Connectors, board assemblies

Abstract

To suppress deformation while suppressing an increase in the size of a housing in a connector having a box-like housing.SOLUTION: A connector mounted onto a front surface to a print substrate, comprises: a plurality of terminals; and a housing 4 holding the plurality of terminals. The housing 4 is constructed by an insulation synthetic resin containing a glass fiber. The housing 4 is formed in a box-like shape while having a bottom wall 41; an upper wall 42; a pair of side walls 43 and 44; a rear wall 45; and an open part 46 that is formed onto a front surface. A plurality of first lightening concave parts 6 is formed in an outer surface of the bottom wall 41, and a plurality of second lightening concave parts 51 to 57 is formed in the outer surface of the upper wall 42. The plurality of first lightening concave parts 6 extends in the front-rear direction of the housing 4, and the rear end parts thereof reach the rear wall 45, and the front end parts thereof do not reach the front surface. The front end parts 62 have a tapering-off taper shape.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a connector and a board assembly in which the connector is surface-mounted on a printed circuit board. [Background technology]

[0002] There is known a connector that includes a box-shaped housing that is open in one direction and terminals that are held in the housing. This housing is obtained by injection molding, in which molten resin is injected into a cavity of a mold, and deformations such as warping and sink marks can occur due to differences in shrinkage during injection molding and the high-temperature environment during soldering of the terminals.

[0003] As a technique for suppressing such deformation of the housing, Patent Document 1 describes forming a flange around the opening of the box-shaped housing and forming a stopper on the flange to suppress the running of molten resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-51028 A Summary of the Invention [Problem to be solved by the invention]

[0005] The technique disclosed in the above Patent Document 1 has a problem in that the size of the housing becomes large due to the formation of the flange and the tang.

[0006] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, an object of the present invention is to suppress deformation of a connector having a box-shaped housing while suppressing an increase in size of the housing. [Means for solving the problem]

[0007] The connector of the present invention comprises a plurality of terminals and a housing holding the plurality of terminals, the housing being made of an insulating synthetic resin containing reinforcing fibers, the housing being formed in a box shape having a bottom wall, a top wall, a pair of side walls, a rear wall, and an opening formed in a front surface, and a lightening recess is formed in an outer surface of at least one of the bottom wall, the top wall, and the pair of side walls, the lightening recess extending in the fore-and-aft direction of the housing, with its rear end reaching the rear wall and its front end not reaching the front surface, and the front end having a tapered shape.

[0008] The board assembly of the present invention includes the connector and a printed circuit board, the connector being surface-mounted on the printed circuit board. Effect of the Invention

[0009] According to the present invention, it is possible to suppress deformation while suppressing an increase in size of the housing. [Brief description of the drawings]

[0010] [Figure 1] 1 is an exploded view of a board assembly including a connector according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view of the substrate assembly of FIG. [Diagram 3] 2A and 2B are diagrams showing the housing of FIG. 1, in which (a) is a perspective view showing the front and top walls, and (b) is a perspective view showing the bottom and rear walls. [Figure 4] 10 is an explanatory diagram illustrating the difference between a housing in which a lightening recess is not formed and a housing of the present invention in which a lightening recess is formed. FIG. [Diagram 5] 4 is a bottom view showing a first modified example of the housing shown in FIG. 3. FIG. [Figure 6] 4 is a bottom view showing a second modified example of the housing shown in FIG. 3. FIG. [Figure 7] 4 is a bottom view showing a third modified example of the housing shown in FIG. 3. FIG. [Figure 8]3. FIG. 9 is a bottom view showing a fourth modified example of the housing shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A "connector" and a "board assembly" according to one embodiment of the present invention will be described with reference to FIGS.

[0012] A board assembly 10 shown in FIGS. 1 and 2 includes a printed board 1, a connector 2 surface-mounted on the printed board 1, and a pair of pegs 7.

[0013] The printed circuit board 1 is provided with a circuit pattern (not shown), pads 13 to which terminals 3 of the connector 2 are soldered, and peg pads 14 to which pegs 7 are soldered. The terminals 3 and pegs 7 are soldered by printing solder on the pads 13 and peg pads 14, and then passing the printed circuit board 1 through a reflow furnace with the terminals 3 and pegs 7 placed on the solder.

[0014] The pair of pegs 7 are made of metal, and are soldered to the peg pads 14 while being press-fitted and held in the housing 4 of the connector 2. The pegs 7 are for mechanically fixing the housing 4 to the printed circuit board 1, and are not electrically connected to the circuit of the printed circuit board 1.

[0015] The connector 2 includes a plurality of terminals 3 and a housing 4 that holds the plurality of terminals 3.

