Abstract: A semiconductor chip package comprises a semiconductor chip with a metal layer formed over the backside surface thereof and a package body encapsulating the chip in a manner that the metal layer on the backside surface of the chip is exposed from the bottom surface of the package body. The package body has a plurality of protruding potions projecting from the bottom surface of the package body. A plurality of bonding wires each has one end electrically connected to the semiconductor chip and the other end exposed from one of the protruding portions of the package body for electrical coupling to an outside circuit. Preferably, the exposed end of each bonding wire has a longitudinal length at least four times larger than the diameter of the bonding wire. The present invention further provides manufacturing methods of the semiconductor chip package.

Abstract: The invention relates to a packaging for a semiconductor chip. A frame that directly surrounds the slot is provide on the carrier board on the side of the nubbins. Said frame is provided with the same height as the nubbins and the slot and the frame surrounding said slot are at least partially filled with a casting compound which is preferably adapted to the thermal expansion coefficients of the semiconductor chip.

Abstract: A fabrication method and semiconductor package provide enhanced performance. The semiconductor package includes a semiconductor die having an integrated circuit (IC), and a substrate having a die side coupled to the IC. A plurality of multi-signal bus bars is coupled to a socket side of the substrate such that the bus bars enable I/O signals to be transported between the substrate and a socket.

Abstract: To accommodate high power densities associated with high performance integrated circuits, heat is dissipated from a surface of a die through a solderable thermal interface to a lid or integrated heat spreader. In one embodiment, the die is mounted on an organic substrate using a C4 and land grid array arrangement. In order to maximize thermal dissipation from the die while minimizing warpage of the package when subjected to heat, due to the difference in thermal coefficients of expansion between the die and the organic substrate, a thermal interface is used that has a relatively low melting point in addition to a relatively high thermal conductivity. Methods of fabrication, as well as application of the package to an electronic assembly, an electronic system, and a data processing system, are also described.

Abstract: A wire bond-less electronic component is for use with a circuit external to the wire bond-less electronic component. The wire bond-less electronic component includes a support substrate (110, 410), an electronic device (130) over the support substrate, and a cover (140, 440, 540) located over the electronic device and the support substrate. The cover includes an interconnect structure (141, 441, 541) electrically coupled to the electronic device and adapted to electrically couple together the electronic device and the circuit for providing impedance transformation of an electrical signal between the electronic device and the circuit.

Abstract: Provided is a heat sink designed to constrain warpage during thermal cycling. The heat sink is composed of a picture frame stiffener and a heat spreader lid. The stiffener has a thickness greater than that of the height of a die bonded on a substrate in the package which the heat sink is or is to be used. The increased thickness of the stiffener beyond conventional designs serves to increase its stiffness and thereby enhance its capacity to constrain the substrate to prevent its warpage during thermal cycling. The thickened stiffener is coupled with an elevated heat spreader lid, that is, a heat spreader lid with a elevated central portion configured for engagement with the picture frame stiffener such that a central portion of at least one side of the heat spreader lid extends into the opening in the picture frame stiffener. As a result, the heat spreader lid is in a position to constrain warpage of the package by applying a counter force against a warping die.

Abstract: A replaceable integrated circuit device which replaces the connecting socket, the interposer and the pins in prior art with plural solder balls on the bottom of the integrated circuit package contacting and connecting the corresponding contact pad on the circuit board for electrical conduction. The contacting surface of the solder balls and the corresponding contact pad can be made as plane or as curve as possible to increase the contacting area. More over, there are many buckling apparatus placed on the circuit board to buckle the integrated circuit package and the circuit board firmly and to provide the extra downward force to make the solder balls and the corresponding contact pad contact and connect each other tightly. In the present invention, for the solder balls contacting the contact pads of the circuit board directly, which reduce the space that a connecting socket used in prior art and improve the usage ratio of the layout on a circuit board.

Abstract: In some embodiments, the invention includes a system having first and second modules; and a circuit board including first and second module connectors to receive the first and second modules, respectively. A first path of conductors extending from the circuit board to the first module connector, to the first module, back to the first module connector, to the circuit board, to the second module connector and to the second module, and wherein the first path in the first module couples to stubs for first and second chips of the first module and the first path in the second module couples to stubs for first and second chips of the first module; and each of the first and second chips include selectable on die terminations.

