Electric part soldered onto printed circuit board
09668347 ยท 2017-05-30
Assignee
Inventors
Cpc classification
H01R43/16
ELECTRICITY
Y10T29/49204
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H05K2201/10613
ELECTRICITY
H01R43/0256
ELECTRICITY
International classification
H05K1/11
ELECTRICITY
H01R43/16
ELECTRICITY
H05K3/30
ELECTRICITY
H01R12/72
ELECTRICITY
Abstract
The electric part to be soldered to a metal pad mounted on a printed circuit board, includes a first surface facing the metal pad, a second surface extending from the first surface in a direction away from the metal pad, and a third surface outwardly extending from the second surface, the second surface and the third surface defining a space in which solder is stored.
Claims
1. An electric part to be soldered to a metal pad formed at a surface of a printed circuit board, said electric part comprising: a first portion facing said metal pad; a second portion extending in a direction away from said metal pad; and a corner portion connecting said first portion and said second portion to each other, wherein the first portion includes: a single first surface facing said metal pad; a pair of second surfaces each extending from one of side edges of said first surface in a direction away from said metal pad; and a pair of third surfaces each outwardly extending from one of said second surfaces, wherein said first surface, said second surfaces, and said third surfaces are formed over said first portion to said second portion through said corner portion, wherein a direction in which each of said third surfaces extends is perpendicular to a direction in which said first portion connects to said corner portion, wherein said second surfaces and said third surfaces define a pair of spaces in each of which solder is stored, each of said spaces extending along one of said side edges of said first surface, and wherein said electric part further comprises a metal plate which is (i) plated at both said first surface and an outer surface of said first portion parallel to the first surface and (ii) not plated at an end surface perpendicular to both said first surface and said outer surface.
2. The electric part as set forth in claim 1, wherein each of said second surfaces inclines relative to said first surface.
3. The electric part as set forth in claim 1, wherein at least one of said first surface, said second surfaces, and said third surfaces is formed with a plurality of recesses.
4. An outer lead of a connector terminal to be soldered to a metal pad formed at a surface of a printed circuit board, said outer lead comprising: a first portion facing said metal pad; a second portion extending in a direction away from said metal pad; and a corner portion connecting said first portion and said second portion to each other, wherein the first portion includes: a single first surface facing said metal pad; a pair of second surfaces each extending from one of side edges of said first surface in a direction away from said metal pad; and a pair of third surfaces each outwardly extending from one of said second surfaces, wherein said first surface, said second surfaces, and said third surfaces are formed over said first portion to said second portion through said corner portion, wherein a direction in which each of said third surfaces extends is perpendicular to a direction in which said first portion connects to said corner portion, wherein said second surfaces and said third surfaces define a pair of spaces in each of which solder is stored, each of said spaces extending along one of said side edges of said first surface, and wherein said outer lead further comprises a metal plate which is (i) plated at both said first surface and an outer surface of said first portion parallel to the first surface and (ii) not plated at an end surface perpendicular to both said first surface and said outer surface.
5. The outer lead as set forth in claim 4, wherein each of said second surfaces inclines relative to said first surface.
6. The outer lead as set forth in claim 4, wherein at least one of said first surface, said second surfaces, and said third surfaces, is formed with a plurality of recesses.
7. An electric part through which a housing is fixed onto a printed circuit board, said electric part comprising: a first segment making contact with said housing; and a second segment soldered to said printed circuit board, wherein said second segment includes: a first portion facing said printed circuit board; a second portion extending in a direction away from said printed circuit board; and a corner portion connecting said first portion and said second portion to each other, wherein the first portion includes: a single first surface facing said printed circuit board; a pair of second surfaces each extending from one of side edges of said first surface in a direction away from said printed circuit board; and a pair of third surfaces each outwardly extending from one of said second surfaces, wherein said first surface, said second surfaces, and said third surfaces are formed over said first portion to said second portion through said corner portion, wherein a direction in which each of said third surfaces extends is perpendicular to a direction in which said first portion connects to said corner portion, wherein said second surfaces and said third surfaces define a pair of spaces in each of which solder is stored, each of said spaces extending along one of said side edges of said first surface, and wherein said outer lead further comprises a metal plate which is (i) plated at both said first surface and an outer surface of said first portion parallel to the first surface and (ii) not plated at an end surface perpendicular to both said first surface and said outer surface.
8. The electric part as set forth in claim 7, wherein each of said second surfaces inclines relative to said first surface.
9. The electric part as set forth in claim 7, wherein at least one of said first surface, said second surfaces, said third surfaces is formed with a plurality of recesses.
