JP5768610B2 - Electrical unit - Google Patents

Description

  The present invention relates to an electrical unit.

2. Description of the Related Art Conventionally, a technique is known in which a semiconductor element module molded with a resin material is further insert-molded with a resin material.
Patent Document 1 listed below describes a resin molded semiconductor sensor formed by insert molding with a second resin material for a sensor unit molded with a first resin material.

  In this patent document 1, in a 1st mold process, a semiconductor sensor element etc. are sealed with mold resin, and it has a form which a connector pin protrudes from a rectangular parallelepiped mold resin. In the second molding step, after the sensor unit is held in the mold, a resin material is injected into the mold, whereby the resin molded semiconductor sensor is insert-molded.

JP 2010-71723 A

  By the way, in the case of insert molding, when a resin material is injected into a mold, a member located on the side where the resin material flows in the mold receives pressure from the resin material flowing in. In particular, as in Patent Document 1, when the mold resin constituting the side surface of the sensor unit is a rectangular parallelepiped shape, the side surface of the mold resin and the inflow direction of the resin material are likely to be orthogonal to each other. Strong pressure tends to be generated on the side surface of the mold resin. Therefore, there is a concern that the internal semiconductor sensor or the like may be damaged by this pressure.

  This invention is completed based on the above situations, Comprising: It aims at providing the electrical equipment unit which can prevent the malfunction of the semiconductor element module by the pressure of the resin material at the time of insert molding .

According to the present invention, a semiconductor element module in which a semiconductor element is sealed with a first mold resin portion is arranged in a mold, and a second resin material is caused to flow into the mold from an inlet provided in the mold. An electrical unit formed so that a second mold resin portion surrounds the first mold resin portion by insert molding performed, wherein the semiconductor element module has a plurality of terminals electrically connected to the semiconductor element. And the first mold resin portion has a flat shape along the terminal arrangement direction, and the end portion of the first mold resin portion in the terminal arrangement direction is tapered. taper is formed, the tapered is provided at a position corresponding to the inlet of the mold, wherein the first mold resin portion, a groove portion extending in a direction along the arrangement direction of the terminal Is formed, the groove has a characterized in that is extended to the inclined surface of the tapered portion.

According to this configuration, when the semiconductor element module is placed in the mold and insert-molded, if the second resin material is introduced from the inlet provided in the mold, the semiconductor element module is placed at a position corresponding to the inlet. It becomes possible to disperse the pressure of the second resin material due to the shape of the provided taper. Therefore, it becomes possible to prevent the malfunction of the semiconductor element module due to the pressure of the second resin material at the time of insert molding.
Further, since the first mold resin part and the second mold resin part are brought into close contact with each other by insert molding, it is possible to improve the heat dissipation of the internal semiconductor element module.
Further, the second resin material can be passed through the groove during insert molding.
In addition, the second resin material flowing in from the inflow port can be efficiently passed from the tapered surface of the fine detail so as to pass through the groove portion.

It is more preferable to have the following configuration in addition to the above configuration .

The semiconductor element is a semiconductor bare chip, and the semiconductor element and the terminal side portion are connected by a bonding wire.
If it does in this way, the malfunction by the pressure at the time of the inflow of the 2nd mold resin part can be prevented about the connection part of the bonding wire in the 1st mold resin part.

-The mold is provided with an outlet through which the second resin material flows out to the outside, and the tapered portions are respectively provided at both ends of the semiconductor element module in the arrangement direction of the terminals, A taper provided at one end in the terminal arrangement direction is provided at a position corresponding to the inflow port, and a taper provided at the other end in the terminal arrangement direction is provided at the outlet. It is provided at the corresponding position.
In this way, the second resin material can easily flow out of the mold.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to prevent the malfunction of a semiconductor element module by the pressure of the resin material at the time of insert molding about an electrical equipment unit.

1 is an exploded perspective view showing an electrical unit according to Embodiment 1. FIG. A perspective view showing a semiconductor element module The perspective view which shows the back surface side of FIG. Front view showing a semiconductor element module Plan view showing a semiconductor element module Bottom view showing the semiconductor element module Left side view showing a semiconductor element module Right side view showing the semiconductor element module AA sectional view of FIG. The perspective view which shows the semiconductor element module before the 1st mold resin part is formed. Sectional drawing which shows the state which the 2nd resin material flowed in the metal mold | die Sectional drawing which shows the state into which the 2nd resin material flowed into the metal mold | die which concerns on Embodiment 2. FIG.

