Packaging piece, preparation method and electrical system

Abstract

The invention relates to a package, a preparation method and an electrical system. There is provided a package including: a mounting substrate to which at least one power chip is attached, the power chip including a power device; and a lead frame including a first chip attachment portion to which at least one collaboration device chip is attached, the collaboration device chip including a collaboration device cooperating with the power device, where heat generated by the collaboration device is lower than that generated by the power device during normal operation, and at least one first lead connected to the first chip attachment portion. Wherein the at least one first lead is coupled to the first surface of the mounting substrate so as to be electrically connected with the power chip.

Description

Technical Field

[0001] The present disclosure relates to a package, a method for manufacturing the same (packaging method), and an electrical system including the package. Background Art

[0002] The packaging of intelligent power modules (IPMs) has received increasing attention. For IPM packages with mature designs, fine design to obtain better performance has become a trend in package design. On the other hand, since IPM packages use expensive advanced mounting substrates for mounting power-side devices, such as direct bond copper (DBC) substrates, to improve heat dissipation performance. This has led to a huge increase in cost.

[0003] In addition, in the IPM packages of the prior art, the lead sizes of the lead frame for connecting to the DBC are mainly designed to ensure the welding strength for the welding process (e.g., solder paste welding), so the lead area is relatively large. At the same time, limited by the DBC layout, the sizes of the leads are not exactly the same or similar, resulting in uneven distribution of the connecting leads. During molding, there is a risk of overflow of the molding compound on the back surface of the DBC substrate.

[0004] Therefore, there is a need in the prior art for improved packages and methods for manufacturing the same (packaging methods). Summary of the Invention

[0005] According to one aspect of the present disclosure, there is provided a package, including: a mounting substrate, at least one power chip attached to a first surface of the mounting substrate, the power chip including a power device; and a lead frame, including a first chip attachment portion and at least one first lead, at least one cooperative device chip attached to the first chip attachment portion, the cooperative device chip including a cooperative device that cooperates with the power device, wherein the heat generated by the cooperative device is lower than that of the power device during normal operation, and wherein the at least one first lead is coupled to the first surface of the mounting substrate to be electrically connected to the power chip.

[0006] According to another aspect of the present disclosure, there is also provided an electrical system, which may include the package according to any embodiment.

[0007] According to another aspect of the present disclosure, there is also provided a method for manufacturing a package, including: attaching a power chip to a first surface of a mounting substrate, the power chip including a power device; attaching a cooperating device chip to a first chip attachment portion of a lead frame, the lead frame further including at least one first lead, the cooperating device chip including a cooperating device that cooperates with the power device, wherein during normal operation, the heat generated by the cooperating device is lower than that of the power device; attaching the at least one first lead to the first surface of the mounting substrate to be electrically connected to the power chip; performing wire bonding, the wire bonding including bonding a first wire to the power device and the cooperating device; and applying a molding compound to at least encapsulate at least a portion of the mounting substrate, the power chip, the cooperating device chip, the first wire, and at least a portion of the lead frame.

[0008] Other features and advantages of the present disclosure will become clear from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The drawings forming a part of the specification depict embodiments of the present disclosure and, together with the description, are used to explain the principles of the present disclosure.

[0010] With reference to the accompanying drawings, the present disclosure can be more clearly understood from the following detailed description, wherein:

[0011] Figure 1 A schematic diagram of an IPM package of the prior art is shown;

[0012] Figure 2 A schematic diagram of a package according to some embodiments of the present disclosure is shown;

[0013] Figure 3 A schematic diagram of a package according to some embodiments of the present disclosure is shown;

[0014] Figure 4 A schematic diagram of a package according to some embodiments of the present disclosure is shown;

[0015] Figure 5 A perspective schematic diagram of a package according to some embodiments of the present disclosure is shown;

[0016] Figure 6 A schematic cross-sectional view of a package according to some embodiments of the present disclosure is shown;

[0017] Figure 7 A schematic cross-sectional view of a package according to other embodiments of the present disclosure is shown; and

[0018] Figure 8 A flowchart of a packaging method according to some embodiments of the present disclosure is shown.

[0019] Note that in the embodiments described below, the same reference numerals are sometimes used commonly between different drawings to denote the same parts or parts having the same functions, and their repeated descriptions are omitted. In this specification, similar reference numerals and letters are used to denote similar items. Therefore, once an item is defined in one drawing, it is not necessary to discuss it further in subsequent drawings.

[0020] For ease of understanding, the positions, dimensions, ranges, etc. of the respective structures shown in the drawings and the like sometimes do not represent the actual positions, dimensions, ranges, etc. Therefore, the disclosed invention is not limited to the positions, dimensions, ranges, etc. disclosed in the drawings and the like. Detailed Embodiments

[0021] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the drawings. It should be noted that: Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and values set forth in these embodiments do not limit the scope of the present disclosure. Additionally, technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification.