Abstract: A semiconductor package production method in which the semiconductor package is produced by having via holes for electrically connecting top and bottom surfaces of a double-sided copper clad substrate and cutting the substrate. The production method includes the steps of: forming wiring patterns between the top and bottom surfaces of the double-sided copper clad substrate; forming via holes each connecting the top and bottom surfaces of the substrate; attaching semiconductor chips on the wiring patterns; sealing an entire body of the substrate with resin; and cutting the substrate on a line which separates the via hole into half, thereby separating the semiconductor packages from one another. Each via hole has an oval shape in top view which is created by forming two or more circular holes partially overlapped with one another on a horizontal surface of the substrate.

Abstract: A semiconductor chip having a functional bump provided on a surface of a semiconductor substrate thereof for electrical connection between an internal circuit thereof and a solid device, and a dummy bump not serving for the electrical connection between the internal circuit and the solid device. The dummy bump may be a stress relieving bump for relieving stresses exerted thereon. The dummy bump may be connected to a low impedance portion. The functional bump and the dummy bump may be provided on a surface protective film. In this case, the dummy bump is provided on a recess formed in the surface protective film.

Abstract: A semiconductor device miniaturizing the plane sizes of memory cells and a peripheral circuit part for a logic circuit and reducing wiring resistance and ensuring the degree of freedom in layout of wires on an interlayer isolation film. The semiconductor device comprises an active region included in a transistor formed on a semiconductor substrate, a wire formed on the semiconductor substrate, an interlayer isolation film covering the active region and the wire and a plug wire having a shape overlapping with both of the wire and the active region in plane, and the plug wire electrically connects the wire and the active region with each other.

Abstract: A low dielectric constant, thermally stable hydrogenated oxidized silicon carbon film which can be used as an interconnect dielectric in IC chips is disclosed. Also disclosed is a method for fabricating a thermally stable hydrogenated oxidized silicon carbon low dielectric constant film utilizing a plasma enhanced chemical vapor deposition technique. Electronic devices containing insulating layers of thermally stable hydrogenated oxidized silicon carbon low dielectric constant materials that are prepared by the method are further disclosed. To enable the fabrication of thermally stable hydrogenated oxidized silicon carbon low dielectric constant film, specific precursor materials having a ring structure are preferred.

Abstract: A method of fabricating an integrated circuit can include forming a laminated conductive line. The laminated conductive line can be formed in a dielectric trench. The laminated conductive line can include alternating barrier layers and copper layers. An integrated circuit includes at least one interconnect layer, the interconnect layer including a number of conductive lines. Each of the conductive lines includes a first thin barrier layer, a first thin copper layer, a second thin barrier layer and a second thin copper layer. The layered or laminated structure can reduce unconstrained void formation.

Abstract: Structures such as source/drain contacts of improved reliability are enabled by the creation and use of quantum conductive barrier layers at the interface between the electrical contact and the shallow diffusion source/drain region. The quantum conductive layers are preferably nitrides or oxynitrides. The improved structure is preferably part of a transistor structure of an integrated circuit device. The contacts structures are especially useful for devices employing ultra-shallow junctions.

Abstract: A dual damascene process is disclosed, in which a contact via and trench pattern is etched into insulating layer(s). The via is first partially filled by selective metal (e.g., tungsten) deposition, thereby forming a partial plug that raises the floor and reduces the effective aspect ratio of the trench and via structure. The remaining portion of the contact via is then filled with a more conductive material (e.g., aluminum). This deposition also at least partially fills the overlying trench to form metal runners. In the illustrated embodiment, hot aluminum deposition fills the portion of the contact via left unoccupied by the selective deposition and overfills into the trench. A further, cold aluminum deposition then follows, topping off the trench prior to planarization.

Abstract: Disclosed are a multi-chip package and a method for manufacturing the multi-chip package. The multi-chip package comprises: a circuit substrate consisting of first, second and third areas which surround three sides of the multi-chip package; and at least two semiconductor chips which are positioned within an internal space of the package defined by the internal surfaces of the above three areas, wherein the semiconductor chips are physically bonded and electrically connected to each other. The method for manufacturing a multi-chip package comprises the steps of: providing a circuit substrate matrix formed with a plurality of unit circuit substrates, each substrate consisting of first, second and third areas; bonding semiconductor chips each unit circuit substrate, so that those chips are physically bonded and electrically connected to the unit circuit substrate; separating unit circuit substrates from the circuit substrate matrix; and folding the unit circuit substrate.

