating film. There is a need to. Further, the plurality of folded portions extending from the upper edge of the side plate portion of the insulating film across the folding line substantially parallel to the folding line have a length in the extending direction that is completely folded back on the side plate portion. Since it is necessary, the protruding portion from the insulating film main body becomes long, and there is a problem that a lot of material is wasted when the film is cut out during film production, and the amount of material used per insulating film is relatively large.

  In view of the above circumstances, the present invention aims to provide an insulating film of this type that does not require the formation of a notch in a printed circuit board and that requires a relatively small amount of material used per insulating film. It is what.

  The present invention is a flexible insulating film interposed between a printed circuit board accommodated in a metal case and an inner wall surface of the metal case, and is opposed to the bottom surface of the printed circuit board fixed to the metal case. And a pair of side plate portions that are continuous with the bottom plate portion on both sides of the bottom plate portion, and are raised along both side surfaces of the printed circuit board by bending at substantially right angles at the folding lines. In the insulating film provided with a folded portion extending to the inside of the side plate portion at the folding line substantially orthogonal to the folding line is extended at both ends of each folding line direction of the side plate portion, An engagement portion that can be engaged with a corner portion of the printed circuit board is provided.

  In one aspect of the present invention, the folded portion is formed with a recess notched to a depth corresponding to the thickness of the printed circuit board from the side edge on the extension line of the folded line of the folded portion. The recess includes an engaging edge that can engage with the upper surface and the end surface of the corner of the printed circuit board inserted into the recess.

  In another aspect of the present invention, instead of the recess, the folded portion is formed with an opening extending substantially parallel to the folding line with a width corresponding to the thickness of the printed circuit board. Engagement edges that can be engaged with both sides and end faces of the corner of the printed circuit board inserted into the opening are provided.

  Furthermore, it is preferable that an engagement piece inserted into a slit formed in the side plate portion protrudes from an end edge of the folding portion in the fold line direction.

  Further, in order to fix a plurality of printed circuit boards, a groove extending with a width corresponding to the thickness of the second printed circuit board in a portion spaced upward from the engaging portion of the folded portion with respect to the first printed circuit board. Alternatively, an opening is formed, and the groove or the opening has an engagement edge that can engage with both sides and an end surface of the corner of the second printed board inserted into the groove or the opening. It may be.

  Furthermore, when a printed circuit board having a long length is used, protrusions that engage with both side edges of the upper surface of the printed circuit board may be provided at an intermediate portion of the side plate portion in the fold line direction. Alternatively, an intermediate portion in the fold line direction of the side plate portion is cut open, and a further fold portion that is folded back inside the side plate portion at a fold line that is substantially perpendicular to the fold line is formed there, and a printed circuit board is formed on the fold portion. You may make it provide the engaging part which can be engaged with the upper surface of this.

  Furthermore, when the length of the metal case is longer than the length of the printed circuit board, an extension portion extending from the edge of the printed circuit board is formed at both ends of the bottom line of the insulating film in the fold line direction. You may make it form the hole for positioning with respect to a metal case in a part. In that case, a tongue piece that is bent in contact with the inner wall surface of the side plate of the metal case may be provided to protrude sideways on the side edge of the extension portion of the bottom plate portion and the upper edge of the side plate portion.

  Further, a plurality of tongue pieces that are bent in contact with the inner top surface of the lid of the metal case may be provided on the upper edge of the side plate portion.

  According to the present invention, the both side plates of the insulating film having flexibility are provided with folded portions that are folded inside the side plates at the folding line. These folded portions have a certain thickness and allowance. In view of the property of the insulating film having flexibility, the folding angle in the vicinity of the folding line becomes shallower than 180 degrees. For this reason, the part near the folding line of the folded part is not in close contact with the inner surface of the side plate part, but is maintained at a position relatively distant from the inner surface of the side plate part, and a gap is generated between the side plate part and the folded part. Therefore, by providing a recess or an opening having a size and shape into which the corners of the four corners of the printed circuit board can be inserted at predetermined portions of the folded part, the corner of the printed circuit board is provided in the recess or the opening. By inserting, the edge of the recess or the opening can be engaged with the upper surface and end surface of the corner of the printed circuit board (in the case of the recess) or the upper and lower surfaces and the end surface (in the case of the opening). And since this engaging part exists in the corner | angular part of the four corners of a printed circuit board, an insulating film can be temporarily fixed by this prior to the accommodation to a metal case.

