Method for manufacturing lead frames and lead frame insert molded products

Abstract

To realize different types of electrical circuits using a shared lead frame.SOLUTION: In a lead frame 10 including first and second frames 13, 14 and a fixed contact piece 15. The fixed contact piece 15 is integrally formed with the first frame 13 via a conductive connection portion 16. The first frame 13, the fixed contact piece 15, and the second frame 14 have mounting parts 13a, 14a, 14b, and 15b to which resistance elements can be mounted, and the first frame 13 and the fixed contact piece 15 have attachment parts 13b and 15a to which resistance elements can be attached. Different types of electric circuits are configured depending on the combination of whether a resistance element is attached to each attachment portion and whether the conductive connection portion 16 is disconnected.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a lead frame that constitutes an electric circuit of a switch device, and a method for manufacturing a lead frame insert-molded product in which the lead frame is integrated with a resin case of the switch device by insert molding.

Background Art

[0002] Conventionally, there has been known a switch device which is used by being connected to an external circuit and incorporates a lead frame constituting an electric circuit. Such a lead frame is generally provided with a plurality of frames including a portion constituting a COM terminal, a NO terminal (or NC terminal), a portion constituting a fixed contact, and the like.

[0003] For example, Patent Document 1 discloses, in order to reduce the size of a switch incorporating a resistance element, a fixed contact piece arranged vertically in line with a first terminal and electrically connected thereto, an operating member that moves vertically, an actuator electrically connected to a second terminal and contacting the fixed contact piece as the operating member moves, and a first resistance element arranged in a region between the actuator and a base and electrically connected in parallel with a contact portion formed of the fixed contact piece and the actuator.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, the above-described switch devices include, as in the one disclosed in Patent Document 1, a type having a parallel electric circuit including a resistance element, a type having a series electric circuit including a resistance element, and also a type including no resistance element.

[0006] However, realizing these different types of switch devices (electrical circuits) requires lead frames with different layouts (shapes) corresponding to each type. When the shape of the lead frames differs, it becomes necessary to design each lead frame with its different shape in order to evaluate its impact on the performance of the switch device, and different molds are required, which leads to increased costs.

[0007] This invention has been made in view of the above, and its objective is to realize different types of electrical circuits using a common lead frame. [Means for solving the problem]

[0008] To achieve the above objective, an example of a lead frame according to the present disclosure comprises first and second frames, each integrally formed with first and second terminal portions connected to an external circuit, and a fixed contact piece, wherein the electrical connection state is switched when the fixed contact piece and the second frame are in contact or not in contact via a movable piece, and the lead frame constitutes an electrical circuit of a switch device, wherein the fixed contact piece is integrally formed with the first frame via a conductive connection portion, and at least one of the first frame and the fixed contact piece and the second frame each have a first mounting portion to which a resistive element that electrically connects the two can be attached, and the first frame and the fixed contact piece each have a second mounting portion to which the resistive element that electrically connects the two can be attached, and the combination of whether or not the resistive element is attached to each mounting portion and whether or not the conductive connection portion is disconnected constitutes an electrical circuit without the resistive element, a series electrical circuit including the resistive element, or a parallel electrical circuit including the resistive element.

[0009] According to this configuration, for example, if (1) the conductive connection part is left (without cutting) and no resistive element is attached (without attachment), an electrical circuit is formed in which current flows through [the first terminal part, the first frame, the conductive connection part, the fixed contact piece, the movable piece, the second frame, and the second terminal part], and which does not include a resistive element.

[0010] Furthermore, for example, if (2) the conductive connection portion is left intact (no cutting) and a resistive element is attached to the first mounting portion (attached), then current flows through [the first terminal portion, the first frame, the conductive connection portion, the fixed contact piece, the movable piece, the second frame, and the second terminal portion], and in parallel with this, a parallel electrical circuit is formed that includes one resistive element through which current flows through [the first terminal portion, the first frame (or the first frame, the conductive connection portion, and the fixed contact piece), the resistive element, the second frame, and the second terminal portion].

[0011] Furthermore, for example, if (3) the conductive connection is cut (cut) and a resistive element is attached to the second mounting part (attached), a series electrical circuit including the resistive element is formed through which current flows [first terminal part, first frame, resistive element, fixed contact piece, movable piece, second frame and second terminal part].

[0012] Furthermore, for example, if (4) the conductive connection is cut (cut) and resistive elements are attached to the first and second mounting parts (attached), current flows through [first terminal part, first frame, resistive element, fixed contact piece, movable piece, second frame and second terminal part], and in parallel with this, a parallel electrical circuit is formed that includes two resistive elements through which current flows [first terminal part, first frame, resistive element, second frame and second terminal part].

[0013] Thus, in the lead frame according to this example disclosure, different types of electrical circuits as illustrated in (1) to (4) above can be configured by combining the presence or absence of mounting of resistive elements to each mounting portion and the presence or absence of cutting of conductive connection portions.

[0014] Furthermore, when configuring different types of electrical circuits, only the installation of resistive elements and the disconnection of conductive connections are required. Therefore, different types of electrical circuits can be realized using a common lead frame, which enables the standardization of design and the sharing of molds, thereby suppressing cost increases.

[0015] Furthermore, in the lead frame described above, the first and second frames and the fixed contact piece are integrated with the resin case by insert molding such that the first and second terminal portions protrude from the bottom of the bottom of the bottom of the bottom of the bottom of the bottom of the bottom of the bottom of the resin case in a parallel direction along the axis of the cylinder, and the fixed contact piece has a projection that extends in the same direction as the first and second terminal portions, and the tip of the projection that protrudes from the bottom when integrated with the resin case may be integrally formed with the first and second terminal portions via a connecting portion.

