JP2017103361A - Case with built-in circuit board with terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a case with built-in circuit board with terminal capable of preventing a circuit board from being damaged by a molten molding resin that is injected from a gate to a bottom face of the circuit board when molding the case, even if thickness of the case is reduced.SOLUTION: The present invention relates to a case 10 with built-in circuit board with terminal comprising a circuit board 20 with which slide-contact patterns 25 and 27 or terminal connection patterns 29, 31 and 33 are formed on a top face; and a terminal 50 that is connected on the terminal connection patterns 29, 31 and 33 of the circuit board 20. A molding resin case 60 is molded in such a manner that the surroundings of the circuit board 20 including a portion to which the terminal 50 is connected, and a bottom face of the circuit board 20 are covered. The case 60 includes a projection 69 that protrudes downwards from a bottom face of the case, and a gate track 73 at the time of molding of the case 60 is provided on a distal end face 69a of the projection 69. The projection 69 with which the gate track 73 is provided is positioned in the vicinity of the bottom face of the circuit board 20 in a portion where the terminal connection patterns 29, 31 and 33 are formed.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a circuit board built-in case with a terminal suitable for use in a rotary electronic component, a slide electronic component, or the like.

  Conventionally, as a case with a built-in circuit board with a terminal used for various electronic parts such as a rotary switch, a rotary variable resistor, a slide switch, and a slide variable resistor, as shown in FIG. And a circuit board (10) on which a circuit pattern (17, 19) made of a resistor pattern or the like is formed is insert-molded in a case (40) made of mold resin so that the circuit pattern (17, 19) is exposed. At the same time, a metal plate terminal (30) connected to the circuit pattern (17, 19) protrudes from the case (40) to the outside, and the slider is placed on the circuit pattern (17, 19) exposed in the case (40). There is a structure in which the detection output between the terminals (30) protruding to the outside is changed by sliding the contact.

  And as shown in FIG. 1 of patent document 1, manufacture of the circuit board built-in case with a terminal installs the circuit board (10) which connected the terminal (30) in a metal mold | die (50, 60), 40) by injecting a high-temperature and high-pressure molten molding resin from the gate (61) of the mold (60) provided on the bottom surface of the cavity (C2).

JP 2003-288971 A

  However, when the thickness of the case (40) is reduced due to the miniaturization of the electronic components, the gate (61) approaches the circuit board (10), the distance between them is shortened, and the case (40) is ejected from the gate (61). There is a possibility that the circuit board (10) may be damaged due to an increase in the collision force with which the high-temperature and high-pressure molten resin collides with the circuit board (10). This problem occurs not only in the case where the circuit board (10) is a flexible circuit board but also in a hard circuit board using a resin-molded board. That is, even in a molded resin circuit board, it has been confirmed by experiments that the portion where the molten molded resin collides is removed by the heat and pressure, and the strength is weakened.

  The present invention has been made in view of the above points, and its purpose is to provide a molten molding resin that is injected from the gate toward the lower surface of the circuit board when the case is molded, even when the thickness of the case is reduced. An object of the present invention is to provide a circuit board built-in case with terminals that can prevent the circuit board from being damaged.

The present invention includes a circuit board having a circuit pattern and a terminal connection pattern connected to the circuit pattern formed on an upper surface, and a terminal connected on the terminal connection pattern of the circuit board, In the case with a circuit board with a terminal configured by molding a case made of molding resin so as to cover the periphery of the circuit board including the portion where the terminals are connected and the lower surface of the circuit board, A protrusion protruding toward the surface is provided, and a gate mark at the time of forming the case is provided on a tip surface of the protrusion.
Since the gate trace for connecting the gate at the time of molding the case is provided on the tip surface of the protrusion provided on the case, the gate is separated from the circuit board and the distance between the two is increased. With this structure, the collision force of the high-temperature and high-pressure molten resin injected from the gate to the circuit board becomes weak, and damage to the circuit board can be effectively prevented. As a result, the thickness of the case can be reduced, and the circuit board built-in case with terminals and the electronic components using the circuit board built-in case with terminals can be thinned.