  That is, according to the present invention, in addition to the effect that the inner bottom surface and both inner wall surfaces of the metal case are completely covered by the bottom plate portion and both side plate portions of the insulating film and the insulating property of the printed board with respect to the metal case is ensured, Insulating film and printed circuit board can be temporarily fixed before mounting the printed circuit board in the metal case without providing any notch in the printed circuit board, making it easy to mount the printed circuit board in the metal case. There is an effect that can be done.

  Moreover, since the said folding | returning part formed in an insulating film is shortly formed in the edge part of the longitudinal direction of a both-sides board part, and it does not project at the upper edge of a both-sides board part, the material per insulating film There is also an effect that the amount used is relatively small.

  In addition, when an opening having a size and shape capable of inserting a corner portion of the printed circuit board is provided at a site away from the bottom plate as an engaging part formed in the folded part of the insulating film, the printed circuit board is Since it can be made to float from the bottom board part of an insulating film, it can prevent that the component soldering surface in the bottom face of a printed circuit board contacts the bottom board part of an insulating film, and damages a bottom board part.

  Moreover, when the engagement piece inserted in the slit formed in the said side-plate part protrudes in the edge of the fold line direction of the said folding | returning part, the return | turnback of the said folding | returning part is prevented and a folding state is maintained. can do.

  Furthermore, a plurality of printed circuit boards can be supported by an insulating film by forming an opening or a groove similar to the above in a portion spaced upward from the above-described engaging part with respect to the printed circuit board.

  Furthermore, when the length of the printed circuit board is long, the protrusion of the printed circuit board can be prevented from being lifted by projecting protrusions that engage with both side edges of the upper surface of the printed circuit board at the intermediate portion of the side plate portion. . Alternatively, the intermediate portion is cut open, and a further folded portion that is folded back inside the side plate portion at a folding line substantially perpendicular to the folding line is formed therein, and the folded portion engages with the upper surface of the printed circuit board. The floating of the printed circuit board can also be prevented by providing the joint portion.

  And when the length of the metal case is longer than the length of the printed circuit board, an extension portion extending from the edge of the printed circuit board is formed at both ends of the fold line direction of the bottom plate portion of the insulating film. It is possible to define a relative position of the insulating film with respect to the metal case by providing a hole for positioning with respect to the metal case in the extension portion, and inserting a protrusion protruding from the surface of the bottom plate portion of the metal case into the hole. it can.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a development view showing a basic structure of an insulating film according to the present invention. The insulating film 1 is made of, for example, a polyester film having a thickness of 0.35 mm having insulating properties and flexibility, and has a rectangular bottom plate portion 11 having a shape substantially matching the planar shape of the printed circuit board 2 (FIG. 3). A pair of side plate portions 12 and 12 that are continuous to the bottom plate portion 11 with fold lines (valley fold lines) L1 and L1 extending along the longitudinal direction of the bottom plate portion 11, and a fold line of each side plate portion 12 It is comprised by the four substantially square folding | turning part 13 extended from the side-plate part 12 on both sides of L1 direction on both sides of the folding line (valley folding line) L2 substantially orthogonal to the folding line L1.

  Each folded portion 13 has a rectangular recess 15 that is notched to a depth corresponding to the thickness of the printed circuit board 2 from the side edge 14 on the extension line of the fold line L1, leaving both ends of the side edge 14. Is provided as an engaging portion for the printed circuit board 2.

  The insulating film 1 may have a thickness of 0.188 mm, 0.25 mm, or 0.5 mm in addition to the thickness of 0.35 mm.

  FIG. 2 is a development view showing a modified configuration of the insulating film of FIG. This insulating film 10 is used when the printed circuit board 2 is accommodated in a metal case 3 (FIG. 5) having a length longer than that of the printed circuit board 2, and has the same configuration as the insulating film 1 in FIG. In addition, extension portions 16 and 16 corresponding to the length of the metal case 3 are provided at both ends of the bottom plate portion 11 in the direction of the fold lines L1 and L1. In order to prevent movement in the longitudinal direction, a long hole 17 into which a positioning projection 33 provided on the metal case 3 is inserted is formed. In addition, in the following description, the case where the insulating film 10 provided with the extension parts 16 and 16 as shown in FIG. 2 is used is demonstrated.

  FIG. 3 is a perspective view showing a state in which the printed board 2 is temporarily fixed to the insulating film 10 before the printed board 2 is accommodated in the metal case 3 via the insulating film 10 of FIG. 2.