10. A method of fabricating an electric part to be soldered to a metal pad formed at a surface of a printed circuit board, the method comprising: punching a metal to make a base part having a predetermined contour; reducing a thickness of said base part at a margin thereof to thereby define a single first surface, a pair of second surfaces, and a pair of third surfaces in such a manner that said first surface faces said metal pad, each of said second surfaces extends from one of side edges of said first surface in a direction away from said metal pad, and each of said third surfaces outwardly extends from one of said second surfaces, said second surfaces and said third surfaces define a pair of spaces in each of which solder is stored, each of said spaces extending along one of said side edges of said first surface; and bending said base part to define a first portion facing said metal pad, a second portion extending away from said metal pad, and a corner portion connecting said first portion and said second portion to each other, said first surface, said second surfaces, and said third surfaces being formed over said first portion to said second portion through said corner portion, wherein a direction in which each of said third surfaces extends is perpendicular to a direction in which said first portion connects to said corner portion, and wherein said outer lead further comprises a metal plate which is (i) plated at both said first surface and an outer surface of said first portion parallel to the first surface and (ii) not plated at an end surface perpendicular to both said first surface and said outer surface.
11. The method as set forth in claim 10, further comprising cutting an extended portion of said base part formed by reducing the thickness of said base part, in a direction from a surface through which said electric part is soldered to said printed circuit board towards an opposite surface.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
(28) Preferred embodiments in accordance with the present invention will be explained hereinbelow with reference to drawings.
(29) As illustrated in
(30) The electric connector 10 includes a housing 20 into which another electric connector (not illustrated) is fit, a plurality of connector terminals 30 housed in a terminal space formed in the housing 20, and each electrically connecting another electric connector, and a fixing part 40 for fixing the housing 20 onto the printed circuit board P.
(31) The housing 20 is formed with an opening (not illustrated) through which another electric connector is fit into the housing 20, and thus, is in the form of a box being open at a front. The housing 20 is formed at opposite sides thereof with holders 21 for equipping the fixing part 40 therewith. The holder 21 defines a slot into which the fixing part 40 is inserted for fixing the fixing part 40 in the holder 21.
(32) The connector terminals 30 are aligned in a line relative to the housing 20. Each of the connector terminals 30 comprises a male terminal, and is soldered onto a metal pad P1 (see
(33) As illustrated in
(34) The pin section 31 is inserted into a female connector of another electric connector to thereby electrically connect with the electric connector. The main body 32 is housed in the terminal space formed in the housing 20. The main body 32 is formed with a pair of wedges 32a to be engaged with a wall 22 (see
(35) The wedges 32a are formed at opposite sides in a width-wise direction of the main body 32. Each of the wedges 32a has a tapered surface inclining in a direction in which the connector terminal 30 is inserted into the housing 20, and is engaged with a sidewall of the terminal space formed within the wall 22 in the housing 20. Each of the extended portions 32b has a rectangular cross-section, and projects in a direction perpendicular to a direction in which the connector terminal 30 is inserted into the housing 20.
(36) The outer lead 33 is in the form of a crank. The outer lead 33 is formed at a distal end thereof with a contact portion 34 through which the connector terminal 30 is soldered to the metal pad P1. Before being inserted into the housing 20, the connector terminal 30 is in the form of a line from the pin section 31 to the contact portion 34 through the main body 32 and the outer lead 33. After being inserted into the housing 20, a distal portion is first bent downwardly, and further bent horizontally to thereby define the crank-shaped outer lead 33.
(37) The fixing part 40 comprises a so-called hold-down to be supported by the holder 21 (see
(38) As illustrated in
(39) The main body 41 includes a plurality of wedges 41a to be engaged with the holder 21, and a pair of extended portions 41b through which a user pushes the fixing part 40 into the holder 21.
(40) The wedges 41a are formed at opposite sides of the main body 41 in a width-wise direction of the main body 41. Each of the wedges 41a has a tapered surface inclining in a direction in which the fixing part 40 is inserted into the holder 21, and is engaged with a groove (not illustrated) formed in the holder 21. Each of the extended portions 41b has a rectangular cross-section, and projects in a direction perpendicular to a direction in which the fixing part 40 is inserted into the holder 21.
(41) The leg 42 has a substantially L-shaped cross-section when viewed from a side, and is formed at a distal end thereof with a contact portion 43 through which the fixing part 40 is soldered onto the metal pad P2.
