Press-fit terminal and connector device

Abstract

To achieve a balance among insertion force, holding force, and contact area in a press-fit terminal having a thickness of 0.75 to 0.85 mm. The press-fit terminal has a press-fit portion including two contact pieces opposed across an observation hole, each of the contact pieces including a parallel portion parallel to each other, a front spring portion, and a rear spring portion, the press-fit portion having a thickness of 0.75 mm or more and 0.85 mm or less, and with respect to the press-fit portion, when a front-side spring strength is set as G1 [mm 3 ], a rear-side spring strength is set as G2 [mm 3 ], G1+G2 is 0.030 or more and 0.080 or less, and when an inclination of the front spring portion with respect to an insertion direction of the press-fit portion is set as θ, G1 tan θ is 0.0024 or more and 0.0070 or less.

Description

Technical Field

[0001] This disclosure relates to press-fit terminals and connector assemblies. Background Technology

[0002] Patent Document 1 discloses a press-fit terminal having a connecting portion consisting of a slit having a width extending through both the inside and outside of the terminal and two opposing beam members separated by the slit. In Patent Document 1, regarding the thickness of the beam members, the thickness of the top and rear ends of the connecting portion is thinner than the thickness of the center of the connecting portion, and regarding the length of the slit, the length from the center of the connecting portion to the rear ends is shorter than the length from the center of the connecting portion to the top ends.

[0003] Patent Document 2 discloses a press-fit terminal having an insertion portion inserted into a through hole, a pressure holding portion connected to the insertion portion and press-fitted into the through hole, and a main body portion connected to the pressure holding portion, with an opening extending along its longitudinal direction from the center of the pressure holding portion toward the main body portion and the insertion portion. In Patent Document 2, the ratio of the length along the longitudinal direction from the center of the pressure holding portion to one end of the opening on the main body portion side, to the length along the longitudinal direction from the center of the pressure holding portion to the other end of the opening on the insertion portion side, is specified to be in the range of 80:220 to 120:180.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2008 / 038331

[0007] Patent Document 2: Japanese Patent Application Publication No. 2008-165987 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] Press-fit terminals are evaluated, for example, by insertion force, holding force, and contact area. Insertion force is the load required to insert the press-fit terminal into the through-hole. Holding force is the load required to pull the press-fit terminal out of the through-hole. Contact area is the area of ​​contact between the press-fit terminal and the inner surface of the through-hole when the terminal is inserted.

[0010] When the insertion force is small, the press-fit terminal is easily inserted into the through-hole, and damage to the substrate is suppressed when inserting the press-fit terminal into the through-hole. Conversely, when the holding force and contact area are large, the press-fit terminal is firmly held to the substrate, and the electrical connection reliability between the press-fit terminal and the circuitry formed on the substrate is improved. Therefore, for press-fit terminals, it is necessary to reduce the insertion force and increase the holding force and contact area.

[0011] Generally, reducing insertion force and increasing retention force and contact area are opposing requirements. Therefore, when discussing the shape of press-fit terminals, it is important to achieve a multidimensional balance between insertion force, retention force, and contact area.

[0012] In particular, for press-fit terminals with a thickness of 0.75~0.85mm, the insertion force tends to increase. When the insertion force is too large, it may damage the substrate. Therefore, for press-fit terminals with a thickness of 0.75~0.85mm, it is more important to achieve a multi-dimensional balance between insertion force, holding force, and contact area within a range that can suppress excessive damage to the substrate.

[0013] Therefore, the present disclosure aims to achieve a multidimensional balance of insertion force, retention force, and contact area for press-fit terminals with a plate thickness of 0.75 to 0.85 mm.

[0014] Solution for solving the problem

[0015] The press-fit terminal disclosed herein is press-fitted into a through-hole formed in a substrate. The press-fit terminal includes a press-fit portion comprising two opposing contact pieces separated by an observation hole. Each of the two contact pieces includes: a parallel portion; a front spring portion extending from the parallel portion in a direction toward insertion into the press-fit portion; and a rear spring portion extending from the parallel portion in a direction opposite to insertion into the press-fit portion. The thickness of the press-fit portion is 0.75 mm or more and 0.85 mm or less. Regarding the press-fit portion, the front spring strength, calculated under the following conditions, is set as G1 [mm]. 3 Set the rear spring strength to G2 [mm]. 3 When G1+G2 is greater than or equal to 0.030 and less than or equal to 0.080, and when the inclination of the front spring portion relative to the insertion direction of the press-fit portion is set to θ, then G1tanθ is greater than or equal to 0.0024 and less than or equal to 0.0070.