<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to FIGS.
The electrical unit 10 according to the present embodiment is arranged between a power source in a vehicle and electrical components such as a lamp and a motor, and performs energization and disconnection of the electrical components. In the following, the vertical direction will be described with reference to FIG. 1, and the horizontal direction will be described with reference to FIG. 4, with the front side of FIG.

(Electrical unit)
As shown in FIG. 1, the electrical unit 10 includes a circuit board 11, a unit main body 20 to which the circuit board 11 is mounted, and a cover 44 that covers the upper part of the unit main body 20.

(Circuit board)
The circuit board 11 has a rectangular shape, and conductive paths (not shown) are formed on both the front and back surfaces by a printed wiring technique.
The circuit board 11 is formed with a large number of terminal insertion holes 12, positioning holes 13 for positioning the unit body 20, and attachment holes 14 for screwing the circuit board 11 to the unit body 20. .

  The terminal insertion hole 12 is formed through at a position corresponding to the board connection terminal 25 </ b> B provided in the upper part of the unit main body 20. The board connection terminal 25B is inserted into the terminal insertion hole 12, and the board connection terminal 25B and the conductive path of the circuit board 11 are electrically connected by flow soldering.

The positioning hole 13 is formed penetratingly at a position corresponding to the positioning convex portion 42 protruding from the upper surface of the unit body 20.
The attachment holes 14 are provided at both ends of the circuit board 11 in the longitudinal direction.
An electronic component (not shown) such as a control IC is mounted on the back surface of the circuit board 11 and connected to the conductive path. The control IC controls on / off of the semiconductor switching element 22 provided in the semiconductor element module 21 described later.

(Unit body)
The unit body 20 is formed by performing insert molding in which a semiconductor element module 21 having a first mold resin portion 26 to be described later is placed in a mold 50 and a second resin material is allowed to flow into the mold 50. The second mold resin portion 33 that constitutes the exterior of the unit body 20 is formed of the second resin material.

(Semiconductor element module)
The semiconductor element module 21 includes a semiconductor element module 21A and a semiconductor element module 21B.
As shown in FIG. 10, the semiconductor element module 21A includes a semiconductor switching element 22 (an example of a “semiconductor element” having the configuration of the present invention), a T-shaped input bus bar 23 on which the semiconductor switching element 22 is placed, An output bus bar 24 provided side by side and connected to the semiconductor switching element 22 by a bonding wire 31; a substrate connecting part 25 provided side by side and connected to the semiconductor switching element 22 by a bonding wire 32; A first mold resin portion 26 that covers the semiconductor switching element 22 is provided.

  The semiconductor switching element 22 is a bare semiconductor chip (bare chip) having electrode pads, and for example, an N-type power MOSFET can be used. An output side power pad (source) and a control pad (gate) are provided on the front surface (front surface) side of the MOSFET, and an input side power pad (drain) is provided on the back surface (rear surface) side.

The power pad on the input side is connected to the input bus bar 23 by soldering.
The power pad on the output side is connected to one end side of the bonding wire 31, and the other end side of the bonding wire 31 is connected to the output bus bar 24 by soldering.

  The control pad of the MOSFET is connected to one end side of the bonding wire 32, and the other end side of the bonding wire 32 is connected to the substrate connection terminal 25B by soldering.

  The input bus bar 23 includes an element placement portion 23A that extends in the left-right direction and in which a plurality of semiconductor switching elements 22 are arranged side by side, and an input terminal 23B that extends downward from an intermediate portion in the left-right direction of the element placement portion 23A It is configured with. A substrate connection terminal 25B extending upward is formed at the left end of the element mounting portion 23A.

A plurality of output bus bars 24 are provided below the element mounting portion 23A in the input bus bar 23, and include a wire connection portion 24A extending in the left-right direction and an output terminal 24B extending downward. Note that the output bus bar 24 located at both the left and right ends is formed with board connection terminals 25B extending upward at the side ends thereof.
The wire connection portion 24 </ b> A serves as a bonding pad connected to one end side of the bonding wire 31.
The input terminals 23 </ b> B and the output terminals 24 </ b> B are protruded from the lower end of the first mold resin portion 26 at the distal ends.