(42) The contact portion 34 of the outer lead 33 and the contact portion 43 of the leg 42 are explained hereinbelow with reference to
(43) The contact portion 34 includes a first surface 51 facing the metal pad P1, a second surface 52 circumferentially extending from the first surface 51 in a direction away from the metal pad P1, and a third surface 53 outwardly circumferentially extending from the second surface 52. The second surface 52 and the third surface 53 define a stepped portion 50. Furthermore, the second surface 52 and the third surface 53 define a space S1 together with the metal pad P1 in which solder is stored.
(44) The contact portion 43 includes a first surface 61 facing the metal pad P2, a second surface 62 circumferentially extending from the first surface 61 in a direction away from the metal pad P2, and a third surface 63 outwardly circumferentially extending from the second surface 62. The second surface 62 and the third surface 63 define a stepped portion 60. Furthermore, the second surface 62 and the third surface 63 define a space S2 together with the metal pad P2 in which solder is stored.
(45) The first surfaces 51 and 61 are designed to have an area which is as large as possible. The first surfaces 51 and 61 face the metal pads P1 and P2 in parallel when the electric connector 10 is mounted on the printed circuit board P.
(46) The second surfaces 52 and 62 incline relative to the metal pads P1 and P2. The third surfaces 53 and 63 extend from upper ends of the second surfaces 52 and 62 almost in parallel with the metal pads P1 and P2.
(47) A method of fabricating both the contact portion 34 of the connector terminal 30 and the contact portion 43 of the fixing part 40 is explained hereinbelow with reference to
(48) First, a metal sheet is punched into a predetermined shape from which each of the connector terminal 30 and the fixing part 40 is fabricated.
(49) Then, a square bar for fabricating the connector terminal 30 or a plate for fabricating the fixing part 40 is put on a die 81 having a flat surface, as illustrated in
(50) A punch 82 has a projection 82a corresponding in shape to the stepped portions 50 and 60 (see
(51) Then, the margin portion 70 is sandwiched between the die 81 and a stripper 83 having a projection 83a having the same shape as that of the stepped portion 71, as illustrated in
(52) In accordance with the above-mentioned steps, the contact portions 34 and 43 can be formed at the margin portion 70 thereof with the stepped portions 50 and 60. As illustrated in
(53) Furthermore, as illustrated in
(54) After forming the contact portion 34 or 43 at the margin portion 70, the square bar is bent into an L-shape to thereby define the outer lead 33, or the plate is bent into an L-shape to thereby define the leg 42.
(55) The contact portion 34 or 43 of the electric part (specifically, the connector terminal 30 and the fixing part 40) in the electric connector in accordance with the embodiment of the present invention is soldered onto the metal pad P1 or P2, as follows.
(56) As illustrated in
(57) Furthermore, since the connector terminal 30 is already plated, even if an end surface 54 of the contact portion 34 is not plated, the solder filling the space S1 therewith can have a height defined by the stepped portion 50, and thus, there is formed a fillet F having a trapezoidal cross-section obliquely extending from the third surface 53 to a surface of the metal pad P1 (see
(58) Thus, the contact portion 34 can increase an area through which the connector terminal 30 is soldered onto the metal pad P1, and form the fillet F between the connector terminal 30 and the metal pad P1, ensuring that a peel resistance of the connector terminal 30 against the metal pad P1 is increased, and reliability is enhanced in electrical connection between the connector terminal 30 and the metal pad P1.
(59) Since the fillets 105 are formed by cutting the notch 104 in the conventional terminal 100 illustrated in
(60) Furthermore, since the second surface 52 inclines relative to the first surface 51, it is possible for the connector terminal 30 to have an area through which the connector terminal 30 is soldered onto the metal pad P1, in comparison with a case in which the second surface 52 is designed to vertically stand relative to the first surface 51, ensuring a peel resistance of the connector terminal 30 against the metal pad P1 can be further enhanced.
(61) For instance, if the contact portion is defined at an outer surface thereof only by an inclining surface, a fillet will rise at an upper portion thereof to an upper portion of the inclining surface, resulting in that the fillet is quite thin at an upper portion thereof, and hence, solder wettability is quite deteriorated.
(62) The fillet F in the contact portion 34 is formed to obliquely extend from the third surface 53 to a surface of the metal pad P1, that is, the fillet F is in the form of a right-angled triangle. Accordingly, the fillet F can have a sufficient thickness even at an upper portion thereof.
(63) As explained so far, since the connector terminal 30 is designed to have the stepped portion 50 at the contact portion 34, the connector terminal 30 can be surely soldered onto the metal pad P1 formed at a surface of the printed circuit board P.