  The printed circuit board 2 includes an upper surface 21 that is a mounting surface for the electronic components 25 and 26, both side surfaces 22 and 22 that are substantially parallel to each other in the longitudinal direction, both end surfaces 23 and 23 in the longitudinal direction, and the electronic components 25 and 26. And a bottom surface 24 which is a soldering surface.

  The insulating film 10 first bends the side plate portions 12 and 12 at the folding lines L1 and L1 with respect to the bottom plate portion 11 at approximately 90 degrees, and further folds the four folded portions 13 at approximately 180 degrees with respect to the folding line L2. , 12, the state shown in FIG.

  FIG. 4 is an enlarged perspective view showing one of the four folded portions 13. As for this folding | turning part 13, the side edge 14 on the extension line of the folding line L1 is contacting the upper surface of the baseplate part 11 by folding in the folding line L2. Then, the leg piece 18 is formed substantially vertically by a distance corresponding to the thickness of the printed circuit board 2 from the side edge 14 at a position slightly away from the folding line L2 so that the leg piece 18 is formed between the folding line L2 and the vertical edge 15a. A leg piece 19 is formed between the vertical edge 15a that rises, a horizontal edge 15b that extends substantially parallel to the side edge 14 from the upper end of the edge 15a to slightly before the end edge 13a of the folded portion 13, and the end edge 13a. As described above, the rectangular engaging recess 15 is constituted by the vertical edge 15 c that falls substantially vertically from the tip of the horizontal edge 15 b to the side edge 14.

  Therefore, the recess 15 and the upper surface of the bottom plate portion 11 of the insulating film 10 form an opening through which a corner portion of the printed board 2 placed on the bottom plate portion 11 can be inserted. .

  In this case, when the printed circuit board 2 is positioned above the insulating film 10 folded and folded in the state shown in FIG. 3, the vertical edge 15a on the folding line L2 side of the recess 15 is formed on the printed circuit board. The front and back positions of the folding line L2 and the vertical edge 15a of the recess 15 are set so as to have a relationship that substantially coincides with the position of the end face 23 in the longitudinal direction 2. The same applies to the remaining three folded portions 13.

  In addition, although the folding | returning part 13 is drawn in the state curved in the circular arc shape seeing from upper direction in the figure, you may have the shape bent in the shape of a character seeing from upper direction.

  FIG. 5 is a perspective view showing a state in which the printed circuit board 2 temporarily fixed to the insulating film 10 is housed in a metal case 3 having a longer length than the printed circuit board 2, and FIG. It is an expansion perspective view which shows the engagement state of the part 13 and the corner | angular part of a printed circuit board.

  The pair of side plate portions 12 and 12 are bent at the folding lines L1 and L1, respectively, and the four folding portions 13 are respectively folded at the folding lines L2 and printed on the insulating film 10 shown in FIG. When the substrate 2 is inserted from above, the corners at the four corners of the printed circuit board 2 are brought into contact with the surface of the folded section 13 of the insulating film 10, respectively, so that the folded section 13 is bent and insertion of the printed circuit board 2 is allowed. The In this state, when the bottom surface 24 of the printed circuit board 2 reaches the bottom plate portion 11 of the insulating film 10, the corners of the printed circuit board 2 match the engagement recesses 15, so that the folded portion 13 is folded as shown in FIG. The leg piece 18 on the line L2 side is moved along the end surface 23 at the corner of the printed circuit board 2 by the restoring force of the folded portion 13, and the vertical edge 15a of the recess 15 is engaged with the end surface 23 of the printed circuit board 2. In addition, the horizontal edge portion 15 b is engaged with the upper surface of the corner portion of the printed circuit board 2, so that the corner portion of the printed circuit board 2 is locked by the folded-back portion 13. And the leg piece 19 by the side of the edge 13a of the folding | turning part 13 is pinched | interposed between the side surface 22 of the printed circuit board 2, and the side-plate part 12 of the insulating film 10, and the folding | turning part 13 is fixed. In addition, as shown in FIG. 6, when the upper part on the side of the edge 13a of the folding | turning part 13 is cut | disconnected previously along the virtual line L3, the assembly | attachment of the printed circuit board 2 with respect to the insulating film 10 will become easy.

