JP3196829U - Complete power management system mounted in a single surface mount package - Google Patents

Abstract

Provided is a complete power management system which is mounted in a single surface mounting package and has improved reliability and low manufacturing cost.
A controller integrated circuit, a power MOSFET coupled to the controller integrated circuit, and a plurality of passive elements having at least one inductor, the controller integrated circuit, the power MOSFET, and the plurality of passive elements Implements a complete power management system 100 by functionally coupling, a controller integrated circuit, a power MOSFET, and a plurality of passive elements mounted on a metal lead frame, and a controller integrated circuit, a power MOSFET, and The plurality of passive elements are sealed with plastic to form a single package.
[Selection] Figure 10A

Description

  Embodiments of the present invention relate to integrated circuit elements and packaging for power management systems.

  Various integrated circuits are commercially available, for example, to assist in power management tasks that control DC / DC voltage conversion, or as constant current controllers.

  DC / DC converter circuits are commonly used as point-of-load (POL) power supplies to drive a wide variety of semiconductor devices from a single “bulk” voltage, for example, routed around a system in an intermediate bus architecture (IBA) It is used. In general, a POL converter circuit is provided to align closely with each semiconductor element and shifts a single IBA voltage to the various voltage levels required for each integrated circuit. Typically, the DC / DC converter drives elements such as an FPGA, a microprocessor, a DSP, an ADC, an SDRAM, and an up / down converter.

  DC / DC converter circuits are also frequently used in systems with rechargeable batteries. These applications are characterized by portability (size, weight, etc.) and the length of service available from a single charge. For example, the efficiency of the DC / DC converter circuit directly affects the standby time and talk time obtained from the mobile phone while the battery is being charged.

  Current control products are generally divided into two categories. It is a constant current control device and a constant current source. The constant current controller accepts a constant DC voltage and converts it to a constant current output. When the input voltage changes or is unstable, the DC / DC converter is first used to stabilize the DC voltage. Subsequently, the constant current control device takes the stable voltage and outputs a constant current. The constant current source generally includes a DC / DC converter and a constant current control device.

  The DC / DC converters and current control devices provided by many integrated circuit (IC) manufacturers are silicon chips that provide only the basic operation of the circuit functions. Thus, the end user can select up to about 22 other components surrounding the integrated circuit to achieve a complete circuit solution. The selection of these components and circuit board design affects the final performance, such as efficiency, ripple voltage, and reliability, in critical areas. Unfortunately, these important features defined by the integrated circuit manufacturer may not be the same as the performance features achieved when the customer completes the circuit on the board by adding external components. . Therefore, until all parts are assembled together on the printed circuit board for the first time, assembling the parts does not provide full circuit functionality, so that functionality must be tested as a subsystem function on the board. Don't be.

  Vishay Intertechnology, Inc., located in Malvern, Pennsylvania, currently offers multiple versions of FunctionPAK® DC / DC converters and current control modules. The FunctionPAK® product is a complete power management system that is implemented in a single surface, such as a BGA package. Advantageously, this product is a complete power management function within a single module. A single package has all circuit components. A single package is also fully tested with strictly defined all circuit parameters as used in the customer's system.

  The FunctionPAK (R) product typically has a multichip module (MCM) circuit package. In general, the term MCM refers to a package having two or more circuit elements. Such packages often have at least one integrated circuit and an interconnect substrate that couples circuit elements and package contacts. The MCM element usually has a laminated substrate, for example. The laminated substrate is, for example, an FR4 printed circuit board, a thin film deposit, a surface laminated circuit (SLC), and / or a ceramic substrate.

  FIG. 1A illustrates a top view of a typical MCM with many individual chip elements, passive elements, and other components mounted on a multilayer printed circuit board (PCB). For example, a typical MCM has an integrated circuit element 1, an inductor 2, a plurality of passive elements 3 such as resistors and / or capacitors, and a multilayer printed circuit board (PCB) 4. The device and printed circuit board may be molded with plastic to produce a single package. FIG. 1A also shows a cross section of a part molded with a plastic seal 5.

