阅读说明：本技术 具有引线尖端检查特征的半导体封装 (Semiconductor package with lead tip inspection feature ) 是由 张超发 K·C·A·苏 陈志文 于 2021-05-21 设计创作，主要内容包括：本发明公开了一种方法,其包括：提供载体；在载体上安装多个半导体管芯；在载体上形成覆盖半导体管芯中的每个的电绝缘包封物材料的区域；去除包封物材料的区段以在半导体管芯中的每个之间的电绝缘包封物材料的区域中形成间隙；在间隙之内形成导电材料；以及沿间隙中的每个使电绝缘包封物材料的区域单个化,以形成多个分立包封物主体。封装半导体器件中的每个包括设置在包封物主体的侧壁上的面向侧壁的端子。对于封装半导体器件中的每个,面向侧壁的端子电连接到相应的封装半导体器件的半导体管芯。由形成在间隙内的导电材料提供每个封装半导体器件的面向侧壁的端子。(The invention discloses a method, which comprises the following steps: providing a vector; mounting a plurality of semiconductor dies on a carrier; forming a region of electrically insulating encapsulant material on the carrier covering each of the semiconductor dies; removing sections of the encapsulant material to form gaps in regions of electrically insulating encapsulant material between each of the semiconductor dies; forming a conductive material within the gap; and singulating the regions of electrically insulating encapsulant material along each of the gaps to form a plurality of discrete encapsulant bodies. Each of the packaged semiconductor devices includes a sidewall-facing terminal disposed on a sidewall of the encapsulant body. For each of the packaged semiconductor devices, the terminals facing the sidewalls are electrically connected to the semiconductor die of the respective packaged semiconductor device. The sidewall-facing terminals of each packaged semiconductor device are provided by a conductive material formed within the gap.)

1. A method of forming a semiconductor device, comprising:

providing a vector;

mounting a plurality of semiconductor dies on the carrier;

forming a region of electrically insulating encapsulant material on the carrier covering each of the semiconductor dies;

removing sections of the encapsulant material to form gaps in the regions of electrically insulating encapsulant material between each of the semiconductor dies;

forming a conductive material within the gap; and

singulating the region of electrically insulating encapsulant material along each of the gaps to form a plurality of discrete encapsulant bodies;

wherein each of the packaged semiconductor devices includes a sidewall-facing terminal disposed on a sidewall of the encapsulant body;

wherein for each of the packaged semiconductor devices, the sidewall-facing terminals are electrically connected to the semiconductor die of the respective packaged semiconductor device,

wherein the sidewall-facing terminals of each packaged semiconductor device are provided from the conductive material formed within the gap.

2. The method of claim 1, wherein for each of the packaged semiconductor devices, the sidewall-facing terminals extend completely between a top surface and a bottom surface of the encapsulant body.

3. The method of claim 2, wherein after singulating the region of electrically insulating encapsulant material, each of the packaged semiconductor devices includes a recess in the sidewall of the encapsulant body extending between the top and bottom surfaces, and wherein for each of the packaged semiconductor devices, the sidewall-facing terminal is disposed within the recess.

4. The method of claim 3, further comprising: another cutting step is performed after singulating the region of electrically insulating encapsulant material such that the sidewall of the encapsulant body is substantially coplanar with the sidewall-facing terminal.

5. The method of claim 1, wherein, for each of the packaged semiconductor devices, the sidewall-facing terminal is a portion or conductive region that extends continuously from the sidewall to one or both of the top surface and the bottom surface of the encapsulant body.

6. The method of claim 1, wherein the encapsulant material comprises a laser-activatable molding compound, and wherein forming the conductive material within the gap comprises:

applying a laser on the laser-activatable molding compound, thereby forming a laser-activated surface in the laser-activatable molding compound; and

performing a plating process that forms the conductive material in the laser-activated surface.

7. The method of claim 6, wherein forming the region of electrically insulating encapsulant material comprises: encapsulating each of the semiconductor dies with a first molding compound material; and forming the laser activatable molding compound on the first molding compound material such that the laser activatable molding compound is exposed at an outer surface of the discrete encapsulant body.