Further, the invention is characterized in that the projection provided with the gate mark is provided in the vicinity of the lower surface of the portion of the circuit board where the terminal connection pattern is formed.
Thereby, the injection pressure of the molten molding resin injected from the gate at the time of case molding effectively becomes a force for pressing the terminal connection pattern of the circuit board against the terminal. In addition, since the melt molding resin is filled in the vicinity of the connection portion between the terminal connection pattern and the terminal in the cavity serving as the case before the other portions, the weld resin is formed on the molding resin molded around the connection portion. Etc. are less likely to occur. From these things, the connection intensity | strength of the said connection part can be raised.

  According to the present invention, it is possible to prevent the circuit board from being damaged by the molten molding resin injected toward the lower surface of the circuit board during case molding. This makes it possible to further reduce the thickness of the case on the lower surface portion of the circuit board.

1 is a perspective view of a rotary electronic component 1. FIG. It is the perspective view which looked at the rotary electronic component 1 from the lower side. 1 is an exploded perspective view of a rotary electronic component 1. FIG. It is the perspective view which looked at the circuit board built-in case 10 with a terminal from the lower side. It is sectional drawing (AA sectional drawing of FIG. 4) of the circuit board built-in case 10 with a terminal. 2 is a perspective view showing a circuit board 20 and terminals 50. FIG. It is manufacturing method explanatory drawing of the circuit board built-in case 10 with a terminal. FIG. 6 is a cross-sectional view showing a state in which the circuit board built-in case with terminal 10 is placed on the main board 190. It is the perspective view which looked at circuit board built-in case 10-2 with a terminal from the lower side. It is a perspective view of circuit board built-in case 10-3 with a terminal. It is the perspective view which looked at the circuit board built-in case with terminal 10-3 from the lower side.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a rotary electronic component 1 configured using a circuit board built-in case 10 with a terminal according to a first embodiment of the present invention, and FIG. 2 is a perspective view of the rotary electronic component 1 as viewed from below. FIG. 3 is an exploded perspective view of the rotary electronic component 1. As shown in these drawings, the rotary electronic component 1 rotatably stores a base 111 of a rotating body 110 to which a slider 150 is attached in a storage portion 61 of a circuit board built-in case 10 with a terminal. The top is covered with a cover 170. In the following description, “up” refers to the direction of the circuit board 20 built in the circuit board built-in case 10 with terminals facing the surface side where the circuit patterns 25 and 27 are exposed, and “down” refers to the circuit pattern 25. , 27 is the direction facing the opposite surface side (back surface side).

  4 is a perspective view of the circuit board built-in case 10 with terminals as viewed from below, FIG. 5 is a cross-sectional view of the circuit board built-in case 10 with terminals (AA cross-sectional view in FIG. 4), and FIG. 6 is a circuit board with terminals. FIG. 2 is a perspective view showing a circuit board 20 and terminals 50 that constitute a built-in case 10. As shown in these drawings, the circuit board built-in case 10 with terminals includes a circuit board 20 having circuit patterns 25, 27 and terminal connection patterns 29, 31, 33 connected to the circuit patterns 25, 27 formed on the upper surface. A terminal 50 connected to the terminal connection patterns 29, 31, 33 of the circuit board 20, and the periphery of the circuit board 20 including a portion of the circuit board 20 to which the terminal 50 is connected and the circuit board 20 A case 60 made of a molded resin is formed so as to cover the lower surface.

