Stacked multichip structure with enhanced protection

Abstract

A stacked multichip electronic assembly having an electronic component subassembly has components including a conductive top clip, first and second semiconductor chips, and a conductive bottom clip assembled in a stacked array. A solder layer is positioned between opposing contact surfaces of the components in the stacked array. When soldered together, this forms an electronic component subassembly. A polymer layer extends between the conductive top clip and the conductive bottom clip and encloses the sides of the first and second semiconductor chips and the solder layer. This polymer layer protects and / or seals the exposed chip surface to prevent mechanical damage from further processes and protects the chip passivation surface from ion contamination that may be introduced from further assembly processes. A package is formed with a molding compound to enclose the electronic component subassembly and the polymer layer, and leads from the conductive top and bottom clips extend to the outside of the body.

Description

Technology Field

[0001] The present application relates to the field of electronic components and, in particular, to a stacked chip placed in a single package for use in various applications such as transient-voltage-suppression (TVS) and Zener devices, among others, high surge power TVS in automobiles, communication base stations, and 5G base station applications, high voltage TVS in electric vehicles, hybrid vehicles, and charging station applications, and low-clamping TVS in automobiles, electric vehicles, hybrid vehicles, charging stations, robotics, as well as other applications. Background Technology

[0002] Electronic components such as TVS diodes are used in numerous applications to protect other semiconductor components from high-voltage transients. Zener diodes are also known and commonly used for voltage control, surge suppressors, and various other applications.

[0003] In addition to these, other electronic components can also be formed as surface-mountable devices for PCB applications. Here, active chip components are located within a package molded with a suitable polymer, and leads extend from the chip to the bottom surface outside the package to connect to the PCB.

[0004] It is also known that certain applications have limited space on a PCB, so they have multi-chip packages in which, for example, two or more TVS chips are stacked layer by layer, the contact surfaces of the chips are soldered together, and soldered to suitable leads. This allows components with higher capacity and / or higher power to be packaged in a smaller footprint, which ultimately results in less space required on the PCB and allows for size reduction or the addition of other features / components while maintaining the same size.

[0005] For such applications having stacked chips located within a package, it would be desirable to provide enhanced in-service reliability.

[0006] A stacked multichip electronic assembly having an electronic component sub-assembly is provided. The electronic component sub-assembly includes a component comprising a conductive top clip having a bottom contact surface and a lead, at least first and second semiconductor chips having top and bottom contact surfaces respectively, as well as a conductive bottom clip having a top contact surface and a lead, and these components are assembled in a stacked array. At least first and second semiconductor chips may be, for example, TVS, Zener, or other electronic devices. A solder layer is positioned between opposing contact surfaces of the components in the stacked array. In an embodiment having only the first and second semiconductor chips, the solder layer is positioned between (a) the top contact surface of the conductive bottom clip and the bottom contact surface of the first semiconductor chip, (b) the top contact surface of the first semiconductor chip and the bottom contact surface of the second semiconductor chip, and (c) the top contact surface of the second semiconductor chip and the bottom contact surface of the conductive top clip, thereby electrically connecting the components. When soldered together, this forms an electronic component subassembly. A polymer layer extending between a conductive top clip and a conductive bottom clip is provided to encapsulate the sides of the first and second semiconductor chips and the solder layer located between them. This polymer layer acts as a protective layer to protect and / or seal the exposed chip surface to prevent any mechanical damage from subsequent processes, such as a mold compound application process for forming a package, as well as to protect the chip passivation surface from any ion contamination that may be introduced from a subsequent assembly process. A body (or package) is formed from the molding compound to encapsulate the electronic component subassembly and the polymer layer. At least a portion of the leads from the conductive top and bottom clips extends outwardly to the body.

[0007] In one embodiment, the polymer layer extends around the bottom contact surface of the conductive top clip and the top contact surface of the conductive bottom clip.

[0008] In an additional embodiment, the lower contact surface of the conductive top clip includes a protrusion forming a chip contact area, and the upper contact surface of the conductive bottom clip includes a protrusion forming a chip contact area, and a polymer layer surrounds the edges of these protrusions. This provides a more robust configuration due to the contact area provided by the side of the protrusion to which the polymer layer can be attached.