[0016] When integrating a lead frame with a bottomed cylindrical resin case by insert molding, it is common practice to position the lead frame on the side of the first and second terminal portions that protrude from the bottom of the resin case in the direction of the cylindrical axis after insert molding. However, with this positioning method, if the conductive connection portion is cut, the edge between the fixed contact piece and the first frame will be severed, making it difficult to position the fixed contact piece.

[0017] In this regard, with the above configuration, since the tip of the projection extending from the fixed contact piece is integrally formed with the first and second terminal portions via the connecting portion, even if the conductive connecting portion is cut, the fixed contact piece can be easily positioned by positioning it on the first and second terminal portion side.

[0018] Furthermore, since the tip of the projection, which is integrally formed with the first and second terminals via the connecting portion, protrudes from the bottom while being integrated with the resin case, it is easy to prevent current from flowing between the first and second terminals via the projection by cutting the connecting portion after insert molding.

[0019] Furthermore, in the lead frame described above, if an electrical circuit including the resistive element is configured, the resistive element may be integrated with the resin case by insert molding.

[0020] This configuration eliminates the risk of melting the resin case due to the heat generated during soldering of the resistive element, as is the case when the resistive element is attached to the first and / or second mounting portion after insert molding. This improves the ease of assembly of the switch device. In addition, since the resistive element is not exposed, corrosion and deterioration of the electrode portion of the resistive element can be suppressed.

[0021] Furthermore, in the lead frame described above, serration grooves may be formed on both the front and back surfaces between the portions constituting electrical contacts in the first and second frames and the fixed contact piece, and the first and second mounting portions.

[0022] With this configuration, when applying solder paste to the first and second mounting parts, the surface tension of the applied solder makes it difficult for the solder to pass through the serration grooves, thus suppressing the outflow of solder paste to the parts that constitute the electrical contacts. In addition, the serration grooves enhance the adhesion between the resin and the metal, which is expected to improve sealing performance.

[0023] Furthermore, a method for manufacturing a lead frame insert molded product according to an example of the present disclosure includes a first frame integrally formed with a first terminal portion, a second frame integrally formed with a second terminal portion extending side by side in the same direction as the first terminal portion, and a fixed contact piece that is integrally formed with the first frame via a conductive connecting portion, extends in the same direction as the first and second terminal portions, and has a protruding portion whose distal end is integrally formed with the first and second terminal portions via a connecting portion. This is a method for manufacturing a lead frame insert molded product in which a lead frame including the above components is integrated with a bottomed cylindrical resin case by insert molding such that the first and second terminal portions protrude side by side in the cylinder axial direction from the bottom of the resin case. The method includes: a pressing step of forming the lead frame from a conductive plate; a first cutting step of cutting the conductive connecting portion in the lead frame formed in the pressing step; a mounting step of mounting a resistance element to the lead frame; a resin sealing step of positioning the lead frame on the first and second terminal portion sides, resin-sealing the resistance element mounted in the mounting step together with the first and second frames and the fixed contact piece by insert molding, and molding the resin case such that the first and second terminal portions and the distal end of the protruding portion protrude from the bottom portion; and a second cutting step of cutting the connecting portion to separate the distal end of the protruding portion from the first and second terminal portions.

[0024] According to this configuration, even when the conductive connecting portion is cut, a lead frame insert molded product in which a lead frame capable of constituting different types of electric circuits while positioning the fixed contact piece is integrated with a resin case can be easily manufactured. Effects of the Invention

[0025] As described above, according to the present invention, different types of electric circuits can be realized with a common lead frame. Brief Description of the Drawings

[0026] [Figure 1]This is a schematic perspective view showing a switch device comprising a lead frame according to one embodiment of the present disclosure. [Figure 2] This is a schematic exploded perspective view showing a switch device. [Figure 3] This is a cross-sectional view taken along the line III-III in Figure 1. [Figure 4] This is a schematic perspective view of the lead frame, with Figure (a) showing the state with the conductive connection remaining, and Figure (b) showing the state with the conductive connection cut off. [Figure 5] This is a schematic perspective view illustrating the contact structure of the movable piece. [Figure 6] This diagram schematically shows an example of an electrical circuit that does not include a resistive element. Figure (a) is a perspective view of the lead frame, and Figure (b) is a circuit diagram. [Figure 7] This diagram schematically shows an example of a parallel electrical circuit containing one resistor element. Figure (a) is a perspective view of the lead frame, and Figure (b) is a circuit diagram. [Figure 8] This diagram schematically shows an example of a parallel electrical circuit containing one resistor element. Figure (a) is a perspective view of the lead frame, and Figure (b) is a circuit diagram. [Figure 9] This diagram schematically shows an example of a series electrical circuit containing one resistor; Figure (a) is a perspective view of the lead frame, and Figure (b) is a circuit diagram. [Figure 10] This diagram schematically shows an example of a parallel electrical circuit containing two resistive elements. Figure (a) is a perspective view of the lead frame, and Figure (b) is the circuit diagram. [Figure 11] This diagram schematically shows an example of a parallel electrical circuit containing two resistive elements. Figure (a) is a perspective view of the lead frame, and Figure (b) is the circuit diagram. [Figure 12] This is a schematic perspective view showing an example of a semi-finished lead frame insert molded product. Figure (a) is a view from diagonally above, and Figure (b) is a view from diagonally below. [Figure 13] This figure schematically illustrates a method for manufacturing a lead frame insert molded product according to one embodiment of the present disclosure. [Figure 14] This diagram schematically illustrates the manufacturing method of a lead frame insert molded product. [Modes for carrying out the invention]

[0027] The following describes an embodiment for implementing an example of this disclosure, based on the drawings.