  As shown in FIG. 6, the circuit board 20 is formed with a shaft support hole 23 formed of a circular through hole in the center of a flat insulating substrate 21, and around the shaft support hole 23 on the upper surface of the insulating substrate 21. Two circuit patterns (hereinafter referred to as “sliding contact patterns”) 25 and 27 are formed concentrically, and three terminal connection patterns 29, 31 and 33 are formed in parallel along the vicinity of one side of the insulating substrate 21. Further, the inner sliding contact pattern 25 and the central terminal connection pattern 31 are connected by the lead pattern 37, and both ends of the outer sliding contact pattern 27 and the terminal connection patterns 29, 33 on the both sides are connected by the lead patterns 35, 39, respectively. Configured. The inner sliding contact pattern 25 is a conductor pattern (common pattern), and the outer sliding contact pattern 27 is a resistor pattern. Between each terminal connection pattern 29,31,33, the resin insertion holes 41 and 43 which are small holes penetrated up and down are formed. In this example, the insulating substrate 21 is a molded product of resin (for example, ABS resin).

  The terminal 50 is configured by forming a metal plate in an elongated shape, and has one end side as a pattern contact portion 51 and the other end side as a protruding portion 53. In the terminal 50, a protrusion 53 protruding from the case 60 after the case 60 is molded is bent downward at a substantially right angle at the base portion.

  The case 60 has a substantially rectangular shape, and is configured by insert-molding the circuit board 20 with which the terminals 50 abut. In the center of the upper surface of the case 60, an accommodating portion 61 made of a substantially circular recess is formed so as to expose the sliding contact patterns 25, 27 of the circuit board 20. In the vicinity of the two corners on the upper surface of the case 60, a pair of small projection-like cover positioning portions 63 protruding upward are formed. A shaft support hole 65 having the same inner diameter as that of the shaft support hole 23 of the circuit board 20 is provided at the center of the case 60. Two cover engaging portions 67 are provided on each of the left and right sides of the side protruding the terminal 50 on the lower surface of the case 60, which are cut out in a tongue-like shape from each side. In addition, a protrusion projecting downward is provided on the lower surface of the case 60 on the side where the terminal 50 protrudes from the shaft support hole 65 and on the opposite side of the shaft support hole 65 by 180 °. 69, 71 are formed. A gate mark 73 at the time of molding the case is formed (positioned) on the tip surface 69a of the protrusion 69 on the terminal 50 side. The gate mark 73 has a diameter smaller than the diameter of the protrusion 69 and its protrusion height is low (it may be the same diameter or the protrusion height may be high). In addition, the tip surface of the gate mark 73 is not limited to the case where it protrudes from the tip surface 69a, but may be the same surface as the tip surface 69a or may be depressed. The trace of the cut surface which cut | disconnects is formed. Small holes 75 reaching the lower surface of the circuit board 20 are formed at positions on the lower surface of the case 60 facing the terminal connection patterns 29, 31, 33 of the circuit board 20.

  FIG. 7 is an explanatory view of a manufacturing method of the circuit board built-in case 10 with terminals. As shown in the figure, in order to manufacture the circuit board built-in case 10 with terminals, the pattern contact portions 51 of the terminals 50 are provided on the terminal connection patterns 29, 31, 33 (see FIG. 6) of the circuit board 20, respectively. In the abutted state, the upper and lower sides are held between the first and second molds 200 and 250. As a result, a cavity C having the shape of the case 60 is formed between the first and second molds 200 and 250. At this time, the gate G is connected to the tip of the cavity portion C11 which becomes the protrusion 69 of the second mold 250. At this time, the terminal 50 and the circuit board 20 are sandwiched between the pressing part 201 provided in the first mold 200 and the pressing part 203 provided in the second mold 250, and the connection between the two is firmly established. It is trying to become. In addition, the three terminals 50 at this time are linear (state before bending), and although not illustrated, the tip side is connected to a strip-shaped connecting plate, and the connecting plate is cut after the case is formed, Each terminal 50 is bent downward.