[0009] In one preferred arrangement, the polymer layer comprises polyimide silicon. However, other polymers may also be used. It is also possible to achieve a desired coefficient of thermal expansion for a specific application by using various polymers with or without fillers.

[0010] In one preferred arrangement, the molding compound is an epoxy molding compound. However, other polymeric materials with or without fillers may also be used.

[0011] In one preferred arrangement, the portions of the leads from the conductive top and bottom clips extending outward from the body include their respective ends extending along the bottom surface of the body. This is suitable for PCB applications. However, for other applications, it is not necessary for the leads to extend along a common surface.

[0012] In another embodiment, an additional component is provided in a stacked array in the form of a copper slug located between at least one of the following: between the lower contact surface of a conductive top clip and the upper contact surface of a second semiconductor chip, between the contact surfaces of adjacent semiconductor chips, or between the lower contact surface of a first semiconductor chip and the upper contact surface of a conductive bottom clip. Here, a solder layer is located between each of the contact surface and the copper slug to provide a conductive contact between the stacked component and the copper slug.

[0013] A multichip stacked electronic assembly may include TVS and / or Zener devices in various packages, and other surface mount or axial lead devices. An electronic component subassembly may be composed of a component comprising two or more chips positioned between conductive top and bottom clips, or a chip with a copper slug positioned between them. The copper slug provides a heat-absorbing reservoir to enhance TVS surge capability, as well as protecting the chip edges from mechanical shock damage.

[0014] Multichip stacked electronic assemblies have many applications. For chips that are TVS or Zener devices, possible applications include high surge power TVS, high voltage TVS, low clamping TVS, asymmetric voltage TVS, or rapidly meeting target voltages from just a combination of stacked chips. Such multichip stacked electronic assemblies can also be applied to other power rectifier applications.

[0015] In another embodiment, a method for assembling a stacked multichip electronic assembly is provided. The method comprises assembling an electronic component subassembly having a stacked array of components—the components comprising a conductive bottom clip having a top contact surface and a lead, at least first and second semiconductor chips having top and bottom contact surfaces, respectively, and a conductive top clip having a bottom contact surface and a lead—and applying a solder layer between opposing contact surfaces of the components in the stacked array. To provide enhanced protection to the exposed chip surface, the method further comprises applying a polymer layer between the conductive top clip and the conductive bottom clip, encapsulating the sides of the first and second semiconductor chips and the solder layer located between them. Additionally, the method comprises molding the electronic component subassembly and the body encapsulating the polymer layer with a molding compound such that at least a portion of the leads from the conductive top and bottom clips extends outward from the body. The molding of the body is preferably performed in a conventional manner.

[0016] In the case of an electronic component subassembly having only first and second semiconductor chips as active components, applying a solder layer includes applying a solder layer between (a) the upper contact surface of a conductive bottom clip and the lower contact surface of a first semiconductor chip, (b) the upper contact surface of a first semiconductor chip and the lower contact surface of a second semiconductor chip, and (c) the upper contact surface of a second semiconductor chip and the lower contact surface of a conductive top clip.

[0017] In another embodiment, a stacked multichip electronic assembly having an electronic component subassembly is provided, the component comprising at least first and second semiconductor chips each having upper and lower contact surfaces, and a solder layer positioned between opposing contact surfaces of the components of the stacked array. A polymer layer encloses the sides of at least the first and second semiconductor chips and the solder layer positioned between them.

[0018] In one embodiment, the component further includes a copper slug located on at least one of the top contact surface of the second semiconductor chip, between the contact surfaces of adjacent semiconductor chips, or on the bottom contact surface of the first semiconductor chip. Here, a solder layer is located between the contact surface and the copper slug, respectively. Brief explanation of the drawing

[0019] The aforementioned aspects of the present invention and many associated advantages will be more easily understood when the following detailed description is taken in conjunction with the accompanying drawings. FIG. 1 is a cross-sectional view of a first embodiment of a stacked multichip electronic assembly. Figure 2 is a cross-sectional view corresponding to the sample according to Figure 1. FIG. 3 is a cross-sectional view of a second embodiment of a stacked multichip electronic assembly. FIG. 4 is a cross-sectional view of a third embodiment of a stacked multichip electronic assembly. FIG. 5 is a cross-sectional view of an electronic component subassembly having several stacked electronic components and a polymer layer protecting the sides of the electronic components. Figure 6 is a flowchart illustrating a method for assembling a stacked multichip electronic assembly. Specific details for implementing the invention