  As shown in FIG. 5, the metal case 3 has a bowl-like cross-sectional shape by a bottom plate portion 31 and both side plate portions 32, 32, and the printed circuit board 2 temporarily fixed to the insulating film 10 is placed in the metal case 3. When accommodated, the bottom plate portion 11 of the insulating film 10 is placed on the bottom plate portion 31 of the metal case 3, and the side plate portions 12, 12 of the insulating film 10 are in close contact with the inner wall surfaces of the side plate portions 32, 32 of the metal case 3. To do. Further, the elongated holes 17 formed in both the extension portions 16 and 16 of the bottom plate portion 11 of the insulating film 10 projecting forward and backward from the both end faces 23 and 23 of the printed circuit board 2 project on the bottom plate portion 31 of the metal case 3. The positioning protrusion 33 provided is engaged to prevent the printed board 2 from moving in the longitudinal direction in the metal case 3.

  FIG. 7 is an enlarged perspective view showing the deformation of the engaging portion with respect to the corner portion of the printed circuit board 2 formed in the folded portion 13 of the insulating film 10 in correspondence with FIG. In this case, the engaging portion is a rectangular opening extending substantially parallel to the folding line L1 with a vertical width corresponding to the thickness of the printed circuit board 2 at a position slightly away from the upper surface of the bottom plate portion 11 of the insulating film 10. The unit 40 is configured. The opening 40 includes opposed vertical edge portions 40a and 40c and opposed horizontal edge portions 40b and 40d, and the vertical edge portion 40a on the folding line L2 side is engaged with the end face 23 of the corner portion of the printed circuit board 2. The horizontal edge portions 40 b and 40 d are configured to engage with the upper surface 21 and the bottom surface 24 of the corner portion of the printed circuit board 2 to lock the corner portion of the printed circuit board 2. With this configuration, the printed circuit board 2 can be lifted from the bottom plate portion 11, and the component soldering surface on the bottom surface 24 of the printed circuit board 2 can be prevented from coming into contact with the bottom plate portion 11 of the insulating film 10 and damaging the bottom plate portion 11. Can do.

  Next, FIG. 8 is a perspective view corresponding to FIG. 4, showing a configuration in which an engagement piece 13 b for the side plate portion 12 protrudes above the end edge 13 a of the folded portion 13 of the insulating film 10. By inserting the engaging piece 13b into the slit 12a formed in the side plate portion 12, the folded portion 13 can be prevented from returning and the folded state can be maintained.

  9 shows that when the length of the printed circuit board 2 is long, the side plate portions 12 and 12 are provided with projections 12b and 12b that engage with both side edges of the upper surface 21 of the printed circuit board 2 to project the insulating film 10. The floating of the printed circuit board 2 from the bottom plate portion 11 can be prevented.

  FIG. 10 is a perspective view corresponding to FIG. 4 showing the configuration of the folded portion 13 that can support two printed boards. In this case, the second printed sheet is substantially parallel to the fold line L1 from the edge of the fold line L1 in the extending direction or from the end of the fold line L1 at a position away from the engagement portion 15 with respect to the printed circuit board 2 of the folded portion 13. A rectangular groove 41 having a width corresponding to the thickness of the substrate (not shown) is formed. The vertical edge 41a at the back of the groove 41 is engaged with the end face of the corner of the second printed circuit board inserted into the groove 41, and the horizontal edges 41a and 41d are printed on the second sheet. By engaging with the top and bottom surfaces of the corners of the substrate, the corners of the printed circuit board 2 are locked. Instead of the groove 41, an opening as shown in FIG. 7 may be provided.

  By the way, if the height of the side plate portions 12 and 12 of the insulating film 10 is substantially matched to the height of the side plate portions 32 and 32 of the metal case 3 in which the printed board 2 is accommodated via the insulating film 10, The upper edges of the side plate portions 12 and 12 of the insulating film 10 abut on the inner top surface of a lid (not shown) placed on the metal case 3, and the upward movement of the insulating film 10 is restricted. The printed circuit board 2 may be accommodated in the metal case 3 having the side plate portions 32 and 32 that are higher than the height of the side plate portions 12 and 12 of the film 10. In that case, as shown in FIG. 11, it is preferable to project a plurality of tongue pieces 42 extending upward on the upper edges of the side plate portions 12, 12 of the insulating film 10. In this case, the tongue piece 42 comes into contact with the inner top surface of the lid of the metal case 3 and is bent according to the height, and the difference in height is absorbed. In this state, the height of the insulating film 10 is increased. The vertical movement can be restricted. Therefore, the single insulating film 10 can be shared with respect to various metal cases 3 having different side plate portions 32 and 32 with different heights.