  The substrate connecting portion 25 includes a wire connecting portion 25A that can connect the bonding wires 31 and 32, and a substrate connecting terminal 25B that protrudes in a rod shape with the wire connecting portion 25A serving as a base end portion.

The wire connection portion 25A has a rectangular parallelepiped shape and has a diameter larger than that of the substrate connection terminal 25B, and the entirety thereof is embedded in the first mold resin portion 26. One surface of the wire connecting portion 25 </ b> A serves as a bonding pad connected to one end side of the bonding wire 32.
The substrate connection terminal 25 </ b> B has a rectangular cross section and is formed above the upper end of the first mold resin portion 26.

  The bonding wires 31 and 32 are made of, for example, aluminum, and wire bonding performed using the bonding wires 31 and 32 can be performed by, for example, ultrasonic connection. The bonding wire 31 is slightly thicker than the bonding wire 32.

  The first mold resin portion 26 is made of, for example, a thermosetting resin material made of an epoxy resin, and has a flat shape extending in a direction along the arrangement direction of the terminals 23B, 24B, and 25B as shown in FIG. Eggplant.

More specifically, the first mold resin portion 26 is provided at the left and right end portions of the plate-like portion 27 with a substantially constant cross-sectional shape extending left and right, and the plate-like portion 27 is tapered. And tapered portions 28A and 28B.
Grooves 30 that extend horizontally in the left-right direction are formed on both surfaces of the plate-like portion 27. Two grooves 30 are provided on the front surface side with a space therebetween, and one groove portion 30 is provided on an intermediate portion in the vertical direction on the rear surface side. The end portions of these groove portions 30 are extended to the portions 28A and 28B (inclined surfaces 29B and 29D thereof).

The tapered portions 28 </ b> A and 28 </ b> B have inclined surfaces 29 </ b> A to 29 </ b> D connected to the upper and lower surfaces 27 </ b> A and 27 </ b> C and the left and right surfaces 27 </ b> B and 27 </ b> D (outer peripheral surfaces) of the plate-like portion 27. Is tapered (inclined).
The inclination angles of the inclined surfaces 29A to 29D are slightly smaller than 45 degrees with respect to the extending direction of the corresponding surfaces 27A to 27D of the plate-like portion 27.
The tips (end surfaces) of the tapered portions 28A and 28B are substantially flat portions 29E.

  Note that the semiconductor element module 21B is a module in which the length in the left-right direction of the semiconductor element module 21A is generally reduced to reduce the number of terminals. The semiconductor element module 21B is provided with tapered portions 28A, 28B and the like. This is the same and will not be described.

(Second mold resin part)
For example, a thermoplastic resin made of polybutylene terephthalate (PBT) is used for the second mold resin portion 33. As shown in FIG. 1, the lower side of the second mold resin portion 33 is a connector that opens downward. The connector 34 is fitted with a mating connector (not shown). The mating connector is electrically connected to a power source, electrical components, etc. via a wire harness (not shown).

The input terminal 23B and the output terminal 24B protruding from the lower end of the first mold resin portion 26 in the semiconductor element module 21 protrude into the connector housing 34 that opens in a cylindrical shape.
On the upper surface of the second mold resin portion 33, a plurality of positioning convex portions 42 fitted into the positioning holes 13 are provided at the peripheral edge portion.

Inner wall portions 35 are erected at both end portions in the width direction on the upper surface of the second mold resin portion 33, and lock protrusions 36 projecting outward are formed on the outer surface of the inner wall portion 35.
A mounting recess 37 in which the terminal module 39 is mounted is formed at the corner of the second mold resin portion 33.
The mounting recess 37 is formed with a plurality of terminal accommodating chambers 38 in which the terminals 40 can be accommodated from the opening on the upper surface side.

  The terminal module 39 is configured by holding a plurality of terminals 40 arranged in two rows by a holding portion 41 made of a synthetic resin. When the terminal module 39 is mounted in the mounting recess 37, the lower ends of the plurality of terminals 40 protrude into the connector housing 34 that opens in a cylindrical shape, and the upper ends of the terminals 40 are connected to the terminal insertion holes 12 of the circuit board 11. Is inserted and soldered.