  Then, when a molten high-temperature and high-pressure melt-molded resin (for example, PET resin, ABS resin, etc.) is press-fitted from the gate G, the melt-molded resin first fills the cavity portion C11 that becomes the protrusion 69, and then the circuit board 20 It includes a cavity portion C12 that becomes the bottom surface of the case 60 and a cavity portion C13 that contacts the circuit board 20 and the terminal 50 while abutting (collising) with the lower surface and pressing it against the first mold 200 side. The cavity portion C14 that becomes the outer peripheral side wall of the circuit board 20 is filled. At this time, since the gate G is provided in the vicinity of the lower surface of the portion of the circuit board 20 where the terminal connection patterns 29, 31, 33 are formed, as described above, melt molding that is injected from the gate G when the case 60 is molded. The injection pressure of the resin effectively becomes a force for pressing the terminal connection patterns 29, 31, and 33 of the circuit board 20 against the terminal 50. Further, in the cavity C to be the case 60, the molten molding resin is filled in the vicinity of the connection portion between the terminal connection patterns 29, 31, 33 and the terminal 50 before the other portions. Welds and the like are less likely to occur in the molding resin that is molded. From these things, the connection intensity | strength of the said connection part can be raised.

  In addition, since the gate G is provided at the tip of the cavity portion C11 that becomes the projection 69, in other words, the gate trace that connects the gate G when the case 60 is molded to the tip surface of the projection 69 provided on the case 60 after molding. Since 73 is provided (positioned), the position of the gate G is separated from the circuit board 20, and the separation distance L1 between the two is increased. For this reason, the collision force of the high-temperature and high-pressure molten resin injected from the gate G to the circuit board 20 is weakened, and the circuit board 20 is damaged (the circuit board 20 is softened by the high-temperature heat and pressure and the collision part becomes a depression. Thus, the strength can be effectively prevented. As described above, this effect is more prominent with respect to the thickness reduction of the case 60. In other words, the thickness of the case 60 as a whole can be reduced by providing the gate G at the tip of the cavity portion C11 that becomes the protrusion 69. A small hole 75 shown in FIG. 4 is formed by the pressing portion 203.

  Returning to FIG. 3, the rotating body 110 is configured by projecting a substantially cylindrical shaft 113 from the center of the upper surface of the substantially disc-shaped base 111. The shaft 113 also projects below the base 111. On the lower surface of the base 111, although not shown, a small protrusion-like attachment portion for inserting a locking hole 159 of the slider 150 described below is formed.

  The slider 150 is configured by forming an elastic metal plate in a substantially disc shape, and a circular through hole 153 that penetrates the shaft 113 of the rotating body 110 is provided at the center of the slider base 151. A set of sliding booklets 155 and 157 are formed around the periphery of the circular arc shape, and both ends thereof are connected to the slider base 151. The sliding booklets 155 and 157 are at positions facing each other by 180 °, and both ends thereof are bent and face obliquely downward. The slider base 151 is formed with a locking hole 159 made of a small hole.

  The cover 170 is provided with a cylindrical shaft support portion 173 that rotatably supports the shaft 113 of the rotating body 110 at the center of a cover body 171 formed by forming a metal plate in a substantially rectangular shape. A pair of tongue-like locking claws 175 protrude from a pair of opposing outer peripheries, and are bent downward at a substantially right angle at the root portion. Positioning portions 177 each having a small hole into which the cover positioning portion 63 is inserted are provided at positions of the cover body 171 facing the pair of cover positioning portions 63 of the case 60.

  In order to assemble the rotary electronic component 1, first, the slider 150 is disposed in advance on the lower surface of the base 111 of the rotating body 110, and at that time, the rotating body 110 is not installed in the locking hole 159 of the slider 150. The part is inserted and the tip thereof is caulked with heat, thereby fixing between them.

  Then, the base 111 of the rotating body 110 to which the slider 150 is attached is inserted into the housing 61 of the circuit board built-in case 10 with a terminal so as to be rotatable, and a cover 170 is placed thereon. At this time, the upper shaft 113 of the rotating body 110 is rotatably inserted into the shaft supporting portion 173 of the cover 170, and the lower shaft 113 of the rotating body 110 is connected to the shaft supporting hole 23 of the circuit board built-in case 10 with a terminal. Further, the locking claw 175 of the cover 170 projects along the outer peripheral side surface of the case 60 to the lower surface side thereof. And if each latching nail | claw 175 is bend | folded to the lower surface side of case 60, the rotary electronic component 1 shown in FIG.1, FIG.2 etc. will be completed. The above assembling procedure is an example, and it goes without saying that the assembly may be performed using other various assembling procedures.