  FIG. 1B illustrates the top surface of another exemplary MCM.

  FIG. 1C illustrates the bottom surface of a typical MCM used in a multi-chip module that utilizes the ball grid array (BGA) packaging method. FIG. 1C shows a typical ball grid array ball 6 used as a package contact that couples the circuitry of a multi-chip module with an adjacent electronics assembly like other components mounted on a processor “mother” board. Is illustrated. FIG. 1C illustrates a typical wiring trace 7. The wiring trace 7 serves to connect various parts of the MCM and a package contact such as a “ball”.

  FunctionPAK® or MCM provides a complete solution and offers many advantages. For example, MCM reduces space and weight, simplifies final product design / development, reduces the number of parts, reduces assembly costs, reduces test time, and reduces time to market.

U.S. Patent No. 6066890

  Current FunctionPAK (R) power management products based on MCM designs sometimes have multiple electrical and thermal limitations as described below. It consists of 1) unintentional parasitic resistance due to thin Cu layer, 2) unintentional parasitic inductance due to package pins, that is, limited current carrying capacity, 3) parasitic heat and insufficient thermal properties together Unintentional reduction of efficiency due to the effects of the unintentional, 4) unintentional output density due to the use of silicon elements (control drive and power MOSFET) packaged by sealing with insufficient thermal conductive mold material 5) unintentional switching frequency due to large switching losses that limit operating temperature and rated current, and 6) unintentional thermal properties due to insufficient thermal conductivity of the materials used. In addition, the design of the FunctionPAK (registered trademark) using the multilayer PCB as a substrate having a different route connection by the BGA may result in insufficient thermal efficiency and heat release. As a result, the operation and reliability of the circuit and active elements can be affected. As mentioned above, when the MCM is molded with plastic, it is believed that the heat-emitting elements of each individual component will not function effectively.

  FIG. 2A shows the components mounted on the surface (mounted on Cu) for the (HighSide11 and LowSide12) MOSFET elements, and other designs utilizing the drive / control device 10 for the DC / DC converter system. Is illustrated. But this solution is not a complete power management system. This is because it does not contain the passive elements required for such a system.

  FIG. 2B illustrates a packaged top surface and X-ray image 30 from the same field of view of the design of FIG. 2A.

  FIG. 2C illustrates a package application according to the design of FIGS. 2A and 2B. The package bottom image 34 illustrates a metal bottom or lead frame (31, 32, and 33) used as a heat sink. Unfortunately, this design does not provide a complete system solution. The reason is that it does not contain the passive elements required for a complete design.

  A complete power management system is therefore described. The complete power management system is mounted using a surface mount package. The system may be drawn into a DC / DC converter system. The system also includes a driver / controller, MOSFET, passive elements (eg, inductor, capacitor, resistor), and optionally a diode in a package mounted on the leadless surface. In various embodiments, the MOSFET may be replaced by an insulated gate bipolar transistor, a so-called IGBT. The system can also be a power management system, a smart power module, or a motion control system. Passive elements may be connected between leadframe connections. The active elements may be coupled by using a metal clip bonding method. In one embodiment, the exposed metal bottom functions as an effective heat sink.

  Advantages of using surface mount packages include high current ratings, reduced parasitic effects, and high efficiency. In addition, embodiments of the present invention can provide greater power dissipation, lower thermal resistance, and smaller footprint for the next stage assembly. Embodiments also reduce assembly costs.

  According to embodiments of the present invention, a standard surface mount package (SMP) is used with an exposed metal bottom. The package may use multi-layer FR4 substrate material (PCB) and Cu leads that replace BGA connections. As a result, the assembly process is simplified and manufacturing costs are reduced. In addition, the performance and reliability of the DC / DC converter is greatly improved.

