Integrated stacked substrate for isolated power modules
The challenges of size reduction and thermal management are solved by using die pads and highly thermally conductive material attachment components in microelectronic devices and utilizing heat to export heat with a thermal shunt, efficient thermal management and size reduction are achieved.
Patent Information
- Application Number
- CN202411499292.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-09-20
- Filing Date
- 2024-10-25
- Publication Date
- 2025-03-21
AI Technical Summary
In microelectronic devices, size reduction and thermal management are two major challenges, especially in multi-chip modules (MCMs), which are difficult to effectively solve these problems in the prior art.
Effective thermal management and size reduction are achieved by using a die pad in a microelectronic device and directly attaching the first and second components to the surface of the die pads through a highly thermally conductive material, respectively, heat is exported to the external leads using a heat shunt.
This technology effectively reduces the size of the microelectronic device and reduces the temperature of the components by optimizing thermal management, thereby improving the reliability and efficiency of the system.
Smart Images
Figure CN119673900A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of microelectronic devices. More particularly, but not exclusively, the present disclosure relates to components in microelectronic devices. Background Art
[0002] Multi-chip modules (MCMs) contain two or more electronic components in a single package to reduce the interconnect length. MCMs have been applied across different fields, including computing, communications, automotive, and consumer electronics. Two challenges are size reduction and thermal management. Summary of the invention
[0003] The present disclosure introduces a microelectronic device, which includes a die pad having a first surface and a second surface opposite to the first surface. A first component is directly attached to the first surface of the die pad by a first thermally conductive material. A second component is directly attached to the second surface of the die pad by a second thermally conductive material. At least a portion of the second component overlaps at least a portion of the first component. The microelectronic device includes a conductive lead extending to the outside of the microelectronic device. The microelectronic device further includes a first thermal shunt connecting the die pad to a first lead in the leads, and a second thermal shunt connecting the die pad to the second lead. The first thermal shunt is closer to the center of the first component than to the center of the second component. The second thermal shunt is closer to the center of the second component than to the center of the first component.
[0004] The present disclosure further introduces a microelectronic device, the microelectronic device comprising: a first die pad having a first surface and a second surface opposite to the first surface; and a second die pad having a third surface and a fourth surface opposite to the third surface. The third surface is coplanar with the first surface of the first die pad, and the fourth surface is coplanar with the second surface of the first die pad. The microelectronic device comprises: a first component directly attached to the first surface of the first die pad by a first thermally conductive material; and a second component directly attached to the fourth surface of the second die pad by a second thermally conductive material. At least a portion of the second component overlaps at least a portion of the first component. The microelectronic device comprises a conductive lead extending to the outside of the microelectronic device. The microelectronic device further comprises a first thermal shunt connecting the first die pad to a first lead of the leads; and a second thermal shunt connecting the second die pad to the second lead. BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Figures 1A to 1H are cross-sectional and top views of an example microelectronic device depicted in stages of formation.
[0006] FIG. 2A to FIG. 2F are cross-sectional and top views of another example microelectronic device depicted in stages of formation.
[0007] FIG. 3A to FIG. 3F are cross-sectional and top views of another example microelectronic device depicted in stages of formation.
[0008] 4A to 4F are cross-sectional and top views of another example microelectronic device depicted in stages of formation. DETAILED DESCRIPTION
[0009] The present disclosure is described with reference to the accompanying drawings. The figures are not drawn to scale, and the figures are provided only to illustrate the present disclosure. Several aspects of the present disclosure are described below with reference to example applications for illustrative purposes. It should be understood that many specific details, relationships and methods are set forth to provide an understanding of the present disclosure. The present disclosure is not limited by the described ordering of actions or events, because some actions can occur in different orders and / or simultaneously with other actions or events. In addition, all described actions or events are not required to implement methods according to the present disclosure.
[0010] In addition, although some of the embodiments described herein are shown in two-dimensional views of various regions having depth and width, it should be clearly understood that these regions are only illustrations of a portion of a device that is actually a three-dimensional structure. Therefore, when manufactured on an actual device, these regions will have three dimensions, including length, width, and depth. In addition, although the present invention has been described by embodiments directed to active devices, these descriptions are not intended to limit the scope or applicability of the present invention. The active devices of the present invention are not intended to be limited to the physical structures described. These structures are included to demonstrate the utility and application of the present invention to the currently preferred embodiments.
[0011] In one aspect, a microelectronic device includes a die pad having a first surface and a second surface opposite to the first surface. The die pad is electrically conductive. The microelectronic device includes a first component directly attached to the first surface of the die pad by a first thermally conductive material. The microelectronic device also includes a second component directly attached to the second surface of the die pad by a second thermally conductive material. The thermal conductivity of the first thermally conductive material and the second thermally conductive material is significantly greater than that of an unfilled epoxy resin, that is, greater than 1 watt / meter-°K (W / m-°K). The first thermally conductive material and the second thermally conductive material provide an effective thermal path from the first component and the second component to the die pad.
[0012] At least a portion of the second component overlaps at least a portion of the first component, thereby advantageously reducing the size of the microelectronic device. The microelectronic device further includes leads extending to the outside of the microelectronic device. The leads are conductive.