[0022] It should be understood that the following description of at least one exemplary embodiment is merely illustrative and is not any limitation to the present disclosure or its application or use. It should also be understood that any implementation manner described herein by way of example does not necessarily indicate that it is more preferred or advantageous than other implementation manners. The present disclosure is not limited by any theory expressed or implied in the above technical field, background art, summary of the invention, or detailed embodiments.

[0023] In addition, for reference purposes only, certain terms may also be used in the following description and are thus not intended to be limiting. For example, unless the context clearly indicates otherwise, words such as "first", "second", and other such numerical words referring to structures or elements do not imply an order or sequence.

[0024] It should also be understood that when the term "comprising / including" is used herein, it indicates the presence of the stated features, wholes, steps, operations, units, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, units, and / or components and / or their combinations.

[0025] As used herein, the term "chip" includes, but is not limited to, a die or bare die.

[0026] Figure 1FIG. 0 shows a schematic top view of an IPM package of the prior art. It should be understood that in the figure, some components are filled with shading or patterns to more clearly distinguish them from other adjacent components.

[0027] As Figure 1 shown, the IPM package 100 of the prior art includes a mounting substrate 11 and a lead frame 13. A power chip 111 and a cooperating device chip 113 that cooperate with the power chip are attached to the mounting substrate 11. The mounting substrate 111 can be, for example, a DBC substrate to provide good heat dissipation. The DBC substrate can include a ceramic layer 101 and metal layers on both sides thereof. The metal layer 103 above the ceramic layer 101 is shown in the figure. The metal layer can be formed of, for example, copper or a copper alloy. The power chip 111 and the cooperating device chip 113 are attached to the metal layer 103 and electrically connected thereto.

[0028] A power device (not shown), such as, but not limited to, an insulated gate bipolar transistor (IGBT), can be provided on the power chip 111. A cooperating device (not shown) that cooperates with the power device, such as, but not limited to, a diode (also called a freewheeling diode) that is anti-parallel to the IGBT, can be provided on the cooperating device chip 113. As an example, three power chips 111 and corresponding three cooperating device chips 11 are shown in the figure. The cooperating device can be electrically connected to the power chip (power device) through, for example, a wire 115 to form a circuit.

[0029] The IMP package 100 can be divided into a power side (or power domain) and a control side (or control domain). Generally, the power side is provided with a high voltage and a large current; while the control side is provided with a low voltage and a low current. The power device and its cooperating device are generally provided on the power side. And a controller for controlling the power device is usually provided on the control side.

[0030] The lead frame 13 can include metal, or can be said to be formed of metal. The metal, such as a copper alloy, includes, but is not limited to, binary, ternary, and quaternary copper-based alloys. The lead frame 13 can include a plurality of separate components. As Figure 1 shown, the lead frame 13 includes a number of leads 131 and 133. As shown in the figure, the lead 131 is attached to the metal layer 103 of the mounting substrate 101. The lead 133 is electrically connected to the corresponding power chip 111 and cooperating device chip 113 through a wire 115.

[0031] The lead frame 13 may further include a chip attachment portion 135, and the controller chip 139 is disposed on the chip attachment portion 135. The controller chip 139 may provide control signals to the power chip 111 through wires 141. The lead frame 13 may further include leads 137 for electrical and physical coupling of the controller chip 139 to the outside.

[0032] In the designs of the prior art, both the IGBT and the diode are disposed on the DBC substrate to enhance heat dissipation. Additionally, the DBC substrate accounts for a quite large portion of the cost of the IPM packaging materials (in some examples, up to 45%), which is the main factor affecting the cost of the IPM packaging.

[0033] The inventors of the present invention have found through research that for IPM packaging, heat is mainly generated by the power devices. Furthermore, the inventors of the present application have proposed the invention disclosed herein through research. According to the embodiments of the present disclosure, the cost of the IPM package can be greatly reduced while still meeting the heat dissipation requirements. According to the embodiments of the present disclosure, one or more problems of the prior art IPM packaging pointed out above are overcome. According to the embodiments of the present disclosure, the layout design of the DBC substrate can also be simplified.

[0034] Figure 2 A schematic diagram of a package according to some embodiments of the present disclosure is shown. Figure 2 A top view of some components of the package (here, some components on the power side) is shown. Note that in Figure 2 and other top views, shading or patterns are added to some of the shown components to better distinguish them from other components.

[0035] As Figure 2 shown, the package 200 may include a mounting substrate 21 and a lead frame 23. At least one power chip 211 is attached to the first surface (2011, Figure 7 ) of the mounting substrate. Preferably, the mounting substrate 21 is a multi-layer substrate. As an example, the mounting substrate 21 may include one of the following: a DBC substrate, a Direct Plated Copper (DPC) substrate, an Active Metal Braze (AMB) substrate, a Direct Bonding Aluminum (DBA) substrate, or an Insulated Metal Substrate. As an example, Figure 2 in the embodiments of Figure 7) and an insulating layer 201 sandwiched between the first and second metal layers. In the DBC substrate, the insulating layer 201 can be formed of a ceramic material, and the metal layers 203 and 207 can be formed of copper. In other embodiments, the metal layer of the mounting substrate can be formed of, for example, copper or aluminum.