  There are many advantages to using SMP. The Cu lead frame in the package is much thicker than that used in the MCM Function Pack (registered trademark). Therefore, the parasitic resistance is greatly reduced as compared with the conventional FunctionPAK (registered trademark). Another advantage is to improve the thermal and electrical performance of the MOSFET by using metal (eg, Cu) clips on the source and drain of the MOSFET. Metal clips may also be used on the diode. In addition, the SMP can pass a much larger current than the MCM FunctionPAK (registered trademark). The reason for this is that the greater the current flowing, the more power loss occurs, which cannot be solved by the MCM Function Pack (registered trademark) structure, which has a high thermal resistance.

  Moreover, SMP can achieve higher efficiency. The reason is that SMP greatly reduces parasitic inductance and associated switching losses and has good thermal properties. SMP also has a higher power density. The reason is that the good thermal characteristics of SMP can release more power and the silicon die is not packaged, resulting in a smaller size. SMP can also operate the circuit at a higher switching frequency. The reason is that SMP reduces switching losses and has a much smaller thermal resistance.

  SMP eliminates the requirement for internal packaging of electrical components. Even without an internal package, exposed circuit components have good thermal properties due to the high thermal conductivity of the lead frame and good electrical properties due to low parasitic inductance. In addition, SMP can reduce costs. The reason is that no internal package is required.

  The SMP embodiment may be extended to provide a new integrated platform for power MOSFET applications, among multiple typical applications. Examples of power MOSFET applications are power management, smart (intelligent) power modules, DC-DC converters, and motion control systems.

It is a non-mold image of MCM which concerns on a prior art. It is a non-mold image of MCM which concerns on a prior art. It is a bottom view of BGA of MCM which concerns on a prior art. It is a top view of the incomplete system based on the prior art using surface mounting technology. FIG. 2B is a top view of the design according to the prior art of FIG. 2A. 2B is a top and bottom view of the design according to the prior art of FIG. 2A. 1 illustrates an embodiment of the present invention for a complete power management system utilizing a leadless surface mount package having a metal bottom. 1 illustrates an embodiment of the present invention for a complete power management system utilizing a leadless surface mount package having a metal bottom. FIG. 4 illustrates the use of active device metal clip bonding in accordance with embodiments of the present invention to improve the electrical and thermal properties of the system. 1 illustrates a device manufacturing process according to the present invention. FIG. 4 illustrates the use of an electrically isolated substrate that groups passive elements into a group with internal connections according to an embodiment of the present invention. 1 illustrates a top view of an embodiment of the present invention. 1 illustrates a top view of an embodiment of the present invention. Fig. 4 illustrates the bottom of the device and the exposed lead frame arrangement according to the present invention. Figure 2 shows a perspective view of an exemplary molded embodiment of the present invention. Figure 2 shows a perspective view of an exemplary unmolded embodiment of the present invention. Fig. 3 illustrates a top view of an exemplary embodiment of the present invention. Figure 2 shows a perspective view of an exemplary unmolded embodiment of the present invention. 1 shows a perspective view of an exemplary embodiment of the present invention. 1 shows a perspective view of a lead frame arrangement according to an exemplary embodiment of the present invention. FIG. 1 shows a perspective view of a lead frame arrangement according to an exemplary embodiment of the present invention. FIG. FIG. 2 shows a top view of a lead frame arrangement according to an exemplary embodiment of the present invention.

  Reference is now made in detail to a complete power management system implemented in a single surface mount package, which is a preferred embodiment of the present invention. An example of this is shown in the accompanying figures. It should be noted that although the present invention has been described in conjunction with the preferred embodiments, the present invention is not limited to these preferred embodiments. Rather, the present invention covers alternatives, modifications and equivalents that may be included within the spirit and scope of the present invention as defined by the claims set forth in the Claims for Utility Model Registration. It is understood as a thing. Furthermore, in the following detailed description of the present invention, various specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described so as not to unnecessarily obscure aspects of the present invention.