  Similarly, when the printed circuit board 2 may be accommodated in the metal case 3 having the bottom plate portion 31 wider than the width of the printed circuit board 2, as shown in FIG. The tongue pieces 44, 45 projecting to the side are integrally provided on one side edge of 16 and the upper edge of the side plate portion 12 on the same side as this side edge. The difference in width is absorbed by abutting against the inner wall surface of the side plate portion 32 and the movement of the insulating film 10 in the width direction can be restricted in this state. Therefore, the single insulating film 10 can be shared with the various metal cases 3 having different widths of the bottom plate portion 31.

  4 includes leg pieces 18 and 19 at both ends of the engaging recess 15 respectively. The leg pieces 19 on the end edge 13a side are formed on the side surface 22 of the printed circuit board 2 and the insulating film 10. Although it is comprised so that the folding | turning part 13 may be fixed by being pinched | interposed between the side-plate parts 12, depending on the case, as shown in FIG. 13, the leg piece 19 by the side of the edge 13a may be abbreviate | omitted. it can. That is, as shown in FIG. 14, when the electronic components 26, 26 fixed on the printed circuit board 2 are close to the folded portions 13, 13, respectively, the side plate portions 12, The folded-back portions 13 and 13 can be fixed by bringing the folded-back portions 13 and 13 into contact with the wall surface on the 12 side.

  Further, in order to prevent the printed circuit board 2 from being lifted when the length of the printed circuit board 2 is long, in the configuration shown in FIG. 9, in the intermediate portion of the side plate portions 12 and 12 of the insulating film 10 in the fold line L1 direction. The protrusions 12b and 12b that engage with both side edges of the upper surface 21 of the printed circuit board 2 are provided, but instead of the protrusions 12b and 12b, other return parts are provided in addition to the return parts 13 and 13 at both ends. May be.

  That is, as shown in FIGS. 15 and 16, an intermediate portion of each side plate portion 12 in the direction of the fold line L1 is cut into an L shape along the fold line L1 and a straight line substantially perpendicular to the fold line L1. In the form in which the void 50 is formed, a folded portion 53 that is folded inside the side plate portion 12 is formed at a folding line L4 that is substantially perpendicular to the folding line L1. An engagement recess 55 having a horizontal edge portion 55 b in contact with the upper surface 21 of the printed circuit board 2 is formed in the folded portion 53 along the bottom edge 54 in contact with the upper surface of the bottom plate portion 11. In the case of the folded portion 53, contrary to the case of FIG. 13, the leg piece close to the folded line L4 is not necessary, and only the leg piece 59 on the vertical edge 55c side of the engaging recess 55 is sufficient.

  In addition, since the void 50 is formed in the side plate portion 12 along with the folded portion 53, when the presence of the void 50 does not adversely affect the insulation between the printed circuit board 2 and the metal case, A folded portion 53 may be provided.

  As apparent from the above description, according to the present embodiment, the inner bottom surface and both inner wall surfaces of the metal case 3 are completely covered by the bottom plate portion 11 and the both side plate portions 12 and 12 of the insulating film 10. In addition to the effect of ensuring the insulation of the printed circuit board 2 with respect to the case 3, the printed circuit board 2 is insulated prior to incorporation into the metal case 3 without providing any notch in the printed circuit board 2. Since it can be temporarily fixed to the film 10, there is an effect that the work of assembling the printed board 2 into the metal case 3 can be facilitated.

  The four folded portions 13 formed on the insulating film 10 extend short at the longitudinal ends of the side plate portions 12 and 12 and project from the upper edges of the side plate portions 12 and 12. Therefore, there is an effect that the amount of material used per insulating film is relatively small.