[0013] The microelectronic device includes a first thermal shunt connecting a die pad to a first lead of the leads. The first thermal shunt is closer to the center of the first component than to the center of the second component. The microelectronic device includes a second thermal shunt connecting the die pad to the second lead of the leads. The second thermal shunt is closer to the center of the second component than to the center of the first component. The thermal conductivity of the first thermal shunt and the second thermal shunt is significantly greater than that of the filled epoxy, that is, greater than 100 W / m-°K. Compared to a comparable microelectronic device lacking the first thermal shunt, the first thermal shunt provides a first effective thermal path from the first component through the first thermally conductive material, through the die pad, and through the first lead. Similarly, compared to a comparable microelectronic device lacking the second thermal shunt, the second thermal shunt provides a second effective thermal path from the second component through the second thermally conductive material, through the die pad, and through the second lead.
[0014] In another aspect, the microelectronic device includes a first die pad having a first surface and a second surface opposite to the first surface. The microelectronic device also includes a second die pad having a third surface and a fourth surface opposite to the third surface. The third surface of the second die pad is coplanar with the first surface of the first die pad, and the fourth surface of the second die pad is coplanar with the second surface of the first die pad. The first die pad and the second die pad are conductive. The microelectronic device includes a first component directly attached to the first surface of the first die pad by a first thermally conductive material. The microelectronic device also includes a second component directly attached to the fourth surface of the second die pad by a second thermally conductive material. At least a portion of the second component overlaps at least a portion of the first component, thereby advantageously reducing the size of the microelectronic device. The microelectronic device further includes leads extending to the outside of the microelectronic device. The leads are conductive.
[0015] The microelectronic device includes a first thermal shunt connecting a first die pad to a first lead in the leads. The microelectronic device includes a second thermal shunt connecting a second die pad to a second lead in the leads. The first thermal shunt and the second thermal shunt have a thermal conductivity greater than that of the filled epoxy. The first thermal shunt provides a first effective thermal path from the first component through the first thermally conductive material, through the first die pad, and through the first lead, as compared to a comparable microelectronic device lacking the first thermal shunt. Similarly, the second thermal shunt provides an effective thermal path from the second component through the second thermally conductive material, through the second die pad, and through the second lead, as compared to a comparable microelectronic device lacking the second thermal shunt.
[0016] Figures 1A to 1H are cross-sectional and top views of an example microelectronic device depicted in stages of formation. Figure 1A (Top view) and Figure 1B ( Figure 1A), the microelectronic device 100 is formed on a lead frame 102. The lead frame 102 is conductive and may primarily include copper. In this example, the lead frame 102 includes a first die pad 104a and may include a second die pad 104b. The lead frame 102 includes a barrier bar 106 and leads 108 adjacent to the barrier bar 106, the leads extending from the barrier bar 106 toward the die pads 104a and 104b.
[0017] The lead frame 102 includes a first heat shunt 110a connecting the first die pad 104a to the first lead 108a of the leads 108. The lead frame 102 includes a second heat shunt 110b connecting the first die pad 104a to the second lead 108b of the leads 108. The lead frame 102 may further include additional heat shunts, such as heat shunts 110c, 110d, and 110e, connecting the first die pad 104a or the second die pad 104b to the corresponding additional leads 108c, 108d, and 108e of the leads 108, respectively. The heat shunts 110a to 110e are adjacent to the die pads 104a and 104b, and are adjacent to the corresponding leads 108a to 108e, respectively. The thermal conductivity of the heat shunts 110a to 110e is significantly greater than that of the filled epoxy.
[0018] The die pads 104a and 104b, the leads 108, and the heat spreaders 110a to 110e may have similar compositions.For example, all elements of the leadframe 102 may have a core layer of copper or Alloy 42 (iron-nickel alloy).
[0019] The first die pad 104a has a first surface 112a and a second surface 112b opposite to the first surface 112a. The second die pad 104b has a third surface 112c and a fourth surface 112d opposite to the third surface 112c. Figure 1A exposed in Figure 1B The second surface 112b and the fourth surface 112d are shown in cross section. Figure 1A are hidden by the first die pad 104a and the second die pad 104b, respectively, but are Figure 1B The third surface 112c of the second die pad 104b is coplanar with the first surface 112a of the first die pad 104a, and the fourth surface 112d of the second die pad 104b is coplanar with the second surface 112b of the first die pad 104a.
[0020] The first component 114a is directly attached to the first surface 112a of the first die pad 104a by the first thermally conductive material 116a. The first thermally conductive material 116a may be recessed from the edge of the first component 114a, may substantially coincide with the edge of the first component 114a, or may extend beyond the edge of the first component 114a. The first component 114a may also be directly attached to the third surface 112c of the second die pad 104b by the second thermally conductive material 116b. The second thermally conductive material 116b may be recessed from the edge of the first component 114a, may substantially coincide with the edge of the first component 114a, or may extend beyond the edge of the first component 114a. The coplanarity of the first surface 112a of the first die pad 104a and the third surface 112c of the second die pad 104b may advantageously facilitate the attachment of the first component 114a to the first die pad 104a and the second die pad 104b. For example, the first component 114a may be embodied as a transformer, a gallium nitride field effect transistor (GaN FET), a microprocessor, or an amplifier. Other embodiments of the first component 114a are within the scope of this example. For example, the first thermally conductive material 116a and the second thermally conductive material 116b may be implemented as an electrically conductive adhesive, an electrically insulating adhesive, or a solder. The first thermally conductive material 116a and the second thermally conductive material 116b may have the same composition, or may have different compositions.