Abstract: A system for underfilling in a chip package includes an underfill mixture that ameliorates the CTE mismatch that typically exists between a packaged die and a resin-impregnated fiberglass mounting substrate. In one embodiment, the system includes an underfill mixture that alone exhibits a CTE that is characteristic of an inorganic-filled underfill composite previously known. An embodiment is also directed to the assembly of a flip-chip package that uses an underfill mixture.

Abstract: A semiconductor device has a wiring pattern formed by etching a conductive layer using a resist pattern as a mask. The semiconductor device includes a contact section and a wiring. The contact section is formed in an interlayer dielectric layer. The wiring has a connection region to be connected to the contact section. The connection region of the wiring has a generally square plan configuration. The wiring has an extension section extending in a non-wiring region in the connection region.

Abstract: Thermal cycling can lead to damaging stress at the upper surface of a semiconductor device chip (10) encapsulated in synthetic resin material (100), particularly in the case of power devices that include an IC. The invention provides a thick ductile layer pattern (50) of, for example, aluminium over most of the top surface of the insulating over-layer (40) of the chip (10). Electrically-isolated parts (50a, 50b, 50c, 50d etc.) of this ductile covering are individually connected to respective underlying conductive areas so as to reduce charging effects across the insulating over-layer (40). A sufficient spacing Z1 is present between these isolated parts (50a, 50b, 50c, 50d etc.) to avoid short circuits as a result of deformation by shearing and smearing during thermal cycling of the device.

Abstract: Glass, for encapsulating a semiconductor, which is substantially free of lead or other harmful ingredients, but which exhibits a sealing temperature of not higher than 710° C., and which stably seals with Dumet. Further, when the glass has a viscosity of 106 dPa·s, the temperature of said glass is not higher than 710° C., and includes two or more of Li2O, Na2O and K2O and B2O3. Also, the glass may comprise: SiO2, B2O3 and Al2O3 in an amount of from 40 to 70%, from 5 to 20% and from 0 to 15% by weight, respectively; MgO, CaO, SrO, BaO and ZnO in a total amount of from 0 to 45% by weight; and Li2O, Na2O and K2O in a total amount of from 5 to 25% by weight.

Abstract: An integrated circuit package is provided with alignment pads which are solid or annular ring shaped. Alignment members such as balls or bullets are attached to the alignment pads via a wetting media. When heated, the wetting media serves to center and seat the alignment members on the alignment pads. When cooled, the wetting media serves to bond the alignment members to the alignment pads.

Abstract: A semiconductor device structure comprises a corner structure enclosed by a delineation region, wherein the shape of the corner structure does not exhibit any symmetry with respect to point symmetry and axial symmetry, such that the corner structure is unambiguously recognizable by an automated alignment system. Furthermore, the inner region of the corner structure may be filled with a pattern indicating the type of material layer in which the corner structure is formed. The corner structure exhibits a strong contrast even if the wafer is subjected to a CMP treatment.

Abstract: A method and apparatus for operating a wind park having maximum permissible output power and a plurality of wind power installations wherein each wind power installation includes an output power and a maximum rated output power. The apparatus, in one aspect, includes a processing unit that is coupled to the plurality of wind power installations to control the output power of at least one of the wind power installations. The processing unit may determine the total output power of all of the plurality of wind power installations and, in response thereto, control the output power of at least one of the plurality of wind power installation so that the total output power of all of the plurality of wind power installations does not exceed the maximum permissible output power of the wind park.

Abstract: In a generator system having a gas turbine (1) and a generator (2), which is driven by the gas turbine (1), an electricity supply network (5) is supplied from an energy reservoir (6) when the output of the gas turbine (1) is inadequate in the case of a load change. In order to overcome the inertia of the gas turbine (1), energy is additionally supplied from the energy reservoir (6) to the generator (2) which, acting as a motor, accelerates the gas turbine (1) until it at least has the output demanded by the network.

Abstract: In order to achieve efficient utilization of components required for the generator operation, during the run-up of a turboset having a gas turbine, a generator and also a rectifier exciter, the latter is operated as an asynchronous generator, via which the rotor winding of the generator is supplied with direct current. As a result, neither slip rings nor a separate starting motor are required for the start-up of the turboset.