[0036] The first metal layer 203 on the ceramic layer 201 can have one or more partitions. Here, as an example, Figure 2 two partitions 203_1 and 203_2 are shown, on which one or more power chips 211 are respectively disposed. In the figure, three power chips 211 are shown disposed on the partition 203_1 of the first metal layer, and one power chip 211 is shown disposed on the partition 203_2. It should be understood that the first metal layer can have more or fewer partitions.

[0037] The power chip 211 can be attached to (and thus, electrically connected to) the surface 2011 of the first metal layer 203 by solder (see Figure 7 ). This surface 2011 of the first metal layer 203 also serves as the first surface of the mounting substrate here. The power chip can include power devices, such as one or more of the following: insulated gate bipolar transistor (IGBT), injection enhanced gate transistor (IEGT), integrated gate-commutated thyristor (IGCT), thyristor, power Schottky diode, etc.

[0038] The lead frame 23 includes metal, or rather, the lead frame can be formed of metal. As an example, the metal can include copper, for example, it can be copper or a copper-containing alloy; it should be understood that the present disclosure is not limited thereto. The lead frame 203 can include a first chip attachment portion 231 and at least one first lead 235. The cooperative device chips 233 are respectively attached to the corresponding first chip attachment portions 231, for example, by solder welding. The cooperative device chips include cooperative devices that cooperate with the power devices, for example, diodes. Taking the IGBT and the diode as the power device and the cooperative device as an example for illustration. In this case, the diode can be connected to the IGBT in an anti-parallel manner. When the IGBT is operating (i.e., a forward voltage is applied to the IGBT), a large current mainly flows through the IGBT, and the freewheeling diode is cut off and does not work, so the heat is mainly generated by the power device (IGBT). When there is a large reverse electromotive force, the diode conducts and guides the current to pass through it, thereby protecting the power device (IGBT). Therefore, the heat generated by the cooperative device (diode) is lower than that of the power device (IGBT).

[0039] The first lead 235 is bonded to the first surface of the mounting substrate 21 (here, the upper surface 2011 of the metal layer 203) to be electrically connected to the power chip. The first lead 235 may protrude and extend outward from the edge of the first die attachment portion 231. Preferably, the edge of the first lead 235 is straight. The adjacent edges of the adjacent first leads 235 are each set to be straight and parallel to each other, and the gap between the adjacent edges is set to be of equal width. Preferably, the first lead 235 is bonded to the mounting substrate 21 by laser welding or ultrasonic welding, thereby improving the bonding reliability. Six first leads 235 are shown in the figure bonded to the partition 203_1 of the first metal layer, and two first leads 235 are bonded to the partition 203_2 of the first metal layer. However, this is merely exemplary, and there may be more or fewer leads. In some embodiments, the lead frame 23 may further include additional leads, here, for example, a lead (second lead) 237 for electrical connection to, for example, the outside of the package and / or other components.

[0040] As shown in the figure, a plurality of first leads 235 are provided at the edge of the lead frame 23 facing the power chip and are arranged to be evenly distributed at this edge. Thus, on the mounting substrate 21 (its metal layer 203), the first leads are also evenly distributed. In this way, when the lead frame 23 is bonded to the mounting substrate 21, the mounting substrate 21 can be uniformly stressed and is not easily displaced or tilted, thereby improving and even eliminating the overflow of the molding compound to the back surface of the DBC substrate.

[0041] In addition, as Figure 2 shown, the lead frame 23 may have a plurality of separate components. As an example, the figure shows components 23_1, 23_2, and a plurality of other components 23_3. It should be understood, however, that this is merely exemplary. For example, the lead frame 23 may have only component 23_1 or component 23_2, or may also have more components. As shown in the figure, component 23_1 includes a die attachment portion 231, a first lead 235, and a second lead 237. Preferably, the die attachment portion 231, the first lead 235, and the second lead 237 are integrally formed. Component 23_2 is shown separated from component 23_1 and includes a die attachment portion 231, a first lead 235, and additional leads (second leads 237) for electrical connection to the outside and / or other components. In addition, other components are also shown in the figure, such as component 23_3, which may include additional leads 239. Only a part of component 23_3 including the lead (third lead) 239 is schematically shown here, but it should be understood that component 23_3 may also include other parts, such as a die attachment portion and / or a first lead arranged in the same or similar manner as component 23_1 and component 23_2.

[0042] Here, it should also be understood that although in this embodiment, the second lead 237 and the third lead 239 are shown and described as being used for external electrical connection, the present disclosure is not limited thereto. For example, in other embodiments, the second lead 237 and the third lead 239 may each not be electrically connected to the outside. Additionally, it should also be understood that the configurations of the first lead, the second lead, and the third lead can be diverse, and their positions, dimensions, shapes, quantities, etc. shown in the figures are all exemplary.