[0028] -Switching device- Figure 1 is a schematic perspective view showing a switch device 1 equipped with a lead frame 10 according to this embodiment, Figure 2 is a schematic exploded perspective view showing the switch device 1, and Figure 3 is a cross-sectional view taken along the line III-III in Figure 1. This switch device 1 is used, for example, as an in-vehicle microswitch, and the first and second terminals 11 and 12 are connected to an external circuit such as an in-vehicle ECU (Electronic Control Unit) to detect the opening and closing of doors, etc.

[0029] For the sake of clarity, the following explanation will define the up / down, front / back, and left / right directions as indicated by the arrows in the diagram, but these do not limit the direction of the switch device 1 during use.

[0030] As shown in Figure 2, the switch device 1 comprises a cover 2, a cap rubber 3, an operator 4, a spring 5, a movable piece 20, a resin case 30, and a lead frame 10. In Figure 2, resistor elements 40 and 42 are attached to the lead frame 10, but the resistor elements 40 and 42 do not necessarily have to be attached, and even if the resistor elements 40 and 42 are attached, their mounting position is not limited to the position shown in Figure 2.

[0031] The lead frame 10, as will be described in detail later, comprises a first frame 13 integrally formed with the first terminal portion 11, a second frame 14 integrally formed with the second terminal portion 12, and a fixed contact piece 15. The second frame 14 and the fixed contact piece 15 are in contact or not in contact via the movable piece 20, thereby forming an electrical circuit in the switch device 1 that switches the electrical connection state.

[0032] The resin case 30 has a substantially rectangular base (bottom) 31 perpendicular to the vertical direction, a pair of first vertical wall portions 32 extending upward from the long side of the base 31, and a pair of second vertical wall portions 33 extending upward from the short side of the base 31, and is formed in the shape of a bottomed rectangular cylinder. As shown in Figures 1 and 3, the resin case 30 is integrated with the first and second frames 13 and 14 and the fixed contact piece 15 by insert molding, such that the first and second terminal portions 11 and 12 protrude from the base 31 in the direction of the cylinder axis (downward). When resistor elements 40 and 42 are attached, the resistor elements 40 and 42 are also integrated with the base 31 by insert molding.

[0033] As shown in Figure 3, the base 31 has a cylindrical positioning boss 34 extending upward from its center. Additionally, a pair of left and right guide portions 35 are formed on the inner surfaces of each first vertical wall portion 32. Furthermore, a pair of pins 36, which can be fitted to vehicle components around the switch device 1, are provided on the outer surface of the front first vertical wall portion 32. Also, a roughly wedge-shaped engaging portion 37 is formed on the outer surface of each second vertical wall portion 33.

[0034] As shown in Figure 3, the spring 5 is attached to the base 31 such that a positioning boss 34 is inserted through the inside of its lower end.

[0035] As shown in Figure 2, the operator 4 has a base portion 4c, a shaft portion 4b extending upward from the center of the base portion 4c, a push button 4a provided at the upper end of the shaft portion 4b, and a pair of guided portions 4e extending downward from the long side of the base portion 4c and facing each other in the front-rear direction. As shown in Figure 3, the base portion 4c and the shaft portion 4b have a truncated cone-shaped recess 4d that is recessed upward. In addition, a sliding portion (not shown) is formed on the inner surface of the rear guided portion 4e.

[0036] As shown in Figure 3, the operator 4 configured in this way has the upper end of the spring 5 housed in the recess 4d, the outer surfaces of the pair of guided portions 4e contact the inner surfaces of the pair of first vertical wall portions 32 of the resin case 30, and each guided portion 4e is attached to the resin case 30 such that it is sandwiched from the left and right by a pair of left and right guide portions 35 formed on the inner surfaces of each first vertical wall portion 32. As a result, the operator 4 is constantly biased upward by the spring 5 and slides straight in the vertical direction along the inner surfaces of each first vertical wall portion 32 and the guide portions 35. Thus, when the push button 4a is pushed downward against the biasing force of the spring 5, the operator 4 slides downward, and the sliding part formed on the inner surface of the rear guided part 4e presses against the engaging projection 23 (see Figure 5) of the movable piece 20, causing the movable piece 20 to swing approximately perpendicular (forward) to the sliding direction of the operator 4, thereby causing the movable piece 20 attached to the fixed contact piece 15 to come into contact with the second frame 14.

[0037] As shown in Figure 3, the cap rubber 3 is attached to the resin case 30 by sandwiching the flange portion 3a between the upper ends of the first and second vertical wall portions 32 and 33 and the outer peripheral edge of the cover 2. When the cap rubber 3 is attached to the resin case 30 in this way, the push button 4a protrudes upward from the opening 3b of the cap rubber 3. The cap rubber 3 prevents foreign matter such as water and dust from entering the resin case 30 and is made of an elastic material such as rubber with excellent properties such as waterproofing, dustproofing, and flexibility, and is designed to elastically deform in accordance with the movement of the operator 4.

[0038] The cover 2 is formed in a roughly rectangular frame shape with a circular opening 2a in its center, and has roughly U-shaped engaging portions 2b extending downward from both ends in the left and right directions. The cover 2 is attached to the resin case 30 when the push button 4a and the cap rubber 3 are inserted into the opening 2a from below, and the outer peripheral edges are placed on the upper ends of the first and second vertical wall portions 32 and 33 so as to sandwich the flange portion 3a of the cap rubber 3, and the engaging portion 2b engages with the engaged portion 37 formed on the outer surface of the second vertical wall portion 33. In this way, the resin case 30 is sealed by covering the open upper part of the bottomed rectangular cylindrical resin case 30 with the cover 2.

[0039] The switch device 1 configured as described above is of the normally open type and is attached to a vehicle member via a pair of pins 36 in such a manner that when a door or the like is opened, the push button 4a is pushed downward. Therefore, when a door or the like is opened, the push button 4a is pushed downward, compressing the spring 5 downward. Consequently, the movable piece 20 fixed to the fixed contact piece 15 swings forward and comes into contact with the second frame 14, causing current to flow (or the current value to change) between the first terminal portion 11 and the second terminal portion 12, thereby allowing the ECU or the like to detect that the door or the like has been opened.