[0020] Certain terms are used for convenience only in the following detailed description and are not limiting. "Right," "Left," "Top," and "Bottom" designate directions in the drawings where reference is made. The terms "one (a)" and "one" as used in the claims and corresponding parts of this specification are defined as including one or more mentioned items unless specifically stated otherwise. These terms include the terms specifically mentioned above, their derivatives, and terms of similar meaning. Phrases such as "at least one" followed by a list of two or more items, such as "A, B, or C," may mean any one of A, B, or C, or any combination thereof. Note that some drawings are depicted partially transparently for the purposes of explanation, example, and demonstration only, and are not intended to indicate that the element itself will be transparent in its final manufactured form.

[0021] Referring to FIGS. 1 and FIGS. 2, a first embodiment (10) of a stacked multi-chip electronic assembly is illustrated. FIGS. 1 is a cross-sectional view illustrating one configuration, while FIGS. 2 is a drawing corresponding to an actual cross-sectional sample of the first embodiment (10) of the stacked multi-chip electronic assembly.

[0022] A stacked multichip electronic assembly (10) comprises an electronic component subassembly (12) having several components stacked together. This includes a conductive bottom clip or pad (20) having a top contact surface (20a) and a lead (22), at least first and second semiconductor chips (30, 32) having a top contact surface (30a, 32a) and a bottom contact surface (30b, 32b), respectively, as well as a conductive top clip (40) having a bottom contact surface (40b) and a lead (42). These components are stacked together. The conductive bottom clip (20) and the conductive top clip (40) are preferably made of copper or a copper alloy. However, other conductive materials may be used. The first and second semiconductor chips (30, 32) may be, for example, a TVS, a Zener, or other electronic device. In the first embodiment (10) of the electronic assembly, first and second semiconductor chips (30, 32) are shown, but additional semiconductor chips may be provided as described in more detail below.

[0023] The above components form a serial arrangement, and a solder layer (50) is positioned between the opposing contact surfaces (20a, 30b; 30a, 32b; 32a, 40b) of the contact surfaces of these components in the stacked arrangement. In a first embodiment (10) of an electronic assembly having only first and second semiconductor chips (30, 32), the solder layer (50) is positioned between (a) the upper contact surface (20a) of the conductive bottom clip (20) and the lower contact surface (30b) of the first semiconductor chip (30), (b) the upper contact surface (30a) of the first semiconductor chip (30) and the lower contact surface (32b) of the second semiconductor chip (32), and (c) the upper contact surface (32a) of the second semiconductor chip (32) and the lower contact surface (40b) of the conductive top clip (40).

[0024] A polymer layer (52) is provided that extends between an upper conductive clip (40) and a lower conductive clip (20) to encapsulate the sides (30c, 32c) of the first and second semiconductor chips (30, 32) as well as the edges of the solder layer (50) located between them, in order to protect and / or seal the exposed chip surface to prevent mechanical damage from additional processes, such as the molding step of the body or package (54) around the electronic component subassembly (12), as well as to add a protective layer to protect the chip passivation surface from any ion contamination. In a first embodiment (10) of the electronic assembly, this polymer layer (52) extends around the lower contact surface (40b) of the conductive upper clip (40) and the upper contact surface (20a) of the lower conductive clip (20) to encapsulate the sides of the first and second semiconductor chips (30, 32) as well as the edges of the solder layer (50). Here, to provide a more robust configuration, the lower contact surface (40b) of the conductive upper clip (40) may include a protrusion (44) (shown in FIG. 1) forming a chip contact area, and the upper contact surface (20a) of the conductive lower clip (20) may include a protrusion (24) (shown in FIG. 1) forming a chip contact area, and the polymer layer (52) surrounds the edges (24c, 44c) of the protrusions (24, 44) as shown in FIG. 1. Alternatively, as shown in FIG. 2, these protrusions (24, 44) may be omitted, and the polymer layer may simply extend from the edge of the contact surface (40b) of the conductive upper clip (40) to the edge of the upper conductive surface (20a) of the conductive lower clip (20).

[0025] In one preferred embodiment, the polymer layer comprises polyimide silicon. Depending on the specific application, other polymers may also be used with or without fillers, such as ceramic fillers, to achieve the desired coefficient of thermal expansion along with the desired adhesion performance.