[0043] As shown in the figure, a wire (first wire) 251 is bonded to the power chip 211 and the cooperating device chip 233 to provide an electrical connection therebetween. Although not shown herein, those skilled in the art will readily understand that pads may be provided on the chips (e.g., the power chip, the cooperating device chip, and the controller chip to be described below), and a section of the wire may be bonded to the pads to provide a mechanical connection and an electrical connection. Preferably, the wire 251 is an aluminum wire; however, the present disclosure is not limited thereto, and for example, a copper wire may also be used. As an example, one electrode of an IGBT chip (which serves as a power chip) may be electrically connected to the metal layer 203 (or a part thereof) of the DBC substrate 21, and one electrode of a diode chip (which serves as a cooperating device chip) may be electrically connected to the lead frame 23 (or its components, such as 23_1), so that the two are electrically connected to each other through the first lead. One end of the wire 251 may be electrically connected to the other electrode of the IGBT chip, and another part may be electrically connected to the other electrode of the diode chip, thereby forming an electrical connection therebetween. When needed, the wire 251 may further be bonded to the corresponding second lead or other components, as Figure 2 shown. It should also be understood that although two wires 251 are shown for each power chip in the figure, the present disclosure is not limited thereto.

[0044] In the package, an installation substrate such as a DBC substrate has excellent heat dissipation performance, but it is also expensive and occupies a quite large part of the cost of the IPM package. In the package, since it is encapsulated by a molding compound, the heat dissipation performance of the lead frame is lower than that of the installation substrate. For the application of IPM packages and power devices, heat has a substantial impact on the performance of the power devices and even the entire package. Therefore, heat dissipation is a particularly important consideration. In the prior art, it has always been inclined to arrange the electronic components on the power side on an installation substrate with better heat dissipation (such as a DBC substrate) to meet the heat dissipation requirements, and this is even more so when the voltage and current tolerated by the power device are higher.

[0045] The inventors of the present application have carefully analyzed the heat dissipation of components in the IPM package of the prior art and realized that the cooperative device chip can be arranged at the lead frame while still meeting the requirements for heat dissipation. In this way, the area of the expensive mounting substrate such as the DBC substrate used can be greatly reduced, thereby greatly reducing the cost of the package. In some examples, the size of the DBC substrate is reduced by up to 45.9%, and the module packaging cost is significantly reduced while still maintaining the same heat dissipation effect of the packaged product.

[0046] For example, the size of the DBC substrate can be 29mm x 12mm x 0.98mm, the thickness of the lead frame can be 0.38mm, and the size of the IGBT chip can be 2.5mm x 2.5mm to 3.5mm x 4.8mm. The size of the diode chip can be 2.2mm x 2.2mm. And according to the embodiments of the present disclosure, not only the part at the diode chip is eliminated, but also the IGBT chip can be made as close as possible to the first lead.

[0047] In addition, since the power-side cooperative device chip is removed from the mounting substrate, the layout design of the mounting substrate is made more flexible and simple. And due to the simplification of the layout of the mounting substrate, the size of the first lead can be designed to be smaller and more evenly distributed, so that ultrasonic welding or laser welding can be applied to join the lead (and the lead frame) to the mounting substrate, reducing the connection failure rate between the lead frame and the mounting substrate and improving the reliability of the product.

[0048] In addition, compared with the prior art, in the embodiments of the present disclosure, the leads are more evenly distributed on the mounting substrate (for example, the DBC substrate), thereby improving or eliminating the overflow problem of the molding compound to the back of the DBC.

[0049] Figure 3 A schematic top view of some components of the package according to some embodiments of the present disclosure is shown. Here, it includes some components on the power side and some components on the control side. Figure 3 The shown package 300 substantially includes Figure 2 all the components of the shown package 200. Additionally, the device 300 further includes some components on the control side. As Figure 3 shown, the lead frame 23 may further include additional components 23_5 for the control side, which are separated from other components 23_1, component 23_2, component 23_3, etc. The component 23_5 of the lead frame may include an additional chip attachment portion (second chip attachment portion) 301 and an additional lead (fourth lead) 331. The chip attachment portion (second chip attachment portion) 301 is also correspondingly separated from the first chip attachment portion 231 of the components 23_1 and 23_2 and its corresponding first lead 235.

[0050] The controller chip 303 is disposed on the chip attachment portion 301 and is electrically connected to the power chip through a wire (second wire) 311; thereby, the controller chip 303 can provide signals to the power chip to control, for example, the operation of related power devices. As an example, Figure 3 Two chip attachment portions 301 and two controller chips 303 are shown. Preferably, the wire 311 can be a copper wire.

[0051] It should be understood that Figure 3 the configuration of the shown component 23_5 is merely exemplary; the present disclosure is not limited thereto. It should also be understood that the configuration of the third lead 331 can be diverse. Multiple different configurations of the third lead 331 are shown in Figure 3 Some leads 331 can communicate with the chip attachment portion 301, while the remaining leads 331 can be isolated from the chip attachment portion 301. The control chip 303 can be electrically connected to the corresponding isolated leads through additional wires ( Figure 3 not shown in the figure, see Figure 6 601).