  3A and 3B illustrate an embodiment of the present invention for a complete power management system 100 that utilizes a leadless surface mount package having a metal bottom. The system may be used for any power management application such as a DC / DC converter, a constant current control device, a motion control system, or a smart power module. According to the embodiment of FIG. 3A, the system includes a controller / driver integrated circuit 101 such as, for example, a Vishay Siliconix Si91966 “High Frequency Pluggable Topology Controller”, MOSFETs (HiMOS103 and LoMOS102), and It has a plurality of passive elements. In the plurality of passive elements in this embodiment, Cn is a capacitor, Ln is an inductor, and Rn is a resistor. Advantageously, the passive elements connect between lead posts in a metal lead frame arrangement, as indicated by L1 and the like.

  For example, the inductor L1 is provided between the lead frame portion 105 and the lead frame portion 106. It should be noted that the inductor L1 is electrically connected to the lead frame portion 105 and the lead frame portion 106 according to an embodiment of the present invention. Optionally, the diode D1 may be connected in a similar manner. The lead frame may comprise Cu or other material suitable for the lead frame such as Al, Au and other metals and alloys. According to an embodiment of the present invention, the lead frame may be multi-layered.

  Note that embodiments in accordance with the present invention are well suited for utilizing industrial standard surface mount packages for components. For example, the resistors and / or capacitors may be provided with an Electronics Technology Council (JEDEC) standard package, such as “0201” or “01005”. Such use of standard parts offers a number of advantages. Such advantages include, for example, multiple power supplies and ready-to-use pick and place technology.

  In the embodiment of the present invention, the passive element may be connected to the lead frame by the method described in Patent Document 1. Passive elements may be connected between the elements of the lead frame to reduce parasitic effects, such as inductance and / or capacitance, and to reduce device space so that, for example, the size of the system can be reduced.

  Embodiments in accordance with the present invention may utilize metal (eg, Cu) clip bonding 110 that connects the active device and the lead frame. This improves the thermal and electrical properties of the system. The active device includes a drive / control device and a MOSFET drive.

  Note that, according to embodiments of the present invention, the full power management system 100 of FIGS. 3A and 3B is implemented by using a leadless surface mount package having a metal bottom. As further described below, the metal bottom may provide an effective heat sink that dissipates heat from the system 100. Note further that the MOSFET may be replaced by an insulated gate bipolar transistor (IGBT) that can be used in motion control systems.

  FIG. 4 illustrates the use of an active element metal clip joint according to an embodiment of the present invention to improve the electrical and thermal properties of the system. As described above, for example, a driving device / control device such as the driving device / control device 101 of FIG. 3B and a MOSFET such as LoMOS 102 and / or HiMOS 103 of FIG. 3B improve the electrical and thermal characteristics of the device. It may be connected to the lead frame by using metal (eg Cu) clip bonding. FIG. 4 illustrates the upper part of the metal clips 111, 112, 113, 114, 115 and 116. Note that the illustrated components that connect via metal clip bonding are inconspicuous.

  FIG. 5 shows an exemplary manufacturing process 120 for a device according to the present invention. Process 120 begins by forming a lead frame at 121. The lead frame may be formed by conventional means such as stamping and bending. At 122, components including integrated circuit (s) and passive elements are installed.

  In accordance with embodiments of the present invention, some components, such as integrated circuits, may utilize wire bonds that couple with lead frames and / or other components.

  At 123, the surface mount bond is reflowed, for example, via a gas phase or infrared process. In 124, the device and lead frame are overmolded with metal encapsulation to form a single package. At 125, the package is laser marked for identification. At 126, excess plastic produced by the molding process is removed, such as, for example, a "protrusion" from the mold seam or a "gate" of a plastic injection gate.

  At 127, the exposed portion of the lead frame is plated to be stable to the surrounding environment and to improve solderability to the next level assembly. At 128, the package is diced. At 129, the device is tested. Those elements that pass the test are subsequently packaged at 130, for example by tape and reel.