[0016] Each terminal 3 is a male terminal obtained by pressing a metal plate or the like. Each terminal 3 has a board connecting portion 31, a male tab 32, a bent portion 33, and a held portion 34. The board connecting portion 31 is one end of the terminal 3 and is a portion soldered to the pad 13. The male tab 32 is the other end of the terminal 3 and is a portion positioned within the housing 4 to fit into a female terminal of a mating connector. The bent portion 33 is an intermediate portion of the terminal 3 and is bent at a right angle. The held portion 34 is a portion between the male tab 32 and bent portion 33 of the terminal 3 and is a portion held by the housing 4.

[0017] The housing 4 is obtained by injection molding using a mold, and is made of insulating synthetic resin containing reinforcing fibers. In this example, the reinforcing fibers include glass fibers, but other fibers such as carbon fibers may also be included. The housing 4 is formed in a box shape with a bottom wall 41, an upper wall 42, a pair of side walls 43, 44, a rear wall 45, and an opening 46 formed in the front surface.

[0018] The bottom wall 41 is placed on the printed circuit board 1. The top wall 42 faces the bottom wall 41 in the thickness direction of the printed circuit board 1. The pair of side walls 43, 44 connect the bottom wall 41 and the top wall 42. Each side wall 43, 44 is provided with a peg holding portion 48 into which a peg 7 is pressed. The rear wall 45 connects the bottom wall 41 and the top wall 42, and also connects the pair of side walls 43, 44 to each other. A terminal press-in portion 49 into which the held portion 34 of the terminal 3 is press-fitted is formed through the rear wall 45. The number of terminal press-in portions 49 is the same as the number of terminals 3.

[0019] A mating connector (not shown) is inserted into the opening 46. The mating connector includes a housing that is inserted into the housing 4 from the opening 46 and engages with the housing 4, and a plurality of female terminals that engage with the terminals 3. A locking protrusion 47 is formed on the inner surface and front end of the upper wall 42 to lock onto the mating connector, thereby maintaining the mated state of the connectors.

[0020] In this specification, the side of connector 2 that is closer to the mating connector in the mating direction is referred to as the front, and the side that is farther from the mating connector in the mating direction is referred to as the rear. In addition, the side that is placed on printed circuit board 1 is referred to as the bottom, and the side that is farther from printed circuit board 1 is referred to as the top.

[0021] The housing 4 has a short side direction in the front-rear direction and a long side direction in the opposing direction of the pair of side walls 43, 44. The bottom wall 41 and the top wall 42 are rectangular in shape with the short side direction being the front-rear direction of the housing 4 and the long side direction being the opposing direction of the pair of side walls 43, 44. Two openings 46 are formed in the longitudinal direction of the housing 4. Two locking projections 47 as described above are also formed in the longitudinal direction of the housing 4. Each locking projection 47 is formed in the center of each opening 46.

[0022] Arrow G in Fig. 3 indicates the position of the gate (resin injection port into the mold cavity) during injection molding of the housing 4. As shown in Fig. 3, the outer surface of the side wall 44 of the housing 4 is the gate position. A gate mark is formed on the outer surface of the side wall 44. The molten resin injected from the gate into the mold cavity flows into the portion that forms the side wall 44 of the cavity, and from there flows into the portion that forms the top wall 42 and the portion that forms the bottom wall 41, and spreads in the front-to-rear direction while heading toward the side wall 43, and wraps around to the portion that forms the rear wall 45, as shown in Fig. 4.

[0023] In order to obtain a housing 4 with high dimensional accuracy in injection molding, it is important to adjust the flow direction and speed of the molten resin flowing through the mold cavity. In this example, in order to adjust these, a plurality of first lightening recesses 6 (corresponding to lightening recesses) are formed on the outer surface of the bottom wall 41, and a plurality of second lightening recesses 51-57 are formed on the outer surface of the top wall 42.

[0024] Each first hollow recess 6 is composed of an equal-width portion 61 extending in the front-rear direction (short-side direction) of the housing 4, and a tapered front end portion 62. That is, the shape is such that the front end of the rectangular equal-width portion 61 is joined to the triangular front end portion 62. The rear end portion of the equal-width portion 61 reaches the rear wall 45. The front end portion 62 does not reach the front surface of the housing 4. In this manner, each hollow recess 6 extends in a direction (short-side direction of the housing 4) perpendicular to the flow direction (longitudinal direction of the housing 4) of the molten resin flowing through the portion forming the bottom wall 41 of the mold cavity. Moreover, in the bottom wall 41, these multiple hollow recesses 6 are arranged in parallel.

[0025] The second recesses 51-57 are made up of a honeycomb-shaped (regular hexagonal) recess 51 and a partial honeycomb-shaped recess 52-57, which are regularly arranged at regular intervals. The second recesses 51-57 are formed to avoid the front end of the upper wall 42.

[0026] The reason why the first recess 6 and the second recesses 51-57 are formed to avoid the front end of the housing 4 is to ensure strength by ensuring the thickness around the front end of the housing 4, i.e., the opening 46. In addition, the first recess 6 changes the flow direction of the molten resin from the front-to-rear direction of the housing 4 to an oblique direction by the tapered shape of the front end 62.