[0021] A first portion of electrical connector 118 may be formed at this step. The first portion of electrical connector 118 may electrically connect first component 114a to one or more of leads 108. For example, the first portion of electrical connector 118 may be implemented as a wire bond or a ribbon bond.
[0022] refer to Figure 1C (Top view) and Figure 1D ( Figure 1C The second component 114b is directly attached to the second surface 112b of the first die pad 104a by the third thermally conductive material 116c. The third thermally conductive material 116c can be recessed from the edge of the second component 114b, can substantially coincide with the edge of the second component 114b, or can extend beyond the edge of the second component 114b. The microelectronic device 100 is shown relative to Figure 1A The view around Figure 1C Similarly, the microelectronic device 100 is shown relative to the vertical axis in the plane of Figure 1B The view revolves around the Figure 1DThe rotation of the microelectronic device 100 between attaching the first component 114a and attaching the second component 114b can replicate the method of forming the microelectronic device 100, wherein the first component 114a and the second component 114b are each sequentially attached to the instantaneous top surface of the lead frame 102. At least a portion of the second component 114b overlaps at least a portion of the first component 114a, thereby bringing the advantage of reducing the size of the microelectronic device 100.
[0023] In versions of this example where the first component 114a is represented as a transformer, the second component 114b may be represented as a primary winding driver circuit or a secondary winding receiver circuit. In versions of this example where the first component 114a is represented as a GaN FET, the second component 114b may be represented as a silicon metal oxide semiconductor field effect transistor (MOSFET) connected to the GaN FET in a cascode configuration. In versions of this example where the first component 114a is represented as a microprocessor, the second component 114b may be represented as a memory management unit or a processor interface chip. In versions of this example where the first component 114a is represented as an amplifier, the second component 114b may be represented as a matrix switch or a transconductor buffer. Other implementations of the second component 114b are within the scope of this example.
[0024] For example, the third thermally conductive material 116c may be implemented as an electrically conductive adhesive, an electrically insulating adhesive, or a solder. The third thermally conductive material 116c may have a different composition than the first thermally conductive material 116a and the second thermally conductive material 116b. The thermal conductivity of the thermally conductive materials 116a to 116c is significantly greater than that of unfilled epoxy resin.
[0025] The first heat shunt 110a is closer to the center of the first component 114a than to the center of the second component 114b, that is, the first distance 120a between the first heat shunt 110a and the center of the first component 114a is less than the alternative distance 122a between the first heat shunt 110a and the center of the second component 114b. Therefore, compared with a comparable microelectronic device lacking the first heat shunt 110a, the first heat shunt 110a provides a first effective thermal path from the first component 114a through the first thermally conductive material 116a, through the first die pad 104a, and through the first lead 108a. The second heat shunt 110b is closer to the center of the second component 114b than to the center of the first component 114a, that is, the second distance 120b between the second heat shunt 110b and the center of the second component 114b is less than the alternative distance 122b between the second heat shunt 110b and the center of the first component 114a. Thus, the second heat spreader 110b provides a second effective thermal path from the second component 114b through the third thermally conductive material 116c, through the first die pad 104a, and through the second lead 108b, compared to a comparable microelectronic device lacking the second heat spreader 110b. The additional heat spreaders 110c, 110d, and 110e provide additional effective thermal paths from the first component 114a through corresponding leads 108c, 108d, and 108e to which the additional heat spreaders 110c, 110d, and 110e, respectively, are adjacent.
[0026] refer to Figure 1E (Top view) and Figure 1F ( Figure 1E ), the third component 114c may be attached to the first component 114a. For example, the third component 114c may be implemented as a passive component, such as a filter. For example, the third component 114c may be attached to the first component 114a by an adhesive or solder.
[0027] At this step, a second portion of electrical connector 118 may be formed to first component 114a, second component 114b, and third component 114c. The second portion of electrical connector 118 may electrically connect any of first component 114a, second component 114b, and third component 114c to each other or to one or more of leads 108, or both. The second portion of electrical connector 118 may be implemented as a wire bond or a ribbon bond, or a combination thereof.
[0028] refer to Figure 1G (Top view) and Figure 1H ( Figure 1GThe encapsulation material 124 is formed around the die pads 104a and 104b, the components 114a, 114b and 114c, the electrical connector 118, the heat shunts 110a to 110e, and the portions of the leads 108 close to the die pads 104a and 104b. The leads 108 extend from the encapsulation material 124 to the outside of the microelectronic device 100. The leads 108 extend from the encapsulation material 124 to the outside of the microelectronic device 100. Figure 1E and Figure 1F The lead wires 108 are shaped into a gull-wing configuration to provide a small outline integrated circuit (SOIC) package for the microelectronic device 100.
[0029] For example, the encapsulation material 124 may be implemented as an epoxy compound. The encapsulation material 124 may include filler particles of silicon dioxide or aluminum oxide to reduce the thermal expansion coefficient of the encapsulation material 124.
[0030] The microelectronic device 100 can then be attached to a circuit substrate, such as a printed circuit board, not shown in an electronic device. The ends of the leads 108 outside the encapsulation material 124 can be attached to the circuit substrate by solder or a conductive adhesive. The first heat shunt 110a provides an effective thermal path from the first component 114a through the first die pad 104a and the first lead 108a to the circuit substrate, thereby advantageously reducing the temperature of the first component 114a during operation of the microelectronic device 100. Similarly, the second heat shunt 110b provides an effective thermal path from the second component 114b through the first die pad 104a and the second lead 108b to the circuit substrate, thereby advantageously reducing the temperature of the second component 114b during operation of the microelectronic device 100.