[0052] Those skilled in the art will readily understand that one or more of the above components 23_1, 23_2, 23_3, 23_5, etc. of the lead frame 23 can be connected, for example, by a tie bar (not shown in the figure) in some intermediate products or intermediate manufacturing processes. The tie bar can be removed after applying the molding compound to separate the above components from each other.

[0053] Figure 4 A schematic top view of a package according to some embodiments of the present disclosure is shown. Figure 4 The shown package substantially includes all components of the Figure 3 shown package 300. The package further includes a mold compound 401. The mold compound 401 at least encapsulates at least a portion of the mounting substrate 21, the power chip 211, the cooperating device chip 233, the first wire 251, and at least a portion of the lead frame 23. In some embodiments, in the case of using, for example, a DBC substrate as the mounting substrate 21, the mold compound can be configured such that the second surface (2071, see Figure 6 or Figure 7 ) of the mounting substrate 21 opposite to the first surface is exposed.

[0054] Figure 5 A perspective simulation view of a package according to some embodiments of the present disclosure is shown to assist in understanding the foregoing planar top view. Figure 5For components that are the same as those in the previous figures, the same reference numerals as those used in the previous figures are adopted, so they will not be repeatedly described here.

[0055] Figure 6 Fig. shows a schematic cross-sectional view of a package according to some embodiments of the present disclosure. Figure 6 For components that are the same as those in the previous figures, the same reference numerals as those used in the previous figures are adopted, so they will not be repeatedly described here. In Figure 6 In the illustrated embodiment, the first chip attachment portion 231 is set to be substantially flush with the first lead 235, while the second lead 237 / third lead 239 is set to be higher than the corresponding first chip attachment portion 231. The leads 237 / 239 are set to be substantially flush with the leads 331 on the opposite side. In this way, the height of the cooperating device chip (e.g., relative to the bottom surface of the package) can be reduced, leaving sufficient clearance for forming the wire 251 thereon. And the lead configuration can be maintained the same as that of the packages in the prior art.

[0056] In addition, since the first wire 251 protrudes above the mounting substrate 21 and the lead frame 23, the thickness of the molding compound and the height of the first wire should be set such that the molding compound is sufficient to cover the first wire (and other wires).

[0057] Figure 7 Fig. shows a schematic cross-sectional view of a package according to other embodiments of the present disclosure. Figure 7 For components that are the same as those in the previous figures, the same reference numerals as those used in the previous figures are adopted, so they will not be repeatedly described here. In Figure 7 In the illustrated embodiment, the first chip attachment portion 231 is further lowered and set to be lower than the first lead 235, while the leads 237 / 239 are set to be higher than both the first chip attachment portion 231 and the first lead 235. In this way, the height of the wire 251 can be further reduced, and thus the height (thickness) of the molding compound can be correspondingly reduced. On the other hand, the cooperating device chip 233 can be made closer to the bottom surface of the package, thereby improving the heat dissipation of the cooperating device chip 233.

[0058] As Figure 6 and 7 shown, the mounting substrate 21 may further include a second metal layer 207 disposed on the insulating layer (e.g., ceramic layer) 201 opposite to the first metal layer 203. The first metal layer 203 and the second metal layer 207 are respectively disposed on both sides of the insulating layer 201. The molding compound 401 can be configured such that the surface 2071 of the second metal layer 207 is exposed. The molding compound also encapsulates the second wire 311 and other wires (e.g., the wire 601 from the control chip 303 to the lead 331).

[0059] Figure 8 The flowchart of a method for preparing a package (or packaging method) according to some embodiments of the present disclosure is shown. As Figure 8 shown, method 800 includes, in step S801, attaching a power chip to a first surface of a mounting substrate, the power chip including a power device. For example, the power chip 211 can be attached to the first surface 2011 of the mounting substrate 21 by vacuum reflow soldering.

[0060] Method 800 further includes, in step S803, attaching a cooperative device chip to a first chip attachment portion of a lead frame, the lead frame further including at least one first lead. The cooperative device chip includes a cooperative device that cooperates with the power device, wherein the heat generated by the cooperative device is lower than that of the power device during normal operation. For example, the cooperative device chip 233 can be attached to the first chip attachment portion 231 of the lead frame 23 by wire soldering.

[0061] Method 800 further includes, in step S805, attaching a first lead to the first surface of the mounting substrate to be electrically connected to the power chip. For example, for example, the components of the lead frame can be supported by a mechanical support structure, such as a tiebar connecting the components of the lead frame, or the lead frame can be clamped by a clip, and the first lead 235 is attached to the first surface 2011 of the mounting substrate 21 by laser soldering or ultrasonic soldering to be electrically connected to the power chip 211.

[0062] Method 800 further includes, in step S807, performing wire bonding. Wire bonding includes bonding a first wire to the power chip and the cooperative device chip. For example, the first wire 251 can be bonded to the power chip 211 and the cooperative device chip 233 by aluminum wire bonding, thereby providing an electrical connection between the power chip 211 and the cooperative device chip 233. The first wire can be, for example, an aluminum wire.