  FIG. 6 illustrates the use of an electrically isolated substrate that groups passive elements into a group with internal connections according to an embodiment of the present invention. In this embodiment, an electrically isolated substrate 131, such as ceramic, for example, may have a plurality of passive elements in a group by internal connection. Thus, such an insulating substrate may be coupled to a part of the lead frame and / or other components.

  7A and 7B illustrate a top view of a complete power management system 100 according to an embodiment of the present invention. MOSFET 701 is illustrated in the upper right corner. It can be seen that the inductor 702 is mounted directly on the “spanning” portion of the lead frame. In this example, a diode 703 indicated by symbol D1 is also used. The diode may be connected to the lead frame by using a metal (eg Cu) clip bonding method. FIG. 7B illustrates a typical design having a typical size.

  FIG. 8 illustrates a complete system bottom and exposed leadframe arrangement 140 (using a leadless surface mount package) in accordance with the present invention. In this embodiment of the present invention, the exposed lead frame located at the bottom of the device functions as an effective heat sink for heat dissipation.

  FIG. 9A shows a perspective view of an exemplary molded embodiment of the present invention. In this example, the device 300 has a system 100 that is coated with a molded plastic package. In the plastic mold, the outer frame is shown, and the internal parts are shown.

  FIG. 9B shows a perspective view of an exemplary unmolded embodiment of the present invention. A complete system 100 having a driver / controller 50, a MOSFET, and passive elements R, L, and C is shown. A drive / control device 50 coupled to the inductor L1 is shown. Other passive elements that connect to the lead frame are also shown.

  FIG. 10A illustrates a top view of an exemplary embodiment of the present invention. As shown, the complete system 100 has passive elements (Cn, Ln, Rn) that connect everywhere in the lead frame, and also has a driver / controller 50 and a MOSFET.

  FIG. 10B shows a perspective view of an exemplary unmolded embodiment of the present invention. As shown, the complete system 100 has passive elements (Cn, Ln, Rn) that connect everywhere in the lead frame, and also has a driver / controller 50 and a MOSFET.

  FIG. 11A shows a perspective view of an exemplary unmolded embodiment of the present invention. As shown, the complete system 100 has passive elements (Cn, Ln, Rn) that connect everywhere in the lead frame, and also has a driver / controller 50 and a MOSFET.

  FIG. 11B shows a perspective view of a lead frame arrangement according to an exemplary embodiment of the present invention. This illustrates the bottom of the system. The lead frame is metal. The lead frame is used as an effective heat sink for heat dissipation.

  FIG. 12A shows a perspective view of a lead frame arrangement according to an exemplary embodiment of the present invention. In the embodiment shown, the parts are exposed.

  FIG. 12B shows a top view of a lead frame arrangement according to an exemplary embodiment of the present invention. This illustrates the bottom of the system. The lead frame is metal. The lead frame is used as an effective heat sink for heat dissipation.

  The foregoing description of a particular embodiment of the present invention, a single surface mount package, has been presented for purposes of illustration and description. The above description of specific examples is not exhaustive, i.e. is not intended to limit the invention to the precise embodiments disclosed. Obviously many modifications and variations are possible in view of the above teachings. The embodiment has been chosen and described in order to best explain the principles and practical application of the invention. This allows one skilled in the art to best utilize the present invention and various embodiments with various modifications to suit the particular application envisaged. It is understood that the technical scope of the present invention is defined by the claims described in "Claims for Utility Model Registration" and their equivalents.