  Then, if the shaft 113 of the rotating body 110 is rotated, the pair of sliding booklets 155 and 157 of the slider 150 rotating integrally therewith slides on the sliding contact patterns 25 and 27 of the circuit board 20, respectively. As a result, the detection output between the terminals 50 changes.

  FIG. 8 is a cross-sectional view showing a state in which the terminal-equipped circuit board built-in case 10 is mounted on the main board 190. Actually, the rotary electronic component 1 using the circuit board built-in case 10 with a terminal is mounted on the main board 190 instead of mounting only the circuit board built-in case 10 with a terminal on the main board 190. For convenience of illustration, only the circuit board built-in case 10 with terminals is shown mounted on the main board 190. As shown in the figure, when the case 10 with built-in circuit board with terminals is placed on the main board 190, the pair of protrusions 69 and 71 on the lower surface of the case 60 are formed by circular small holes provided in the main board 190. It is inserted into the positioning holes 191 and 192 and positioned. At the same time, the protrusions 53 of the three terminals 50 of the circuit board built-in case 10 with terminals are inserted into the terminal mounting holes 193 formed of slit-like small holes provided in the main board 190 and are provided on the lower surface of the main board 190. The pattern 195 is electrically and mechanically connected by solder 197 or the like. That is, in this example, the protrusions 69 and 71 are positioning protrusions. The reason why the protrusions 69 and 71 are positioned on the main board 190 is to prevent a mechanical load from being applied to the connection portion between the terminal 50 and the main board 190 and to perform reliable positioning. In other words, if the projection 69 provided with the gate trace 73 is also used as the positioning projection, it is not necessary to separately form the projection provided with the gate trace 73, which is preferable. Further, as shown in FIG. 8, if the height of the protrusion 69 including the gate trace 73 is formed so as not to exceed the thickness of the main substrate 190, the gate trace 73 does not protrude from the lower surface of the main substrate 190. This is preferable because it does not hinder the installation of various devices (not shown) installed below the main board 190.

  FIG. 9: is the perspective view which looked at the circuit board built-in case 10-2 with a terminal which concerns on 2nd Embodiment of this invention from the lower side. In the circuit board built-in case 10-2 with terminal shown in the figure, the same or corresponding parts as those in the circuit board built-in case 10 with terminal according to the embodiment shown in FIGS. Is suffixed with "-2"). Note that matters other than those described below are the same as those in the embodiment shown in FIGS.

  The terminal-equipped circuit board built-in case 10-2 is a surface mount type, and the only difference from the terminal-equipped circuit board built-in case 10 is the shape of the terminal 50-2. That is, after protruding from the side surface of the case 60, the protruding portion 53 of the terminal 50-2 is once bent downward and further bent in the opposite direction to face the horizontal direction. As a result, the lower surface of the tip portion of the protruding portion 53 is substantially flush with the lower surface of the case 60, and surface mounting is possible.

  FIG. 10 is a perspective view of a circuit board built-in case 10-3 with terminal according to the third embodiment of the present invention, and FIG. 11 is a perspective view of the circuit board built-in case 10-3 with terminal viewed from below. In the circuit board built-in case 10-3 with terminal shown in both figures, the same or corresponding parts as those in the circuit board built-in case 10 with terminal according to the embodiment shown in FIGS. Is suffixed with "-3"). Note that matters other than those described below are the same as those in the embodiment shown in FIGS.

  This terminal board built-in case 10-3 with a terminal is used for a slide-type electronic component. That is, the circuit board built-in case 10-3 with terminals has linear circuit patterns 25-3, 27-3 and three terminal connection patterns (not shown) connected to the circuit patterns 25-3, 27-3 on the upper surface. The circuit board 20-3 thus formed and the terminals 50-3 connected to the respective terminal connection patterns of the circuit board 20-3 are connected to the terminals 50-3 of the circuit board 20-3. The molded resin case 60-3 is formed so as to cover the periphery of the circuit board 20-3 including the portion and the lower surface of the circuit board 20-3.