[0063] Method 800 further includes, in step S809, applying a molding compound. For example, the molding compound 401 is applied to at least encapsulate at least a portion of the mounting substrate 21, the power chip 211, the cooperative device chip 233, the first wire 251, and at least a portion of the lead frame 23, as Figure 4 , Figure 6 and Figure 7 shown.

[0064] In some embodiments, after the molding compound is applied, the tiebar between the components of the lead frame can be removed.

[0065] In some embodiments, the mounting substrate may include a first metal layer, a second metal layer, and an insulating layer sandwiched between the first and second metal layers. The power chip is attached to the surface of the first metal layer, and the surface of the first metal layer serves as the first surface of the mounting substrate. The lead frame may include a metal, such as copper.

[0066] In some embodiments, the lead frame may further include at least one second lead, wherein at least one first lead, the first chip attachment portion, and at least one second lead are integrally formed. In some embodiments, the molding compound is further configured to expose the second surface of the mounting substrate opposite to the first surface.

[0067] In some embodiments, due to being encapsulated by the molding compound, the heat dissipation performance of the lead frame is lower than that of the mounting substrate. In some embodiments, the first chip attachment portion is provided to be substantially flush with the first lead. In other embodiments, the first chip attachment portion is provided to be lower than the first lead.

[0068] In some embodiments, the lead frame may include two or more first leads, and the first leads are disposed at the edge of the lead frame facing at least one power chip, and the two or more first leads are arranged to be evenly distributed at the edge.

[0069] In some embodiments, the lead frame further includes a third lead, the third lead is separated from the second chip attachment portion and the second lead, and the first wire is also bonded to the third lead.

[0070] In some embodiments, method 800 may further include, in step S806, attaching a controller chip to the second chip attachment portion of the lead frame, and the second chip attachment portion is separated from the first chip attachment portion and the first lead. For example, the controller chip 303 may be attached to the second chip attachment portion 301 by adhesive bonding.

[0071] There is no particular limitation on the order of execution of step S801, step S803, and step S806, as long as it is performed before the wire bonding step. For example, step S801 and step S803 may be performed simultaneously, so that the time required for the process flow can be saved. Again, for example, any one of step S801, step S803, and step S806 may be performed before the other two.

[0072] In some embodiments, performing wire bonding further includes: bonding a second wire to the controller chip and the power chip. For example, a copper wire or a gold wire (the second wire) 311 may be bonded to the controller chip 301 and the power chip 211 by copper wire bonding or gold wire bonding. The molding compound 401 is further configured to encapsulate the second wire 311.

[0073] The present application also contemplates an electrical system, which may include a package according to any embodiment of the present disclosure. As an example, the electrical system may include, for example, an inverter, a new energy vehicle, a wind power system, a solar power generation system, an energy storage system, or any other device or system that requires the application of the package of the present disclosure.

[0074] The present disclosure also contemplates the following items.

[0075] Item 1. A package, comprising: a mounting substrate, at least one power chip attached to a first surface of the mounting substrate, the power chip including a power device; and a lead frame, including a first chip attachment portion and at least one first lead, at least one cooperating device chip attached to the first chip attachment portion, the cooperating device chip including a cooperating device that cooperates with the power device, wherein during normal operation, the heat generated by the cooperating device is lower than that of the power device, and wherein the at least one first lead is coupled to the first surface of the mounting substrate for electrical connection with the power chip.

[0076] Item 2. The package according to Item 1, wherein: the mounting substrate includes a first metal layer and a second metal layer and an insulating layer sandwiched between the first and second metal layers, the at least one power chip is attached to the surface of the first metal layer, and the surface of the first metal layer serves as the first surface of the mounting substrate; and the lead frame includes metal.

[0077] Item 3. The package according to Item 1, wherein: the lead frame further includes at least one second lead for electrical connection to the outside of the package, and the at least one first lead, the first chip attachment portion, and the at least one second lead are integrally formed.

[0078] Item 4. The package according to any one of Items 1-3, wherein: in the package, the heat dissipation performance of the lead frame is lower than that of the mounting substrate.

[0079] Item 5. The package according to Item 1, wherein: the package is an IPM package, and the mounting substrate includes one of the following: a DBC substrate, a DPC substrate, an AMB substrate, a DBA substrate, or an IMS substrate; the power device includes one or more of the following: an IGBT, an IGET, an IGCT, a thyristor, a power Schottky diode; and the cooperating device includes a diode.

[0080] Item 6. The package according to Item 1, wherein the first chip attachment portion is arranged to be substantially flush with the first lead or lower than the first lead.

[0081] Item 7. The package as described in Item 3, wherein: the at least one second lead is disposed higher than the first chip attachment portion and the at least one first lead.