[0026] Referring further to FIGS. 1 and 2, a body (54) containing an electronic component subassembly (12) and a polymer layer (52) is formed from a molding compound such that at least a portion of the leads (22, 42) extends outward from the conductive bottom and top clips (20, 40) to the body (54). As shown in FIG. 1, the portion of the leads (22, 42) from the conductive bottom and top clips (20, 40) extending outward from the body (54) includes respective ends (22c, 42c) that extend along the bottom surface of the body (54). This is useful for a surface-mounted electronic assembly (10), but the leads (22, 42) may also extend straight outward from the side of the body for other types of electronic assemblies.

[0027] In a preferred embodiment, the molding compound is an epoxy molding compound. However, other polymeric materials with or without fillers may also be used.

[0028] Now, referring to FIG. 3, a second embodiment (10') of a stacked multichip electronic assembly is illustrated. The second embodiment (10') of the electronic assembly is similar to the first embodiment (10) of the electronic assembly described above. However, in this case, the components of the electronic component subassembly (12') include two additional semiconductor chips (34, 36) located between the first and second semiconductor chips (30, 32) of the stacked array. These two additional semiconductor chips (34, 36) each have a lower contact surface (34b, 36b) as well as an upper contact surface (34a, 36a). Additionally, the component of the electronic component subassembly (12') further comprises a copper slug (60) located between the lower contact surface (40b) of the upper conductive clip (40) and the upper contact surface (32a) of the second semiconductor chip (32), between adjacent contact surfaces (30a, 34b; 34a, 36b; 36a, 32b) of the semiconductor chips (30, 32, 34, 36), or between the lower contact surface (30b) of the first semiconductor chip (30) and the upper contact surface (20a) of the conductive lower clip (20). In the illustrated embodiment, the copper slug (60) is located at each of these locations, but this is not mandatory, and the copper slug (60) may be located at only some of these locations. For example, the copper slug (60) may be positioned only between the lower contact surface (40b) of the upper conductive clip (40) and the upper contact surface (32a) of the second semiconductor chip (32), and between the lower contact surface (30b) of the first semiconductor chip (30) and the upper contact surface (20a) of the conductive lower clip (20). The side (60c) of the copper slug (60) extends to at least the side (30c, 32c, 34c, 36c) of the semiconductor chip (30, 32, 34, 36) to protect the side (30c, 32c, 34c, 36c) of the semiconductor chip (30, 32, 34, 36) from mechanical impact damage.Here, the solder layer (50) is located between the contact surfaces of the copper slug (60) facing the contact surfaces of the bottom conductive clip (20), semiconductor chips (30, 32, 34, 36), and the top conductive clip (40).

[0029] Referring further to FIG. 3, in this case, the polymer layer (52') extends around the lower contact surface (40b) of the upper conductive clip (40) and the upper contact surface (20a) of the lower conductive clip (20), and encloses the sides (30c, 32c, 34c, 36c) of the semiconductor chips (30, 32, 34, 36), as well as the sides (60c) of the copper slug (60) and the edges of the solder layer (50).

[0030] A body (54') containing an electronic component subassembly (12') and a polymer layer (52') is formed from a molding compound such that at least a portion of the leads (22, 42) extends from the conductive bottom and top clips (20, 40) to the outside of the body (54').

[0031] Referring to FIG. 4, a third embodiment (10'') of a stacked multichip electronic assembly is illustrated. This third embodiment (10'') of the electronic assembly is similar to the second embodiment (10') and includes an electronic component subassembly (12'') formed in the same manner as the electronic component subassembly (12') mentioned above. However, in this embodiment, the polymer layer (52'') surrounds the edges (24c', 44c) of the protrusions (24, 44) of the bottom and top conductive clips (20, 40), respectively. This arrangement provides a larger contact area with the conductive clips (20, 40) with respect to the polymer layer (52''), thereby providing a more robust arrangement.

[0032] A body (54'') containing an electronic component subassembly (12'') and a polymer layer (52'') is formed from a molding compound such that at least a portion of the leads (22, 42) extends from the conductive bottom and top clips (20, 40) to the outside of the body (54'').