[0031] FIG. 2A to FIG. 2F are cross-sectional and top views of another example microelectronic device depicted in stages of formation. Figure 2A (Top view) and Figure 2B ( Figure 2A ), the microelectronic device 200 is formed on a lead frame 202. The lead frame 202 is conductive. In this example, the lead frame 202 includes a first die pad 204a and a second die pad 204b. The lead frame 202 includes a barrier bar 206 and a lead 208 adjacent to the barrier bar 206, and the lead extends from the barrier bar 206 toward the die pads 204a and 204b.
[0032] The lead frame 202 includes a first heat shunt 210a connecting the first die pad 204a to the first lead 208a of the leads 208. The lead frame 202 of this example includes a second heat shunt 210b connecting the first die pad 204a to the second lead 208b of the leads 208. The lead frame 202 of this example further includes a third heat shunt 210c connecting the second die pad 204b to the third lead 208c of the leads 208, and includes a fourth heat shunt 210d connecting the second die pad 204b to the fourth lead 208d of the leads 208. The heat shunts 210a to 210d are adjacent to the die pads 204a and 204b, and are adjacent to the corresponding leads 208a to 208d, respectively. The thermal conductivity of the heat shunts 210a to 210d is significantly greater than that of the filled epoxy resin.
[0033] The first die pad 204a has a first surface 212a and a second surface 212b opposite to the first surface 212a. The second die pad 204b has a third surface 212c and a fourth surface 212d opposite to the third surface 212c. Figure 2A exposed in Figure 2B The second surface 212b and the fourth surface 212d are shown in cross section. Figure 2A are hidden by the first die pad 204a and the second die pad 204b, but are Figure 2B The third surface 212c of the second die pad 204b is coplanar with the first surface 212a of the first die pad 204a, and the fourth surface 212d of the second die pad 204b is coplanar with the second surface 212b of the first die pad 204a.
[0034] The first component 214a is directly attached to the first surface 212a of the first die pad 204a by the first thermally conductive material 216a, and is directly attached to the third surface 212c of the second die pad 204b by the second thermally conductive material 216b. The coplanarity of the first surface 212a of the first die pad 204a and the third surface 212c of the second die pad 204b can advantageously facilitate attaching the first component 214a to the first die pad 204a and the second die pad 204b. For example, the first thermally conductive material 216a and the second thermally conductive material 216b can be implemented as an electrically conductive adhesive, an electrically insulating adhesive, or a solder.
[0035] refer to Figure 2C (Top view) and Figure 2D ( Figure 2C ), the microelectronic device 200 is shown relative to Figure 2A The view around Figure 2CSimilarly, the microelectronic device 200 is shown relative to the vertical axis in the plane of Figure 2B The view revolves around the Figure 2D The axis of the plane of the second die pad 204a is rotated 180 degrees. The second component 214b is directly attached to the second surface 212b of the first die pad 204a through the third thermally conductive material 216c. At least a portion of the second component 214b overlaps with at least a portion of the first component 214a, thereby bringing the advantage of reduced size of the microelectronic device 200. The third component 214c is directly attached to the fourth surface 212d of the second die pad 204b through the fourth thermally conductive material 216d. At least a portion of the third component 214c overlaps with at least a portion of the first component 214a, thereby bringing the additional advantage of reduced size of the microelectronic device 200.
[0036] The first heat spreader 210a is closer to the center of the first component 214a than to the center of the second component 214b, that is, the first distance 220a between the first heat spreader 210a and the center of the first component 214a is less than the alternative distance 222a between the first heat spreader 210a and the center of the second component 214b. Therefore, the first heat spreader 210a provides an effective thermal path from the first component 214a through the first thermally conductive material 216a, through the first die pad 204a, and through the first lead 208a, compared to a comparable microelectronic device lacking the first heat spreader 210a.
[0037] The second heat spreader 210b is closer to the center of the second component 214b than to the center of the first component 214a, that is, the second distance 220b between the second heat spreader 210b and the center of the second component 214b is less than the alternative distance 222b between the second heat spreader 210b and the center of the first component 214a. Therefore, the second heat spreader 210b provides an effective thermal path from the second component 214b through the third thermally conductive material 216c, through the first die pad 204a, and through the second lead 208b, compared to a comparable microelectronic device lacking the second heat spreader 210b.
[0038] The third heat spreader 210c is closer to the center of the first component 214a than to the center of the third component 214c, that is, the third distance 220c between the third heat spreader 210c and the center of the first component 214a is less than the alternative distance 222c between the third heat spreader 210c and the center of the third component 214c. Therefore, the third heat spreader 210c provides an effective thermal path from the first component 214a through the second thermally conductive material 216b, through the second die pad 204b, and through the third lead 208c, compared to a comparable microelectronic device lacking the third heat spreader 210c.
[0039] The fourth thermal shunt 210d is closer to the center of the third component 214c than to the center of the first component 214a, that is, the fourth distance 220d between the fourth thermal shunt 210d and the center of the third component 214c is less than the alternative distance 222d between the fourth thermal shunt 210d and the center of the first component 214a. Therefore, the fourth thermal shunt 210d provides an effective thermal path from the third component 214c through the fourth thermally conductive material 216d, through the second die pad 204b to the fourth lead 208d, as compared to a comparable microelectronic device lacking the fourth thermal shunt 210d.