[0040] On the other hand, when the door or the like is closed, the biasing force of the spring 5 pushes the push button 4a upward, and the movable piece 20 returns to its original position, causing the fixed contact piece 15 and the second frame 14 to become non-contact, and current stops flowing between the first terminal portion 11 and the second terminal portion 12 (or the current value changes), which allows the ECU or the like to detect that the door or the like has been closed.

[0041] -Lead frame- Figure 4 is a schematic perspective view of the lead frames 10 and 10', where Figure 4(a) shows the state with the conductive connection portion 16 remaining, and Figure 4(b) shows the state with the conductive connection portion 16 cut off. The lead frame 10 is formed from a conductive plate by a stamping press using a mold (not shown), and as shown in Figure 4(a), it comprises a first terminal portion 11, a second terminal portion 12, a first frame 13, a second frame 14, and a fixed contact piece 15.

[0042] The first terminal portion 11 is integrally formed with the lower end of the first frame 13, and after extending downward from the lower end of the first frame 13, the bifurcated portion is bent forward, extending further forward than the first frame 13. The first frame 13 is provided with a first mounting portion 13a for mounting the resistive element 40 and a second mounting portion 13b for mounting the resistive element 42. In addition, serration grooves 13c are formed on both the front and back surfaces of the portion between the second mounting portion 13b and the first mounting portion 13a (the portion that constitutes an electrical contact) of the first frame 13.

[0043] The second terminal portion 12 is integrally formed with the lower end of the second frame 14, and after extending downward from the lower end of the second frame 14, the bifurcated portion is bent forward, extending further forward than the second frame 14. As shown in Figure 4(a), the second terminal portion 12 and the first terminal portion 11, and the second frame 14 and the first frame 13, are formed to be aligned left and right on the same plane. The second frame 14 has a second fixed contact portion 18 formed by bending its upper end forward. While the second frame 14 is perpendicular to the front-rear direction, the second fixed contact portion 18 is formed to be perpendicular to the up-down direction, thereby ensuring reliable contact with the movable contact portion 24 of the movable piece 20, which will be described later.

[0044] Furthermore, the second frame 14 is provided with a first mounting portion 14a for mounting the resistive element 40 and a first' mounting portion 14b for mounting the resistive element 41. The first mounting portion 14a is paired with the first mounting portion 13a of the first frame 13, and by mounting (attaching) the resistive element 40 to the first mounting portion 14a and the first mounting portion 13a, the first frame 13 and the second frame 14 are electrically connected. In addition, serration grooves 14c are formed on both the front and back surfaces of the second frame 14 in the area between the second fixed contact portion 18 (the part that constitutes an electrical contact) and the first' mounting portion 14b, and in the area between the first mounting portion 14a (the part that constitutes an electrical contact) and the first' mounting portion 14b.

[0045] As shown in Figure 4(a), the fixed contact piece 15 is integrally formed with the first frame 13 via a conductive connection portion 16. The fixed contact piece 15 has a first fixed contact portion 17 that extends upward in a substantially L-shape from its upper end. Furthermore, the fixed contact piece 15 has a projection 19 that extends downward from its lower end.

[0046] Furthermore, the fixed contact piece 15 is provided with a first' mounting portion 15b for attaching a resistive element 41 and a second mounting portion 15a for attaching a resistive element 42. The first' mounting portion 15b is paired with the first' mounting portion 14b of the second frame 14, and by attaching (mounting) the resistive element 41 to the first' mounting portion 15b and the first' mounting portion 14b, the fixed contact piece 15 and the second frame 14 are electrically connected. Also, the second mounting portion 15a is paired with the second mounting portion 13b of the first frame 13, and by attaching (mounting) the resistive element 42 to the second mounting portion 15a and the second mounting portion 13b, the first frame 13 and the fixed contact piece 15 are electrically connected. Furthermore, the fixed contact piece 15 has serration grooves 15c formed on both the front and back surfaces of the portion between the first fixed contact portion 17 (the portion that constitutes an electrical contact) and the second mounting portion 15a and the first' mounting portion 15b.

[0047] Here, the movable piece 20 will be described. Figure 5 is a schematic perspective view illustrating the contact structure of the movable piece 20. As shown in Figure 5, the movable piece 20 has a mounting portion 21, an arm portion 22, an engaging projection 23, and a movable contact portion 24. A notch 21a is formed in the mounting portion 21, and the mounting portion 21 is attached to the first fixed contact portion 17 of the fixed contact piece 15 by sandwiching the first fixed contact portion 17 with the notch 21a. The arm portion 22 extends to the left from the rear end of the mounting portion 21. The engaging projection 23 extends forward from the upper end of the arm portion 22 and is in contact with a sliding portion formed on the inner surface of the rear guided portion 4e. When the push button 4a is not pushed down, the movable contact portion 24 extends forward from the tip of the arm portion 22 (the left end) to just before the second fixed contact portion 18 of the second frame 14.

[0048] As described above, by configuring the movable piece 20, when the push button 4a is pushed downward against the biasing force of the spring 5, the operator 4 slides downward, and the engaging projection 23 that is in contact with the sliding part is pushed forward. As a result, the arm 22 swings forward, and the movable contact part 24, which had stopped in front of the second fixed contact part 18, slides (contacts) with the second fixed contact part 18 and reaches approximately directly above the second fixed contact part 18, as shown in Figure 5. In this way, the movable contact part 24 comes into contact with the second fixed contact part 18, and the fixed contact piece 15 (first fixed contact part 17) and the second frame 14 (second fixed contact part 18) are electrically connected via the movable piece 20.