Abstract: The present invention provides an apparatus, system, and method of utilizing a Home Power Unit (“HPU”) which functions as a battery charger for a Hybrid Electric Vehicle (“HEV”) or as a generator, utilizing the HEV's electrical power to operate external electrical devices. In its simplest form, the HPU comprises a Transformer, inverter means, rectifier means, a control unit, connection means to the HEV and external electrical loads or sources and switching means to change operation between charger and generator function. Alternative embodiments of the present invention utilize the HEV's existing components thereby avoiding component redundancy within the HPU. Specifically, in the first alternative embodiment, the inverter means are utilized within the vehicle, therefore, requiring only filter and transformer to be added to the vehicle. In the second alternative embodiment, the vehicle's DC-to-DC Converter is utilized as opposed to implementing a transformer.

Abstract: In a mounted-into-automobile device having a mounted-into-automobile device body and a faceplate 15 attached to this mounted-into-automobile device body detachably, the faceplate 15 is composed of a faceplate for right steering wheel car and a faceplate for left steering wheel car, and both the faceplates 15 are constituted so that they can be connected to the mounted-into-automobile device body.

Abstract: A switch module in an instrument panel of a motor vehicle contains multiple switch assemblies connected by wiring to a controller. Multiple devices controlled by the switch assemblies are connected by wiring to the controller. The controller has a programmed matrix correlating a switch input from each particular switch assembly in the module with a particular device to place each particular device under control of the corresponding switch assembly.

Abstract: A portable contactless object (10) featuring a main chip (12) and a main antenna (14) enabling communication between the chip and the reader associated with the portable contactless object. This portable contactless object also features at least one contactless peripheral device (16), having a function different than that of the main chip not connected by ohmic contact to the latter and requiring only a small amount of energy to operate.

Abstract: A linear motor drive apparatus has a fixed element (22) having a guide mechanism (23), a movable element (21) guided by the guide mechanism (23) so as to move along a reference plane (P), parallel rows of first magnets (30, 31) disposed in parallel to both sides of the reference plane (P) and mounted to the fixed element 22, and parallel rows of second magnets (26, 27) disposed in parallel to both sides of the reference plane (P) and mounted to the movable element (21), wherein the parallel rows of first magnets (30, 31) has planar symmetry with respect to the reference plane (P), and wherein a steel plate (40) is provided so as to be parallel to the reference plane (P) at an intersection part of the movable element (21) with the reference plane (P), the steel plate (4) having a narrowed end part.

Abstract: A dual-directionally operated dynamo set includes a housing, an actuating mechanism slidably mounted in the housing in a reciprocal manner, a dual-motion structure mounted in the housing and driven by the actuating mechanism, and a dynamo device mounted in the housing and driven by the dual-motion structure. Thus, the generator of the dynamo device may be operated successively to generate the electric power along dual directions in a reciprocal manner without stopping, thereby enhancing the generation efficiency of the electric power.

Abstract: A miniature brushless dc fan motor comprises an annular housing, a bearing assembly, a permanent magnet set, a blade set and a coil set. The permanent magnet set is inserted into a hub of the blade set which is located at a center. A shaft is extended through the permanent magnet set to form a rotor. The coil set is secured to an inner circumference of the annular housing and radially aligned with the permanent magnet set. An air channel is formed between the permanent magnet set and the coil set, and adapted to accommodate the blade set.

Abstract: A rotating electric machine exhibits a substantially level axial temperature rise distribution by supplying a coolant which is sufficiently cooled to a central portion of an iron core which is most distant from each of the axial ends of the iron core. A plurality of ventilating passages, which continuously extend in the peripheral direction, are provided in the axial direction between a stator frame and a stator iron core, and coolers are provided in the ventilating passages. A coolant boosted by a booster is cooled by the coolers and is allowed to flow to a central portion of the stator iron core in the direction from the outer peripheral side to the inner peripheral side of the stator iron core via ventilating passages which communicate with the central portion of the stator iron core.

Abstract: A vehicle AC generator include a frame, stator, rotor, rectifier, protective cover, and cooling fan. The rectifier includes plural rectifying elements consisting of positive and negative rectifying elements and is secured on an outer end portion of the frame. The rectifier includes larger-diameter and smaller-diameter fins. The negative rectifying elements are mounted on the larger-diameter fin. The positive rectifying elements are mounted on the smaller-diameter fin. The protective cover includes an axial opening facing the smaller-diameter fin. The frame includes a radial opening formed with the aid of a radially outer end of the frame, a radial air passage formed with facing the larger-diameter fin, and plural grooves. Each groove positionally corresponds to a mounted position of each rectifying element on the larger-diameter fin and is formed on the radial air passage to connect a radially outer end and a radially inner end of the frame.

