Patent Description:
<FIG> shows a connector <NUM> described in <CIT> (hereinafter referred to as Patent Literature <NUM>) as a conventional example of an electronic component of this type, and <FIG> is an enlarged illustration of its cross section. The connector <NUM> is structured with contacts <NUM> insert-molded on a housing (referred to as insulator in Patent Literature <NUM>) <NUM>. In <FIG>, <FIG> indicates a lead portion of the contact <NUM>, and 11b indicates a fitting portion of the contact <NUM>.

<FIG> shows a contact member <NUM> for insertion into a mold, where multiple contacts <NUM> are provided in a corm-like form across slits between a lead-side frame <NUM> and a fitting-side frame <NUM>.

<FIG> shows a state during mold pressing of an insert mold structure. In <FIG>, <NUM> indicates a middle die plate, <NUM> indicates a basement on which the middle die plate <NUM> is integrally provided protruding therefrom, and <NUM> indicates a pair of sliding die plates which can move on the basement <NUM> into contact with and away from the opposite side surfaces of the middle die plate <NUM>. Further, <NUM> indicates a movable die plate and <NUM> indicates a cavity.

The sliding die plates <NUM> are provided with first protrusions <NUM>, which are oriented to enter the slits in the fitting portions 11b of the contact member <NUM>, and second protrusions <NUM>, which are oriented to enter the slits in the lead portions 11a of the contact member <NUM>, as shown in <FIG>. The contact member <NUM> is positioned by the first protrusions <NUM> and the second protrusions <NUM>, and during mold pressing, the lead-side frame <NUM> and the fitting-side frame <NUM> are pressed and fixed by the movable die plate <NUM> and the sliding die plates <NUM>, respectively. In <FIG>, contact members <NUM> are indicated by bold lines.

After injecting resin into a cavity <NUM> and molding it, the mold is opened to remove the connector, and the lead portions 11a and the fitting portions 11b are cut into a certain length and snapped off, thus yielding the connector <NUM> shown in <FIG>.

<CIT> discloses an electrical plug connector that includes a plug insulated housing which is integrally formed and plug terminals. A transition segment connected between first and second contact portions of each plug terminal allows the first contact portion to be in contact with and arranged substantially parallel to the second contact portion, so that connectors with reduced width can be manufactured. In addition, the shaping space between a first recessed portion and a second recessed portion of each plug terminal receive materials for forming the plug insulated housing, thus improving the structural strength of the connector. Moreover, embedded ends allow the plug terminals to be secured with the plug bottom wall, so that the plug terminals would not detach from the plug insulated housing easily during manufacturing or operation. The structural strength of the electrical plug connector can be improved, and the plug terminals can be properly assembled with the plug insulated housing.

<CIT> discloses a cantilever spring that is positioned in a slit in a shell, and has a free end and a fixed end fixed to the shell. The cantilever spring extends in a height direction of the shell. The fixed end of the cantilever spring is positioned near a part that is attachable to a board, and the free end of the cantilever spring is apart from that part.

For an electronic component having terminals insert-molded on the housing, like the connector <NUM> mentioned above, the terminals need to be positioned at the time of molding so that the terminals are at predetermined positions. According to Patent Literature <NUM>, the sliding die plates <NUM> are provided with the first protrusions <NUM> and the second protrusions <NUM>, such that the contacts <NUM> are inserted into the grooves between the protrusions to be positioned.

However, in the case of thus inserting and positioning the terminals by providing grooves in the mold, setting a too narrow clearance (gap) between a terminal and a groove in the groove width direction degrades the insertability of the terminals into the grooves, which can cause the mold and the terminals to interfere with each other to damage the terminals, for example. Accordingly, the clearances between a terminal and a groove need to be large to a certain degree, in which case there can be a situation such as resin leaking from the clearances between the terminals and the grooves during molding.

The leaked resin creates resin burrs, which will be present over a portion of a terminal that protrudes from the housing. Thus, if the portion of the terminal that protrudes from the housing is a point of soldering to a land on a substrate, for example, soldering quality or strength could become insufficient due to the presence of the resin burrs. If the portion of the terminal that protrudes from the housing is a point of contact with a terminal of a mating electronic component, for example, contact quality could be compromised due to the presence of the resin burrs or the resin burrs could be scratched off at the time of contact to create chips.

In view of these circumstances, an object of the present invention is to provide a method of manufacturing an electronic component that can reduce formation of resin burrs, which adversely affect quality, and further an electronic component to which such a method of manufacture is applicable.

The present invention provides a method of manufacturing an electronic component, having the features of independent claim <NUM>. A preferred embodiment is described in dependent claim <NUM>.