[0016] The conditions are as follows:

[0017] • Set the insertion direction of the press-fit terminal to forward, and set the opposite direction to the insertion direction to backward;

[0018] • The position 0.1 mm backward from the front end of the observation hole is set as the front reference, and the position 0.1 mm forward from the rear end of the observation hole is set as the rear reference;

[0019] • Assuming a front reference plane perpendicular to the outer edge of the front spring portion from the inner edge of the front reference portion, and setting the moment of inertia of the front spring portion section in this front reference plane as I1 [mm]4 ];

[0020] • Assuming a rear reference plane perpendicular to the outer edge of the rear spring portion from the inner edge of the rear reference portion, the moment of inertia of the section of the rear spring portion in this rear reference plane is set as I² [mm]. 4 ];

[0021] • The length of the insertion direction of the press-fit portion from the intersection of the straight line extending from the intersection of ...

[0022] • The length of the insertion direction of the press-fit portion from the intersection of the straight line extending from the point of intersection of the rear reference surface and the outer edge of the rear spring portion in a direction perpendicular to the rear reference surface and the straight line extending along the outer edge of the parallel portion to the rear end of the observation hole is defined as L2 [mm].

[0023] • Set the front spring strength G1 to I1 / L1 [mm] 3 The strength G2 of the rear spring is set to I2 / L2 [mm]. 3 ].

[0024] Invention Effects

[0025] According to this disclosure, for press-fit terminals with a plate thickness of 0.75 to 0.85 mm, it is possible to achieve a multidimensional balance between insertion force, holding force, and contact area. Attached Figure Description

[0026] Figure 1 This is a front view showing the press-fit terminal of the embodiment.

[0027] Figure 2 This is an explanatory diagram showing the state of the press-fit part inserted into the through hole.

[0028] Figure 3 yes Figure 2 Sectional view along line III-III.

[0029] Figure 4 This is a cross-sectional view showing other press-fit terminals.

[0030] Figure 5 This is an explanatory diagram showing the cross-sectional shape of the front spring section in the front reference plane.

[0031] Figure 6 This is a schematic diagram showing the connector assembly.

[0032] Figure 7 This is a graph showing the evaluation results of the press-fit terminals.

[0033] Figure 8 This is a graph showing the evaluation results of the press-fit terminals. Detailed Implementation

[0034] [Description of embodiments of this disclosure]

[0035] First, embodiments of this disclosure will be described.

[0036] The press-fit terminals disclosed herein are as follows.

[0037] (1) Pressed into a through hole formed in a substrate, the press-fit terminal has a press-fit portion, the press-fit portion including two contact pieces facing each other across an observation hole, each of the two contact pieces including: a parallel portion that is parallel to each other; a front spring portion that extends from the parallel portion in the direction of insertion into the press-fit portion; and a rear spring portion that extends from the parallel portion in the direction opposite to the direction of insertion into the press-fit portion, the thickness of the press-fit portion being 0.75 mm or more and 0.85 mm or less, and regarding the press-fit portion, the front spring strength calculated under the following conditions is set as G1 [mm]. 3 Set the rear spring strength to G2 [mm]. 3 When G1+G2 is greater than or equal to 0.030 and less than or equal to 0.080, and when the inclination of the front spring portion relative to the insertion direction of the press-fit portion is set to θ, then G1tanθ is greater than or equal to 0.0024 and less than or equal to 0.0070.

[0038] The conditions are as follows:

[0039] • Set the insertion direction of the press-fit terminal to forward, and set the opposite direction to the insertion direction to backward;

[0040] • The position 0.1 mm backward from the front end of the observation hole is set as the front reference, and the position 0.1 mm forward from the rear end of the observation hole is set as the rear reference;

[0041] • Assuming a front reference plane perpendicular to the outer edge of the front spring portion from the inner edge of the front reference portion, and setting the moment of inertia of the front spring portion section in this front reference plane as I1 [mm] 4 ];

[0042] • Assuming a rear reference plane perpendicular to the outer edge of the rear spring portion from the inner edge of the rear reference portion, the moment of inertia of the section of the rear spring portion in this rear reference plane is set as I² [mm]. 4 ];

[0043] • The length of the insertion direction of the press-fit portion from the intersection of the straight line extending from the intersection of ...

[0044] • The length of the insertion direction of the press-fit portion from the intersection of the straight line extending from the point of intersection of the rear reference surface and the outer edge of the rear spring portion in a direction perpendicular to the rear reference surface and the straight line extending along the outer edge of the parallel portion to the rear end of the observation hole is defined as L2 [mm].

[0045] • Set the front spring strength G1 to I1 / L1 [mm] 3 The strength G2 of the rear spring is set to I2 / L2 [mm]. 3 ].

[0046] Based on this press-fit terminal, since G1+G2 is 0.030 or more and 0.080 or less, and G1tanθ is 0.0024 or more and 0.0070 or less, for press-fit terminals with a thickness of 0.75 mm or more and 0.85 mm or less, the insertion force, holding force and contact area can be balanced in multiple dimensions.