Abstract: A resolver stator includes a stator coil which is fixed to magnetic poles of the resolver stator by a resin softer than an epoxy, whereby disconnection in the stator coil is avoided when the resolver stator is used in an environment in which temperature varies in a wide range. Wire ends of the stator coil are each wound around a terminal and fixed thereto such that one part of the wound wire end is left free from the terminal, whereby disconnection of wires is avoided.

Abstract: The invention provides a reluctance generator for an eddy current braking system in a vehicle. The reluctance generator has a field winding and a compensation winding, which induce magnetomotive forces. The magnetomotive force induced by the compensation winding balances the magnetomotive force generated by a rotor in the reluctance generator. The field winding has less inductance.

Abstract: An anticondensation device particularly for electric motors, comprising a box-like body that contains the stator windings inside which the enclosure for a rotor is arranged hermetically, a cover to be fixed over the bottom of the box-like body, spaced therefrom, to define an interspace and a perimetric air passage gap. The bottom has through holes, and corresponding first collars protrude perimetrically to the holes toward the cover and enter with play second collars that protrude from the cover toward the bottom. An air passage pathway is formed between the first and second collars. The box-like body is arranged in functional configuration with its bottom substantially vertical.

Abstract: A cup ring and a holding-plate are disposed at each side of a front bracket of a stator of a motor, to fix in place an outer ring of a front ball-bearing of the rotor of the motor in order to prevent creep between a bearing housing and the outer ring. A thickness of a bearing shim is adjusted such that a distance between an end portion of a tube section of the cup ring and a first end face of the outer ring is less than 0.1 mm. The holding plate is temporarily fixed to a given place of the motor shaft, and then screwed down thereto with a screw, so that the holding plate moves and solidly contacts the outer ring of the front ball bearing. An outer diameter of the motor shaft extending between the given place and the bearing is smaller than a center hole of the holding plate such that the holding plate does not contact the motor shaft.

Abstract: Embodiments of the present invention are directed to gear transmission apparatus that are configured to largely eliminate the cogging effects and to reduce the backlash effects. In one embodiment, a transmission apparatus comprises a follower gear, a first drive gear set coupled with the follower gear to drive the follower gear, and a second drive gear set coupled with the follower gear to drive the follower gear. The first drive gear set includes at least one gear, and the second drive gear set includes at least one gear. A first motor is coupled with the first drive gear set. The first motor includes a first rotor having a plurality of poles which are movably disposed relative to a plurality of magnets. A second motor is coupled with the second drive gear set. The second motor includes a second rotor having a plurality of poles which are movably disposed relative to a plurality of magnets.

Abstract: Permanent magnet machines including doubly salient machines having one or more permanent magnets located at least partly and preferably entirely within the stator teeth, thereby avoiding weakening of the stator structure while reducing acoustic noise. The magnets may be located in only a subset of the stator teeth, thereby lowering magnet material and manufacturing costs, and all such magnets may have north poles directed toward an interior of the machine, resulting in reduced cogging and negative torques with improved torque densities. The permanent magnets may also extend within the stator teeth on an angle or diagonal, thereby allowing use of magnets which are wider than the teeth themselves to produce greater flux. Further, a magnetizing device having a single coil may be used to simultaneously magnetize all the stator magnets with a common polarity.

Abstract: An AC motor-generator includes a rotor made up of a first inductor core and a second inductor core arrayed in an axial direction of a rotary shaft. A plurality of permanent magnets are arrayed at an interval of 2&pgr; in electrical angle of an armature away from each other in the periphery of each of the first and second inductor cores. Each permanent magnet is magnetized in a radius direction of the first and second inductor cores so as to be opposed to a magnetomotive force produced by a field winding, thereby resulting in quick disappearance of the magnetic flux of the field upon disappearance of the magnetomotive force from the field winding.