[0082] Item 8. The package as described in Item 1, further comprising: a first wire, the first wire being attached to the power chip and the cooperative device chip; and a molding compound that at least encapsulates at least a portion of the mounting substrate, the power chip, the cooperative device chip, the first wire, and at least a portion of the lead frame, wherein the molding compound exposes a second surface of the mounting substrate that is opposite to the first surface.

[0083] Item 9. The package as described in Item 1, wherein: the at least one first lead is disposed at an edge of the lead frame facing the at least one power chip, the at least one first lead includes two or more first leads, and the two or more first leads are disposed to be evenly distributed at the edge.

[0084] Item 10. The package as described in Item 8, further comprising: a controller chip for controlling the power device, wherein the controller chip is disposed on a second chip attachment portion of the lead frame and is electrically connected to the power chip through a second wire, the second chip attachment portion is separated from the first chip attachment portion and the at least one first lead, and the molding compound further encapsulates the second wire.

[0085] Item 11. The package as described in Item 8, wherein the lead frame further includes a third lead that is separated from the first chip attachment portion and the first lead and is used for electrical connection to the outside, and the first wire is attached to the third lead.

[0086] Item 12. An electrical system comprising the package as described in any one of Items 1 - 11.

[0087] Item 13. A method for preparing a package, comprising: attaching a power chip to a first surface of a mounting substrate, the power chip including a power device; attaching a cooperating device chip to a first chip attachment portion of a lead frame, the lead frame further including at least one first lead, the cooperating device chip including a cooperating device that cooperates with the power device, wherein heat generated by the cooperating device is lower than that of the power device during normal operation; attaching the at least one first lead to the first surface of the mounting substrate to be electrically connected to the power chip; performing wire bonding, which includes bonding a first wire to the power device and the cooperating device; and applying a molding compound to encapsulate at least a part of the mounting substrate, the power chip, the cooperating device chip, the first wire, and at least a part of the lead frame.

[0088] Item 14. The method according to Item 13, wherein: the mounting substrate includes a first metal layer, a second metal layer, and an insulating layer sandwiched between the first and second metal layers, the at least one power chip is attached to a surface of the first metal layer, the surface of the first metal layer serving as the first surface of the mounting substrate, the lead frame includes metal, the lead frame further includes at least one second lead, wherein the at least one first lead, the first chip attachment portion, and the at least one second lead are integrally formed, and the molding compound is configured to expose a second surface of the mounting substrate opposite to the first surface.

[0089] Item 15. The method according to Item 13, wherein: the heat dissipation performance of the lead frame is lower than that of the mounting substrate when encapsulated by the applied molding compound.

[0090] Item 16. The method according to Item 13, wherein the first chip attachment portion is arranged to be substantially flush with the first lead or lower than the first lead.

[0091] Item 17. The method according to Item 13, wherein: the at least one first lead is arranged at an edge of the lead frame facing the at least one power chip, the at least one first lead includes two or more first leads, and the two or more first leads are arranged to be evenly distributed at the edge.

[0092] Item 18. The method as described in Item 13, wherein the lead frame further includes a third lead, the third lead is separated from the second chip attachment portion and the second lead, and wherein the first wire is also bonded to the third lead. The method further includes: attaching a controller chip to the second chip attachment portion of the lead frame, the second chip attachment portion being separated from the first chip attachment portion and the first lead. Wherein performing wire bonding further includes wire-bonding a second wire to the controller chip and the power chip, and wherein the molding compound also encapsulates the second wire.

[0093] Item 19. The method as described in Item 13, wherein: the package is an IPM package, the mounting substrate includes one of the following: DBC substrate, DPC substrate, AMB substrate, DBA substrate or IMS substrate; the power device includes one or more of the following: IGBT, IGET, IGCT, thyristor, power Schottky diode; the cooperating device includes a diode.

[0094] Those skilled in the art should be aware that the boundaries between operations (or steps) described in the above embodiments are merely illustrative. Multiple operations can be combined into a single operation, a single operation can be distributed among additional operations, and operations can be performed at least partially overlapping in time. Moreover, alternative embodiments can include multiple instances of a particular operation, and the order of operations can be changed in various other embodiments. However, other modifications, variations, and substitutions are also possible. Therefore, this specification and the drawings should be regarded as illustrative rather than restrictive.

[0095] Although some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and not for limiting the scope of the present disclosure. The embodiments disclosed herein can be combined arbitrarily without departing from the spirit and scope of the present disclosure. Those skilled in the art should also understand that various modifications can be made to the embodiments without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. An encapsulation, comprising: A mounting substrate, at least one power chip being attached to a first surface of the mounting substrate, the power chip comprising a power device; And A lead frame, comprising a first chip attachment portion and at least one first lead, at least one cooperative device chip being attached to the first chip attachment portion, the cooperative device chip comprising a cooperative device that cooperates with the power device, wherein during normal operation, heat generated by the cooperative device is lower than that of the power device, Wherein the at least one first lead is coupled to the first surface of the mounting substrate for electrical connection with the power chip.