The cover 44 has a rectangular shape and is formed with a peripheral wall portion 45 whose peripheral edge protrudes downward. The left and right portions of the peripheral wall portion 45 are external to the inner wall portion 35 of the second mold resin portion 33. Fit.
Lock receiving portions 46 are formed on the left and right portions of the peripheral wall portion 45 at positions corresponding to the lock protrusions 36 to be externally fitted to the lock protrusions and to be elastically engaged with the lock protrusions 36. The cover 44 is placed on the upper portion of the unit main body 20 by elastically engaging the lock protrusion 36 and the lock receiving portion 46.

As shown in FIG. 11, the mold 50 includes an upper mold 51 and a lower mold 52, and a resin-filled recess 53 is formed in the mold 50 according to the shape of the second mold resin portion 33. .
When the upper mold 51 and the lower mold 52 in the mold 50 are fitted together, an inflow path 54 for flowing the second resin material into the mold 50 at the boundary between the upper mold 51 and the lower mold 52, 2 An outflow passage 55 for discharging the resin material from the mold 50 to the outside is formed.

The end of the inflow path 54 is an inflow port 54A, and the start end of the outflow path 55 is an outflow port 55A.
Here, when the semiconductor element module 21A is held in the mold 50, the inlet 54A and the outlet 55A are arranged so that the inlet 54A is located at the right end of the first mold resin portion 26 in the semiconductor element module 21 (terminal arrangement). The outlet 55A is located in the vicinity (position corresponding to the tip 28A) provided at the one end in the direction) and the outlet 55A is the left end (terminal) of the first mold resin part 26 in the semiconductor element module 21. It is configured to be located in the vicinity (position corresponding to the tip detail 28B) of the tip detail 28B provided at the other end in the arrangement direction of.

Next, a method for manufacturing the electrical unit 10 will be described.
The semiconductor switching element 22 is soldered to the element mounting portion 23A of the input bus bar 23 by a reflow process to electrically connect the power pad (drain) on the input side and the input bus bar 23, and to the power pad (source) on the output side. ) And the wire connection portion 24 </ b> A of the output bus bar 24. Further, between the control pad (gate) and the corresponding wire connection portion 25A of the substrate connection portion 25, wire bonding is performed with an ultrasonic wave using the bonding wire 32 (FIG. 10).

Then, this is placed in a mold (not shown), and the first resin material is poured into the mold to form a semiconductor element module 21A in which the first mold resin portion 26 is formed (FIG. 2).
Next, as shown in FIG. 11, the semiconductor element module 21 is placed in the lower mold 52, sandwiched between the upper molds 51, and the terminals 23 </ b> B, 24 </ b> B, 25 </ b> B are held and positioned in the mold 50. At this time, the taper 28A is arranged in the vicinity of the inlet 54A provided in the mold 50 (a position corresponding to the inlet 54A), and the taper 28B is in the vicinity of the outlet 55A provided in the mold 50. (Position corresponding to the outlet 55A).

  Next, when the second resin material is poured into the inflow path 54 (from the direction of the arrow X1), the second resin material is poured from the inlet 54A toward the tapered portion 28A, and the semiconductor element module 21 and the resin filling recess 53 are Passes through (through the groove 30) to the tapered portion 28B side. From here, it flows into the outflow port 55A, passes through the outflow passage 55 (from the direction of the arrow X2) and is discharged to the outside.

  Next, when the poured second resin material is hardened in the mold 50, the semiconductor element module 21 surrounded by the second mold resin portion 33 is taken out from the upper mold 51 and the lower mold 52, and the inflow path 54 and the outflow path 55 are taken out. The unit main body 20 is formed by cutting off the unnecessary second resin material left in the portion from the second mold resin portion 33.

Next, as shown in FIG. 1, each board connection terminal 25 </ b> B of the unit main body 20 is passed through each terminal insertion hole 12 of the circuit board 11, and the positioning protrusion 42 is fitted into the positioning hole 13 so that the circuit board 11 is attached. The unit body 20 is positioned at the top.
Further, screws 56 are passed through the mounting holes 14 of the circuit board 11 and screwed to the mounting portions 43 of the second mold resin portion 33. Thereby, the circuit board 11 is fixed to the unit main body 20.
Then, each board connection terminal 25 </ b> B protruding from the upper surface of the circuit board 11 is flow soldered to the conductive path of the circuit board 11.