According to the invention, a method of manufacturing an electronic component having a housing with terminals insert-molded thereon is provided, in which each of the terminals includes a tapered portion having a tapered width and an extension portion extending from a narrow-side distal end of the tapered portion, and a mold defining a cavity for molding the housing includes a first die and second dies. The method includes: after positioning the extension portion in one of grooves formed in one surface of each of the second dies, sliding the second dies relative to the extension portion to make tip edges of opposite side surfaces of the groove facing the cavity abut against opposite side surfaces that form tapering of the tapered portion; and performing molding while keeping the first die in close contact with the one surface of each of the second dies, and keeping part of the tapered portion and the extension portion lying in the groove held between a bottom surface of the groove and the first die with a remaining portion of the tapered portion lying in the cavity, thus forming a connection portion protruding from the housing with the part of the tapered portion and the extension portion.

According to the method of manufacturing an electronic component according to an embodiment of the present invention, resin leakage during insert molding of terminals on a housing can be prevented, and hence issues such as resin burrs forming at the connection portions of the terminals protruding from the housing due to resin leakage can be eliminated.

Moreover, since the electronic component according to an embodiment of the present invention has a configuration to which the method of manufacturing an electronic component according to an embodiment of the present invention is applicable, electronic components with no resin burrs at the connection portions of the terminals protruding from the housing can be yielded.

Embodiments and examples of the present invention will now be described with reference to the drawings in comparison with conventional structures.

<FIG> and <FIG> each show a general structure of a connector as an example of the electronic component to which the present embodiment is applicable. <FIG> shows a connector <NUM> according to an example that is useful for understanding the present invention and <FIG> shows a connector <NUM> of a conventional structure shown as comparison to <FIG>. The connector <NUM>, <NUM> serves one of a pair of board-to-board connectors and is intended to be surface-mounted on a substrate.

The connector <NUM> is formed from a housing <NUM> made of resin and a total of six terminals <NUM> arranged in two rows. The housing <NUM> is rectangular parallelepiped shaped, with a recess <NUM> formed in an upper surface 31a. One end side of each terminal <NUM> is embedded in one of side walls <NUM>, which are situated across the recess <NUM>, so as to run down the side wall <NUM>, while the other end side sits on a bottom surface 31b of the housing <NUM> and protrudes from the housing <NUM>. The portion of the terminal <NUM> that protrudes from the housing <NUM> forms a connection portion <NUM>. In the connector <NUM>, the portion of the terminal <NUM> that lies on the bottom surface 31b of the housing <NUM>, including the connection portion <NUM>, is in a simple rectangular shape.

Meanwhile, the connector <NUM> is, as with the connector <NUM>, formed from a housing <NUM> made of resin and a total of six terminals <NUM> arranged in two rows. One end side of each terminal <NUM> is embedded in one of side walls <NUM> situated across a recess <NUM> which is formed in an upper surface 41a of the housing <NUM> of a rectangular parallelepiped shape, while the other end side sits on a bottom surface 41b of the housing <NUM> and protrudes from the housing <NUM>, as with the connector <NUM>. However, the portion of the terminal <NUM> that lies on the bottom surface 41b of the housing <NUM> has a different shape from that of the connector <NUM>.

Specifically, in this example, the other end side of each terminal <NUM> lying on the bottom surface 41b of the housing <NUM> consists of a tapered portion <NUM> having a tapered width, an extension portion <NUM> extending from a narrow-side distal end of the tapered portion <NUM>, and a basal portion <NUM> continuous from a wide-side proximal end of the tapered portion <NUM>. Part of the tapered portion <NUM> and the extension portion <NUM> protrude from the housing <NUM>, while the remaining portion of the tapered portion <NUM> and the basal portion <NUM> are embedded in the housing <NUM>. In this example, a connection portion <NUM> protruding from the housing <NUM> is formed of a part of the tapered portion <NUM> and the extension portion <NUM>.

For the aforementioned connector <NUM>, the terminals <NUM> are structured by being insert-molded on the housing <NUM>, and for the connector <NUM>, the terminals <NUM> are also structured by being insert-molded on the housing <NUM>. <FIG> shows a method of manufacture according to an embodiment of the present invention, by means of such insert molding for the manufacture of the connector <NUM> as an example.

The forming mold in this example consists of an upper die (first die) <NUM>, a lower die <NUM>, and two sliding dies (second dies) <NUM>, where the lower die <NUM> is housed and supported in a base <NUM> and protrudes from the base <NUM>, and the two sliding dies <NUM> are slidable on the base <NUM>. The illustrations (<NUM>) to (<NUM>) in <FIG> indicate states in the insert molding process in sequence, and <FIG> shows states as seen from a direction in which the upper die <NUM> lies, with the illustration of the upper die <NUM> omitted. In one surface (upper surface) of each of the two sliding dies <NUM>, grooves <NUM> for housing and positioning the connection portions <NUM> of the terminals <NUM> are formed. On an upper surface of the lower die <NUM>, there are formed step portions <NUM>, on which the end portions of the terminals <NUM> opposite the connection portions <NUM> are placed. The insert molding process is described below in sequence.

This completes the insert molding, upon which the mold is opened and the carriers not illustrated are cut and removed, so that the connector <NUM> is complete.