8. The method of claim 6, wherein the plating process is an electroplating process.

9. The method of claim 6, wherein the plating process is an electroless plating process.

10. The method of claim 1, wherein each of the semiconductor dies includes a plurality of conductive terminals disposed on a major surface and a back surface opposite the major surface, and wherein the semiconductor dies are each mounted on the carrier such that the major surface faces away from the carrier.

11. The method of claim 1, wherein each of the semiconductor dies includes a major surface having a plurality of bond pads and a back surface opposite the major surface, wherein the semiconductor dies are each mounted on the carrier such that the major surface faces the carrier.

12. The method of claim 11, further comprising: removing the carrier from the region of electrically insulating encapsulant material; and transferring the region of electrically insulating encapsulant material to a transfer laminate prior to removing the section of the encapsulant material, and wherein removing the section of encapsulant material and forming the conductive material are performed with the region of electrically insulating encapsulant material disposed on the transfer laminate.

13. A packaged semiconductor device, comprising:

a semiconductor die comprising a plurality of bond pads;

an encapsulant body of electrically insulating encapsulant material, the encapsulant body encapsulating the semiconductor die;

a sidewall-facing terminal disposed on a sidewall of the enclosure body,

wherein the sidewall-facing terminal is electrically connected to one of the bond pads;

wherein the sidewall-facing terminals extend completely between the top and bottom surfaces of the enclosure body, and

wherein the electrically insulating encapsulant material comprises a laser-activatable molding compound.

14. The packaged semiconductor device of claim 13, wherein the sidewall-facing terminals extend continuously from the sidewall of the encapsulant body to a major surface of the encapsulant body that intersects the sidewall of the encapsulant body.

15. The packaged semiconductor device of claim 14, wherein the packaged semiconductor device comprises a groove in the sidewall of the encapsulant body extending between the top surface and the bottom surface, and wherein the sidewall-facing terminal is disposed within the groove.

16. The packaged semiconductor device of claim 14, wherein the sidewall-facing terminal is substantially coplanar with the sidewall of the encapsulant body.

17. The packaged semiconductor device of claim 13, wherein the packaged semiconductor device is configured as an integrated circuit.

18. The packaged semiconductor device of claim 14, wherein the encapsulant body comprises a first molding compound material encapsulating the semiconductor die, and wherein the laser-activatable molding compound is formed on the first molding compound material such that the laser-activatable molding compound is exposed at an outer surface of the encapsulant body.

19. The packaged semiconductor device of claim 14, wherein a back surface of the semiconductor die is exposed at the bottom surface of the encapsulant body.

20. The packaged semiconductor device of claim 14, wherein the back surface of the semiconductor die is covered by the encapsulant body.

Background

Leadless semiconductor packages are designed with terminals that are substantially coextensive with the encapsulant body. Examples of leadless semiconductor packages include DFN (dual flat no lead) and QFN (quad flat no lead) packages, for example. Leadless semiconductor packages provide significant advantages over leaded packages, including small footprint and low material cost. However, the I/O density of these packages is constrained by the minimum spacing between the conductive bond pads and the planar footprint of the encapsulant body. In many applications, it is desirable to reduce device size while maintaining or increasing the I/O density of the device. It is therefore desirable to provide a leadless package with increased I/O capability for a given planar footprint.

Disclosure of Invention

A method of forming a semiconductor device is disclosed. According to an embodiment, the method comprises: providing a vector; mounting a plurality of semiconductor dies on a carrier; forming a region of electrically insulating encapsulant material on the carrier covering each of the semiconductor dies; removing sections of the encapsulant material to form gaps in regions of electrically insulating encapsulant material between each of the semiconductor dies; forming a conductive material within the gap; and singulating regions of electrically insulating encapsulant material along each of the gaps to form a plurality of discrete encapsulant bodies. Each of the packaged semiconductor devices includes a sidewall-facing terminal disposed on a sidewall of the encapsulant body. For each of the packaged semiconductor devices, the terminals facing the sidewalls are electrically connected to the semiconductor die of the respective packaged semiconductor device. The sidewall-facing terminals of each packaged semiconductor device are provided by a conductive material formed within the gap.

