BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments are described below with reference to the drawings, wherein like numerals illustrate like parts.
FIGS. 1A and 1B show an exemplary embodiment of a printed board. FIG. 1A is a front elevation view. FIG. 1B is a right side elevation view of FIG. 1A.
FIGS. 2A and 2B show other views of the bus bar shown in FIG. 1A. FIG. 2A is a perspective view of the bus bar. FIG. 2B is a right side elevation view of FIG. 2A.
FIGS. 3A and 3B show a through-hole. FIG. 3A is an enlarged section view of a through-hole, illustrating a first step. FIG. 3B is a cross section view of the through-hole taken along line A-A in FIG. 3A.
FIGS. 4A and 4B show the through hole. FIG. 4A is an enlarged section view of the through-hole, illustrating a second step. FIG. 4B is a cross section view of the through-hole taken along lines B-B in FIG. 4A.
FIGS. 5A and 5B show the through hole. FIG. 5A is an enlarged section view of the through-hole, illustrating a third step. FIG. 5B is a cross section view of the through-hole taken along lines C-C in FIG. 5A.
FIGS. 6A and 6B show a through hole according to a second embodiment. FIG. 6A is an enlarged section view of a through-hole in a second embodiment, illustrating a second step. FIG. 6B is a cross section view of the through-hole taken along lines D-D in FIG. 6A.
FIGS. 7A and 7B show branched terminal portions according to a second embodiment. FIG. 7A is a front elevation view of an alteration of the branched terminal portions in the second embodiment, illustrating a first step. FIG. 7B is a front elevation view of the branched terminal portions, illustrating a second step.
FIGS. 8A and 8B show branched terminal portions according to a third embodiment. FIG. 8A is a front elevation view of the branched terminal portions in a third embodiment, illustrating a second step of bending the one of the branched terminal portions. FIG. 8B is a front elevation view of the branched terminal portions, illustrating a second step of bending the other of the branched terminal portions.
FIG. 9 is a front elevation view of a related-art printed board.
DETAILED DESCRIPTION OF EMBODIMENTS
Referring now to the drawings, exemplary embodiments of the present invention will be described below.
As shown in FIGS. 1A and 1B, an exemplary embodiment of a printed board 10 invention includes a printed board body 11 on which electronic parts 20 are mounted, and a bus bar 12 bonded, e.g., by soldering, to the printed board body 11 by a reflow process. A terminal 12a provided on the bus bar 12 is inserted into a through-hole 11a in the printed board body 11.
The printed board body 11, as shown in FIGS. 1A and 1B, can include an insulation board 11b and a conductor 11c printed on one side of the insulation board 11b. The electronic parts 20 are mounted on the printed conductor 11c.
The printed board body 11 includes through-holes 11a that extend through the insulation board 11b and the printed conductor 11c. As shown in FIG. 3A, lands are provided on the opposite sides of the printed board body 11 around the through-holes 11a.
The bus bar 12, as shown in FIGS. 2A and 2B, can be formed into an L-shaped configuration having a bent portion 12b at an end of the flat bus bar 12. The terminals 12a extend from an end of the bent portion 12b of the bus bar 12 to be opposed to the through-holes 11a. It will be appreciated that, instead of a bus bar with an L-shaped configuration, various other bus bar shapes can be used. Further, while the Figures generally show that the branched terminal portions 12c and 12d appear to be U-shaped, various other shapes can also be used. Additionally, the branched terminal portions 12c and 12d need not be the same length or width.
Each terminal 12a of the bus bar 12 has branched terminal portions 12c and 12d located at a position on the bus bar that is inserted into the through-hole 11a. The branched terminal portions 12c and 12d enter the through-hole 11a and protrude from the through-hole 11a. One of the branched terminal portions (i.e., 12c in FIG. 4B) can be clinched by a jig 30 and bent in a thickness direction of the bus bar 12 by the jig 30.
As shown in FIGS. 4A and 4B, the bar-like jig 30 can include a slant surface 30a on a distal end of the jig. The branched terminal portions 12c are bent in the thickness direction of the bus bar 12 when the slant surface 30a pushes the branched terminal portions 12c upward in the thickness direction of the bus bar 12.
When the bus bar 12 is bonded to the printed board body 11, a bonder H flows into the through-hole 11a to electrically connect the bus bar 12 on one side of the printed board body 11 to the printed conductor 11c on the other side of the printed board body 11.
Next, an exemplary method for producing a printed board of the present invention will be described below.