[0049] On the other hand, when the biasing force of the spring 5 causes the operator 4 to slide upward and return to its original position, the force with which the sliding part pushes the engaging projection 23 forward weakens (the sliding part returns to a state where it is merely in contact with the engaging projection 23), and as a result the movable piece 20 returns to its original position, the fixed contact piece 15 (first fixed contact part 17) and the second frame 14 (second fixed contact part 18) become non-contact.

[0050] As is clear from comparing Figure 4(a) and Figure 4(b), the only difference between lead frame 10 and lead frame 10' is whether the conductive connection portion 16 remains (lead frame 10) or whether the conductive connection portion 16 is cut off (lead frame 10'). Therefore, lead frame 10 and lead frame 10' can naturally be formed by punching and bending processes using the same mold.

[0051] As described above, the lead frame 10 allows for the creation of multiple different electrical circuit patterns by combining the presence or absence of the resistive elements 40, 41, and 42 attached to each mounting portion 13a, 13b, 14a, 14b, 15a, and 15b with the presence or absence of the conductive connection portion 16.

[0052] - Electrical circuit patterns - In the following explanation, it is assumed that the first terminal section 11 and the second terminal section 12 are electrically connected to an external circuit such as an ECU, and that a current of a certain magnitude is supplied to the first terminal section 11 so that current flows from the first terminal section 11 to the second terminal section 12.

[0053] <Electrical Circuit Pattern 1> Figure 6 is a schematic diagram of an example of an electrical circuit that does not include a resistive element, where Figure 6(a) is a perspective view of the lead frame 10 and Figure 6(b) is a circuit diagram. As shown in Figure 6(a), when the conductive connection portion 16 is left intact (no cutting) and no resistive element is attached (no attachment), an electrical circuit without a resistive element is constructed as shown in Figure 6(b), in which current flows in the order of first terminal portion 11 → first frame 13 → conductive connection portion 16 → fixed contact piece 15 → (first fixed contact portion 17) → movable piece 20 → (second fixed contact portion 18) → second frame 14 → second terminal portion 12.

[0054] In this case, the ECU detects that the door is open when it recognizes that current is flowing through the second terminal 12, while it detects that the door is closed when it recognizes that no current is flowing through the second terminal 12.

[0055] <Electric Circuit Pattern 2> FIG. 7 is a diagram schematically illustrating an example of a parallel electric circuit including one resistance element 40, in which FIG. 7(a) is a perspective view of a lead frame 10 and FIG. 7(b) is a circuit diagram. As shown in FIG. 7(a), when the conductive connection portion 16 is retained (no cutting) and the resistance element 40 is attached to first attachment portions 13a and 14a (attached), current flows in the order of: first terminal portion 11 → first frame 13 → conductive connection portion 16 → fixed contact piece 15 → (first fixed contact portion 17) → movable piece 20 → (second fixed contact portion 18) → second frame 14 → second terminal portion 12; and in parallel with this path, current flows in the order of: first terminal portion 11 → first frame 13 → (first attachment portion 13a) → resistance element 40 → (first attachment portion 14a) → second frame 14 → second terminal portion 12. Thus, a parallel electric circuit including one resistance element 40 as shown in FIG. 7(b) is configured.

[0056] In this case, even when the switch device 1 is off, current flows through the resistance element 40 side, so the inter-terminal voltage between the first terminal portion 11 and the second terminal portion 12 is a voltage value determined by the resistance value of the resistance element 40 (for example, V1). Therefore, when the ECU recognizes the voltage value V1 of the inter-terminal voltage, it is detected that a door or the like is closed.

[0057] On the other hand, when the switch device 1 is turned on, current also flows through the movable piece 20 side, so the inter-terminal voltage is a voltage value determined by the resistance value of the contact resistance of the movable piece 20 and the like (for example, V2, which is less than V1). Therefore, when the ECU recognizes the voltage value V2 that is lower than the voltage value V1, it is detected that a door or the like is open.

[0058] In contrast to these cases, when the electric wires connected to the first terminal portion 11 and the second terminal portion 12 are disconnected, no current flows between the first terminal portion 11 and the second terminal portion 12. Therefore, when the ECU recognizes that no current flows through the second terminal portion 12, the disconnection can be detected.

[0059] <Electric Circuit Pattern 3> Figure 8 schematically shows an example of a parallel electrical circuit including one resistor element 41, where Figure (a) is a perspective view of the lead frame 10 and Figure (b) is a circuit diagram. As shown in Figure 8(a), when the conductive connection portion 16 is left intact (no cutting) and the resistive element 41 is attached to the first' mounting portions 14b and 15b (attached), current flows in the order of first terminal portion 11 → first frame 13 → conductive connection portion 16 → fixed contact piece 15 → (first fixed contact portion 17) → movable piece 20 → (second fixed contact portion 18) → second frame 14 → second terminal portion 12, and in parallel with this, current flows in the order of first terminal portion 11 → first frame 13 → conductive connection portion 16 → fixed contact piece 15 → (first' mounting portion 15b) → resistive element 41 → (first' mounting portion 14b) → second frame 14 → second terminal portion 12, forming a parallel electrical circuit including one resistive element 41 as shown in Figure 8(b).

[0060] In this case as well, similar to pattern 2 above, the opening and closing of doors, etc., and disconnections are detected by monitoring the voltage value of the terminal voltage between the first terminal section 11 and the second terminal section 12.