Abstract: A rotor assembly for an alternator includes an electrical wire defining an excitation winding. A first pole piece and a second pole piece each have a generally circular body defining an axis of rotation and an outer radial periphery. A plurality of pole fingers are spaced radially about and extend axially from the outer radial periphery of each pole piece parallel to the axis of rotation. Each pole piece includes a plurality of mounting surfaces spaced radially about the outer radial periphery between the pole fingers. A plurality of permanent magnets are positioned on the mounting surfaces, each of the permanent magnets being secured to the pole pieces by a threaded fastener extending therethrough and engaging the pole pieces.

Abstract: A field part of an electronically switched two-phase reluctance machine includes a plurality of individually wound U-shaped yoke assemblies. Each assembly includes winding carrying U-shaped magnets attached to a non-magnetic carrier frame. Each yoke assembly has winding connections which are interconnected by a form-defined, axially mountable electric conductor compound. Power conducting electric components are electrically connected to the electric connector compound as well.

Abstract: An electrical isolation layer capable of inhibiting, if not preventing, a first conductive material from electrically passing or bleeding into a second conductive material and thereby causing a high resistance connection among the conductive materials is provided. The isolation layer has particular application when arranged between a conductive roebel filler and conductive strands sheathed by a porous insulator carrying a high voltage within a stator of a dynamoelectric machine used in a power generation plant.

Abstract: In an electric motor with a stator and a rotor which includes at least a stack of laminations (2) layered by sheets and provided with slots (8) for receiving rotor windings, at the end face (3, 4) of at least one stack of laminations (2) at least one rotor end sheet (5) is provided which is made of high-strength fine-grain structural steel and exhibits, at least in proximity of the rotor axis, the geometric shape of the sheets layered in the stack of laminations (2). With such a rotor, high speeds and a high operational safety can be ensured.

Abstract: A stator with radial winding invention comprises a single pole plate formed by punching a plate having excellent conductivity in magnetism and having an appropriate thickness. The pole plate includes a central tubular portion defining a central hole. A plurality of pole arms project from an outer periphery of the tubular portion and extend radially. Each pole arm terminates at an edge. At least one pole face projects from each edge and extends along a direction perpendicular to a plane on which the edge lies.

Abstract: An improved flat or cylindrical mechanical electric commutator with neutral segments (4) between the current carrying segments which allow the current carrying carbon brushes (11, 12, 13, 14) in a brush holder (7) to pass from a negative current carrying segment to a positive current carrying segment or the opposite charge current in the base of the commutator without allowing the face or any part of the carbon brush to touch both the negative and positive segments in the base of the commutator at the same time, resulting in the switching of the electric current to an energized coil of an electric motor, electrical generator or electric apparatus or device, at predetermined intervals and times to suit the design requirements of the energized coil, electric motor of the stepper, brushless DC and switched design, electric generator or electric apparatus or device, while the commutator can accommodate single phase electrical circuits, double phase electrical circuits, three phase electrical circuits or any numbe

Abstract: A cover plate for an electric motor which has a brush array and interference suppression devices has additional electronic components mounted directly on the cover to determine the speed of the electric motor and for diagnosis. Contact with the interference suppression devices and the additional electronic components is achieved through electrical conductors which are located directly on the cover plate. Flexible use of the electric motor is ensured through the high temperature stability of the cover plate.

Abstract: A brush replacement kit for use with a dynamo electric machine of the kind having a yoke, apertures in the yoke through which brushes of the machine are accessible, and a brush holder assembly for supporting the brushes in a predetermined alignment in relation to a commutator or slip-ring assembly of the machine, the kit comprising replacement brushes of a length exceeding the length of the conventional brushes for the machine, and a cover component comprising a cylindrical band for attachment around the exterior of the yoke to close said brush access apertures in use, said band including radially outwardly extending protrusions to be positioned over said apertures of the yoke in use and thereby to accommodate the additional length of the replacement brushes.

Abstract: In a rotary electric machine, a collar for restricting expansion of coil ends includes a boss fitted on an armature rotation shaft, a flange radially extending from the boss and a pressing portion for pressing coil ends toward an armature core. The thickness of the boss is greater than that of the flange, so that the force F1 that is caused by deflection of the flange when coil ends expand due to a temperature increase is smaller than the force F2 that is required to remove the boss from the rotation shaft. The force F1 is applied to the boss in a direction that the collar separates from the armature core. Because the pressing portion presses against the coil ends toward the armature core through an insulation ring, the coil ends are restricted from expanding by a centrifugal force when the armature rotates.