[0047] (2) In the press-fit terminal of (1), G1+G2 can also be 0.030 or more and 0.060 or less, and G1tanθ can be 0.0028 or more and 0.0060 or less. For press-fit terminals with a thickness of 0.75 mm or more and 0.85 mm or less, the insertion force, holding force and contact area can be further balanced in multiple dimensions.

[0048] (3) In the press-fit terminal of (1) or (2), the thickness of the press-fit part may be 0.8 mm.

[0049] (4) In the press-fit terminal of (1) or (2), the outer edge of the front spring portion may be inclined toward the inside of the width direction of the press-fit portion as it moves forward, and the outer edge of the rear spring portion may be inclined toward the inside of the width direction of the press-fit portion as it moves backward. As a result, the front spring portion and the rear spring portion are prone to deformation.

[0050] (5) In any of the press-fit terminals in (1) and (4), the outward portion of the parallel part may be formed into an arc shape when viewed along the insertion direction. As a result, the contact area between the parallel part and the inner circumferential surface of the through hole increases.

[0051] (6) It can also be a connector device, comprising: a connector including a press-fit terminal of (5); and a substrate having a through hole, wherein the press-fit portion of the press-fit terminal is pressed into the through hole, and viewed along the insertion direction, the radius of curvature of the outward portion of the parallel portion is the same as or smaller than the inner circumferential radius of the through hole. As a result, the contact area between the parallel portion and the inner circumferential surface of the through hole increases.

[0052] [Details of the embodiments of this disclosure]

[0053] Specific examples of the press-fit terminals and connector devices of this disclosure are described below with reference to the accompanying drawings. Furthermore, this disclosure is not limited to these examples, but is intended, by way of the claims, to include all modifications within the meaning and scope equivalent to the claims.

[0054] [Implementation Method]

[0055] The press-fit terminal of the embodiment will be described below. Figure 1 This is a front view showing the press-fit terminal 20. Figure 2 This is an explanatory diagram showing the press-fit part 30 inserted into the through hole 13. Figure 2 The image shows the press-fit terminal 20 before being inserted into the through hole 13 and the press-fit terminal 20 already inserted into the through hole 13. Figure 3 yes Figure 2 Sectional view along line III-III.

[0056] The press-fit terminal 20 is a terminal that is pressed into a through-hole 13 formed in the substrate 12. Here, the substrate 12 is formed from an insulating board such as a glass epoxy resin board. A through-hole 13 is formed in the substrate 12, penetrating both the surface and the interior. The through-hole 13 can be circular or square. A conductive layer 13f is formed on the inner surface of the through-hole 13, and the conductive layer 13f is formed of a metal such as copper. When the press-fit terminal 20 is pressed into the through-hole 13, the press-fit terminal 20 contacts the conductive layer 13f and is electrically connected to it. The conductive layer 13f can also be connected to a circuit formed on the surface of the substrate 12.

[0057] The press-fit terminal 20 is formed from metals such as copper or copper alloys. The press-fit terminal 20 can also be formed, for example, by stamping a metal sheet. A plating layer of tin, tin alloy, or the like can also be formed on the surface of the press-fit terminal 20.

[0058] The press-fit terminal 20 includes a press-fit portion 30. In this embodiment, a top end portion 22 is connected to one end of the press-fit portion 30, and a base end portion 26 is connected to the other end of the press-fit portion 30. The top end portion 22 is the portion that is first inserted into the through hole 13 when the press-fit terminal 20 is inserted into the through hole 13. The base end portion 26 is the portion that is connected to the conductive layer 13f on the through hole 13 side. (To be described later...) Figure 6 In the example shown, the base end 26 is connected to the connector terminal portion 54. The direction in which the press-fit portion 30 is inserted is set to forward, and the direction opposite to the insertion direction is set to backward.

[0059] The press-fit portion 30 is the portion disposed between the top end portion 22 and the base end portion 26. The width W2 (the maximum width here) of the press-fit portion 30 is greater than the width W1 of the top end portion 22, and also greater than the diameter φ of the through hole 13. Therefore, the press-fit portion 30 can contact the inner circumferential surface of the through hole 13. It can also be understood that the press-fit portion 30 is a portion used to obtain electrical connection with the conductive layer 13f by maintaining contact with the inner circumferential surface of the through hole 13.

[0060] More specifically, the press-fit terminal 20 is generally formed as an elongated plate extending in a straight line.

[0061] The tip portion 22 includes a tapered section that gradually narrows towards the tip. Due to the presence of this tapered section, the press-fit terminal 20 can be easily inserted into the through hole 13. The tip portion may also include a continuous rectangular plate-like portion of the same width. In this case, the tapered section may also be formed closer to the tip than the rectangular plate-like portion. The tip portion 22 can be inserted into the through hole 13 with a gap between it and the inner circumferential surface of the through hole 13.