  Next, the cover 44 is covered from above the unit main body 20, and the lock receiving portion 46 of the cover 44 is elastically engaged with the lock protrusion 36 of the unit main body 20. Thereby, the electrical unit 10 is formed.

According to this embodiment, the following operations and effects are achieved.
(1) The semiconductor element module 21A (21) in which the semiconductor switching element 22 (semiconductor element) is sealed with the first mold resin portion 26 is placed in the mold 50, and the first through the inlet 54A provided in the mold 50. 2 is an electrical unit 10 in which the second mold resin part 33 is formed so as to surround the first mold resin part 26 by insert molding performed by allowing a resin material to flow into the mold 50, and the semiconductor element module 21A is A plurality of terminals 23B, 24B, and 25B that are electrically connected to the semiconductor switching element 22 are provided, and the first mold resin portion 26 has a flat shape along the direction in which the terminals 23B, 24B, and 25B are aligned, The right end portion (end portion in the terminal arrangement direction) of the mold resin portion 26 is formed with a taper 28A that tapers the end. It is provided in the vicinity of the inlet 54A of the mold 50 (a position corresponding to the inlet 54A).

According to the present embodiment, when the semiconductor element module 21A is placed in the mold 50 and insert-molded (insert molding), the second resin material is allowed to flow from the inlet 54A provided in the mold 50. The pressure of the second resin material can be dispersed by the shape of the tapered portion 28A provided near the inlet 54A (position corresponding to the inlet 54A). Therefore, it is possible to prevent the malfunction of the semiconductor element module 21A due to the pressure of the second resin material at the time of insert molding.
Further, since the first mold resin part 26 and the second mold resin part 33 are brought into close contact with each other by insert molding, it is possible to improve the heat dissipation of the internal semiconductor element module 21.

(2) The first mold resin portion 26 is formed with a groove portion 30 extending in a direction along the arrangement direction of the terminals 23B, 24B, and 25B.
If it does in this way, the 2nd resin material can be flowed through the groove part 30 in the case of insert molding.

(3) The groove 30 extends to the inclined surfaces 29B and 29D of the tapered portions 28A and 28B.
If it does in this way, it will become possible to flow the 2nd resin material which flowed in from inflow port 54A through groove part 30 from inclined surfaces 29B and 29D of tapered part 28A efficiently.

(4) The semiconductor switching element 22 is a semiconductor bare chip, and the semiconductor switching element 22 and the terminal side portion are connected by bonding wires 31 and 32.
If it does in this way, the malfunction by the pressure at the time of the inflow of the 2nd mold resin part 33 can be prevented about the connection part of the bonding wires 31 and 32 in the 1st mold resin part 26. FIG.

(5) The mold 50 is provided with an outlet 55A through which the second resin material flows out. The tapered portions 28A and 28B are formed in the left-right direction (terminals) of the first mold resin portion 26 in the semiconductor element module 21. 28A are arranged at both ends of the right and left ends (one end in the terminal arrangement direction), and the tip 28A is located near the inlet 54A (position corresponding to the inlet 54A). In addition to being provided, a tip 28B provided at the left end (the other end in the terminal arrangement direction) is provided in the vicinity of the outlet 55A (a position corresponding to the outlet 55A).
In this way, the second resin material can easily flow out of the mold 50.

<Embodiment 2>
A second embodiment will be described with reference to FIG. In the following, the same components as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.
In the first embodiment, in order to form the second mold resin portion 33, the mold 50 is provided with the inlet 54A and the outlet 55A of the second resin material, but in the second embodiment, unlike the first embodiment, In order to form the two-mold resin portion 33, only the second resin material inlet 54A is provided in the mold 60, and the second resin material outlet 55A is not provided. Therefore, the left end side of the mold 60 has a closed shape. Other configurations are the same as those of the first embodiment.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the said embodiment, although the electrical equipment unit 10 was set as the structure provided with two semiconductor element modules 21A and 21B, it is not restricted to this, An electrical equipment unit is one semiconductor element module, or three or more. You may comprise so that it may be provided.

