JP7163891B2 - electronic device - Google Patents

Description

The present invention relates to electronic devices.

Conventionally, a press-fit terminal is press-fitted into a through-hole formed in a printed circuit board, and the press-fit terminal and the through-hole are electrically connected by contacting the wall surface of the through-hole ( For example, see Patent Document 1).

JP 2018-133156 A

In a structure in which the press-fit terminal contacts the wall surface of the through hole, if the contact pressure of the press-fit terminal against the wall surface of the through hole becomes excessive, cracks may occur on the wall surface of the through hole, and whitening may occur. If the whitening phenomenon occurs, migration may occur when a voltage is applied in a humid environment, and insulation reliability may decrease. Conversely, if the contact pressure of the press-fit terminal against the wall surface of the through-hole becomes too small, there is concern that the mechanical connection strength between the press-fit terminal and the through-hole will decrease. Under these circumstances, there is a demand for a structure that ensures electrical connection between the press-fit terminal and the through-hole while maintaining insulation reliability and also ensures mechanical connection strength between the press-fit terminal and the through-hole. there is

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to ensure electrical connection between the press-fit terminal and the through-hole while maintaining insulation reliability, and to provide a mechanical connection between the press-fit terminal and the through-hole. It is an object of the present invention to provide an electronic device capable of appropriately reconciling the securing of sufficient connection strength.

According to the first aspect of the invention, the press-fit terminals (3, 21, 31, 41, 51, 63, 83) are press-fitted into the through-holes (4, 64, 84) formed in the printed circuit board. The press-fit terminal has a flat plate surface (9, 69, 89), a plate thickness surface (10, 70, 90) connected to the flat plate surface, and convex portions (11, 22, 32, 33, 71, 91) projecting from the flat plate surface. ) and The through-hole has a conducting part (7, 67, 87) with a metal film on the wall surface and a fixed part (8, 68, 88) with no metal film on the wall surface. In a state in which the press-fit terminal is press-fitted into the through-hole, the convex portion contacts the conducting portion and the plate thickness surface is fixed to the fixing portion.

In a state where the press-fit terminal is press-fitted into the through-hole, the conductive portion where the convex portion contacts the conductive portion and the fixed portion where the plate thickness surface is fixed to the fixed portion are separated. By appropriately suppressing the contact pressure of the press-fit terminal against the wall surface of the through-hole, it is possible to eliminate concerns about the occurrence of whitening. connection can be secured. Since there is no need for a conductive connection between the press-fit terminal and the through-hole at the fixed location, even if a crack occurs on the wall surface of the through-hole, there is no need to consider the occurrence of migration under a humid environment. As a result, it is possible to appropriately ensure both electrical connection between the press-fit terminal and the through-hole and mechanical connection strength between the press-fit terminal and the through-hole while maintaining insulation reliability.

FIG. 2 is a perspective view of a press-fit terminal and a printed circuit board showing the first embodiment; Top view of printed circuit board Perspective view of convex part The top view which shows the state by which the press-fit terminal was press-fitted by the through-hole. The perspective view of the convex part which shows 2nd Embodiment A perspective view of a convex portion showing a third embodiment The top view which shows the state by which the press-fit terminal was press-fitted by the through-hole. The front view of the press-fit terminal which shows 4th Embodiment The front view of the press-fit terminal which shows 5th Embodiment A perspective view of a press-fit terminal and a printed circuit board showing a sixth embodiment. The top view which shows the state by which the press-fit terminal was press-fitted by the through-hole. A perspective view of a press-fit terminal and a printed circuit board showing a seventh embodiment. The top view which shows the state by which the press-fit terminal was press-fitted by the through-hole.

Several embodiments of an electronic device are described below with reference to the drawings. In each embodiment shown below, the same reference numerals are given to parts corresponding to the contents described in the preceding embodiments, and redundant description may be omitted.

(First embodiment)
A first embodiment will be described with reference to FIGS. 1 to 4. FIG. As shown in FIG. 1 , the electronic device 1 includes a printed circuit board 2 and press-fit terminals 3 . A through hole 4 is formed in the printed circuit board 1 . The through hole 4 has an elongated opening surface 5 . The lengthwise dimension of the opening surface 5 (indicated by A1 in FIG. 1) is slightly longer than the widthwise dimension (indicated by B1 in FIG. 1) of the press-fit terminal 3 on the tip side thereof, and the rear end of the press-fit terminal 3 The dimension in the direction perpendicular to the longitudinal direction of the opening 5 (indicated by A2 in FIG. 1) is slightly shorter than the dimension in the width direction (indicated by B2 in FIG. 1) of the press-fit terminal. 3 (indicated by B3 in FIG. 1).