It is an expanded view which shows the basic composition of the insulating film by this invention. It is an expanded view which shows the deformation | transformation structure of the insulating film by this invention. FIG. 3 is a perspective view showing a state in which the printed circuit board is temporarily fixed to the insulating film prior to housing the printed circuit board in the metal case using the insulating film of FIG. 2. It is an expansion perspective view which shows the folding | turning part of FIG. It is a perspective view which shows the state in which the printed circuit board temporarily fixed to the insulating film is accommodated in the metal case whose length is longer than a printed circuit board. It is an expansion perspective view which shows the engagement state of the folding | turning part of an insulating film, and the corner | angular part of a printed circuit board. It is an expansion perspective view which shows the deformation | transformation of the engaging part with respect to the corner | angular part of the printed circuit board formed in the folding | turning part of an insulating film corresponding to FIG. It is an expansion perspective view corresponding to FIG. 4 of the folding | turning part provided with the engagement piece with respect to a side-plate part. It is a perspective view of the insulating film provided with the processus | protrusion engaged with the both side edges of the upper surface of a printed circuit board in a side plate part. FIG. 5 is a perspective view corresponding to FIG. 4, showing a configuration of a folded portion that can support two printed boards. It is a perspective view of the insulating film which can respond to various metal cases from which the height of a side plate part differs. It is a perspective view of the insulating film which can respond to various metal cases from which the width of a baseplate part differs. FIG. 5 is an enlarged perspective view corresponding to FIG. 4, showing a modified configuration of the folded portion. It is a top view of the principal part which shows the combination structure of the printed circuit board which can use the folding | turning part shown in FIG. 13, and an insulating film. FIG. 5 is an enlarged perspective view corresponding to FIG. 4 and showing a configuration of a folded portion provided at both ends of the side plate portion. It is a perspective view of the insulating film provided with the folding | turning part shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,10 Insulating film 2 Printed circuit board 3 Metal case 11 Insulating film bottom plate part 12 Insulating film side plate part 13, 53 Insulating film folded part 15, 55 Folded part engaging recess 16 Extension part of insulating film bottom plate part L1 Folding line L2, L4 Folding line

Claims (10)

A flexible insulating film interposed between a printed circuit board housed in a metal case and an inner wall surface of the metal case, and a bottom plate portion facing the bottom surface of the printed circuit board, and the bottom plate portion In the insulating film comprising a pair of side plate portions that are continuous with the bottom plate portion on both sides of the bottom plate portion and rise along the both side surfaces of the printed board by bending at substantially right angles at the bending line,
At both ends of the fold line direction of each of the side plate portions, a fold portion that is folded back inside the side plate portion at a fold line that is substantially orthogonal to the fold line extends, and the fold portion includes the printed circuit board. An insulating film for a printed circuit board, wherein an engaging portion capable of engaging with a corner portion is provided.   The folded portion is formed with a recess cut out to a depth corresponding to the thickness of the printed circuit board from a side edge on the extension line of the folded line of the folded portion, and the recessed portion is inserted into the recessed portion. The insulating film according to claim 1, further comprising an engagement edge portion that can engage with an upper surface and an end surface of a corner portion of the printed circuit board.   An opening that extends substantially parallel to the fold line with a width corresponding to the thickness of the printed circuit board is formed in the folded portion, and the opening is formed at a corner of the printed circuit board that is inserted into the opening. The insulating film according to claim 1, further comprising an engaging edge portion that can be engaged with both surfaces and an end surface.   The insulating film according to claim 2 or 3, wherein an engagement piece to be inserted into a slit formed in the side plate portion protrudes from an end edge of the folding portion in the extending direction of the fold line.   A groove or opening that extends substantially parallel to the fold line with a width corresponding to the thickness of another printed circuit board is further formed in a portion of the folded portion that is spaced upward from the engaging part with respect to the printed circuit board, 5. The groove or opening includes an engaging edge that can be engaged with both sides and an end surface of a corner of the other printed circuit board inserted into the groove or opening. The insulating film of any one of these.   The engagement protrusion which engages with the both-sides edge of the upper surface of the said printed circuit board is formed in the intermediate part of the said fold line direction of the said side plate part, The any one of Claim 1 to 5 characterized by the above-mentioned. Insulation film.   An intermediate portion of the side plate portion in the fold line direction is cut open, and a further fold portion is formed inside the side plate portion at a fold line substantially perpendicular to the fold line. The insulating film according to claim 1, further comprising an engaging portion that can be engaged with an upper surface of the printed circuit board.   An extension portion extending from the edge of the printed circuit board is formed at both ends of the bottom plate portion in the fold line direction, and a positioning hole for the metal case is formed in the extension portion. The insulating film according to claim 1, wherein the insulating film is a film.   9. A plurality of tongue pieces projecting from the upper edge of the side plate portion, which are bent in contact with the inner top surface of the lid of the metal case. Insulation film.   A tongue piece that is bent in contact with an inner wall surface of the side plate of the metal case is provided on the side edge of both the extension portions of the bottom plate portion and the upper edge of the side plate portion so as to protrude sideways. The insulating film according to claim 8.

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