Patent Description:
Among connectors for mediating high-speed transmission of signals between a circuit board and an expansion board, there is a type of connector in which a socket type connector to be mounted on a circuit board side, a plug type connector to be mounted on an expansion board side, and terminals of both connectors are electrically connected by fitting the plug type connector to the frontage of the connector. This type of connector is called as a mezzanine connector.

As an example of documents disclosing a technique related to this type of connector, <CIT> (hereinafter referred to as "Patent Document <NUM>") can be taken up. The connector described in this document has a box-shaped housing and contacts arranged side by side on its wall surface. The bottom surface of the housing of this connector is provided with a boss inserted into a positioning hole in a circuit board, and contacts are provided at the frontage on the opposite side to the side with the boss of the housing. The reflow mounting of this type of connector on a circuit board is performed by placing the connector at a predetermined position on the board with the cap attached to the connector, raising the temperature from ordinary temperature to about <NUM> degrees to melt the solder, and returning it to ordinary temperature.

By the way, both the housing and the cap of this type of connector are formed of resin as a material, but if the molding directions of the resin of the housing and the cap are different, there may be a large difference in thermal expansion coefficients of the two elements during reflow. In this case, there was a problem that excessive expansion of the cap caused the housing of the connector to be pressed and widened, which caused distortion of the housing of the connector and occurrence of solder cracks.

The present disclosure has been made in view of such a problem, and one of the objects is to provide a technical means capable of preventing housing distortion and solder cracks during reflow of the housing and the cap.

Patent document <CIT> disclosed a suction cover for connectors (reset connector and plug connector) constituting a board-to-board type connector device.

Patent document <CIT> disclosed a connector set including at least one of a header and a socket and a jointer.

The object of the invention is attained as disclosed in claim <NUM>.

Here is disclosed a connector set including a plurality of connectors and a cap to be attached to the plurality of connectors when the plurality of connectors are reflow-mounted on an external substrate. Each one end portion of the connectors and the cap is provided with a fitted portion and a fitting portion to be fitted in the fitted portion, and the fitted portion is provided with an opening portion for moving the fitting portion so as to absorb thermal expansion from one end portion side to the other end portion side due to temperature conversion of reflow.

The fitted portion is a longitudinal hole provided in the connector, the fitting portion is a positioning longitudinal pin provided on the cap, a round hole is provided on an opposite side to a side of the connector where the longitudinal hole is provided, and a positioning pin to be fitted in the round hole is provided on an opposite side to a side of the cap where the positioning longitudinal pin is provided.

Further, the connector may include a housing with a plurality of slots separated by a partition wall, and a plurality of contacts arranged in the slots.

Further, the plurality of connectors may be arranged in a direction orthogonal to an extending direction of the slots and held by the cap.

Further, a number of the slots in one connector may be two.

Further, the housing may have a bottom portion, two first wall portions and two second wall portions respectively facing each other across the slots, the first wall portions may extend in a direction orthogonal to the slots, the cap may be provided with a hooking spring, and when the cap is attached to the connector in such a manner that the positioning pin is inserted into the round hole, the positioning longitudinal pin is inserted into the longitudinal hole, and the hooking spring is fitted inside the first wall portion, the connector may be supported from the inside by the hooking spring of the cap.

Further, the housing may have a rotationally asymmetrical shape when viewed from a direction in which a connector of a communication counterpart is fitted.

Further, a part of connectors of the plurality of connectors and the remaining connectors may be arranged in opposite directions and mounted on the substrate.

In accordance with a second embodiment of the present disclosure, there is provided a connector gathered by a cap and to be reflow-mounted on an external substrate. The connector includes: a plurality of slots extending in one direction and separated by a partition wall; a bottom portion that constitutes a bottom of the connector; two first wall portions that extend in a direction orthogonal to the slots and face each other across the slots; and two second wall portions that extend in a direction parallel to the slots and face each other across the slots so as to surround the slots together with the two first wall portions, wherein one first wall portion of the two first wall portions is provided with a round hole for fitting with a positioning pin of the cap, the other first wall portion of the two first wall portions is provided with a longitudinal hole for fitting with a positioning longitudinal pin of the cap. The longitudinal hole is opened on the other side. When the cap expands together with the connector, the positioning longitudinal pin fitted in the longitudinal hole moves toward the other side in the longitudinal hole.