Through hole 4 is formed in a manner in which a plurality of holes are connected. A central wall surface 4a of the through-hole 4 is roughened by drilling, for example. A wall surface 4b on the end side of the through hole 4 is formed smoothly with relatively high dimensional accuracy by forming the hole by router processing, for example.

As shown in FIG. 2, the wall surface 4a on the central side of the through hole 4 is recessed, and the metal film 6 is attached to the recessed wall surface 4a. The wall surface of the through hole 4 has a central wall surface 4a to which the metal film 6 is adhered, which serves as a conductive portion 7, and both end wall surfaces 4b to which the metal film 6 is not adhered, which serve as fixed portions 8. The metal film 6 is, for example, a plating film, and since the wall surface 4a is roughened by drilling as described above, the plating seed layer easily adheres to the wall surface 4a, thereby facilitating the formation of the metal film 6. .

The press-fit terminal 3 has a rectangular shape as a whole, and includes a flat plate surface 9, a plate thickness surface 10 connected to the flat plate surface 9, and a convex portion 11 projecting from the flat plate surface 9 in a direction perpendicular to the surface direction. The plate thickness surface 10 is formed by shearing when the press-fit terminal 3 is formed from a strip or the like by press working. The press-fit terminal 3 is easily press-fitted into the through hole 4 because the dimension in the width direction of the tip side is shorter than the dimension in the longitudinal direction of the through hole 4 .

As shown in FIG. 3, the flat plate surface 9 is formed with holes 12a and 12b extending in the press-fitting direction. A convex portion 11 having a smooth curved surface is formed. That is, the convex portion 11 has a curved central portion 11a, and both the terminal front end side 11b and the terminal rear end side 11c are connected to the flat plate surface 9. As shown in FIG.

The height of the convex portion 11, that is, the dimension of the portion of the convex portion 11 that protrudes from the flat plate surface 9 (indicated by H1 in FIG. 3) is determined when the press-fit terminal 3 is press-fitted into the through-hole 4 as will be described later. The contact portions 13 and 14 of the central portion 11a are of such dimensions that they come into contact with the conductive portion 7. As shown in FIG. Further, the contact portions 13 and 14 are subjected to a coining process, and have a smooth curved shape instead of an acute-angled shape. In the present embodiment, a structure in which the convex portion 11 having a smooth curved surface in the press-fitting direction is formed has been described. It may be configured to be In that case, the convex portion 11 may be embossed. Further, although the configuration has been described in which the two contact portions 13 and 14 of the central portion 11a are in contact with the conductive portion 7 when the press-fit terminal 3 is press-fitted into the through hole 4, only one contact portion of the central portion 11a is provided. A configuration in which contact is made with the conductive portion 7 is also acceptable. That is, the manner in which the contact portion of the central portion 11 a of the convex portion 11 contacts the conductive portion 7 depends on the design of the convex portion 11 .

In the configuration described above, the press-fit terminal 3 is attached to the printed circuit board 2 by press-fitting the press-fit terminal 3 into the through hole 4 . When the press-fit terminal 3 is press-fitted into the through-hole 4, as shown in FIG. is fixed to the fixing portion 8 of the through-hole 4 . At this time, the convex portion 11 of the press-fit terminal 3 comes into contact with the conductive portion 7 of the through-hole 4 , thereby ensuring electrical connection between the press-fit terminal 3 and the through-hole 4 . The mechanical connection strength between the press-fit terminal 3 and the through hole 4 can be ensured by fixing the terminal 10 to the fixing portion 8 of the through hole 4 . Further, since the contact portions 13 and 14 of the convex portion 11 are subjected to coining treatment, the press-fit terminal 3 can be smoothly press-fitted, and the contact portions 13 and 14 and the conductive portion 7 are brought into surface contact with each other. , the conductive connection between the press-fit terminal 3 and the through hole 4 can be reliably secured.