Independently or in combination, for each of the packaged semiconductor devices, the sidewall-facing terminals extend completely between the top and bottom surfaces of the encapsulant body.

Independently or in combination, after singulating the region of electrically insulating encapsulant material, each of the packaged semiconductor devices includes a recess in a sidewall of the encapsulant body extending between the top and bottom surfaces, and for each of the packaged semiconductor devices, a terminal facing the sidewall is disposed within the recess.

Independently or in combination, the method further comprises a further cutting step after singulating the region of electrically insulating encapsulant material such that the sidewalls of the encapsulant body are substantially coplanar with the terminals facing the sidewalls.

Independently or in combination, for each of the packaged semiconductor devices, the sidewall-facing terminal is a portion or conductive region that extends continuously from the sidewall to one or both of the top and bottom surfaces of the encapsulant body.

Independently or in combination, the encapsulant material includes a laser-activatable molding compound, and forming the conductive material within the gap includes applying a laser on the laser-activatable molding compound, thereby forming a laser-activated surface in the laser-activatable molding compound, and performing a plating process that forms the conductive material in the laser-activated surface.

Independently or in combination, forming the region of electrically insulating encapsulant material comprises: encapsulating each of the semiconductor dies with a first molding compound material; and forming a laser-activatable molding compound on the first molding compound material such that the laser-activatable molding compound is exposed at the outer surface of the discrete encapsulant body.

Independently or in combination, the plating process is an electroplating process.

Independently or in combination, the plating process is an electroless plating process.

Individually or in combination, each of the semiconductor dies includes a plurality of conductive terminals disposed on a major surface and a back surface opposite the major surface, and wherein the semiconductor dies are each mounted on the carrier such that the major surface faces away from the carrier.

Independently or in combination, each of the semiconductor dies includes a major surface having a plurality of bond pads and a back surface opposite the major surface, wherein the semiconductor dies are each mounted on the carrier such that the major surface faces the carrier.

Independently or in combination, the method further comprises: removing the carrier from the region of electrically insulating enclosure material; and transferring the area of electrically insulating encapsulant material to the transfer laminate prior to removing the section of encapsulant material, and removing the section of encapsulant material and forming the conductive material is performed with the area of electrically insulating encapsulant material disposed on the transfer laminate.

A packaged semiconductor device is disclosed. According to an embodiment, the packaged semiconductor device comprises: a semiconductor die comprising a plurality of bond pads; an encapsulant body of an electrically insulating encapsulant material encapsulating the semiconductor die; a sidewall-facing terminal disposed on the sidewall of the encapsulant body, the sidewall-facing terminal being electrically connected to one of the bond pads; the sidewall-facing terminals extend completely between the top and bottom surfaces of the encapsulant body, and the electrically insulating encapsulant material includes a laser-activatable molding compound.

Independently or in combination, the sidewall-facing terminals extend continuously from the sidewall of the enclosure body to a major surface of the enclosure body that intersects the sidewall of the enclosure body.

Independently or in combination, the packaged semiconductor device includes a groove in a sidewall of the encapsulant body extending between the top surface and the bottom surface, and wherein the terminal facing the sidewall is disposed within the groove.

Independently or in combination, the packaged semiconductor device according to claim 14, wherein the terminals facing the sidewalls are substantially coplanar with the sidewalls of the encapsulant body.

Independently or in combination, the packaged semiconductor device is configured as an integrated circuit.

Independently or in combination, the encapsulant body includes a first molding compound material encapsulating the semiconductor die, and wherein the laser-activatable molding compound is formed on the first molding compound material such that the laser-activatable molding compound is exposed at an outer surface of the encapsulant body.

Independently or in combination, the back surface of the semiconductor die is exposed at the bottom surface of the encapsulant body.

Independently or in combination, the back surface of the semiconductor die is covered by an encapsulant body.

Those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.

Drawings

The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts. Features of the various illustrated embodiments may be combined unless mutually exclusive. Embodiments are depicted in the drawings and are described in detail in the following description.