[0033] Now, referring to FIG. 5, an electronic component subassembly (112) similar to the electronic component subassembly (12') described above is illustrated, except that a separate conductor attachment is not provided as part of the component of the stacked array. The subassembly (112) may be integrated into a discrete package or into a module, or may have a conductor similar to or different from the conductive clip (20, 40) described above that is attached in a subsequent manufacturing step. Here, the electronic component subassembly (112) may use fewer or more semiconductor chips, but includes a copper slug (60) located on at least one of the following: on the upper contact surface (32a) of the second semiconductor chip (32), between adjacent contact surfaces (30a, 34b; 34a, 36b; 36a, 32b) of the semiconductor chips (30, 32, 34, 36), or on the lower contact surface (30b) of the first semiconductor chip (30), as described above. In the illustrated embodiment, the copper slug (60) is located at each of these locations, but this is not mandatory, and the copper slug (60) may be located at only some of these locations. For example, the copper slug (60) may be located only on the upper contact surface (32a) of the second semiconductor chip (32) and the lower contact surface (30b) of the first semiconductor chip (30). Alternatively, the copper slug may be omitted.

[0034] The side (60c) of the copper slug (60) extends to at least the side (30c, 32c, 34c, 36c) of the semiconductor chip (30, 32, 34, 36) to protect the side (30c, 32c, 34c, 36c) of the semiconductor chip (30, 32, 34, 36) from mechanical shock damage. Here, the solder layer (50) is positioned between the contact surfaces of each copper slug (60) facing each contact surface of the semiconductor chip (30, 32, 34, 36).

[0035] Referring further to FIG. 5, in this case, the polymer layer (152) encloses the sides (30c, 32c, 34c, 36c) of the semiconductor chips (30, 32, 34, 36) as well as the sides (60c) of the copper slug (60) and the edges of the solder layer (50). Those skilled in the art will recognize that the number of semiconductor chips (30, 32, 34, 36) in the electronic component subassembly (12, 12', 12'', 112) can be varied, for example, five semiconductor chips, six semiconductor chips, or more can be provided in the electronic component subassembly, and that the use of the copper slug (60) is optional depending on the specific application.

[0036] Additionally, in the disclosed embodiment, the polymer layer (52, 52', 52'', 152) encloses the sides of the semiconductor chip (30, 32, 34, 36) as well as the edges of the solder layer (50) and the sides (60c) of the copper slug (60), but if it is within an electronic component subassembly (12, 12', 12''), some of the benefits of the present invention can still be achieved even if the polymer layer is applied less than all sides and edges.

[0037] Now, referring to FIG. 6, a method for assembling a stacked multichip electronic assembly (10, 10', 10'') is provided. The method comprises assembling electronic component subassemblies (12, 12', 12'') into a stacked array of components (20, 30, 32, 34, 36, 60 and 40 (also optionally (60))). The component comprises a conductive bottom clip (20) having an upper contact surface (20a) and leads (22), as well as additional semiconductor chips (34, 36, etc.), but includes at least first and second semiconductor chips (30, 32) each having upper contact surfaces (30a, 32a, 34a, 36a) and lower contact surfaces (30b, 32b, 34b, 36b), and a conductive top clip (40) having a lower contact surface (40b) and leads (42). This is illustrated in step (72) of FIG. 6. These components are arranged in a stacked array.

[0038] As mentioned in step (74), a solder layer (50) is applied between the opposing contact surfaces of the stacked array components to form an electronic component subassembly (12, 12', 12'').

[0039] To provide a more robust assembly that protects and / or seals the exposed chip surface, prevents mechanical damage from additional processes, and protects the chip passivation surface from any ion contamination that may be introduced from subsequent assembly processes, a polymer layer (52, 52', 52'') is applied between a conductive top clip (40) and a conductive bottom clip (20) to enclose the sides (30c, 32c) of the first and second semiconductor chips (30, 32), as well as the surfaces (34c, 36c) of any additional semiconductor chips (34, 36) and the edges of the solder layer (50) located between them. This is shown in step (76) of FIG. 6. If present, the sides (60c) of the copper slug (60) are also enclosed. The polymer layer (52, 52') may extend around the lower contact surface (40b) of the upper conductive clip (40) and the upper contact surface of the conductive lower clip (20) to provide a wider surface area for contact with the conductive lower and upper clips (20, 40), for example, as shown in FIGS. 2 and 3, or may extend around the edges (24c, 44c) of the protrusions (24, 44) of the conductive lower and upper clips (20, 40) as shown in FIGS. 1 and 4.