According to the first embodiment, the following effects can be obtained. In the structure in which the press-fit terminal 3 is press-fitted into the through-hole 4 formed in the printed circuit board 2, the conductive portion where the convex portion 11 of the press-fit terminal 3 contacts the conductive portion 7 of the through-hole 4, and the plate thickness of the press-fit terminal 3 The surface 10 is configured to be separated from the fixing portion fixed to the fixing portion 8 of the through hole 4 . By moderately suppressing the contact pressure of the press-fit terminal 3 against the wall surface of the through-hole 4, the concern about whitening can be eliminated. 4 can be ensured. Since there is no need for conductive connection between the press-fit terminal 3 and the through-hole 4 at the fixed location, even if a crack occurs in the wall surface of the through-hole 4, migration under a humid environment does not have to be considered. good. As a result, it is possible to appropriately ensure both the electrical connection between the press-fit terminal 3 and the through hole 4 and the mechanical connection strength between the press-fit terminal 3 and the through hole 4 while maintaining insulation reliability. can.

The convex portion 11 has a curved surface in the press-fitting direction, and the curved surface is brought into contact with the conducting portion 7. - 特許庁The contact stress between the convex portion 11 and the conductive portion 7 can be dispersed by bringing the curved surface of the convex portion 11 into contact with the conductive portion 7, thereby further suppressing the whitening phenomenon.

The convex portion 11 is arranged to continue to the flat plate surface 9 in the press-fitting direction. By connecting the convex portion 11 to the flat plate surface 9 in the press-fitting direction, an increase in stress due to contact between the convex portion 11 and the conductive portion 7 can be dispersed, and the whitening phenomenon can be further suppressed.

The opening surface 5 of the through-hole 4 has an elongated hole shape, the projection 11 contacts the conductive portion 7 at the central side of the opening surface 5 in the longitudinal direction, and the plate thickness surface 10 is formed at both ends of the opening surface 5 in the longitudinal direction. It was fixed to the fixing part 8. - 特許庁Since the opening surface 5 of the through hole 4 is elongated, it is possible to secure a certain distance between the conductive portion and the fixed portion, thereby reducing the stress generated in the conductive portion and improving the insulation reliability. can enhance sexuality.

The conducting part 7 and the fixing part 8 are provided in separate holes. By forming a hole that will become the conductive portion 7 by, for example, drilling, it is possible to facilitate attachment of a plating seed, for example, that will become the metal film 6 . Further, by forming the hole that becomes the fixing portion 8 by, for example, router processing, it is possible to obtain a smooth wall surface with relatively high dimensional accuracy and suppress the generation of an excessive press-fitting load.

(Second embodiment)
A second embodiment will be described with reference to FIG. The second embodiment differs from the above-described first embodiment in the manner of connection between the convex portion and the flat portion of the press-fit terminal. As shown in FIG. 5, in the press-fit terminal 21, the convex portion 22 has a central portion 22a formed into a curved surface, and the terminal front end side 22b continues to the flat plate surface 9, while the terminal rear end side 22c is not connected to the flat plate surface 9, and only the terminal tip end side 22b is connected to the flat plate surface 9 in a cantilever structure. The height of the convex portion 22, that is, the dimension of the portion of the convex portion 22 that protrudes from the flat plate surface 9 is also determined by the contact portions on the left and right sides of the center portion 22a when the press-fit terminal 21 is press-fitted into the through-hole 4, as will be described later. The dimensions are such that 23 and 24 are in contact with the conductive portion 7 . The contact portions 23 and 24 are also subjected to a coining process, and have a smooth curved shape instead of an acute-angled shape.

According to the second embodiment, the projection 22 has a cantilever structure in which only the terminal tip side 22b continues to the flat plate surface 9. As shown in FIG. The rigidity of the convex portion 22 can be reduced, the contact stress between the convex portion 22 and the conductive portion 7 can be further reduced, and the whitening phenomenon can be further suppressed.

(Third Embodiment)
3rd Embodiment is described with reference to FIG.6 and FIG.7. 3rd Embodiment differs in the number of the convex parts in a press-fit terminal with respect to 1st Embodiment mentioned above. As shown in FIG. 6, the press-fit terminal 31 has projections 32 and 33 projecting from the flat plate surface 9 in a direction orthogonal to the surface direction. Holes 34a to 34c are formed in the flat plate surface 9, and the protrusions 32 and 33 are pressed in the plane direction with respect to the press-fitting direction by pressing the portions between the holes 34a to 34c, for example, by press working. are arranged in a direction orthogonal to each other. The protrusions 32 and 33 have the same shape as the protrusion 11 described in the first embodiment.

According to the third embodiment, the two protrusions 32 and 33 are arranged in the direction orthogonal to the press-fitting direction in the planar direction. The structure is such that the press-fit terminal 31 and the conductive portion 7 are connected at multiple points. By ensuring that one contact is in contact with the conducting portion 7, the risk of poor conduction can be reduced.