In accordance with a third embodiment of the present disclosure, there is provided a connector set including a plurality of connectors and a cap to be attached to the connectors when the connectors are reflow-mounted on an external substrate, wherein the cap has a box shape provided with an opening for accommodating and holding the connectors, and an adsorption sheet is adsorbed on a surface opposite to the opening side of a plurality of caps.

Here, a split slit may be formed between the adjacent connectors.

Hereinafter, a connector <NUM> and a cap <NUM> forming a connector set according to one embodiment of the present disclosure will be explained with reference to the drawings. This connector <NUM> is a so-called socket type connector. The connector <NUM> is used by fitting with a so-called plug type connector. The connector <NUM> and the plug type connector <NUM> are separately mounted on two electronic substrates. When the header of a communication counterpart connector is fitted into the slot <NUM> of the connector <NUM>, contacts <NUM> of the two connector <NUM> are electrically connected to each other, and high speed differential transmission based on PAM (Pulse Amplitude Modulation) becomes possible. The cap <NUM> is attached to the connector <NUM> when the connector <NUM> is reflow-mounted on the board.

In the following description, the attaching direction of the cap <NUM> to the connector <NUM> is appropriately referred to as the Z direction, a direction orthogonal to the Z direction is appropriately referred to as the X direction and a direction orthogonal to the Z direction and the X direction is appropriately referred to as Y direction. In addition, the +Z side may be referred to as an upper side, the -Z side may be referred to as a lower side, the +X side may be referred to as a front side, the -X side may be referred to as a rear side, the +Y side may be referred to as a left side, and the -Y side may be referred to as a right side.

As shown in <FIG>, the connector <NUM> has a housing <NUM>, solder tab terminals <NUM>, and contacts <NUM>. The housing <NUM> of the connector <NUM> is formed by injecting resin in the arrow B direction of <FIG> which is the longitudinal direction thereof. The housing <NUM> of the connector <NUM> has a rotationally asymmetrical shape.

More specifically, the housing <NUM> of the connector <NUM> is provided with two slots <NUM>. The two slots <NUM> extend in the X direction. The housing <NUM> has a bottom portion <NUM> that constitutes the bottom of the housing <NUM>, wall portions <NUM> and wall portions <NUM> respectively facing each other in the X direction and the Y direction across the slots <NUM>, and a partition wall <NUM> separating the two slots <NUM> in a frontage surrounded by the wall portions <NUM> and the wall portions <NUM>. The wall portions <NUM> extend in the Y direction, and the wall portions <NUM> extend in the X direction. In the present disclosure, the wall portions <NUM> and the wall portions <NUM> correspond to, for example, the first wall portions and the second wall portions that are defined in claims, respectively.

As shown in <FIG>, the end portion of the partition wall <NUM> on the -X side is connected to the wall portion <NUM> on the -X side. As shown in <FIG>, the end portion of the partition wall <NUM> on the +X side is not connected to the wall portion <NUM> on the +X side, and a gap <NUM> is formed between the end portion of the partition wall <NUM> on the +X side and the wall portion <NUM> on the +X side.

A round hole <NUM> is provided in the middle of the wall portion <NUM> on the -X side in the Y direction. A longitudinal hole <NUM> is provided in the middle of the wall portion <NUM> on the +X side in the Y direction. The longitudinal hole <NUM> is opened on the +X side. Rectangular grooves <NUM> are provided on the +Y side and the -Y side of the holes in the wall portion <NUM> on the -X side and the wall portion <NUM> on the +X side. The rectangular grooves <NUM> are recessed from the upper surfaces of the wall portions <NUM> toward the bottom portion <NUM>. Holes are perforated at the bottoms of the rectangular grooves <NUM>, and the solder tab terminals <NUM> are fitted and fixed in the holes. As shown in <FIG>, the solder tab terminal <NUM> has an elongated substrate portion <NUM> and two projecting piece portions <NUM> rising from two end portions of one long side of the substrate portion <NUM>. The two projecting piece portions <NUM> are fitted into the holes at the bottom of the rectangular groove <NUM> of the housing <NUM>.