Fig. 1, which includes fig. 1A-1H, depicts method steps for forming a packaged semiconductor device according to an embodiment. Fig. 1A-1F depict method steps from a cross-sectional perspective, and fig. 1G-1H depict packaged semiconductor devices from an isometric perspective.

Fig. 2, which includes fig. 2A-2F, depicts method steps for forming a packaged semiconductor device according to an embodiment.

Fig. 3, which includes fig. 3A-3F, depicts method steps for forming a packaged semiconductor device according to an embodiment.

Fig. 4 depicts a packaged semiconductor device according to an embodiment from an isometric view.

Fig. 5 depicts a packaged semiconductor device according to an embodiment from an isometric view.

Fig. 6, which includes fig. 6A and 6B, depicts an assembly of two packaged semiconductor devices mounted on a circuit board according to an embodiment. Fig. 6A depicts the assembly from a plan view perspective. Fig. 6B depicts the assembly from a side view perspective.

Fig. 7, which includes fig. 7A and 7B, depicts an assembly of two packaged semiconductor devices mounted on a circuit board according to an embodiment. Fig. 7A depicts the assembly from an isometric view. Fig. 7B depicts the assembly from a side view perspective.

Detailed Description

Embodiments described herein include a molded semiconductor package having terminals formed along sidewalls of an encapsulant body. These side-wall facing terminals are formed by laser structuring techniques. According to this technique, the encapsulated encapsulant body includes a laser-activatable molding compound that is selectively activated by application of a laser to activate the surface metal. The conductive material is formed in the laser activated region by a plating process such as electroplating or electroless plating. Using this advantageous technique, the side wall facing terminals may be formed to extend across the full thickness of the enclosure body. These sidewall-facing terminals can act as LTI (lead tip inspection) features to check the integrity of the solder connections. In addition, or in the alternative, the sidewall-facing terminals may be configured as independent contact points for direct electrical connection.

Referring to fig. 1, selected method steps for forming a semiconductor package according to an embodiment are illustrated. Referring to fig. 1A, a carrier 100 is provided. In general, the carrier 100 may be any structure compatible with batch processing techniques for semiconductor devices. For example, the carrier may be a large metal panel, e.g., an 18 "x 24" panel, capable of accommodating tens or hundreds of semiconductor dies. In an embodiment, the carrier 100 includes a conductive metal, e.g., copper, aluminum, etc.

A plurality of semiconductor die 102 are mounted on a carrier 100. Although four of the semiconductor dies 102 are depicted mounted on the carrier 100, in principle, the methods described herein may be used with any number of dies (i.e., two or more dies) to form multiple packaged semiconductor devices simultaneously. The semiconductor die 102 may have a wide variety of device configurations. For example, the semiconductor die 102 may be configured as a discrete switching device, such as a MOSFET (metal oxide semiconductor field effect transistor), an IGBT (insulated gate bipolar transistor), a HEMT (high electron mobility transistor), and the like. The semiconductor die 102 may also be configured as an integrated device, e.g., a controller, processor, sensor, amplifier, etc.

Each semiconductor die 102 includes a plurality of conductive bond pads 104 that provide I/O terminals of the device, such as gates, sources, drains, collectors, emitters, and the like. According to an embodiment, a vertical interconnect structure 106 is formed on the bond pad 104. These vertical interconnect structures 106 elevate the electrical contacts to the I/O terminals of the device above the major surface of the semiconductor die 102. The vertical interconnect structure 106 may include conductive materials such as copper, gold, aluminum, nickel, etc., and alloys and solder materials thereof. For example, the vertical interconnect structures 106 may be wire bolt bumps or metal posts.

A semiconductor die 102 is mounted on a carrier 100 with a major surface 101 of the die 102 facing away from the carrier 100. Thus, the bond pads 104 of the semiconductor die 102 face away from the carrier 100. The rear surface 103 of the die 102 is fixed to the carrier 100 by an adhesive material. In the embodiment of fig. 1A, the die 102 is secured to a carrier using an adhesive tape 108. For example, the adhesive tape 108 may be a plasticized PVC film.