[0062] The base end portion 26 includes a continuous rectangular plate-like portion of the same width. The two edges of this rectangular plate-like portion are parallel to each other. The width of the base end portion 26 is less than the width W2 of the press-fit portion 30. The base end portion may not be rectangular plate-like. For example, the base end portion may be a shape that gradually narrows or widens towards the press-fit portion. The base end portion may also have a portion that is wider than the width of the press-fit portion.

[0063] A press-fit portion 30 is disposed between the top end portion 22 and the base end portion 26. The press-fit portion 30 includes two opposing contact pieces 34 spaced apart from an eyehole 31. The eyehole 31 is an elongated hole in the direction connecting the top end portion 22 and the base end portion 26. Specific examples of the shape of the eyehole 31 include a perfect circle, an ellipse, a square, and a rectangle. The eyehole 31 is preferably elongated in the direction in which the press-fit terminal is inserted. The contact pieces 34 are formed as elongated plates. One end of each of the two contact pieces 34 is connected to the top end portion 22. The other end of each of the two contact pieces 34 is connected to the base end portion 26.

[0064] Each of the two contact pieces 34 has a parallel portion 36, a front spring portion 35, and a rear spring portion 37.

[0065] The parallel portions 36 of the two contact pieces 34 are arranged parallel to each other. More specifically, the outer edges 36a of the two parallel portions 36 can also be arranged in a straight line and parallel to each other in the front-back direction. The inner edges of the two parallel portions 36 can also be arranged in a straight line and parallel to each other in the front-back direction. However, depending on the shape of the observation hole 31, sometimes part or all of the inner edges of the two parallel portions 36 are depicted as curved.

[0066] The front spring portion 35 extends forward from the parallel portion 36 in the direction of insertion into the press-fit terminal 20. The front spring portion 35 is the portion that deforms more easily than the parallel portion 36 when the press-fit portion 30 is inserted into the through hole 13. The outer edge 35a of the front spring portion 35 slopes inward toward the width direction of the press-fit portion 30 as it moves forward. That is, the outer edge 35a of the front spring portion 35 connects to the outer edge 36a of the parallel portion 36 at the rear end, gradually slopes inward toward the width direction of the press-fit portion 30 as it moves forward, and connects to the outer edge of the top portion 22 at the front end.

[0067] The outer edge 35a of the front spring portion 35 can be entirely straight, entirely curved, or a combination of both. The outer edge 35a of the front spring portion 35 and the outer edge 36a of the parallel portion 36 can be connected by a curve or an angle. Here, the outer edge 35a of the front spring portion 35 and the outer edge 36a of the parallel portion 36 are connected by a curve that convexes outwards. The outer edge 35a of the front spring portion 35 and the outer edge of the top end portion 22 can be connected by a curve, an angle, or a straight line. Here, the outer edge 35a of the front spring portion 35 and the outer edge of the top end portion 22 are connected by a straight line.

[0068] The rear spring portion 37 extends from the parallel portion 36 in the opposite direction (rearward) to the insertion direction of the press-fit terminal 20. The rear spring portion 37 is the portion that deforms more easily than the parallel portion 36 when the press-fit portion 30 is inserted into the through hole 13. Because the front spring portion 35 and the rear spring portion 37 are easily deformed before and after the parallel portion 36, the parallel portion 36 can be displaced inward without significant tilting. The outer edge 37a of the rear spring portion 37 tilts inward toward the width direction of the press-fit portion 30 as it moves rearward. That is, the outer edge 37a of the rear spring portion 37 connects to the outer edge 36a of the parallel portion 36 at the front end, gradually moves inward toward the width direction of the press-fit portion 30 as it moves rearward, and connects to the outer edge of the base end portion 26 at the rear end.

[0069] The outer edge 37a of the rear spring portion 37 can be entirely straight, entirely curved, or a combination of both. The outer edge 37a of the rear spring portion 37 and the outer edge 36a of the parallel portion 36 can be connected either curvedly or at an angle. Similarly, the outer edge 37a of the rear spring portion 37 and the outer edge of the base end portion 26 can be connected either curvedly or at an angle. Here, the middle portion of the outer edge 37a of the rear spring portion 37 is straight, while its two end portions are curved.

[0070] Viewed from the insertion direction of the press-fit terminal 20, the outward portion of the parallel portion 36 is formed as an outwardly convex arcuate surface 36f. When the outward portion of the parallel portion 36 is formed as an arcuate surface 36f, it is expected that the arcuate surface 36f will contact the inner peripheral surface of the through hole 13 with a larger area.