[0040] As indicated in step (78), the method further comprises molding the electronic component subassembly (12, 12', 12'') and the body (54, 54', 54'') containing the polymer layer into a molding compound such that at least a portion of the leads (22, 42) extends outward from the conductive top and bottom clips (40, 20) to the body (54).

[0041] The method may further include assembling an electronic component subassembly (12', 12''), comprising positioning a copper slug (60) between the lower contact surface (40b) of the upper conductive clip (40) and the upper contact surface (32a) of the second semiconductor chip (32), between adjacent contact surfaces (32b, 36a; 36b, 34a; 34b, 30a) of the semiconductor chips (30, 32) (also any additional semiconductor chips (34, 36)), or between the lower contact surface (30b) of the first semiconductor chip (30) and the upper contact surface (20a) of the lower conductive clip (20). The method will then include applying a solder layer (50) between each of the opposing contact surfaces and the copper slug (60).

[0042] The fabrication of the electronic component subassembly (112) illustrated in FIG. 5 can be performed in a manner similar to the above steps (72, 74, 76) without the conductive clips (20, 40) of the stacked array.

[0043] It will be understood that the foregoing is presented merely as an example and is not an arbitrary limitation. It is conceivable that various alternatives and modifications to the described embodiments may be made without departing from the essence and scope of the invention. Accordingly, since the invention has been described in detail, it should be understood and clear to those skilled in the art that many physical modifications, of which only a few are illustrated in the detailed description of the invention, may be made without altering the original concepts and principles illustrated in this specification. It is also understood that numerous embodiments comprising only parts of the preferred embodiments may be possible for these parts without altering the original concepts and principles illustrated in this specification. Accordingly, the embodiments and optional configurations are illustrative and / or descriptive in all respects and are not limiting, and the scope of the invention is defined by the appended claims rather than the detailed description above, and all alternative embodiments and modifications to the embodiments that fall within the meaning and equivalent scope of the claims should be included therein.