FIGS. 3A and 3B show a first step in a method for producing an embodiment of a printed board. In a bonding step, a bonder H is previously bonded on the periphery of each through-hole 11a in the printed board body 11. When the bus bar 12 is disposed on one side of the printed board body 11, the terminals 12a of the bus bar 12 are inserted into the through-holes 11a in the printed board body 11 so that distal ends of the terminals 12a protrude from the other side of the printed board body 11. As a result, the branched terminal portions 12c and 12d project from the other side of the printed board body 11 on which the printed conductor 11 is formed.
FIGS. 4A and 4B show a second step in a method for producing an embodiment of a printed board. The slant surface 30a on the distal end of the jig 30 contacts the branched terminal portions 12c that project from the printed conductor 11c. Subsequently, the jig 30 is pushed up so that the jig clinches the branched terminal portions 12c to bend them in the thickness direction of the printed board body 11. Consequently, the bus bar 12 is held on the printed board body 11.
FIGS. 5A and 5B show a third step in a method for producing an embodiment of a printed board. The printed board body 11 that holds the bus bar 12 is placed in a reflow furnace. The bonders H bonded around the through-holes 11a are melted under a high temperature atmosphere and flow into the through-holes 11a to interconnect the terminals 12a of the bus bar 12 and the printed conductor 11c on the printed board body 11.
According to the above construction, since it is possible to prevent the bus bar 12 from falling off from the printed board body 11 by bending the branched terminal portions 12c extending from the bus bar 12, it is possible to prevent the bus bar 12 from floating up from the printed board body 11 on account of a difference in thermal expansion between the bus bar 12 and the printed board body 11 in the reflow process. Accordingly, since the bus bar 12 and printed board body 11 are reliably interconnected by the bonders, it is possible to reduce the risk of failure in the connection between the bus bar 12 and the printed board body 11.
FIGS. 6A and 6B show a second embodiment of the printed board. The second embodiment differs from the first embodiment with respect to the fact that branched terminal portions 42c and 42d are bent away from each other in the thickness direction of the bus bar 12 and bonded to the printed board body 11.
The second embodiment differs from the first embodiment with respect to the second step in the method of producing the printed board. As shown in FIGS. 6A and 6B, a jig 50 has a triangular cross section at least at the distal end of the jig. The triangular cross-section has opposed slant surfaces 50a. The slant surfaces 50a of the jig 50 are inserted into a space between the branched terminal portions 42c and 42d, and the surfaces 50a clinch and bend the portions 42c and 42d while widening the portions 42c and 42d in a width direction.
According to the above construction, since the two branched terminal portions 42c and 42d are bent away from each other in the through-hole 11a, it is possible to stably hold the bus bar 12 on the printed board body 11 even if the printed board body 11 is inclined or an external load is applied to the bus bar 12.
FIGS. 7A and 7B show an alteration of the branched terminal portions 42c and 42d.
Each of two branched terminal portions 62c and 62d includes a recess 12e on the outer side and an outward curved portion 12f on the inner side that is adapted to conform to the slant surfaces 70a of a jig 70. As described above, the recesses 12e help the branched terminal portions 62c and 62d to become deformed upon bending the branched terminal portions 62c and 62d, while the curved portions 12f assist the jig 70 to enter a space between the branched terminal portions.
Since the other structures and operational effects in the second embodiment are similar to those of the first embodiment, like reference numerals are given to like elements, and explanations of those elements are omitted.
FIGS. 8A and 8B show a third exemplary embodiment of a printed board. The third exemplary embodiment differs from the first exemplary embodiment with respect to the fact that branched terminal portions 82c and 82d are bent away from each other in the thickness direction of the bus bar 12.
A second step in the third exemplary embodiment of a method for producing the printed board differs from the second step in the first exemplary embodiment. As shown in FIGS. 8A and 8B, the distal end of a jig 90 used in the third exemplary embodiment has a triangular cross section. The triangular cross section has opposed slant surfaces 90a.
One of the slant surfaces 90a on the distal end of the jig 90 contacts branched terminal portions 82c. The jig 90 is then pushed up so that the jig 90 clinches the branched terminal portions 82c to bend them in the thickness direction of the printed board body 11. Next, the other slant surface 90a of the jig 90 contacts branched terminal portions 82d. Then, the jig 90 is pushed up so that the jig 90 clinches the branched terminal portions 82d to bend them in the thickness direction of the printed board body 11.
According to the above construction, it is possible to stably hold the bus bar 12 on the printed board body 11 even if the printed board body 11 is inclined or an external load is applied to the bus bar 12.
Since the other structures and operational effects in the third exemplary embodiment are similar to those of the first exemplary embodiment, like reference numerals are given to like elements, and explanations of those elements are omitted.
While the invention has been described above in connection with exemplary embodiments, these embodiments should be viewed as illustrative and not limiting. Various changes, substitutes and/or improvements are possible within the spirit and scope of the invention.
Patent Application
20080080154