[0071] The radius of curvature r of the arcuate surface 36f is preferably the same as or smaller than the inner circumferential radius (φ / 2) of the through hole 13 into which the pressure-fit terminal 20 is inserted. When the radius of curvature r of the arcuate surface 36f is the same as the inner circumferential radius (φ / 2) of the through hole 13, it is expected that the arcuate surface 36f will be in contact with the inner circumferential surface of the through hole 13 as a whole. Furthermore, the fact that the radius of curvature r of the arcuate surface 36f and the inner circumferential radius (φ / 2) of the through hole 13 are the same can also include the case where they are the same within the same manufacturing tolerance range. For example, the radius of curvature r of the arcuate surface 36f can also be the same relative to the inner circumferential radius (φ / 2) of the through hole 13 within an tolerance range of ±20%. Furthermore, even when the radius of curvature r of the curved surface is smaller than the inner circumferential radius (φ / 2) of the through hole 13, compared to the case where the radius of curvature r of the curved surface 136f is larger than the inner circumferential radius (φ / 2) of the through hole 13, it can be expected that the central curved surface portion of the curved surface 36f will contact the inner circumferential surface of the through hole 13 with a larger area (see reference). Figure 3 The range is E1). This is because we consider the following: for example Figure 4 As shown, when the radius of curvature r of the arc surface 136f is greater than the inner circumferential radius (φ / 2) of the through hole 13, the two edge portions of the arc surface 136f contact the inner circumferential surface of the through hole 13 with a smaller area than in the case described above (refer to...). Figure 4 (Circular portion E2). Even if the radius of curvature r of the arc surface is less than the inner circumferential radius (φ / 2) of the through hole 13, the radius of curvature r of the arc surface is preferably more than 70% of the inner circumferential radius (φ / 2) of the through hole 13.

[0072] The outward portions of the front spring portion 35 and the rear spring portion 37 are also formed into arc-shaped surfaces, just as described above.

[0073] Viewed from the insertion direction of the press-fit terminal 20, the outward portions of the parallel portion 36, the front spring portion 35, and the rear spring portion 37 are not necessarily formed in the above-described shape. For example, the outward portions of the parallel portion 36, the front spring portion 35, and the rear spring portion 37 may also be formed as planes. Furthermore, as... Figure 4 As shown, it is not excluded that the radius of curvature r of the arc surface 136f is larger than the inner circumferential radius (φ / 2) of the through hole 13.

[0074] The thickness of the press-fit portion 30 is formed to be 0.75 mm or more and 0.85 mm or less. Preferably, the thickness of the press-fit portion 30 is 0.8 mm. Here, the thickness of 0.8 mm, as understood from the technical common sense of those skilled in the art, includes the thickness within the manufacturing tolerance range. The manufacturing tolerance is, for example, 0.8 mm ± 40 μm.

[0075] Thus, when the thickness of the press-fit portion 30 is 0.75 mm or more but less than 0.85 mm, the following considerations are taken into account: when forming a press-fit terminal with a shape suitable for a thinner press-fit portion or a similar shape, the insertion force into the through hole becomes excessive. This is because the increase in the thickness of the press-fit portion directly affects the increase in the insertion force. On the other hand, the substrate itself is not necessarily strengthened according to the increase in the thickness of the press-fit portion, or a substrate with excellent strength is used. Therefore, when the thickness of the press-fit portion 30 is 0.75 mm or more but less than 0.85 mm, it becomes more important to achieve a multi-dimensional balance between the insertion force, holding force, and contact area within a range that can suppress excessive damage to the substrate.

[0076] From this perspective, the size and shape of each part of the press-fit part 30 are configured as follows.

[0077] First, regarding the press-fit part 30, the front spring strength calculated under the following conditions is set as G1 [mm]. 3 Set the rear spring strength to G2 [mm]. 3 When ], then G1+G2 is greater than 0.030 and less than 0.080.

[0078] Furthermore, when the inclination of the front spring portion 35 relative to the insertion direction of the press-fit portion 30 is set to θ, G1tanθ is 0.0024 or more and 0.0070 or less.

[0079] [condition]

[0080] First, the front reference SF is set 0.1 mm backward from the front end of the observation hole 31. Figure 1 In the diagram, the front reference SF is represented by a straight line orthogonal to the front-rear direction. Similarly, the rear reference SR is set 0.1 mm forward from the rear end of the observation hole 31. Figure 1In the middle, the rear reference SR is represented by a straight line orthogonal to the front and rear directions.

[0081] Assume that the inner edge of the front spring portion 35 in the front reference SF is perpendicular to the outer edge 35a of the front spring portion 35. Here, the front reference surface TF perpendicular to the outer edge 35a of the front spring portion 35 refers to the front reference surface TF perpendicular to the observable outer edge 35a of the front spring portion 35 when the press-fit portion 30 is viewed along its thickness direction. Let the moment of inertia of the section of the front spring portion 35 in this front reference surface TF be I1 [mm]. 4 ].