[0027] By forming the above-mentioned first lightening recess 6 and second lightening recesses 51-57, the flow timing above and below the mold cavity is uniform, and a housing 4 with high dimensional accuracy can be obtained. In addition, by not having a constant flow direction, the orientation of the glass fibers becomes complex as shown in Fig. 4, the strength of the entire housing 4 becomes uniform, and warping and deformation when exposed to heat are suppressed. Therefore, a housing 4 with high dimensional accuracy can be obtained while suppressing an increase in size.

[0028] Furthermore, in the board assembly 10 in which the connector 2 is mounted on the printed circuit board 1, the front end 62 of the first recess 6 is positioned outside the edge of the printed circuit board 1. With this arrangement, air passes along the first recess 6 during the reflow process, and heat is stably supplied to the pads 13 of the printed circuit board 1. This prevents heat build-up and suppresses solder mounting defects.

[0029] Furthermore, by employing the above-described first hollowed recess 6, it is possible to reduce the size and simplify the mold for manufacturing the housing 4. That is, since the first hollowed recess 6 has a shape that extends in the opening and closing direction of the mold, the shape of the first hollowed recess 6 can be formed without using a slide core.

[0030] Although a slide core is necessary to form the second recesses 51-57, the second recesses 51-57 are superior in terms of dimensional stability to the first recesses 6. Therefore, in the housing 4 of this embodiment, the second recesses 51-57 are formed in the vicinity of the locking projection 47, which requires high dimensional accuracy.

[0031] Next, modified examples of the housing 4 described above will be described with reference to Figures 5 to 8. In the above embodiment, the first lightening recess 6 is formed to avoid the longitudinal center of the bottom wall 41, but in the first modified example shown in Figure 5, it is formed over the entire longitudinal area of ​​the bottom wall 41 (excluding the front end portion).

[0032] In the second to fourth modified examples shown in Figs. 6 to 8, first recesses 6, 6b to 6e having different lengths are combined. Each housing of the second to fourth modified examples can be formed by a dedicated mold that does not use a slide core, but can also be formed by a common mold that includes a slide core. In that case, this is possible by shifting the position of the slide core relative to the main mold in the opening and closing direction of the main mold. By adjusting the length and layout of the first recesses 6, 6b to 6e as in the second to fourth modified examples, the flow direction and flow speed of the molten resin flowing through the mold cavity can be adjusted.

[0033] In the above-described embodiment and modified example, the first hollowed-out recess is formed only in the bottom wall 41, but the present invention is not limited to this, and it is sufficient that the hollowed-out recess 6 is formed in at least one outer surface of the bottom wall 41, the upper wall 42, and the pair of side walls 43, 44.

[0034] The above-described embodiment merely shows a typical form of the present invention, and the present invention is not limited to this embodiment. In other words, the present invention can be embodied in various modifications without departing from the gist of the present invention. As long as the configuration of the present invention is still provided even with such modifications, it is of course included in the scope of the present invention. [Explanation of symbols]

[0035] 1 Printed circuit board 2 Connector 3 Terminal 4. Housing 6, 6b~6e First hollow recess (hollow recess) 10 Board assembly 41 Bottom wall 42 Upper Wall 43,44 side wall 45 Back wall 46 Opening 51~57 Second recess

Claims

1. The connector includes a plurality of terminals and a housing that holds the plurality of terminals, The housing is made of an insulating synthetic resin containing reinforced fibers, The housing is formed in a box shape having a bottom wall, a top wall, a pair of side walls, a rear wall, and an opening formed in a front surface, A recess is formed in an outer surface of at least one of the bottom wall, the top wall, and the pair of side walls. The recessed portion extends in the front-rear direction of the housing, with its rear end reaching the rear wall and its front end not reaching the front surface, and the front end is tapered. A connector characterized by:

2. A plurality of the recesses are formed on the outer surface of the bottom wall, and the recesses are arranged in parallel.

2. The connector according to claim 1 .

3. A locking projection for locking with a mating connector is formed on the inner surface of the upper wall, The recess is not formed on the outer surface of the upper wall, A plurality of second recesses are formed on the outer surface of the upper wall, The plurality of second recesses are constituted by a honeycomb-shaped recess and a partial honeycomb-shaped recess.

2. The connector according to claim 1 .

4. the upper wall has a rectangular shape with a short side direction corresponding to the front-rear direction of the housing and a long side direction corresponding to the opposing direction of the pair of side walls, The outer surface of one of the pair of side walls is used as a gate position during molding.

2. The connector according to claim 1 .

5. A connector according to any one of claims 1 to 4, and a printed circuit board, The connector is surface mounted on the printed circuit board. A substrate assembly comprising:

6. The front end of the recess is positioned outside the edge of the printed circuit board.

6. The substrate assembly according to claim 5.

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