As shown in <FIG>, on the lower sides of the inner surfaces of the wall portions <NUM> on the +X side and the -X side on the slots <NUM> sides, there are engaging pieces <NUM> projecting to the slots <NUM> sides.

Grooves <NUM> are provided in the inner surfaces of the wall portions <NUM> and the side surfaces of the partition wall <NUM>. Contacts <NUM> are accommodated in the grooves <NUM>. As shown in <FIG>, the contact <NUM> has a linear portion <NUM> extending in one direction, a terminal portion <NUM> at one end of the linear portion <NUM>, and a fork portion <NUM> at the other end of the linear portion <NUM>. The terminal portion <NUM> is bent into a doglegged shape. The fork portion <NUM> is bifurcated. Solder <NUM> is caulked and fixed to the fork portion <NUM>. The contacts <NUM> are held in the grooves <NUM> of the wall portions <NUM> and the partition wall <NUM>, and the fork portions <NUM> of the contacts <NUM> and the solder <NUM> are exposed on the opposite side to the grooves <NUM> side through the holes in the bottom portion <NUM>.

As shown in <FIG> and <FIG>, the cap <NUM> has a box shape with a width in the X direction and the Y direction slightly larger than that of eight connectors <NUM> arranged side by side. The cap <NUM> is formed by injecting resin in the arrow "A" direction of <FIG> which is the longitudinal direction thereof.

As shown in <FIG>, an opening <NUM> for accommodating and holding the connectors <NUM> is provided on the -Z side of the cap <NUM>. The cap <NUM> has a top plate portion <NUM> that becomes a ceiling of the cap <NUM>, wall portions <NUM> and wall portions <NUM> respectively facing each other in the X direction and the Y direction across the opening <NUM>. A hooking spring <NUM> and a spring accommodation portion <NUM> are provided at a position corresponding to each slot <NUM> of eight housings <NUM> inside the wall portion <NUM> on the -X side and the wall portion <NUM> on the +X side. As shown in <FIG>, the lower end portion <NUM> of the hooking spring <NUM> projects outward in a triangular shape.

A positioning pin <NUM> is provided at a position corresponding to the round hole <NUM> between the adjacent spring accommodation portions <NUM> inside the wall portion <NUM> on the -X side. The positioning pin <NUM> has a shape to be put in the round hole <NUM>. A positioning longitudinal pin <NUM> is provided at a position corresponding to the longitudinal hole <NUM> between the adjacent spring accommodation portions <NUM> inside the wall portion <NUM> on the +X side. The positioning longitudinal pin <NUM> has a shape to be put in the longitudinal hole <NUM>.

The attachment of the cap <NUM> to the connectors <NUM> and the reflow mounting thereof are performed as follows. First, the eight connectors <NUM> are arranged so that the orientation of the gaps <NUM> of a part of the connectors <NUM> and the orientation of the gaps <NUM> of the remaining connectors <NUM> are reversed (for example, the gaps <NUM> of two connectors <NUM> in the middle are on the -X side, and the gaps <NUM> of two connectors <NUM> at both ends are on the +X side).

Next, the cap <NUM> is attached to the eight connectors <NUM> in such a manner that the positioning pins <NUM> are fitted into the round holes <NUM> on the -X side, the positioning longitudinal pins <NUM> are fitted into the longitudinal holes <NUM> on the +X side, and the hooking springs <NUM> are fitted inside the wall portions <NUM> on the +X side and the -X side. As shown in <FIG>, when the cap <NUM> is attached to the eight connectors <NUM>, the lower end portions <NUM> of the hooking springs <NUM> of the cap <NUM> engage with the engaging pieces <NUM> of the connectors <NUM>, and the connectors <NUM> are supported from the inside in the X direction by the hooking springs <NUM> of the cap <NUM>.