[0082] Similarly, assuming a rear reference plane TR perpendicular to the outer edge 37a of the rear spring portion 37 in the rear reference SR, the moment of inertia of the section of the rear spring portion 37 in the rear reference plane TR is set as I2 [mm]. 4 ].

[0083] Furthermore, when viewing the press-fit portion 30 from the front view along its thickness direction, the straight line M1 is extended from the intersection of the front reference surface TF and the outer edge 35a of the front spring portion 35 in a direction perpendicular to the front reference surface TF. Additionally, the straight line M2 is extended along the outer edge 36a of the parallel portion 36. The length of the press-fit portion 30 in the insertion direction from the intersection point P1 of the straight lines M1 and M2 to the front end of the observation hole 31 is set to L1 [mm]. Similarly, when viewing the press-fit portion 30 from the front view, the straight line N1 is extended from the intersection of the rear reference surface TR and the outer edge 37a of the rear spring portion 37 in a direction perpendicular to the rear reference surface TR. The length of the press-fit portion 30 in the insertion direction from the intersection point P2 of the straight line N1 and the straight line N2 (M2) extended along the outer edge 36a of the parallel portion 36 to the rear end of the observation hole 31 is set to L2 [mm].

[0084] Furthermore, the front spring strength G1 is set to I1 / L1 [mm]. 3 The rear spring strength G2 is defined as I2 / L2 [mm]. 3 ].

[0085] [Regarding the moment of inertia of a cross section]

[0086] The moment of inertia of a cross section is a quantity that represents the ease with which a component can be deformed, corresponding to its cross-sectional shape. The moments of inertia of the cross sections in the aforementioned front reference plane TF and rear reference plane TR can be calculated, for example, as follows.

[0087] The cross-sectional shape of the front spring portion 35 in the front reference surface TF is, for example, as follows: Figure 5 The shape shown is the result of combining a rectangular first part A and a second part B, which is a portion of a circle cut by a straight line. Therefore, the moment of inertia of the cross section in the front reference plane TF can be considered to be the sum of the moment of inertia of the first part A and the moment of inertia of the second part B.

[0088] In this cross-sectional shape, when the thickness of the press-fit part 30 is set to t [mm], the radius of curvature of the outward part of the press-fit part 30 is set to r [mm], and the dimension from the inward part to the outward part from the observation hole 31 side is set to the spring thickness h [mm], the moment of inertia of the cross section in the front reference plane TF is calculated by the following formula.

[0089] [Mathematical Expression 1]

[0090]

[0091] Furthermore, in the above formula, Ia is the moment of inertia of the section of part A (part 1), and Ib is the moment of inertia of the section of part B (part 2). Additionally, Sa is the cross-sectional area of ​​part A (part 1), and Sb is the cross-sectional area of ​​part B (part 2). Further, ya is the position of the neutral axis of part A (part 1), yb is the position of the neutral axis of part B (part 2), and y is the position of the neutral axis of the entire assembly of part A (part 1) and part B (part 2).

[0092] The moment of inertia of the cross section in the rear reference plane TR can also be calculated in the same way as above.

[0093] The method for calculating the moment of inertia of the cross section described above is one example. The moment of inertia of the cross section can be calculated using a method based on the cross-sectional shape of the front spring part 35 in the front reference plane TF and the cross-sectional shape of the rear spring part 37 in the rear reference plane TR.

[0094] Based on the press-fit terminal 20 constructed in this way, since G1+G2 is 0.030 [mm] 3 Above and 0.080 [mm] 3 Furthermore, since G1tanθ is 0.0024 or more and 0.0070 or less, for press-fit terminals 20 with a thickness of 0.75 mm or more and 0.85 mm or less, the insertion force, holding force and contact area can be balanced in multiple dimensions.

[0095] When such a press-fit terminal 20 is provided at a location where vibration is applied, it can be appropriately used in situations where it is desired to securely hold the press-fit terminal 20 to the substrate 12 at a power supply location.

[0096] In the aforementioned press-fit terminal 20, G1+G2 can also be 0.030 [mm]. 3 Above and 0.060 [mm] 3 For the following, G1tanθ is 0.0028 or more and 0.0060 or less. Therefore, for press-fit terminals 20 with a thickness of 0.75 mm or more and 0.85 mm or less, the insertion force, holding force, and contact area can be further balanced in multiple dimensions.

[0097] Furthermore, the outer edge 35a of the front spring portion 35 is inclined inward in the width direction of the press-fit portion 30 as it moves forward, and the outer edge 37a of the rear spring portion 37 is inclined inward in the width direction of the press-fit portion 30 as it moves rearward. Therefore, when the press-fit terminal 20 is pressed into the through hole 13, the press-fit portion 30 can be easily deformed due to the presence of the front spring portion 35 and the rear spring portion 37, which have outer edges 35a and 37a inclined relative to the parallel portion 36.