  In the circuit board 20-3, two sliding contact patterns 25-3 and 27-3 are formed on the upper surface of the elongated insulating substrate 21-3, and along the vicinity of one end of the insulating substrate 21-3. Three terminal connection patterns (not shown) are formed in parallel, and further drawn out from one end of one sliding contact pattern 25-3 and from both ends of the other sliding contact pattern 27-3. Two lead patterns 26-3a and 26-3b are connected to the terminal connection patterns, respectively.

  The case 60-3 has a substantially long rectangular shape, and is configured by insert-molding the circuit board 20-3 that contacts the terminal 50-3. On the upper surface side of the case 60-3, a storage portion 61-3 made of a long and rectangular recess is formed so as to expose the sliding contact patterns 25-3 and 27-3 of the circuit board 20-3. ing. A plurality of placement portions 77-3 projecting so as to extend linearly are formed at positions surrounding the outer periphery of the lower surface of the case 60-3. A protrusion 69-3 having a gate mark 73-3 is formed in the vicinity of the lower surface of the lower surface of the case 60 where the terminal connection pattern of the circuit board 20-3 is formed.

  In the case of the circuit board built-in case with terminal 10-3, the effect of providing the gate trace 73-3 on the tip end surface 69a-3 of the protrusion 69-3 is produced as in the case with the circuit board built-in case 10 with terminal. . In this example, the protrusion 69-3 is not used as a positioning protrusion. Further, the height of the mounting portion 77-3 is made higher than the tip of the gate mark 73-3, and as a result, when the terminal-equipped circuit board built-in case 10-3 is placed on another member, the projection 69 is provided. The tip of -3 is prevented from coming into contact with other members.

  In the above embodiment, the linear direction is shown as the slide movement direction. However, the slide movement direction is a concept including various directions other than the linear direction, such as an arc direction and other curved directions.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Is possible. Note that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited. For example, in the above example, a sliding contact pattern (the sliding contact pattern may be a switch pattern) is used as the circuit pattern formed on the upper surface of the circuit board, but other various circuit patterns may be used. Further, the shape of the protrusion for providing the gate mark may be various shapes other than the cylindrical shape. In the above example, the position where the protrusion for providing the gate mark is set near the lower surface of the portion where the terminal connection pattern of the circuit board is formed. However, the present invention is not limited to this and may be installed at various other positions. good.

  Moreover, as long as there is no contradiction in the objective, a structure, etc., the embodiment shown by the said description and each figure can combine the description content of each other. In addition, the above description and the description of each drawing can be an independent embodiment even if it is a part of it, and the embodiment of the present invention is an embodiment in which the above description and each drawing are combined. It is not limited to.

1 Rotating electronic component 10 Case with built-in circuit board with terminal 20 Circuit board 25, 27 Sliding contact pattern (circuit pattern)
29, 31, 33 Terminal connection pattern 50 Terminal 60 Case 69 Projection 69a Tip surface 73 Gate mark 110 Rotating body (moving body)
150 Slider 170 Cover

Claims (2)

A circuit board having a circuit pattern and a terminal connection pattern connected to the circuit pattern formed on an upper surface; and a terminal connected to the terminal connection pattern of the circuit board; and connecting the terminals of the circuit board In a circuit board built-in case with terminals configured by molding a case made of molded resin so as to cover the periphery of the circuit board including the portion and the lower surface of the circuit board,
The case is provided with a protrusion protruding downward from the lower surface thereof,
A circuit board built-in case with a terminal, wherein a gate mark at the time of molding the case is provided on a tip surface of the protrusion. It is a circuit board built-in case with a terminal of Claim 1,
The circuit board built-in case with a terminal, wherein the protrusion provided with the gate mark is provided in the vicinity of the lower surface of the portion of the circuit board where the terminal connection pattern is formed.

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