Claims (34)

Controller integrated circuit;
A power MOSFET coupled to the controller integrated circuit;
A plurality of passive elements having at least one inductor;
A device comprising:
The controller integrated circuit, the power MOSFET, and the plurality of passive elements are functionally coupled to implement a complete power management system,
The controller integrated circuit, the power MOSFET, and the plurality of passive elements are mounted on a metal lead frame, and the controller integrated circuit, the power MOSFET, and the plurality of passive elements are sealed with plastic. To form a single package,
apparatus.   The apparatus of claim 1, wherein a portion of the metal lead frame is exposed at a back surface of the package.   3. The apparatus of claim 2, wherein a portion of the metal lead frame is provided to thermally couple with a printed circuit board.   The apparatus of claim 1, wherein the metal lead frame comprises Cu.   The apparatus of claim 1 further comprising metal clip bonding.   The apparatus of claim 4, further comprising metal clip bonding.   The apparatus of claim 1, wherein the plurality of passive elements comprise diodes.   2. The apparatus of claim 1, wherein a termination of the at least one inductor is directly mounted on a portion of the lead frame and electrically connected to a portion of the lead frame.   The apparatus of claim 1, wherein the controller integrated circuit, the power MOSFET, and the plurality of passive elements are functionally coupled by non-substrate coupling.   The apparatus of claim 1, wherein a portion of the lead frame provides a current path that couples terminations of at least two independent passive elements of the plurality of passive elements.   11. The apparatus of claim 10, wherein the at least two independent passive elements are mounted directly on a portion of the lead frame. A device having a complete power management system,
The complete power management system is:
Controller integrated circuit;
A power MOSFET coupled to the controller integrated circuit;
A plurality of passive elements having at least one inductor;
Have
The controller integrated circuit, the power MOSFET, and the plurality of passive elements are functionally coupled to implement the complete power management system, and the controller integrated circuit, the power MOSFET, and the plurality of passive elements The device is provided on a leadless surface mount package,
apparatus.   The apparatus of claim 12, wherein the leadless surface mount package further comprises an exposed metal bottom.   13. The apparatus of claim 12, wherein the exposed metal bottom functions as a heat sink for heat dissipation.   The apparatus of claim 12, wherein the plurality of passive elements further comprises resistors and capacitors.   13. The apparatus of claim 12, wherein each of the plurality of passive elements is coupled between a power post and a lead post of a metal lead frame that couples to the controller integrated circuit.   The apparatus of claim 16, wherein the metal lead frame comprises Cu.   The apparatus of claim 12, further comprising a diode.   13. The apparatus of claim 12, wherein the controller integrated circuit, the power MOSFET, and the plurality of passive elements are connected to a lead frame by using metal clip bonding.   The apparatus of claim 19, wherein the metal clip comprises Cu.   The apparatus of claim 18, wherein the diodes connect by using metal clip bonding.   The apparatus of claim 12, wherein the complete power management system is a DC / DC converter.   23. The apparatus of claim 22, wherein the leadless surface mount package has a first package contact that accepts a DC input voltage and a second package contact that provides a controlled DC output voltage.   The apparatus of claim 12, wherein the complete power management system is a motion control circuit.   The apparatus of claim 12, wherein the complete power management system is a smart power module.   The apparatus of claim 12, wherein the complete power management system comprises a constant current controller.   27. The apparatus of claim 26, wherein the leadless surface mount package has a first package contact that receives a DC input voltage and a second package contact that supplies a constant output current.   13. The apparatus of claim 12, wherein the controller integrated circuit, the power MOSFET, and the plurality of passive elements are functionally coupled by non-substrate coupling. Controller integrated circuit;
A power MOSFET coupled to the controller integrated circuit; and a plurality of passive elements having inductors, resistors, and capacitors;
A DC / DC converter system comprising:
The controller integrated circuit, the power MOSFET, and the plurality of passive elements are provided on a leadless surface mount package having an exposed metal bottom;
system.   30. The system of claim 29, wherein the exposed metal bottom functions as a heat sink for heat dissipation.   30. The system of claim 29, wherein each of the plurality of passive elements is coupled between a power post and a lead post of a metal lead frame that couples to the controller integrated circuit.   30. The system of claim 29, further comprising a diode.   30. The system of claim 29, wherein the controller integrated circuit, the power MOSFET, and the plurality of passive elements are connected to a lead frame by using metal clip bonding.   34. The system of claim 33, wherein the metal clip comprises Cu.

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