[0098] In addition, since the outward portion of the parallel portion 36 is formed on the arc-shaped surface 36f, the parallel portion 36 can easily contact the inner peripheral surface of the through hole 13 with a larger surface area, thus making the contact area larger.

[0099] In particular, when the radius of curvature r of the arc surface 36f is the same as or smaller than the radius of the through hole 13, the central part of the arc surface 36f can easily have a larger contact area with the inner circumferential surface of the through hole 13, thus enabling a larger contact area.

[0100] Figure 6 This diagram illustrates a connector assembly 50 in which the aforementioned press-fit terminal 20 is press-fitted into the substrate 12. The connector assembly 50 includes the substrate 12 and a connector 60. The connector 60 includes the aforementioned press-fit terminal 20. Figure 6 In this connector 60, a connector terminal portion 54 is integrally connected to the base end 26 of the press-fit terminal 20. The connector terminal portion 54 is connected to the base end 26 in a bent state (here, a vertically bent state). The connector terminal portion 54 can also be connected to the base end 26 in a straight line. The base end of the press-fit terminal 20 and the connector terminal portion 54 are inserted into the connector housing 61 of the connector 60. The base end can also protrude from the connector housing 61. The connector terminal portion 54 is arranged to protrude from the bottom of the space inside the connector housing 61 toward the opening. Here, a plurality of press-fit terminals 20 are installed in the connector housing 61. Therefore, a plurality of connector terminal portions 54 are arranged vertically at intervals inside the connector housing 61. In addition, a plurality of press-fit terminals 20 protrude from the outer surface of the connector housing 61. Furthermore, the plurality of press-fit terminals 20 protruding from the outer surface of the connector housing 61 are simultaneously pressed into a plurality of through holes 13. With the plurality of press-fit terminals 20 pressed into the plurality of through holes 13, the connector 60 is mounted and fixed to the substrate 12. The object on which the connector 60 is mounted and fixed to the substrate 12 can also be referred to as the substrate 10 with connector.

[0101] The housing 52 is box-shaped, having a space for receiving the substrate 12. An opening 53 is formed in the housing 52, exposing the connector housing 61 to the outside. With the connector housing 61 disposed within the opening 53, the substrate 12 is fixed within the housing 52. The substrate 12 within the housing 52 can be fixed using screw fastening structures, embedding structures, or a combination thereof.

[0102] In the connector device 50 described above, the press-fit portion 30, with a thickness of 0.75 mm or more and 0.85 mm or less, can be inserted into the through hole 13 without excessive insertion force, thus suppressing damage to the substrate 12. Furthermore, after insertion, the holding force and contact area are also good, thus enabling the formation of a connector device in which the press-fit portion 30 is firmly held on the substrate 12, and the electrical connection reliability between the press-fit terminal 20 and the substrate 12 is also good.

[0103] Furthermore, when the radius of curvature r of the outward portion of the parallel portion 36 is the same as the inner circumferential radius of the through hole 13, the contact area between the press-fit portion 30 and the inner circumferential surface of the through hole 13 increases.

[0104] [Example]

[0105] In this embodiment, examples A1-A4, B1-B5, C1-C5, and D1-D4, which involve varying G(G1+G2) and G1tanθ based on the press-fit terminal 20 described in the above embodiments, are used to illustrate the evaluation of insertion force, holding force, and contact area. The evaluation is derived through CAE (Computer Aided Engineering) analysis using the finite element method.

[0106] For examples A1-A4, G(G1+G2) is 0.077; for examples B1-B5, G(G1+G2) is 0.052; for examples C1-C5, G(G1+G2) is 0.033; and for examples D1-D4, G(G1+G2) is 0.027. The value of G1tanθ changes within each group of examples A1-A4, B1-B5, C1-C5, and D1-D4. Furthermore, the thickness of the press-fit terminal 20 is 0.8 mm, and the diameter φ of the through hole 13 is 1.45 mm.

[0107] Figure 7 and Figure 8 The evaluation results are shown in the figure. As can be seen from the figure, in examples A1, B1, B2, B3, B4, C2, C3, C4, and C5, where G(G1+G2) is ≥0.030 and ≤0.080, and G1tanθ is ≥0.0024 and ≤0.0070, a multidimensional balance can be achieved between the insertion force, holding force, and contact area. For example, it can be achieved that the insertion force is ≤104.8N, the holding force is ≥42.4N, and the contact area is 1.01mm². 2 .