(Fourth embodiment)
A fourth embodiment will be described with reference to FIG. 4th Embodiment differs in the shape of a press-fit terminal with respect to 1st Embodiment mentioned above. As shown in FIG. 8, the press-fit terminal 41 has holes 42a and 42b extending in the press-fit direction on the left and right sides of the position where the protrusion 11 is formed on the flat plate surface 9. As shown in FIG.

According to the fourth embodiment, since the holes 42a and 42b are formed, the stress when the press-fit terminal 41 is press-fitted into the through-hole 4 can be relieved, and the occurrence of excessive press-fit load can be suppressed. be able to.

(Fifth embodiment)
A fifth embodiment will be described with reference to FIG. 5th Embodiment also differs in the shape of a press-fit terminal with respect to 1st Embodiment mentioned above. As shown in FIG. 9, the press-fit terminal 51 has a slit 52 extending in the press-fit direction on the tip side of the position where the projection 11 is formed on the flat plate surface 9 .

According to the fifth embodiment, when the press-fit terminal 51 is press-fitted into the through-hole 4, the greatest stress is generated when contacting the upper end of the through-hole 4. It is possible to relax the stress at the time of contact and suppress the occurrence of an excessive press-fitting load.

(Sixth embodiment)
A sixth embodiment will be described with reference to FIGS. 10 and 11. FIG. 6th Embodiment differs in the shape of a convex part and a through-hole with respect to 1st Embodiment mentioned above. As shown in FIG. 10 , the electronic device 61 includes a printed circuit board 62 and press-fit terminals 63 . A through hole 64 is formed in the printed circuit board 61 . The through hole 64 has an elongated opening surface 65 . The longitudinal dimension of the opening surface 65 (indicated by A11 in FIG. 10) is slightly longer than the widthwise dimension of the tip side of the press-fit terminal 63 (indicated by B11 in FIG. 10). The dimension in the direction perpendicular to the longitudinal direction of the opening surface 65 (indicated by A12 in FIG. 10) is slightly shorter than the width direction dimension (indicated by B12 in FIG. 10) of the press-fit terminal. It is slightly longer than the thickness dimension of 63 (indicated by B13 in FIG. 10).

The through-hole 64 differs from the through-hole 4 described in the first embodiment in that the wall surface on the central side is not recessed, and the rest of the configuration is the same as the through-hole 4 . In other words, the walls of the through-hole 64 are such that the wall surface 64a on the central side to which the metal film 66 is adhered serves as a conducting portion 67, and the wall surfaces 64b on both end sides to which the metal film 66 is not adhered serve as fixing portions 68. .

The press-fit terminal 63 differs from the press-fit terminal 3 described in the first embodiment in the shape of the convex portion, and the rest of the configuration is the same as that of the press-fit terminal 3 . That is, the press-fit terminal 63 has a rectangular shape as a whole, and includes a flat plate surface 69, a plate thickness surface 70 connected to the flat plate surface 69, and a convex portion 71 projecting from the flat plate surface 69 in a direction perpendicular to the surface direction. The height of the convex portion 71, that is, the dimension of the portion of the convex portion 71 that protrudes from the flat plate surface 69, is determined so that the upper end portion 71a is in contact with the conducting portion 67 when the press-fit terminal 63 is press-fitted into the through-hole 64, as will be described later. The dimensions are such that they can come into contact with each other.

In the configuration described above, the press-fit terminal 63 is attached to the printed circuit board 62 by press-fitting the press-fit terminal 63 into the through hole 64 . When the press-fit terminal 63 is press-fitted into the through-hole 64, as shown in FIG. It is fixed to the fixing portion 68 of the through hole 64 . At this time, the convex portion 71 of the press-fit terminal 63 comes into contact with the conductive portion 67 of the through-hole 64, so that the electrical connection between the press-fit terminal 63 and the through-hole 64 can be secured, and the plate thickness surface of the press-fit terminal 63 By fixing 70 to fixing portion 68 of through hole 64, mechanical connection strength between press-fit terminal 63 and through hole 64 can be ensured.

According to the sixth embodiment, the same effects as those of the first embodiment can be obtained. It is possible to appropriately balance securing of mechanical connection strength with the through hole 64 .

(Seventh embodiment)
7th Embodiment is described with reference to FIG.12 and FIG.13. 7th Embodiment differs in the shape of a press-fit terminal and a through-hole with respect to 1st Embodiment mentioned above. As shown in FIG. 12 , the electronic device 81 includes a printed circuit board 82 and press-fit terminals 83 . A through hole 84 is formed in the printed circuit board 82 . The through hole 84 has a circular opening surface 85 . A wall surface 84 a to which a metal film 86 is attached serves as a conductive portion 87 , and a wall surface 84 b to which no metal film 86 is attached serves as a fixed portion 88 .