Claims

Claim 1 As a stacked multichip electronic assembly: an electronic component subassembly having components - said components: a conductive bottom clip having an upper contact surface and a lead, at least a first semiconductor chip and a second semiconductor chip having upper and lower contact surfaces, respectively, a conductive top clip having a bottom contact surface and a lead - said conductive bottom clip, the first semiconductor chip, the second semiconductor chip, and the conductive top clip are arranged in a stacked array - and a solder layer positioned between opposing contact surfaces of said components in the stacked array -; a polymer layer extending only between said conductive top clip and said conductive bottom clip, encapsulating only the sides of said first semiconductor chip and said second semiconductor chip, and encapsulating only the edges of said solder layer positioned between them; A stacked multichip electronic assembly comprising: a body formed of a molding compound that encloses the electronic component subassembly and the polymer layer, wherein at least a portion of the leads from the conductive lower clip and the conductive upper clip extends to the outside of the body. Claim 2 A stacked multi-chip electronic assembly according to claim 1, wherein only the first semiconductor chip and the second semiconductor chip are present, and the solder layer is located between (a) the upper contact surface of the conductive lower clip and the lower contact surface of the first semiconductor chip, (b) the upper contact surface of the first semiconductor chip and the lower contact surface of the second semiconductor chip, and (c) the upper contact surface of the second semiconductor chip and the lower contact surface of the conductive upper clip. Claim 3 A stacked multichip electronic assembly according to claim 1, wherein the polymer layer extends around the lower contact surface of the conductive upper clip and the upper contact surface of the conductive lower clip. Claim 4 A stacked multichip electronic assembly according to claim 3, wherein the lower contact surface of the conductive upper clip includes a protrusion forming a chip contact area, the upper contact surface of the conductive lower clip includes a protrusion forming a chip contact area, and the polymer layer surrounds the edges of the protrusions. Claim 5 A stacked multichip electronic assembly according to claim 1, wherein the polymer layer comprises polyimide silicon. Claim 6 A stacked multichip electronic assembly according to claim 1, wherein the molding compound is an epoxy molding compound. Claim 7 A stacked multichip electronic assembly according to claim 1, wherein the portion of the lead from the conductive upper clip and the conductive lower clip extending outwardly of the body includes each end extending along the lower surface of the body. Claim 8 A stacked multichip electronic assembly according to claim 1, wherein the components further comprise a copper slug located in at least one of: between the lower contact surface of the conductive upper clip and the upper contact surface of the second semiconductor chip, between the contact surfaces of adjacent semiconductor chips, and between the lower contact surface of the first semiconductor chip and the upper contact surface of the conductive lower clip, and the solder layer is located between each of the contact surfaces and the copper slug. Claim 9 A method for assembling a stacked multichip electronic assembly, comprising the steps of: assembling an electronic component subassembly having components of a stacked array, wherein the components include a conductive bottom clip having an upper contact surface and a lead, at least a first semiconductor chip and a second semiconductor chip each having upper and lower contact surfaces, and a conductive top clip having a bottom contact surface and a lead; and applying a solder layer between opposing contact surfaces of the components of the stacked array; applying a polymer layer only between the conductive top clip and the conductive bottom clip, encapsulating the sides of the first semiconductor chip and the second semiconductor chip, and encapsulating only the edges of the solder layer located between them; and molding the body with a molding compound that encapsulates the electronic component subassembly and the polymer layer such that at least a portion of the lead from the conductive top clip and the conductive bottom clip extends outward from the body. Claim 10 A method for assembling a stacked multi-chip electronic assembly according to claim 9, wherein the at least first semiconductor chip and the second semiconductor chip comprise only the first semiconductor chip and the second semiconductor chip, and the step of applying the solder layer comprises (a) between the upper contact surface of the conductive lower clip and the lower contact surface of the first semiconductor chip, (b) between the upper contact surface of the first semiconductor chip and the lower contact surface of the second semiconductor chip, and (c) between the upper contact surface of the second semiconductor chip and the lower contact surface of the conductive upper clip. Claim 11 A method for assembling a stacked multichip electronic assembly according to claim 9, wherein the polymer layer extends around the lower contact surface of the conductive upper clip and the upper contact surface of the conductive lower clip. Claim 12 A method for assembling a stacked multichip electronic assembly, wherein, in claim 9, the lower contact surface of the conductive upper clip comprises a protrusion forming a chip contact area, the upper contact surface of the conductive lower clip comprises a protrusion forming a chip contact area, and the method further comprises the polymer layer surrounding the edges of the protrusions. Claim 13 A method for assembling a stacked multichip electronic assembly according to claim 9, wherein the polymer layer comprises polyimide silicon. Claim 14 A method for assembling a stacked multichip electronic assembly, wherein, in claim 9, the molding compound is an epoxy molding compound. Claim 15 A method for assembling a stacked multichip electronic assembly, wherein, in claim 9, the portion of the lead from the conductive upper clip and the conductive lower clip extending outwardly from the body includes each end extending along the lower surface of the body. Claim 16 A method for assembling a stacked multi-chip electronic assembly, wherein the step of assembling the electronic component subassembly further comprises the step of positioning a copper slug in at least one of the following: between the lower contact surface of the conductive upper clip and the upper contact surface of the second semiconductor chip, between the contact surfaces of adjacent semiconductor chips, and between the lower contact surface of the first semiconductor chip and the upper contact surface of the conductive lower clip; and the step of applying the solder layer comprises the step of applying the solder layer between each of the contact surfaces and the copper slug. Claim 17 A stacked multichip electronic assembly comprising: an electronic component subassembly having components, wherein the components each comprise: at least a first semiconductor chip and a second semiconductor chip having an upper contact surface and a lower contact surface, and a solder layer positioned between opposing contact surfaces of the components in a stacked array; and a polymer layer that encloses only the sides of the at least first semiconductor chip and the second semiconductor chip and encloses the edges of the solder layer positioned between them. Claim 18 A stacked multichip electronic assembly according to claim 17, wherein the components further comprise a copper slug located on at least one of the upper contact surface of the second semiconductor chip, between the contact surfaces of adjacent semiconductor chips, and on the lower contact surface of the first semiconductor chip, and the solder layer is located between each of the contact surfaces and the copper slug. Claim 19 A stacked multichip electronic assembly according to claim 17, wherein the polymer layer comprises polyimide silicon.

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