[0040] refer to Figure 2E (Top view) and Figure 2F ( Figure 2E ), the electrical connector 218 can be formed to the first component 214a, the second component 214b, and the third component 214c. For example, the electrical connector 218 can electrically connect the second component 214b and the third component 214c to the instance of the lead 208, and electrically connect to the first component 214a. Other configurations of the electrical connector 218 are within the scope of this example.
[0041] The encapsulation material 224 is formed around the die pads 204a and 204b, the components 214a, 214b and 214c, the electrical connector 218, the heat spreaders 210a to 210d, and the portions of the leads 208 that are proximate to the die pads 204a and 204b. The leads 208 extend from the encapsulation material 224 to the exterior of the microelectronic device 200. The leads 208 extend from the die pads 204a and 204b to the exterior of the microelectronic device 200. Figure 2C and Figure 2D The barrier bar 206 is cut. The lead 208 is shaped into a J-lead configuration to provide a J-lead package for the microelectronic device 200.
[0042] FIG. 3A to FIG. 3F are cross-sectional and top views of another example microelectronic device depicted in stages of formation. Figure 3A (Top view) and Figure 3B ( Figure 3A ), the microelectronic device 300 is formed on a lead frame 302. The lead frame 302 is conductive. In this example, the lead frame 302 includes a first die pad 304a and a second die pad 304b. The lead frame 302 of this example further includes a die support pillar 326, which is positioned adjacent to the first die pad 304a and opposite to the second die pad 304b. The lead frame 302 includes a barrier bar 306 and a lead 308 adjacent to the barrier bar 306, and the lead extends from the barrier bar 306 toward the die pads 304a and 304b.
[0043] The lead frame 302 includes a first heat shunt 310a connecting the first die pad 304a to the first lead 308a of the leads 308. The lead frame 302 of this example includes a second heat shunt 310b connecting the first die pad 304a to the second lead 308b of the leads 308. The lead frame 302 of this example further includes a third heat shunt 310c connecting the second die pad 304b to the third lead 308c of the leads 308. The heat shunts 310a to 310c are adjacent to the die pads 304a and 304b, and are adjacent to the corresponding leads 308a to 308c, respectively. The thermal conductivity of the heat shunts 310a to 310c is significantly greater than that of the filled epoxy resin.
[0044] The first die pad 304a has a first surface 312a and a second surface 312b opposite to the first surface 312a. The second die pad 304b has a third surface 312c and a fourth surface 312d opposite to the third surface 312c. Figure 3A exposed in Figure 3B The second surface 312b and the fourth surface 312d are shown in cross section. Figure 3A are hidden by the first die pad 304a and the second die pad 304b, but are Figure 3B The third surface 312c of the second die pad 304b is coplanar with the first surface 312a of the first die pad 304a, and the fourth surface 312d of the second die pad 304b is coplanar with the second surface 312b of the first die pad 304a.
[0045] The first component 314a is directly attached to the first surface 312a of the first die pad 304a by the first thermally conductive material 316a. The first portion of the electrical connector 318 can be formed at this step. The first portion of the electrical connector 318 can electrically connect the first component 314a to one or more of the leads 308.
[0046] refer to Figure 3C (Top view) and Figure 3D ( Figure 3C ), the microelectronic device 300 is shown relative to Figure 3A The view around Figure 3C Similarly, the microelectronic device 300 is shown relative to the vertical axis in the plane of Figure 3B The view revolves around the Figure 3DThe axis of the plane of the microelectronic device 300 is rotated 180 degrees. The second component 314b is directly attached to the second surface 312b of the first die pad 304a through the second thermally conductive material 316b, and is directly attached to the fourth surface 312d of the second die pad 304b through the third thermally conductive material 316c. The coplanarity of the second surface 312b of the first die pad 304a and the fourth surface 312d of the second die pad 304b can advantageously facilitate the attachment of the second component 314b to the first die pad 304a and the second die pad 304b. At least a portion of the second component 314b overlaps at least a portion of the first component 314a, thereby bringing the advantage of reduced size of the microelectronic device 300. The second component 314b can be attached to the die support pillar 326 to provide stability while attaching the second component 314b to the first die pad 304a and the second die pad 304b.
[0047] The first heat spreader 310a is closer to the center of the first component 314a than to the center of the second component 314b, that is, the first distance 320a between the first heat spreader 310a and the center of the first component 314a is less than the alternative distance 322a between the first heat spreader 310a and the center of the second component 314b. Therefore, the first heat spreader 310a provides an effective thermal path from the first component 314a through the first thermally conductive material 316a, through the first die pad 304a, and through the first lead 308a, compared to a comparable microelectronic device lacking the first heat spreader 310a.
[0048] In this example, the second component 314b is the only component attached to the second die pad 304b. Therefore, the second thermal shunt 310b provides an effective thermal path from the second component 314b through the third thermally conductive material 316c, through the second die pad 304b, and through the second lead 308b, compared to a comparable microelectronic device lacking the second thermal shunt 310b. Similarly, the third thermal shunt 310c provides an effective thermal path from the second component 314b through the second thermally conductive material 316b, through the second die pad 304b, and through the third lead 308c, compared to a comparable microelectronic device lacking the third thermal shunt 310c.
[0049] A second portion of the electrical connector 318 may be formed at this step. The second portion of the electrical connector 318 may electrically connect the second component 314b to one or more of the leads 308. Other configurations of the electrical connector 318 are within the scope of this example.