2. The encapsulation according to claim 1, wherein: The mounting substrate comprises a first metal layer and a second metal layer and an insulating layer sandwiched between the first and second metal layers, the at least one power chip being attached to a surface of the first metal layer, the surface of the first metal layer serving as the first surface of the mounting substrate; And The lead frame comprises metal.

3. The encapsulation according to claim 1, wherein: The lead frame further comprises at least one second lead for electrical connection to the outside of the encapsulation, and The at least one first lead, the first chip attachment portion, and the at least one second lead are integrally formed.

4. The encapsulation according to any one of claims 1 - 3, wherein: In the encapsulation, heat dissipation performance of the lead frame is lower than that of the mounting substrate.

5. The encapsulation according to claim 1, wherein: The encapsulation is an IPM encapsulation, The mounting substrate comprises one of the following: DBC substrate, DPC substrate, AMB substrate, DBA substrate, or IMS substrate; The power device comprises one or more of the following: IGBT, IGET, IGCT, thyristor, power Schottky diode; The cooperative device comprises a diode.

6. The package according to claim 1, wherein The first chip attachment portion is arranged to: Be substantially flush with the first lead, or Be lower than the first lead.

7. The encapsulation according to claim 3, wherein: The at least one second lead is arranged to be higher than the first chip attachment portion and the at least one first lead.

8. The encapsulation according to claim 1, further comprising: A first wire, the first wire being attached to the power chip and the cooperative device chip; And A molding compound that at least encapsulates at least a portion of the mounting substrate, the power chip, the cooperative device chip, the first wire, and at least a portion of the lead frame, Wherein the molding compound exposes a second surface of the mounting substrate opposite to the first surface.

9. The encapsulation according to claim 1, wherein: The at least one first lead is disposed at an edge of the lead frame facing the at least one power chip, the at least one first lead comprising two or more first leads, Wherein the two or more first leads are arranged to be evenly distributed at the edge.

10. The encapsulation according to claim 8, further comprising: A controller chip for controlling the power device, Wherein, the controller chip is disposed on a second chip attachment portion of the lead frame and is electrically connected to the power chip through a second wire, and the second chip attachment portion is separated from the first chip attachment portion and the at least one first lead. The molding compound also encapsulates the second wire.

11. The package according to claim 8, wherein the lead frame further includes a third lead, the third lead is separated from the first chip attachment portion and the first lead for electrical connection to the outside, and wherein the first wire is attached to the third lead.

12. An electrical system, comprising the package according to any one of claims 1-11.

13. A method for manufacturing a package, comprising: attaching a power chip to a first surface of a mounting substrate, the power chip including a power device; attaching a cooperating device chip to a first chip attachment portion of a lead frame, the lead frame further including at least one first lead, the cooperating device chip including a cooperating device that cooperates with the power device, wherein during normal operation, the heat generated by the cooperating device is lower than that of the power device; attaching the at least one first lead to the first surface of the mounting substrate for electrical connection to the power chip; performing wire bonding, the wire bonding including bonding a first wire to the power device and the cooperating device; and applying a molding compound to encapsulate at least a portion of the mounting substrate, the power chip, the cooperating device chip, the first wire, and at least a portion of the lead frame.

14. The method according to claim 13, wherein: the mounting substrate includes a first metal layer, a second metal layer, and an insulating layer sandwiched between the first and second metal layers, the at least one power chip is attached to a surface of the first metal layer, and the surface of the first metal layer serves as the first surface of the mounting substrate, the lead frame includes metal, the lead frame further includes at least one second lead, wherein the at least one first lead, the first chip attachment portion, and the at least one second lead are integrally formed, and the molding compound is configured to expose a second surface of the mounting substrate opposite to the first surface.

15. The method according to claim 13, wherein: in the case of being encapsulated by the applied molding compound, the heat dissipation performance of the lead frame is lower than that of the mounting substrate.

16. The method according to claim 13, wherein The first chip attachment portion is arranged to: be substantially flush with the first lead, or be lower than the first lead.

17. The method according to claim 13, wherein: the at least one first lead is disposed at an edge of the lead frame facing the at least one power chip, the at least one first lead includes two or more first leads, wherein the two or more first leads are arranged to be evenly distributed at the edge.

18. The method according to claim 13, wherein the lead frame further includes a third lead, the third lead is separated from the second chip attachment portion and the second lead, and wherein the first wire is also bonded to the third lead. The method further includes: Attaching a controller chip to a second chip attachment portion of a lead frame, the second chip attachment portion being separated from the first chip attachment portion and the first lead, wherein performing wire bonding further includes wire-bonding a second wire to the controller chip and the power chip, wherein the molding compound further encapsulates the second wire.

19. The method according to claim 13, wherein: The package is an IPM package, The mounting substrate includes one of the following: a DBC substrate, a DPC substrate, an AMB substrate, a DBA substrate, or an IMS substrate; The power device includes one or more of the following: an IGBT, an IGET, an IGCT, a thyristor, a power Schottky diode; The cooperating device includes a diode.

Images