The press-fit terminal 83 has a bar shape as a whole, and includes a flat plate surface 89 , a plate thickness surface 90 connected to the flat plate surface 89 , and a convex portion 91 projecting from the flat plate surface 89 in a direction perpendicular to the surface direction. The height of the convex portion 91, that is, the dimension of the portion of the convex portion 91 that protrudes from the flat plate surface 89 is determined so that the upper end portion 91a is in contact with the conductive portion 87 when the press-fit terminal 83 is press-fitted into the through-hole 84 as will be described later. The dimensions are such that they can come into contact with each other.

In the configuration described above, the press-fit terminal 83 is attached to the printed circuit board 82 by press-fitting the press-fit terminal 83 into the through hole 84 . When the press-fit terminal 83 is press-fitted into the through-hole 84, as shown in FIG. It is fixed to the fixing portion 88 of the through hole 84 . At this time, the convex portion 91 of the press-fit terminal 83 comes into contact with the conductive portion 87 of the through-hole 84, so that the electrical connection between the press-fit terminal 83 and the through-hole 84 can be secured, and the plate thickness surface of the press-fit terminal 83 The mechanical connection strength between the press-fit terminal 83 and the through hole 84 can be ensured by fixing the 90 to the fixing portion 88 of the through hole 84 .

According to the seventh embodiment, it is possible to obtain the same effects as in the first embodiment. It is possible to appropriately balance securing of mechanical connection strength with the through hole 84 .

(Other embodiments)
Although the present disclosure has been described with reference to examples, it is understood that it is not limited to such examples or structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and configurations, as well as other combinations and configurations including single elements, more, or less, are within the scope and spirit of this disclosure.

In the drawings, 1, 61, 81 are electronic devices; 2, 62, 82 are printed circuit boards; 3, 21, 31, 41, 51, 63, 83 are press-fit terminals; , 86 are metal films, 7, 67, 87 are conductive parts, 8, 68, 88 are fixed parts, 9, 69, 89 are plate surfaces, 10, 70, 90 are plate thickness surfaces, 11, 22, 32, 33 , 71 and 91 are projections, 42a and 42b are holes, and 52 is a slit.

Claims (10)

In an electronic device in which press-fit terminals (3, 21, 31, 41, 51, 63, 83) are press-fitted into through-holes (4, 64, 84) formed in a printed circuit board,
The press-fit terminal includes flat plate surfaces (9, 69, 89), plate thickness surfaces (10, 70, 90) connected to the flat plate surfaces, and convex portions (11, 22, 32, 33, 71, 91) and
The through-hole has a conductive portion (7, 67, 87) with a metal film attached to the wall surface and a fixed portion (8, 68, 88) with no metal film attached to the wall surface,
1. An electronic device according to claim 1, wherein said convex portion is in contact with said conducting portion and said plate thickness surface is fixed to said fixing portion in a state in which said press-fit terminal is press-fitted into said through-hole. 2. The electronic device according to claim 1, wherein the convex portion has a curved surface in the press-fitting direction, and the curved surface contacts the conductive portion. 3. The electronic device according to claim 1, wherein the convex portion is continuous with the flat plate surface in the press-fitting direction. 4. The electronic device according to claim 3, wherein the convex portion has a cantilever structure in which the tip end side of the terminal continues to the flat plate surface. 5. The electronic device according to any one of claims 1 to 4, wherein a plurality of said protrusions are provided. 6. The electronic device according to claim 5, wherein the plurality of protrusions are provided side by side in a direction perpendicular to the press-fitting direction in the plane direction. The through hole has an elongated opening surface,
the convex portion is in contact with the conducting portion on the central side in the longitudinal direction of the opening surface;
The electronic device according to any one of claims 1 to 6, wherein the plate thickness surface is fixed to the fixing portion on both longitudinal end sides of the opening surface. The through hole is configured by connecting a plurality of holes,
The electronic device according to any one of claims 1 to 7, wherein the conducting portion and the fixing portion are provided in separate holes that are connected to each other. The electronic device according to any one of claims 1 to 8, wherein the press-fit terminal has a hole formed between the convex portion and the plate thickness surface on the flat plate surface. 10. The electronic device according to any one of claims 1 to 9, wherein the press-fit terminal has a slit formed between the convex portion and the tip of the terminal on the flat plate surface.

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