Next, the eight connectors <NUM> gathered by the cap <NUM> are placed on a predetermined position of an electronic substrate, and are put into a reflow device. The temperature in the device is changed from <NUM> to <NUM> to <NUM>. As the temperature rises, the cap <NUM> expands together with the housing <NUM>. Here, as shown in <FIG>, the injection direction of the cap <NUM> and the injection direction of the housings <NUM> are orthogonal to each other. For injection molded products, thermal expansion is more likely to occur in the direction orthogonal to the injection direction than the injection direction, and there is a difference of about <NUM> times between the thermal expansion coefficient in the injection direction and the thermal expansion coefficient in the orthogonal direction. When the cap <NUM> is heated while being attached to the connectors <NUM>, the expansion amount of the cap <NUM> in the X direction becomes larger than the expansion amount of the connectors <NUM> in the X direction. Since the positioning pins <NUM> of the cap <NUM> are fitted in the round holes <NUM> of the connectors <NUM> and do not move, the portion of the cap <NUM> on the +X side of the positioning pins <NUM> expands to the +X side. When the cap <NUM> expands together with the connectors <NUM>, the longitudinal holes <NUM> of the connectors <NUM> play a role of "clearance", and the positioning longitudinal pins <NUM> fitted in the longitudinal holes <NUM> move in the longitudinal holes <NUM> toward the opening portions on the +X side.

When the temperature exceeds <NUM>, the solder <NUM> at the tip end portions of the contacts <NUM> of the connectors <NUM> is melted, and when the temperature returns to ordinary temperature, the solder <NUM> solidifies. The contacts <NUM> of the connectors <NUM> and the pads of the electronic substrate are connected to each other by the solidification of the solder <NUM>. After the connectors <NUM> are attached to the electronic substrate, the cap <NUM> is removed from the connectors <NUM>.

The details of the configuration of the present embodiment are mentioned above. The connector set according to the present embodiment includes a plurality of connectors <NUM> and a cap <NUM> to be attached to the plurality of connectors <NUM> when the plurality of connectors <NUM> are reflow-mounted on a substrate. Each one end portion of the connectors <NUM> and the cap <NUM> is provided with a longitudinal hole <NUM> as a fitted portion and a positioning longitudinal pin <NUM> as a fitting portion to be fitted in the longitudinal hole <NUM>. The longitudinal hole <NUM> is provided with an opening portion for moving the positioning longitudinal pin <NUM> so as to absorb thermal expansion from one end side to the other end side due to the temperature conversion of reflow. Accordingly, it is possible to prevent distortion of the housings <NUM> and occurrence of solder cracks during reflow of the housings <NUM> of the connectors <NUM> and the cap <NUM>.

Further, in the present embodiment, the housing <NUM> of the connector <NUM> has a rotationally asymmetrical shape. Thus, the connector of the communication counterpart also has a rotationally asymmetrical shape, so that it is possible to provide a connector that is unlikely to cause reverse insertion.

Claim 1:
A connector set comprising a plurality of connectors (<NUM>) and a cap (<NUM>) to be attached to the plurality of connectors when the plurality of connectors (<NUM>) are reflow-mounted on an external substrate, wherein
each one side end portion of the connectors (<NUM>) and the cap (<NUM>) is provided with a fitted portion (<NUM>) and a fitting portion (<NUM>) to be fitted in the fitted portion (<NUM>), wherein
the fitted portion (<NUM>) is a longitudinal hole (<NUM>) provided in the connector (<NUM>),
the fitting portion (<NUM>) is a positioning longitudinal pin (<NUM>) provided on the cap (<NUM>), wherein
a round hole (<NUM>) is provided on an opposite side to a side of the connector (<NUM>) where the longitudinal hole (<NUM>) is provided, and
a positioning pin (<NUM>) to be fitted in the round hole (<NUM>) is provided on an opposite side to a side of the cap (<NUM>) where the positioning longitudinal pin (<NUM>) is provided;
and wherein the fitted portion (<NUM>) is sidewise open on an outside of the connectors (<NUM>) so as to allow the fitting portion (<NUM>)
to move from one side end portion to the other side end portion opposite to the one side end portion due to thermal expansion caused by temperature conversion of reflow.