[0061] <Electrical Circuit Pattern 4> Figure 9 is a schematic diagram showing an example of a series electrical circuit including one resistor 42, where Figure 9(a) is a perspective view of the lead frame 10' and Figure 9(b) is a circuit diagram. As shown in Figure 9(a), when the conductive connection part 16 is cut (cut) and the resistor 42 is attached to the second mounting parts 13b and 15a (attached), a series electrical circuit including the resistor 42 is formed as shown in Figure 9(b), in which current flows in the following order: first terminal part 11 → first frame 13 → (second mounting part 13b) → resistor 42 → (second mounting part 15a) → fixed contact piece 15 → (first fixed contact part 17) → movable piece 20 → (second fixed contact part 18) → second frame 14 → second terminal part 12.

[0062] In this case as well, similar to Pattern 1 above, the ECU detects that the door is open when it recognizes that current is flowing through the second terminal 12, while it detects that the door is closed when it recognizes that no current is flowing through the second terminal 12.

[0063] <Electrical Circuit Pattern 5> Figure 10 is a schematic diagram showing an example of a parallel electrical circuit including two resistors 41 and 42. Figure 10(a) is a perspective view of the lead frame 10', and Figure 10(b) is a circuit diagram. As shown in Figure 10(a), when the conductive connection part 16 is cut (cut) and the resistors 41 and 42 are attached to the first' mounting parts 14b, 15b and the second mounting parts 13b, 15a respectively (attached), the circuit proceeds as follows: First terminal part 11 → First frame 13 → (Second mounting part 13b) → Resistor 42 → (Second mounting part 15a) → Fixed contact piece 15 → (First fixed contact part 17) → Movable piece 20 → (Second fixed contact part 18) → Second frame Current flows in the order of 14 → second terminal section 12, and in parallel with this, current flows in the order of first terminal section 11 → first frame 13 → (second mounting section 13b) → resistor element 42 → (second mounting section 15a) → fixed contact piece 15 → (first' mounting section 15b) → resistor element 41 → (first' mounting section 14b) → second frame 14 → second terminal section 12, forming a parallel electrical circuit including two resistor elements 41 and 42 as shown in Figure 10(b).

[0064] In this case, even when the switch device 1 is off, current flows through the resistor element 41, so the terminal voltage between the first terminal 11 and the second terminal 12 becomes a voltage value determined by the resistance values ​​of resistor elements 41 and 42 (for example, V1'). Therefore, the ECU detects that the door or the like is closed by recognizing the terminal voltage value V1'.

[0065] On the other hand, when the switch device 1 is turned on, current also flows to the movable piece 20 side, so the inter-terminal voltage becomes a voltage value determined by the resistance values of the contact resistance of the resistance element 42, the movable piece 20 and the like (for example, V2' (<V1')). Therefore, when the ECU recognizes the voltage value V2' lower than the voltage value V1', it is detected that a door or the like is open.

[0066] In contrast to these, when the ECU recognizes that no current flows through the second terminal portion 12, a disconnection is detected.

[0067] <Electric Circuit Pattern 6> FIG. 11 is a diagram schematically showing an example of a parallel electric circuit including two resistance elements 40 and 42, wherein FIG. 11(a) is a perspective view of a lead frame 10', and FIG. 11(b) is a circuit diagram. As shown in FIG. 11(a), when the conductive connection portion 16 is cut (with cutting) and the resistance elements 40 and 42 are attached to the first attachment portions 13a, 14a and the second attachment portions 13b, 15a respectively (with attachment), current flows in the order of the first terminal portion 11 → the first frame 13 → (the second attachment portion 13b) → the resistance element 42 → (the second attachment portion 15a) → the fixed contact piece 15 → (the first fixed contact portion 17) → the movable piece 20 → (the second fixed contact portion 18) → the second frame 14 → the second terminal portion 12, and in parallel therewith, current flows in the order of the first terminal portion 11 → the first frame 13 → (the first attachment portion 13a) → the resistance element 40 → (the first attachment portion 14a) → the second frame 14 → the second terminal portion 12, thus forming a parallel electric circuit including two resistance elements 40 and 42 as shown in FIG. 11(b).

[0068] In this case, even when the switch device 1 is turned off, current flows through the resistance element 40 side, so the inter-terminal voltage between the first terminal portion 11 and the second terminal portion 12 becomes a voltage value determined by the resistance value of the resistance element 40 (for example, V1''). Therefore, when the ECU recognizes the voltage value V1'' of the inter-terminal voltage, it is detected that a door or the like is closed.

[0069] On the other hand, when the switch device 1 is turned on, current flows to the movable piece 20, so the terminal voltage becomes a voltage value determined by the resistance value of the contact resistance of the resistive element 42 and the movable piece 20 (for example, V2" (>V1)). Therefore, when the ECU recognizes a voltage value V2" that is higher than the voltage value V1", it is detected that the door or the like is open.

[0070] In response to these issues, the ECU detects that no current is flowing through the second terminal 12, thereby detecting a break in the wire.

[0071] -Manufacturing method for lead frame insert molded products- As described above, in this embodiment, the switch device 1 is assembled using a lead frame insert molded product 50 (see Figure 14(c)) in which the lead frames 10, 10' are integrated with the base 31 of the resin case 30 by insert molding. More specifically, in the lead frame insert molded product 50, the lead frames 10, 10' are integrated with the resin case 30 such that the first and second terminal portions 11, 12 protrude downward (in the direction of the cylinder axis) from the base 31 of the bottomed cylindrical resin case 30, side by side. An example of a method for manufacturing such a lead frame insert molded product 50 will be described below.

[0072] Figure 12 is a schematic perspective view showing an example of a semi-finished product 50' of a lead frame insert molded product 50, where Figure (a) is a view from diagonally above and Figure (b) is a view from diagonally below. When integrating the lead frames 10, 10' with the resin case 30 by insert molding, it is common to position them on the side of the first and second terminal portions 11, 12 that protrude from the base 31 in the direction of the cylindrical axis after insert molding.