[0050] refer to Figure 3E (Top view) and Figure 3F ( Figure 3EThe encapsulation material 324 is formed around the die pads 304a and 304b, the components 314a and 314b, the electrical connector 318, the heat shunts 310a to 310c, and the portions of the leads 308 close to the die pads 304a and 304b. The leads 308 extend from the encapsulation material 324 to the outside of the microelectronic device 300. The leads 308 extend from the encapsulation material 324 to the outside of the microelectronic device 300. Figure 3C and Figure 3D The blocking bar 306 is cut off. The leads 308 are shaped into a straight lead configuration to provide a dual in-line package (DIP) for the microelectronic device 300.
[0051] 4A to 4F are cross-sectional and top views of another example microelectronic device depicted in stages of formation. Figure 4A (Top view) and Figure 4B ( Figure 4A ), the microelectronic device 400 is formed on a lead frame 402. The lead frame 402 is conductive. In this example, the lead frame 402 includes a first die pad 404a, a second die pad 404b, a third die pad 404c, and a fourth die pad 404d. The lead frame 402 includes a barrier bar 406 and a lead 408 adjacent to the barrier bar 406, and the lead extends from the barrier bar 406 toward the die pads 404a to 404d.
[0052] In this example, each of the die pads 404a to 404d is connected to two specific leads 408a to 408h in the leads 408 by two heat shunts 410a to 410h, respectively. The lead frame 402 includes a first heat shunt 410a and a second heat shunt 410b that connect the first die pad 404a to the first lead 408a and the second lead 408b in the leads 408, respectively. The lead frame 402 includes a third heat shunt 410c and a fourth heat shunt 410d that connect the second die pad 404b to the third lead 408c and the fourth lead 408d in the leads 408, respectively. The lead frame 402 includes a fifth heat shunt 410e and a sixth heat shunt 410f that connect the third die pad 404c to the fifth lead 408e and the sixth lead 408f in the leads 408, respectively. The lead frame 402 includes a seventh heat shunt 410g and an eighth heat shunt 410h that respectively connect the fourth die pad 404d to the seventh lead 408g and the eighth lead 408h of the leads 408. The heat shunts 410a to 410h are adjacent to the corresponding die pads 404a to 404d and are adjacent to the corresponding leads 408a to 408h, respectively. The thermal conductivity of the heat shunts 410a to 410h is significantly greater than the filled epoxy resin.
[0053] The first die pad 404a has a first surface 412a and a second surface 412b opposite to the first surface 412a. The second die pad 404b has a third surface 412c and a fourth surface 412d opposite to the third surface 412c. The third die pad 404c has a fifth surface 412e and a sixth surface 412f opposite to the fifth surface 412e. The fourth die pad 404d has a seventh surface 412g and an eighth surface 412h opposite to the seventh surface 412g.
[0054] The first surface 412a, the third surface 412c, the fifth surface 412e and the seventh surface 412g are Figure 4A The second surface 412b, the fourth surface 412d, the sixth surface 412f and the eighth surface 412h are exposed in Figure 4A The first surface 412a, the second surface 412b, the third surface 412c and the fourth surface 412d are hidden by the die pads 404a to 404d respectively. Figure 4B The first surface 412a, the third surface 412c, the fifth surface 412e and the seventh surface 412g are coplanar, and the second surface 412b, the fourth surface 412d, the sixth surface 412f and the eighth surface 412h are coplanar.
[0055] The first component 414a is directly attached to the first surface 412a of the first die pad 404a by a first thermally conductive material 416a. The second component 414b is directly attached to the third surface 412c of the second die pad 404b by a second thermally conductive material 416b.
[0056] A first portion of electrical connector 418 may be formed at this step. The first portion of electrical connector 418 may electrically connect first component 414a and / or second component 414b to one or more of leads 408.
[0057] refer to Figure 4C (Top view) and Figure 4D ( Figure 4C ), the microelectronic device 400 is shown relative to Figure 4A The view around Figure 4C Similarly, the microelectronic device 400 is shown relative to the vertical axis in the plane of Figure 4B The view revolves around the Figure 4DThe third component 414c is directly attached to the sixth surface 412f of the third die pad 404c through the third thermally conductive material 416c, and is directly attached to the eighth surface 412h of the fourth die pad 404d through the fourth thermally conductive material 416d. The third component 414c may also be directly attached to the second surface 412b of the first die pad 404a through the fifth thermally conductive material 416e, and / or may be directly attached to the fourth surface 412d of the second die pad 404b through the sixth thermally conductive material 416f. In order to improve Figure 4C For readability, the fifth thermally conductive material 416e and the sixth thermally conductive material 416f are not Figure 4C But in Figure 4D Shown in cross section.
[0058] At least a portion of the third component 414c overlaps at least a portion of the first component 414a, thereby bringing the advantage of reducing the size of the microelectronic device 400. At least a portion of the third component 414c may overlap at least a portion of the second component 414b, thereby bringing the additional advantage of reducing the size of the microelectronic device 400.
[0059] The first heat spreader 410a and the second heat spreader 410b are closer to the center of the first component 414a than to the center of the third component 414c. Therefore, the first heat spreader 410a and the second heat spreader 410b provide a first effective thermal path from the first component 414a through the first thermally conductive material 416a, through the first die pad 404a, and through the first lead 408a and the second lead 408b, respectively, compared to a comparable microelectronic device lacking the first heat spreader 410a and the second heat spreader 410b.