(64) As illustrated in
(65) Similarly to the connector terminal 30, the contact portion 43 is able to increase an area through which the fixing part 40 is soldered onto the metal pad P2, by an area of the second surface 62 in comparison with a contact portion not formed with the stepped portion 60.
(66) Furthermore, since the fixing part 40 is already plated, even if an end surface 64 of the contact portion 43 is not plated, the solder filling the space S2 therewith can have a height defined by the stepped portion 60, and thus, there is formed a fillet F having a trapezoidal cross-section obliquely extending from the third surface 53 to a surface of the metal pad P2 (see
(67) Thus, the contact portion 43 can increase an area through which the fixing part 40 is soldered onto the metal pad P2, and form the fillet F between the fixing part 40 and the metal pad P2, ensuring that a peel resistance of the fixing part 40 against the metal pad P2 is increased, and reliability is enhanced in electrical connection between the fixing part 40 and the metal pad P2.
(68) Furthermore, the contact portion 43 defined by the first to third surfaces 61 to 63 is formed from the leg 42 horizontally extending and facing the metal pad P2, to the main body 41 vertically extending relative to the metal pad P2, through a corner portion 44 connecting the leg 42 and the main body 41 to each other, and hence, the solder B covers therewith not only a horizontally extending surface of the leg 42, but also an arcuate surface of the corner portion 44 and a vertically extending surface of the main body 41. Thus, an area through which the fixing part 40 is soldered onto the metal pad P2 can be increased.
(69) As explained so far, since the fixing part 40 is designed to have the stepped portion 60 at the contact portion 43, the fixing part 40 can be surely soldered onto the metal pad P2 formed at a surface of the printed circuit board P.
(70) Hereinbelow is explained a case in which a connector terminal or a fixing part is first made of a non-plated metal, and then, they are plated with a metal.
(71) As illustrated in
(72) Since the end surface 54 is plated, the fillet F is able to have a height higher than the third surface 53. Thus, a peel resistance of the connector terminal 30X against the metal pad P1 can be increased by virtue of an increase in an area through which the connector terminal 30X is soldered onto the metal pad P1, caused by the end surface 54 of the contact portion 34, and further, by virtue of the fillet F having an increased height.
(73) Furthermore, as illustrated in
(74) As illustrated in
(75) Similarly to the connector terminal 30X, since the end surface 64 is plated, the fillet F is able to have a height higher than the third surface 63. Thus, a peel resistance of the fixing part 40X against the metal pad P2 can be increased by virtue of an increase in an area through which the fixing part 40X is soldered onto the metal pad P2, caused by the end surface 64 of the contact portion 43, and further, by virtue of the fillet F having an increased height.
(76) The applicant carried out an experiment to compare a peel resistance among the fixing part 40 fabricated of a plated metal, a fixing part 40Y fabricated of a plated metal, but not formed with the stepped portion 60, a fixing part 40Z first fabricated of a non-plated metal, and then, plated, and not formed with the stepped portion 60, and the above-mentioned fixing part 40X first fabricated of a non-plated metal, and then, plated, and formed with the stepped portion 60.
(77) As illustrated in
(78) It is understood in view of the result that the fixing part 40 having the contact portion 43 formed with the spaces S2 is able to effectively enhance the peel resistance relative to the fixing part 40Z. Furthermore, it is also understood that since the end surface 64 (see
(79) In the above-mentioned embodiment, the first to third surfaces 51 to 53 or 61 to 63 are all designed to be flat. As an alternative, the first, second and/or third surfaces may be formed with a plurality of recesses or grooves. This ensures that a total area through which the connector terminal 30 or the fixing part 40 is soldered onto the metal pad P1 or P2 can be increased.
INDUSTRIAL APPLICABILITY
(80) The electric part in accordance with the present invention, such as the connector terminal 30 and the fixing part 40, is suitable to an electric connector used broadly in fields such as an automobile industry, an electric/electronic device industry, and a machinery industry, as a communication device for an electric wire through which electric signals are transmitted.
(81) While the present invention has been described in connection with certain preferred embodiments, it is to be understood that the subject matter encompassed by way of the present invention is not to be limited to those specific embodiments. On the contrary, it is intended for the subject matter of the invention to include all alternatives, modifications and equivalents as can be included within the spirit and scope of the following claims.
(82) The entire disclosure of Japanese Patent Application No. 2013-195877 filed on Sep. 20, 2013 including specification, claims, drawings and summary is incorporated herein by reference in its entirety.