Referring to fig. 1B, a region of electrically insulating encapsulant material 110 is formed on carrier 100. Any of a variety of molding techniques (e.g., injection molding, transfer molding, compression molding, etc.) may be used to form the regions of electrically insulative encapsulant material 110. An area of electrically insulating encapsulant material 110 is formed such that the major surface 101 of each semiconductor die 102 is covered by the encapsulant material. As a result, each of the semiconductor die 102 is embedded within the encapsulant material.

According to an embodiment, the region of electrically insulating encapsulant material 110 is formed such that the vertical interconnect structures 106 are exposed at an upper surface of the encapsulant material. This may be accomplished using a two-step process in which a region of electrically insulating encapsulant material 110 is initially formed to include an upper surface over the vertical interconnect structures 106, and the upper surface is locally thinned (e.g., polished, ground, etched, etc.) to expose the upper ends of the vertical interconnect structures 106. Alternatively, the vertical interconnect structures 106 may be exposed from the encapsulant material by performing a one-step molding process, wherein a molding chamber is configured to form an upper surface of the encapsulant material below an upper end of the vertical interconnect structures 106.

The region of electrically insulating encapsulant material 110 is formed to include a laser-activatable molding compound. As used herein, "laser-activatable molding compound" refers to a molding compound that includes at least one additive, for example, in the form of a metal oxide (spinel type), which is activated by a focused laser beam to become an active metal for subsequent electroless or electroplating processes. In addition to additives, "laser-activatable molding compounds" also include polymeric materials as base materials. Examples of these polymers include thermosetting polymers having a resin matrix, ABS (acrylonitrile butadiene styrene), PC/ABS (polycarbonate/acrylonitrile butadiene styrene), PC (polycarbonate), PA/PPA (polyimide/polyphthalamide), PBT (polybutylene terephthalate), COP (cyclic olefin polymer), PPE (polyphenylene ether), LCP (liquid crystal polymer), PEI (polyethyleneimine or polyethylenimine), PEEK (polyether ether ketone), PPS (polyphenylene sulfide), and the like.

According to an embodiment, the region of electrically insulating encapsulant material 110 is formed to include both laser-activatable and non-laser-activatable molding compounds, i.e., molding compounds without laser-activatable metal additives. For example, the regions of electrically insulating encapsulant material 110 may be formed by a two-step process. In a first step, each of the semiconductor dies 102 is encapsulated by a first molding material. The first molding material may include a polymeric material, such as an epoxy material, a thermoset plastic, or the like. The first molding material is formed as an inner encapsulant body surrounding the semiconductor die 102. In a second step, a laser-activatable molding compound is formed around the inner enclosure body. As a result, the laser-activatable molding compound is present at the upper surface of the region of electrically insulating encapsulant material 110 and in the lateral regions between each of the semiconductor dies 102.

Referring to fig. 1C, a section of the encapsulant material is removed. This may be done using techniques such as etching or drilling. These sections are removed to form gaps (e.g., trench-like structures) 112 in the encapsulant material between each of the semiconductor dies 102. According to an embodiment, the gap 112 is formed to extend completely through an area of the electrically insulating encapsulant material 110, thereby exposing the adhesive tape 108 and/or the carrier 100. The gaps 112 may be formed in a transverse pattern along a single cross-sectional plane. The view of FIG. 1C shows a cross-sectional plane extending through the center of the gap. In another cross-sectional plane parallel to and offset from this cross-sectional plane, the regions between the semiconductor die 102 may be filled with an encapsulant material in a similar manner as shown in fig. 1B. From a plan view perspective, the gaps 112 may be formed in a crisscross pattern, with each semiconductor die 102 surrounded on each side by a plurality of gaps 112.

Referring to fig. 1D, a conductive material 114 is formed over the encapsulant material. Specifically, the conductive material 114 is formed on an upper surface of the encapsulant material opposite the carrier 100. This conductive material 114 is structured into a terminal 116 facing the major surface, which contacts one of the vertical interconnect structures 106. Further, a conductive material 114 is formed in the gap 112. Specifically, the conductive material 114 is formed along the sidewalls of the encapsulant material facing the gap 112. This conductive material 114 is structured into a sidewall-facing terminal 118. The sidewall-facing terminals 118 may also be electrically connected to the semiconductor die. For example, the sidewall-facing terminals 118 may be part of a continuous conductive structure that includes the primary surface-facing terminals 116 and contacts the vertical interconnect structures 106, e.g., as shown in the illustrated embodiment. Alternatively, conductive connectors (e.g., clips, wires, etc.) may be provided within the encapsulant body to form electrical connections between the sidewall-facing terminals 118 and the semiconductor die 102.