[0060] The third thermal shunt 410c and the fourth thermal shunt 410d are closer to the center of the second component 414b than to the center of the third component 414c. Therefore, the third thermal shunt 410c and the fourth thermal shunt 410d provide a second effective thermal path from the second component 414b through the second thermally conductive material 416b, through the second die pad 404b, and through the third lead 408c and the fourth lead 408d, respectively, compared to a comparable microelectronic device lacking the third thermal shunt 410c and the fourth thermal shunt 410d.
[0061] In this example, the third component 414c is the only component attached to the third die pad 404c. Therefore, compared to a comparable microelectronic device lacking the fifth thermal shunt 410e and the sixth thermal shunt 410f, the fifth thermal shunt 410e and the sixth thermal shunt 410f provide a third effective thermal path from the third component 414c through the third thermally conductive material 416c, through the third die pad 404c, and through the fifth lead 408e and the sixth lead 408f, respectively. Similarly, the third component 414c is the only component attached to the fourth die pad 404d. Thus, the seventh thermal shunt 410g and the eighth thermal shunt 410h provide a fourth effective thermal path from the third component 414c through the fourth thermally conductive material 416d, through the fourth die pad 404d, and through the seventh lead 408g and the eighth lead 408h, respectively, compared to a comparable microelectronic device lacking the seventh thermal shunt 410g and the eighth thermal shunt 410h.
[0062] A second portion of the electrical connector 418 may be formed at this step. The second portion of the electrical connector 418 may electrically connect the third component 414c to one or more of the leads 408. Other configurations of the electrical connector 418 are within the scope of this example.
[0063] refer to Figure 4E (Top view) and Figure 4F ( Figure 4E The lead 408 is Figure 4C and Figure 4D The lead wire 408 is formed to extend beyond the first component 414a and the second component 414b, such as Figure 4F . Encapsulation material 424 is formed around die pads 404a and 404b, components 414a, 414b, and 414c, electrical connectors 418, thermal shunts 410a to 410e, and portions of leads 408 proximate to die pads 404a and 404b. Leads 408 extend through encapsulation material 424 and are exposed at the bottom surface of microelectronic device 400 to provide microelectronic device 400 with a quad flat no-lead (QFN) package.
[0064] Various features of the examples disclosed herein may be combined in other manifestations of example microelectronic devices. For example, microelectronic devices 100, 200, 300, and 400 may be configured as SOIC packages, J-lead packages, DIP, or QFN packages. Microelectronic devices 100, 200, 300, and 400 may include one or more components attached to another component, such as reference 1. Figure 1E and Figure 1FThe microelectronic devices 100, 200, 300 and 400 may include electrical connections 118, 218, 318 and 418 between a component and a lead or between two components, respectively, in any configuration.
[0065] Although various embodiments of the present disclosure have been described above, it should be understood that they are presented only by way of example and not limitation. Without departing from the spirit or scope of the present disclosure, many changes may be made to the disclosed embodiments according to the disclosure herein. Therefore, the breadth and scope of the present invention should not be limited by any of the above-described embodiments. In fact, the scope of the present disclosure should be defined according to the attached claims and their equivalents.
Claims
1. A microelectronic device comprising: a die pad having a first surface and a second surface opposite to the first surface, the die pad being electrically conductive; a first component directly attached to the first surface of the die pad by a first thermally conductive material; a second component directly attached to the second surface of the die pad by a second thermally conductive material, wherein at least a portion of the second component overlaps at least a portion of the first component; Leads extending to the outside of the microelectronic device, the leads being conductive; a first thermal shunt connecting the die pad to a first one of the leads, the first thermal shunt being electrically conductive, wherein the first thermal shunt is closer to a center of the first component than to a center of the second component; and A second thermal shunt connects the die pad to a second one of the leads, the second thermal shunt being electrically conductive, wherein the second thermal shunt is closer to the center of the second component than to the center of the first component.
2. The microelectronic device of claim 1 , wherein the die pad is a first die pad, and the microelectronic device further comprises: a second die pad having a third surface and a fourth surface opposite the third surface, the second die pad being electrically conductive, wherein the first component is directly attached to the third surface of the second die pad by a third thermally conductive material; and A third thermal shunt connects the second die pad to a third of the leads, the third thermal shunt being electrically conductive, wherein the third thermal shunt is closer to the center of the first component than to the center of the second component.
3. The microelectronic device according to claim 2, further comprising: a third component directly attached to the fourth surface of the second die pad by a fourth thermally conductive material, wherein at least a portion of the third component overlaps with at least a portion of the first component; and A fourth thermal shunt connects the second die pad to a fourth of the leads, the fourth thermal shunt being electrically conductive, wherein the fourth thermal shunt is closer to a center of the third component than to the center of the first component.
4. The microelectronic device of claim 1, further comprising an additional component attached to the first component.
5. The microelectronic device of claim 1, wherein the die pad, the first heat spreader, the second heat spreader, and the leads are elements of a lead frame.
6. A method of forming a microelectronic device, comprising: providing a lead frame having a die pad, leads, a first thermal shunt connecting the die pad to a first one of the leads, and a second thermal shunt connecting the die pad to a second one of the leads; attaching a first component to a first surface of the die pad via a first thermally conductive material; and a second component is attached to a second surface of the die pad opposite the first surface by a second thermally conductive material; wherein: The die pad, the leads, the first thermal shunt, and the second thermal shunt are electrically conductive; at least a portion of the second component overlaps at least a portion of the first component; The first heat diverter is closer to the center of the first component than to the center of the second component; and The second heat diverter is closer to a center of the second component than to a center of the first component.