[0073] More specifically, as shown in Figure 12(b), the first and second terminal portions 11 and 12 are formed from a conductive plate by punching press processing while connected to a bathtub-shaped frame portion 60. As shown in Figures 12(a) and (b), four pilot holes 63 are formed in the frame portion 60, and these pilot holes 63 are used to position the lead frames 10 and 10' during insert molding. In addition, as shown in Figure 12(a), the frame portion 60 has a contact prevention portion 61 formed by bending forward the portion 61' (see Figure 13(a)) that extends to the left and right of the first and second terminal portions 11 and 12. This contact prevention portion 61 suppresses contact between products, thereby preventing deformation of the bent portion (contact portion).

[0074] However, with this method, if the conductive connection portion 16 is cut, the connection between the first frame 13 and the fixed contact piece 15 will be severed. In other words, the connection between the frame portion 60 having the pilot hole 63 and the fixed contact piece 15 will be severed, which could make it difficult to position the fixed contact piece 15.

[0075] Therefore, in this embodiment, as shown in Figure 4, a projection 19 is provided on the fixed contact piece 15 that extends in the same direction as the first and second terminal portions 11 and 12, and as shown in Figure 12(b), a tip portion 19a that protrudes from the base 31 while being integrated with the resin case 30, and is integrally formed with the first and second terminal portions 11 and 12 via a connecting portion 19b.

[0076] By providing such projections 19 on the fixed contact piece 15, even if the conductive connection portion 16 is cut, the fixed contact piece 15 remains connected to the first and second terminal portions 11 and 12 via the projections 19. Therefore, the fixed contact piece 15 can be easily positioned by positioning it on the first and second terminal portions 11 and 12 side (the four pilot holes 63).

[0077] Furthermore, since the tip 19a of the projection 19, which is integrally formed with the first and second terminal portions 11 and 12 via the connecting portion 19b, protrudes from the base 31 while being integrated with the resin case 30, it is easy to prevent current from flowing between the first terminal portion 11 and the second terminal portion 12 via the projection 19 by cutting the connecting portion 19b after insert molding.

[0078] Figures 13 and 14 schematically illustrate the method for manufacturing the lead frame insert molded product 50. The method for manufacturing the lead frame insert molded product 50 in this embodiment includes a punching press step, a bending press step, a first cutting step, a mounting step, a resin sealing step, a second cutting step, and a third cutting step, as shown in the examples in Figures 13 and 14.

[0079] First, in the punching press process, as shown in Figure 13(a), a first terminal portion 11, a second terminal portion 12, a first frame 13, a second frame 14, a fixed contact piece 15 having a projection 19, and a frame portion 60 having a portion 61' that extends alongside the first and second terminal portions 11 and 12 are punched out from the conductive plate.

[0080] Next, in the bending press process, as shown in Figure 13(b), the second fixed contact portion 18, which is on the same plane as the second frame 14, is bent forward so as to be perpendicular to the vertical direction, and portion 61' is bent forward so as to be perpendicular to the frame portion 60, thereby forming a pair of contact prevention portions 61.

[0081] In relation to the claims, the punching press process and bending press process in this embodiment correspond to the "pressing process for forming a lead frame from a conductive plate."

[0082] Next, in the first cutting step, as shown in Figure 13(c), the conductive connection portion 16 connecting the first frame 13 and the fixed contact piece 15 is cut. In this way, even if the conductive connection portion 16 is cut, the tip portion 19a of the projection 19 of the fixed contact piece 15 is integrally formed with the first and second terminal portions 11 and 12 via the connection portion 19b, so the first frame 13 and the fixed contact piece 15 remain connected via the projection 19 and the first terminal portion 11.

[0083] Next, in the mounting process, the resistive elements 40 and 42 are mounted on the lead frame 10' as shown in Figure 13(d). More specifically, similar to the example in Figure 11, the resistive elements 40 are mounted on the first mounting sections 13a and 14a, and the resistive elements 42 are mounted on the second mounting sections 13b and 15a. At this time, the resistive elements 40 and 42 are mounted to the first mounting sections 13a and 14a and the second mounting sections 13b and 15a by, for example, the reflow soldering method, that is, by melting the solder paste applied to the first mounting sections 13a and 14a and the second mounting sections 13b and 15a with heat.

[0084] Next, in the resin encapsulation process, the lead frame 10' is positioned using the four pilot holes 63 of the frame portion 60. Then, the resistor elements 40 and 42 mounted in the mounting process are resin-encapsulated together with the first and second frames 13 and 14 and the fixed contact piece 15 by insert molding. As shown in Figure 14(a), the resin case 30 is molded so that the first and second terminal portions 11 and 12 and the tip 19a of the projection portion 19 protrude from the base 31. This completes the semi-finished product 50'. In this way, even if the conductive connection portion 16 is cut, the fixed contact piece 15 is connected to the first and second terminal portions 11 and 12 via the projection portion 19, making it easy to position the fixed contact piece 15.

[0085] Next, in the second cutting step, as shown in Figure 14(b), the connecting portion 19b is cut, separating the tip portion 19a of the projection 19 from the first and second terminal portions 11 and 12.

[0086] In the third cutting step, the frame portion 60 is separated from the first and second terminal portions 11 and 12, thereby completing the lead frame insert molded product 50 as shown in Figure 14(c).

[0087] -Mechanism / Effect- According to the lead frame 10 of this embodiment, different types of electrical circuits, as illustrated in patterns 1 to 6 above, can be configured by combining whether or not the resistive elements 40, 41, and 42 are attached to each mounting portion 13a, 13b, 14a, 14b, 15a, and 15b, and whether or not the conductive connection portion 16 is cut.

[0088] Furthermore, when configuring different types of electrical circuits, only the installation of resistive elements 40, 41, and 42 and the disconnection of the conductive connection part 16 are required. Therefore, different types of electrical circuits can be realized using a common lead frame 10, which enables the standardization of design and the sharing of molds, thereby suppressing cost increases.