(2) In the above embodiment, the tapered portions 28A and 28B are provided at the left and right ends of the first mold resin portion 26, but only the tapered portions 28A are provided at positions corresponding to the inlet 54A of the second resin material, The tapered portion 28B may not be provided.

(3) The tapered portions 28A and 28B are provided in the vicinity of the inlet 54A and the outlet 55A as positions corresponding to the inlet 54A and the outlet 55A of the second resin material. It does not have to be near. For example, although tapered portions 28A and 28B are provided in the direction in which the second resin material flows or flows out slightly away from the inlet 54A or the outlet 55A, the second resin material flows into the tapered portion 28A side with a relatively strong pressure. It may be configured to flow out from the tapered portion 28B side.

(4) Although the N-type MOSFET is used as the semiconductor switching element 22 in the above embodiment, the present invention is not limited to this. For example, other switching elements such as a P-type MOSFET and a transistor can be used. It is also possible to use a semiconductor element having no switching function other than the semiconductor switching element.
(5) In the said embodiment, although inclined surface 29A-29D was provided corresponding to all the surfaces 27A-27D of the plate-shaped part 27, it is not restricted to this, Of the surfaces 27A-27D of the plate-shaped part 27 One to three inclined surfaces corresponding to any one to three surfaces may be provided to have a tapered shape.
(6) In the above embodiment, the semiconductor element module 21A is placed in the mold 50 and insert molding is performed to allow the second resin material to flow. However, this insert molding is performed by applying pressure to the second resin material. It is also possible to use injection molding to flow into the mold 50. This makes it possible to disperse the strong pressure of the second resin material due to the shape of the tapered portion 28A provided in the vicinity of the inflow port 54A. Therefore, the semiconductor element module is more affected by the pressure of the second resin material at the time of insert molding. The trouble of 21A can be prevented.

DESCRIPTION OF SYMBOLS 10 ... Electrical unit 11 ... Circuit board 12 ... Terminal insertion hole 20 ... Unit main body 21 (21A, 21B) ... Semiconductor element module 22 ... Semiconductor switching element (semiconductor element)
DESCRIPTION OF SYMBOLS 23 ... Input bus bar 23A ... Element mounting part 23B ... Input terminal 24 ... Output bus bar 24A ... Wire connection part 24B ... Output terminal 25 ... Substrate connection part 25A ... Wire connection part 25B ... Substrate connection terminal 26 ... First mold resin part 27 ... Plate-like part 27A-27D ... Plate-like part surface 28A, 28B ... Tapered 29A-29D ... Inclined surface 30 ... Groove part 31, 32 ... Bonding wire 33 ... Second mold resin part 34 ... Connector housing 50, 60 ... Gold Mold 51 ... Upper mold 52 ... Lower mold 53 ... Resin filled recess 54 ... Inflow path 54A ... Inlet 55 ... Outlet path 55A ... Outlet

Claims (3)

Insert molding is performed by placing a semiconductor element module in which a semiconductor element is sealed with a first mold resin portion in a mold and allowing a second resin material to flow into the mold from an inlet provided in the mold. An electrical unit formed so that the second mold resin part surrounds the first mold resin part,
The semiconductor element module is
A plurality of terminals electrically connected to the semiconductor element;
The first mold resin portion has a flat shape along the arrangement direction of the terminals,
A taper that tapers the end is formed at an end of the first mold resin portion in the terminal arrangement direction, and the taper is at a position corresponding to the inlet in the mold. Provided ,
In the first mold resin portion, a groove portion extending in a direction along the arrangement direction of the terminals is formed, and the groove portion is extended to the inclined surface of the tapered portion . 2. The electrical unit according to claim 1, wherein the semiconductor element is a semiconductor bare chip, and the semiconductor element and the terminal side portion are connected by a bonding wire . The mold is provided with an outlet through which the second resin material flows out.
The tapered portions are respectively provided at both ends of the semiconductor element module in the terminal arranging direction, and the tapered portions provided at one end in the terminal arranging direction are at positions corresponding to the inflow ports. The electrical unit according to claim 1 or 2 , wherein a tapered portion provided at the other end in the arrangement direction of the terminals is provided at a position corresponding to the outlet. .

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