According to an embodiment, a laser structuring process is used to form the conductive material 114 on the region of the encapsulant material 110. Advantageously, this laser structuring process provides a great degree of flexibility in the location and structure of the conductive material 114. In particular, using conventional techniques, the above-described structures including terminals 116 facing the major surface and terminals 118 facing the sidewalls can be difficult or impossible to form with the geometries disclosed herein because of the necessary precision required to form these structures in a small area.

The laser structuring process includes a laser activation step. The laser activation step is performed by directing a laser beam onto selected areas of the laser-activatable molding compound. Energy from the laser beam creates a laser activated region in the encapsulant body. The laser-activated region includes a metal complex present at the surface of the laser-activatable molding compound and is capable of acting as a nucleus for a metal plating process, examples of which are described in more detail below. In contrast, the portions of the laser-activatable molding compound not exposed to the laser beam do not have exposed metal complexes capable of acting as nuclei during the metal plating process.

The plating process selectively forms conductive material in the laser-activated regions of the molding compound, while substantially not forming conductive material in the non-activated regions of the laser-activatable molding compound. This means that most of the metal formed by the plating process (e.g., greater than 95%, 99%, etc.) is formed in the laser activated region. Furthermore, the conductive material formed in the laser activated region forms defined conductive tracks or pads in the encapsulant body. In general, the plating process may be any metal plating process that utilizes a seed material as a basis for depositing metal thereon. These plating processes include electroless plating processes and electroplating processes.

According to an embodiment, the plating process is an electroless plating process. According to this technique, the semiconductor device is immersed in a chemical bath containing metal ions (e.g., Cu + ions, Ni + ions, Ag + ions, etc.), which react with the organometallic complex in the region activated later, thereby forming a complete elemental layer from the chemical bath. The plating process may begin with a cleaning step to remove laser debris and may be followed by additive build-up of the plated metal using a chemical bath. Optionally, after the plating process, an additional metal coating, e.g., a coating comprising Ni, Au, Sn/Pb, Ag/Pd, etc., may be applied over the deposited metal.

Referring to fig. 1E, the carrier 100 is removed. This is done, for example, using chemical etching techniques. The adhesive tape 108 may also be removed. As a result, the lower surface of the region of electrically insulating encapsulant material 110 is exposed. At this stage, the area of electrically insulating encapsulant material 110 remains unaffected by the bridge portion 120 of encapsulant material between each of the gaps 120. The cross-sectional view of FIG. 1E is taken along a different cross-sectional plane than that of FIG. 1D, which extends through bridge portion 120.

Referring to fig. 1F, a singulation process is performed. The singulation process may be performed by transferring a region of the electrically insulating encapsulant material 110 to a temporary carrier 122, which may be, for example, a laminate transfer carrier. Subsequently, the region of electrically insulating encapsulant material 110 is singulated along a cutting plane 123 that extends along the gap 112 and through the bridge portion 120 of encapsulant material. As a result, a plurality of discrete encapsulant bodies are formed. The regions of electrically insulating encapsulant material 110 may be singulated according to any of a variety of dicing techniques, such as mechanical cutting or sawing, chemical cutting, laser ablation, and the like.

Referring to fig. 1G, an example of a semiconductor package 200 produced after performing the singulation process of fig. 1F is shown, according to an embodiment. This semiconductor package 200 includes an encapsulant body 202 having sidewalls 204 extending between a top surface 206 of the encapsulant body 202 and a bottom surface (not shown) of the encapsulant body 202. The enclosure body 202 includes a recess (i.e., recessed region) 208 in the sidewall 204. The groove 208 is obtained by cutting an area of the electrically insulating encapsulant material 110 along a cutting plane 123, the cutting plane 123 extending through the center of the gap 112, as shown in fig. 1F. The sidewall-facing terminals 118 are exposed within the grooves 208. The sidewall-facing terminals 118 may cover each surface of the groove 208. For example, the groove 208 may have a three-sided configuration, with two outer walls facing each other and an inner wall spaced from the side wall 204. Each of these surfaces may be activated during the laser activation step and, thus, the sidewall-facing terminals 118 may be disposed along each of these interior surfaces of the groove 208.

