Motor power pack with overmolded printed circuit board integrated connector
A motor electronics unit includes a printed circuit board having a first side and a second side with electronic components connected to the printed circuit board. An electrical conductor is connected to the printed circuit board. A heat sink is connected to the printed circuit board. A pre-molded electrical connector shroud has a portion of the electrical conductor positioned within the electrical connector shroud. A housing has an endcap, both co-molded in a low pressure injection molding process of a thermally conductive polymeric material. The endcap encapsulates the printed circuit board including the electronic components connected to the printed circuit board and covers a first portion of the heat sink, with a second portion of the heat sink uncovered by the polymeric material of the endcap to permit heat transfer away from the printed circuit board. The endcap also encapsulates a portion of the electrical connector shroud.
1. A motor electronics unit, comprising:
a printed circuit board having a first side and a second side;
at least one electrical conductor connected to the printed circuit board;
a heat sink positioned proximate to the printed circuit board;
a pre-molded electrical connector shroud having a portion of the at least one electrical conductor positioned within the electrical connector shroud; and
a housing molded from a low pressure injection molded thermally conductive polymeric material, the housing including a first side and a side surface, wherein first side of the housing is proximal to the first side of the printed circuit board and is distal to the second side of the printed circuit board,
wherein the housing encapsulates the printed circuit board such that the printed circuit board is fixed within a substantially solid inner body of the housing, wherein the pre-molded electrical connector shroud extends longitudinally away from the first side of the housing.
2. The motor electronics unit of claim 1 , wherein a second section of the electrical connector shroud extends out from an end surface of the housing and freely away from the housing.
3. The motor electronics unit of claim 1 , wherein a first section of the electrical connector shroud defines a flange extending around a perimeter of the electrical connector shroud.
4. The motor electronics unit of claim 3 , wherein the flange includes a step.
5. The motor electronics unit of claim 1 , wherein the at least one electrical conductor defines first and second input electrical power conductors supplying power to the printed circuit board.
6. The motor electronics unit of claim 1 , wherein the at least one electrical conductor defines multiple pins transmitting communication signals.
7. The motor electronics unit of claim 1 , wherein a first portion of the heat sink defining a flange is overmolded to fix the heat sink to the printed circuit board, and a second portion of the heat sink extends outward from an end surface of the housing, the second portion having multiple fins.
8. The motor electronics unit of claim 1 , wherein the housing includes a housing portion filling a gap between the printed circuit board and the heat sink.
9. The motor electronics unit of claim 1 , wherein: a portion of the at least one electrical conductor is encapsulated by the substantially solid inner body.
10. The motor electronics unit of claim 1 , wherein: the substantially solid inner body has a motor cavity receiving an electrical motor when the motor electronics unit is connected to the electrical motor; and the housing includes a cross contact positioned within the motor cavity and connected to the at least one electrical conductor and to the motor electrically that electrically connects the printed circuit board to the electrical motor.
11. The motor electronics unit of claim 1 , wherein the pre-molded electrical connector shroud is connected to the housing via an epoxy layer, wherein the at least one electrical conductor extends through the epoxy layer and the substantially solid inner body.
12. The motor electronics unit of claim 1 , wherein the substantially solid inner body defines a recess such that a sensor positioned on the second side of the printed circuit board is exposed to sense a position of a motor shaft, wherein the recess extends from a motor cavity such that a portion of the motor shaft can extend through the recess.
13. A motor electronics unit, comprising:
a printed circuit board having a first side and a second side and having electronic components connected to the printed circuit board; at least one electrical conductor connected to the printed circuit board;
a heat sink connected to the printed circuit board;
a pre-molded electrical connector shroud having a portion of the at least one electrical conductor positioned within the pre-molded electrical connector shroud;
a housing having an endcap, a first side, and a second side, both the housing and the endcap co-molded in a low pressure injection molding process of a thermally conductive polymeric material, wherein the first side is proximal to the first side of the printed circuit board and is distal to the second side of the printed circuit board, wherein:
the endcap encapsulates the printed circuit board including the electronic components connected to the printed circuit board and covers a first portion of the heat sink, with a second portion of the heat sink uncovered by the polymeric material of the endcap to permit heat transfer away from the printed circuit board; and
the endcap encapsulates a portion of the electrical connector shroud, wherein the pre-molded electrical connector shroud extends longitudinally along an axis defined as perpendicular to the first side of the housing.
14. The motor electronics unit of claim 13 , wherein the endcap encapsulates a first section of the at least one electrical conductor.
15. The motor electronics unit of claim 14 , wherein:
the housing includes a substantially solid inner body; and
a second section of the at least one electrical conductor is encapsulated by the substantially solid inner body.
16. The motor electronics unit of claim 13 , wherein:
the endcap extends in a direction perpendicular to the printed circuit board; and
the heat sink includes a step portion completely encapsulated by the endcap.
17. The motor electronics unit of claim 13 , wherein the first side of the printed circuit board includes at least one field-effect transistor positioned in a predetermined area and electrically connected to the at least one electrical conductor, with the heat sink positioned above the predetermined area.
18. A motor electronics unit, comprising:
a printed circuit board having a first side and a second side and having electronic components connected to the printed circuit board;
at least one electrical conductor connected to the first side of the printed circuit board;
a heat sink connected to the first side of the printed circuit board;
a pre-molded electrical connector shroud having a portion of the at least one electrical conductor positioned within the electrical connector shroud; and
a housing having an endcap, a first side, and a second side, both the housing and the endcap co-molded in a low pressure injection molding process of a thermally conductive polymeric material, wherein the first side is proximal to the first side of the printed circuit board and is distal to the second side of the printed circuit board, wherein:
the endcap encapsulates the printed circuit board including the electronic components connected to the printed circuit board and covers a first portion of the heat sink, with a second portion of the heat sink uncovered by the polymeric material of the endcap to permit heat transfer away from the printed circuit board;
the endcap encapsulates a portion of the electrical connector shroud; and
the endcap encapsulates a first section of the at least one electrical conductor;
wherein the at least one electrical conductor extends from an inner surface of the housing and does not extend beyond a mating surface of the housing,
wherein the housing encapsulates the printed circuit board such that the printed circuit board is fixed within a substantially solid inner body of the housing, wherein the pre-molded electrical connector shroud extends longitudinally away from the first side of the housing.