[0108] Furthermore, it is known that in examples B1, B2, B3, C3, C4, and C5, where G(G1+G2) is 0.030 or higher and 0.060 or lower, and G1tanθ is 0.0028 or higher and 0.0060 or lower, the insertion force, holding force, and contact area can be further balanced in multiple dimensions. For example, it is known that an insertion force of 100.1 N or lower, a holding force of 43.4 N or higher, and a contact area of ​​1.01 mm² can be achieved. 2 .

[0109] Furthermore, the structures described in the above embodiments and variations can be appropriately combined as long as they do not contradict each other.

[0110] Explanation of reference numerals in the attached figures

[0111] 10 substrates with connectors

[0112] 12 substrate

[0113] 13 Through holes

[0114] 13f conductive layer

[0115] 20 Press-fit terminals

[0116] 22. Top part

[0117] 26. Base end

[0118] 30 Press-fit part

[0119] 31 Observation Hole

[0120] 34 contact pads

[0121] 35 Front Spring Section

[0122] 35a Outer edge

[0123] 36 Parallel Department

[0124] 36a Outer edge

[0125] 36f, 136f curved surfaces

[0126] 37 Rear Spring Section

[0127] 37a Outer edge

[0128] 50 Connector Assembly

[0129] 52. Outer shell

[0130] 53 Opening

[0131] 54 Connector Terminal Section

[0132] 60 connector

[0133] 61 Connector Housing

[0134] Part 1

[0135] Part B

[0136] TF front reference plane

[0137] TR Back Reference Surface

Claims

1. A press-fit terminal, press-fitted into a through-hole formed in a substrate, The press-fit terminal has a press-fit portion, which includes two contact pieces facing each other across an observation hole. Each of the two contact pieces includes: Parallel portions that are parallel to each other; a front spring portion that extends from the parallel portions in the direction of insertion into the press-fit portion; And the rear spring portion extends from the parallel portion in a direction opposite to the direction in which the press-fit portion is inserted. The thickness of the press-fit part is 0.75 mm or more and 0.85 mm or less. Regarding the press fit portion, when a front side spring strength calculated under the condition described below is set as G1 [mm 3 ] and a rear side spring strength is set as G2 [mm 3 ], then G1 + G2 is 0.030 or more and 0.080 or less, Furthermore, when the inclination of the front spring portion relative to the insertion direction of the press-fit portion is set as θ, then G1tanθ is 0.0024 or more and 0.0070 or less. The conditions are as follows: • Set the insertion direction of the press-fit terminal to forward, and set the opposite direction to the insertion direction to backward; • The position 0.1 mm backward from the front end of the observation hole is set as the front reference, and the position 0.1 mm forward from the rear end of the observation hole is set as the rear reference; • assuming a front reference plane perpendicular to an outer edge of the front spring portion from an inner edge of the front spring portion in the front reference, the moment of inertia of the cross section of the front spring portion in this front reference plane is set to Ii [mm 4 ]; • Assuming a rear reference plane perpendicular to the outer edge of the rear spring portion from the inner edge of the rear reference portion, the moment of inertia of the section of the rear spring portion in this rear reference plane is set as I² [mm]. 4 ]; • The length of the insertion direction of the press-fit portion from the intersection of the point where the front reference surface and the outer edge of the front spring portion intersect in a direction perpendicular to the front reference surface and the point where the intersection of the point where the intersection of the line and the line extending along the outer edge of the parallel portion intersects to the front end of the observation hole is defined as L1 [mm]. • The length of the insertion direction of the press-fit portion from the intersection of the point where the rear reference surface and the outer edge of the rear spring portion intersect in a direction perpendicular to the rear reference surface and the intersection of the point where the line intersects with the point where the line intersects with the outer edge of the parallel portion to the rear end of the observation hole is defined as L2 [mm]. • Set the front spring strength G1 to I1 / L1 [mm] 3 The strength G2 of the rear spring is set to I2 / L2 [mm]. 3 ].

2. The press-fit terminal according to claim 1, wherein, G1+G2 is greater than 0.030 and less than 0.

060. G1tanθ is greater than 0.0028 and less than 0.0060.

3. The press-fit terminal according to claim 1, wherein, The thickness of the press-fit part is 0.8 mm.

4. The press-fit terminal according to claim 1, wherein, The outer edge of the front spring portion is inclined inward toward the width direction of the press-fit portion as it moves forward. The outer edge of the rear spring portion is inclined inward toward the width direction of the press-fit portion as it moves toward the rear.

5. The press-fit terminal according to any one of claims 1 to 4, wherein, The outward portion of the parallel section forms an arc shape when viewed along the insertion direction.

6. A connector device comprising: Connector, including the press-fit terminal as described in claim 5; and The substrate has through holes. The press-fit portion of the press-fit terminal is pressed into the through hole. Viewed along the insertion direction, the radius of curvature of the outward portion of the parallel section is the same as or smaller than the inner circumferential radius of the through hole.

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