7. The method according to claim 6, wherein: The die pad is a first die pad; The lead frame includes a second die pad having a third surface and a fourth surface opposite the third surface; and The lead frame includes a third thermal shunt connecting the second die pad to a third of the leads; and The method further includes attaching the first component to the third surface of the die pad by a third thermally conductive material; wherein: The second die pad is electrically conductive; The third heat diverter is electrically conductive; and The third heat spreader is closer to the center of the first component than to the center of the second component.
8. The method of claim 7, wherein the lead frame comprises a fourth thermal shunt connecting the second die pad to a fourth of the leads, the fourth thermal shunt being electrically conductive; and The method further includes attaching a third component directly to the fourth surface of the second die pad through a fourth thermally conductive material, at least a portion of the third component overlapping at least a portion of the first component, wherein the fourth heat spreader is closer to a center of the third component than to a center of the first component.
9. The method of claim 6, further comprising attaching an additional component to the first component. 10 . The method of claim 6 , wherein attaching the first component to the die pad is performed before attaching the second component to the die pad.
11. A microelectronic device comprising: a first die pad having a first surface and a second surface opposite to the first surface, the first die pad being electrically conductive; a first component directly attached to the first surface of the first die pad by a first thermally conductive material; a second die pad having a third surface and a fourth surface opposite to the third surface, the third surface being coplanar with the first surface of the first die pad, and the fourth surface being coplanar with the second surface of the first die pad, the second die pad being conductive; a second component directly attached to the fourth surface of the second die pad by a second thermally conductive material, wherein at least a portion of the second component overlaps at least a portion of the first component; Leads extending to the outside of the microelectronic device, the leads being conductive; a first thermal shunt connecting the first die pad to a first one of the leads, the first thermal shunt being electrically conductive; and A second thermal shunt connects the second die pad to a second one of the leads, the second thermal shunt being electrically conductive.
12. The microelectronic device of claim 11 , further comprising: a third die pad having a fifth surface and a sixth surface opposite to the fifth surface, the fifth surface being coplanar with the first surface of the first die pad, and the sixth surface being coplanar with the second surface of the first die pad, the third die pad being electrically conductive, wherein the first component is directly attached to the fifth surface of the third die pad through a third thermally conductive material; and A third thermal shunt connects the third die pad to a third lead of the leads, the third thermal shunt being electrically conductive.
13. The microelectronic device of claim 12, further comprising: a fourth die pad having a seventh surface and an eighth surface opposite to the seventh surface, the seventh surface being coplanar with the first surface of the first die pad, and the eighth surface being coplanar with the second surface of the first die pad, the fourth die pad being conductive; a third component directly attached to the seventh surface of the fourth die pad by a fourth thermally conductive material, wherein at least a portion of the third component overlaps with at least a portion of the first component; and A fourth thermal shunt connects the fourth die pad to a fourth lead of the leads, the fourth thermal shunt being electrically conductive.
14. The microelectronic device of claim 11, further comprising a component attached to the first component.
15. The microelectronic device of claim 11, wherein the first die pad, the second die pad, the first thermal shunt, the second thermal shunt, and the leads are elements of a lead frame.
16. A method of forming a microelectronic device, comprising: A lead frame is provided, the lead frame having a first die pad, a second die pad, leads, a first thermal shunt connecting the first die pad to a first one of the leads, and a second thermal shunt connecting the second die pad to a second one of the leads; wherein: The lead, the first and second die pads, and the first and second thermal shunts are electrically conductive; The first die pad has a first surface and a second surface opposite to the first surface; and The second die pad has a third surface coplanar with the first surface of the first die pad and a fourth surface opposite to the first surface, the fourth surface coplanar with the second surface of the first die pad; attaching a first component to the first surface of the first die pad via a first thermally conductive material; and A second component is attached to the fourth surface of the second die pad by a second thermally conductive material, wherein at least a portion of the second component overlaps at least a portion of the first component.
17. The method of claim 16, wherein: The lead frame includes a third die pad having a fifth surface and a sixth surface opposite to the fifth surface, the fifth surface being coplanar with the first surface of the first die pad, the third die pad being conductive; and the leadframe comprising a third thermal shunt connecting the third die pad to a third of the leads, the third thermal shunt being electrically conductive; and The method further includes attaching the first component directly to the fifth surface of the third die pad through a third thermally conductive material.
18. The method of claim 17, wherein the lead frame comprises a fourth die pad having a seventh surface and an eighth surface opposite the seventh surface, the seventh surface being coplanar with the first surface of the first die pad, and the eighth surface being coplanar with the second surface of the first die pad, the fourth die pad being electrically conductive, and the lead frame comprising a fourth thermal shunt connecting the fourth die pad to a fourth of the leads, the fourth thermal shunt being electrically conductive; and The method further includes attaching a third component directly to the seventh surface of the fourth die pad through a fourth thermally conductive material, wherein at least a portion of the third component overlaps at least a portion of the first component.
19. The method of claim 16, further comprising attaching an additional component directly to the first component.
20. The method of claim 16, wherein attaching the first component to the first die pad is performed before attaching the second component to the second die pad.