[0089] Furthermore, when constructing an electrical circuit including resistors 40, 41, and 42, the resistors 40, 41, and 42 are integrated with the resin case 30 by insert molding. This eliminates the risk of melting the resin case 30 due to the heat of soldering the resistors 40, 41, and 42, as can occur when the resistors 40, 41, and 42 are attached after insert molding, thus improving the ease of assembly of the switch device 1. In addition, since the resistors 40, 41, and 42 are not exposed, corrosion and deterioration of the electrode parts of the resistors 40, 41, and 42 can be suppressed.

[0090] Furthermore, since serration grooves 13c, 14c, and 15c are formed on both the front and back surfaces of the lead frame 10, when applying solder paste to each mounting portion 13a, 13b, 14a, 14b, 15a, and 15b, the surface tension of the applied solder makes it difficult for the solder to pass over the serration grooves 13c, 14c, and 15c, thus suppressing the outflow of solder paste. In addition, the serration grooves 13c, 14c, and 15c enhance the adhesion between the resin and the metal, which can be expected to improve sealing performance.

[0091] Furthermore, according to the manufacturing method of this embodiment, even when the conductive connection portion 16 is cut, a lead frame insert molded product 50 can be easily manufactured in which a lead frame 10' capable of configuring different types of electrical circuits is integrated with a resin case 30 while positioning the fixed contact piece 15.

[0092] (Other embodiments) The present invention is not limited to its embodiments and can be implemented in various other ways without departing from its spirit or main features.

[0093] In the above embodiment, the switch device 1 was configured as a normally open type, but it is not limited to this and may be configured as a normally closed type.

[0094] Thus, the embodiments described above are merely illustrative in all respects and should not be interpreted restrictively. Furthermore, any modifications or changes that fall within the equivalent scope of the claims are all within the scope of the present invention. [Industrial applicability]

[0095] According to the present invention, different types of electrical circuits can be realized with a common lead frame, making it extremely useful for manufacturing lead frames that constitute the electrical circuits of switch devices, and for manufacturing lead frame insert molded products in which the lead frame is integrated with a resin case by insert molding. [Explanation of Symbols]

[0096] 1. Switching device 10, 10' Lead Frame 11 1st terminal section 12 2nd terminal section 13. First Frame 13a, 14a First mounting section 13b, 15a Second mounting section 13c, 14c, 15c serrated groove 14. Frame 2 14b, 15b First mounting section 15 Fixed contact piece 16 Conductive connection 19 Protrusion 19a Tip 19b Connection section 20 Movable piece 30 resin cases 31 Base (bottom) 40, 41, 42 Resistor elements 50 Lead frame insert molded parts

Claims

1. A lead frame constituting an electrical circuit of a switch device, comprising first and second frames integrally formed with first and second terminal portions connected to an external circuit, respectively, and a fixed contact piece, wherein the electrical connection state is switched when the fixed contact piece and the second frame are in contact or not in contact via a movable piece, The above-mentioned fixed contact piece is integrally formed with the first frame via a conductive connection portion. The first frame and at least one of the fixed contact piece and the second frame each have a first mounting portion to which a resistive element that electrically connects them can be attached. The first frame and the fixed contact piece each have a second mounting portion to which the resistive element that electrically connects them can be attached. The first and second frames and the fixed contact piece are integrated with the resin case by insert molding such that the first and second terminal portions protrude from the bottom of the bottom cylindrical resin case in the direction of the cylindrical axis. The above-mentioned fixed contact piece has a projection that extends in the same direction as the first and second terminal portions. The above-mentioned projection is integrated with the above-mentioned resin case, and the tip portion that protrudes from the bottom portion is integrally formed with the first and second terminal portions via the connecting portion. A lead frame characterized by configuring an electrical circuit without the resistive element, a series electrical circuit including the resistive element, or a parallel electrical circuit including the resistive element, by combinations of whether or not the resistive element is attached to each of the above-mentioned mounting parts and whether or not the conductive connection part is disconnected.

2. In the lead frame described in claim 1 above, In the case of configuring an electrical circuit including the above-mentioned resistive element, the lead frame is characterized in that the resistive element is integrated with the resin case by insert molding.

3. In the lead frame described in claim 1 above, A lead frame characterized in that serration grooves are formed on both the front and back surfaces between the portions constituting electrical contacts in the first and second frames and the fixed contact piece, and the first and second mounting portions.

4. A method for manufacturing a lead frame insert molded product in which a lead frame comprising a first frame integrally formed with a first terminal portion, a second frame integrally formed with a second terminal portion extending in the same direction as the first terminal portion, and a fixed contact piece integrally formed with the first frame via a conductive connection portion, extending in the same direction as the first and second terminal portions, and having a projection at its tip integrally formed with the first and second terminal portions via a connection portion, is integrated with a bottomed cylindrical resin case by insert molding such that the first and second terminal portions protrude from the bottom of the bottom of the cylindrical resin case in the direction of the cylindrical axis, A pressing process for forming the lead frame from a conductive plate, A first cutting step involves cutting the conductive connection portion in the lead frame formed in the above pressing step, The mounting process involves attaching a resistive element to the lead frame described above. A resin sealing step in which, while positioning the lead frame on the first and second terminal portions, the resistor element mounted in the mounting step is resin-sealed together with the first and second frames and the fixed contact piece by insert molding, thereby forming the resin case so that the tips of the first and second terminal portions and the protrusions protrude from the bottom portion. A method for manufacturing a lead frame insert molded product, characterized by including a second cutting step of cutting the above-mentioned connecting portion and separating the tip of the above-mentioned projection from the first and second terminal portions.

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