Here, before describing the method of manufacturing the connector <NUM> according to the present embodiment, how resin leakage can occur to create resin burrs at the connection portions <NUM> of the terminals <NUM> in the manufacture of the connector <NUM> of the conventional structure, which is insert-molded as mentioned above, is described with reference to <FIG>.

Illustrations (<NUM>) to (<NUM>) in <FIG> show the relation between the connection portion <NUM> of a terminal <NUM> and a sliding die <NUM> and how resin leakage occurs in the portion in which the connection portion <NUM> of one terminal <NUM> of the connector <NUM> lies, which is shown in <FIG> in enlarged view. Illustrations (<NUM>) to (<NUM>) in <FIG> correspond to (<NUM>) to (<NUM>) of the insert molding process shown in <FIG>. In (<NUM>) of <FIG>, <NUM> indicates the resin to form the housing <NUM>.

In a state when the sliding die <NUM> has been slid and the mold is pressed, a clearance c still exists between the groove <NUM> of the sliding die <NUM> and the connection portion <NUM> of the terminal <NUM>. Thus, this clearance c causes resin leakage and the leaked resin form resin burrs <NUM>, which adheres to the connection portion <NUM> and will remain on it. The state shown in (<NUM>) of <FIG> is when the connection portion <NUM> deviates to one side (is decentered) with respect to the groove <NUM>.

In contrast, <FIG> shows how resin leakage can be prevented, that is, formation of resin burrs can be reduced, in the method of manufacturing the connector <NUM> according to the present embodiment in comparison to <FIG>. The molding steps shown in (<NUM>) to (<NUM>) of <FIG> are described in sequence below.

While the present embodiment has been described taking the connector <NUM> as an example, examples that can prevent resin leakage during insert molding to reduce the formation of resin burrs by thus constructing the connection portion of each terminal protruding from the housing with a part of the tapered portion and the extension portion are further described with reference to <FIG>.

<FIG> shows a connector <NUM> according to an unclaimed example that is useful for understanding the present invention. The connector <NUM> is a connector for surface mounting on a substrate, as with the connector <NUM> shown in <FIG>. On the connector <NUM>, terminals <NUM> for signals and terminals <NUM> for power supply are insert-molded on a housing <NUM> and further reinforcement fittings <NUM> are insert-molded as well. The terminals <NUM>, <NUM> and the reinforcement fittings <NUM> all have connection portions 72a, 73a, 74a protruding from the housing <NUM>, and these connection portions 72a, 73a, 74a are soldered to lands on a substrate. In this example, the connection portions 72a, 73a, 74a all have the same shape as that of the connection portions <NUM> of the connector <NUM>. In <FIG>, 72b, 73b, and 74b indicate tapered portions, respectively.

<FIG> shows, as an example, a portion at an end portion of a connector <NUM> in which a reinforcement fitting <NUM> is insert-molded on a housing <NUM>. The reinforcement fitting <NUM> has connection portions <NUM> to <NUM> protruding from the housing <NUM>, and the connection portions <NUM> to <NUM> are soldered to lands on a substrate. The connection portions <NUM> to <NUM> all have the same shape as that of the connection portions <NUM> of the connector <NUM>. In <FIG>, 83a and 85a indicate tapered portions, respectively.

<FIG> shows, as another example, a connector <NUM> with both ends of a terminal <NUM> insert-molded on a housing <NUM> projecting from the housing <NUM>. A connection portion <NUM> protruding vertically from the housing <NUM> serves as a point of fitting and contact with a terminal of the mating connector, while a connection portion <NUM> protruding horizontally from the housing <NUM> serves as a point of soldering to a land on a substrate. The connection portions <NUM>, <NUM> all have the same shape as that of the connection portions <NUM> of the connector <NUM>. In <FIG>, 93a and 94a indicate tapered portions, respectively.

While different examples have been described, the electronic component to which the embodiment is directed is not limited to a connector but can be any device that has terminals insert-molded on the housing and connection portions protruding from the housing provided at the terminals.

Claim 1:
A method of manufacturing an electronic component (<NUM>) having a housing (<NUM>) with terminals insert-molded thereon, in which
each of the terminals (<NUM>) includes a tapered portion (<NUM>) having a tapered width and an extension portion (<NUM>) extending from a narrow-side distal end of the tapered portion, and
a mold defining a cavity (<NUM>) for molding the housing includes a first die (<NUM>) and second dies (<NUM>), wherein the method comprises:
after positioning the extension portion in one of grooves (<NUM>) formed in one surface of each of the second dies, sliding the second dies relative to the extension portion to make tip edges of opposite side surfaces (55a, 55b)of the groove facing the cavity abut against opposite side surfaces (46a, 46b) that form tapering of the tapered portion; and
performing molding while keeping the first die in close contact with the one surface of each of the second dies (<NUM>), and keeping part of the tapered portion and the extension portion lying in the groove held between a bottom surface of the groove and the first die with a remaining portion of the tapered portion lying in the cavity, thus forming a connection portion (<NUM>) protruding from the housing with the part of the tapered portion and the extension portion.