Referring to fig. 1G, another cutting step has been performed to eliminate the grooves 208 in the sidewall 204 of the enclosure body 202. This may be accomplished by selecting the cutting plane of another cutting step to be parallel to the side wall 204 and to coincide with the inner face of the groove 208. Another cutting step may be performed by mechanical cutting or sawing, chemical cutting, laser ablation, etc. This further cutting step may be performed on the same temporary carrier 122 as the step of fig. 1F, or may be performed after transferring the encapsulant body to a further carrier.

The other cutting step of fig. 1G is optional. In some cases, the groove 208 in the enclosure body 202 may be acceptable or preferred. For example, it may be preferable to retain the groove 208 to enhance adhesion with the solder material. In that case, another cutting step of fig. 1H may be omitted, such that the package 200 of fig. 1G represents the final product. Alternatively, it may be preferable to eliminate the recess 208 to provide a package side that can be placed flush against another surface. In that case, the further cutting step may be performed such that the package 200 of fig. 1H represents the final product.

Referring to fig. 2, selected method steps for forming a molded semiconductor package are illustrated, in accordance with an embodiment. The process steps of fig. 2 may be substantially the same as or similar to the corresponding process steps of fig. 1, except as noted below. As shown in fig. 2A, instead of using an adhesive tape 108, each of the semiconductor dies 102 is mounted on the carrier 100 by providing a die attach material 124 (e.g., a conductive or non-conductive adhesive) between the back surface 103 of each semiconductor die 102 and the carrier 100. The die attach material 124 is formed such that portions of the carrier 100 between each semiconductor die 102 are exposed. Subsequently, as shown in fig. 2B and 2C, a region of electrically insulating encapsulant material 110 is formed, for example, in a similar manner as previously described, and a gap 112 is formed in the region of electrically insulating encapsulant material 110. Next, as shown in fig. 2D, a conductive material 114 is formed over the encapsulant material. The conductive material 114 may be formed by a laser structuring process. According to an embodiment, this laser structuring process comprises a laser activation step as described above, followed by an electroplating process. Electroplating refers to any process that uses an electric current to form a thin metal coating on the outer surface of a charged element. According to this technique, the device and cathode are immersed in a water-based solution, and a potential difference is generated between the immersed cathode and the immersed conductive object (acting as an anode). In this case, the metal complex present at the surface of the laser-activatable molding compound acts as an anode. Further, the portion of carrier 100 exposed from die attach material 124 acts as an anode. Dissolved metal ions from the cathode form attach to the cathode and thereby form a deposition area of conductive metal, e.g., copper. It can be seen that the electroplating process completely fills the gap 112 in the encapsulant material. Thus, as shown in fig. 2E and 2F, the carrier 100 is removed and a singulation process is performed, for example, in a manner similar to that described above. In this case, the terminals 118 facing the sidewalls are coplanar with the sidewalls of the encapsulant material after the initial dicing step. Thus, another cutting step, for example, the one described with reference to fig. 1H, may be omitted.

Referring to fig. 3, selected processing steps for forming a packaged semiconductor device are illustrated, in accordance with another embodiment. The process steps of fig. 3 may be substantially the same as or similar to the corresponding process steps of fig. 1, except as noted below. As shown in fig. 3A, the semiconductor dies 102 are each mounted on the carrier 100 such that a major surface 101 of each die faces the carrier 100. The conductive terminals of the semiconductor die (vertical interconnect structures 106 in this example) then adhere to the adhesive tape 108, and the back surface 103 of the semiconductor die 102 faces away from the carrier 100. Referring to fig. 3B, a region of electrically insulating encapsulant material 110 is formed. Referring to fig. 3C, the carrier 100 and the adhesive tape 108 are removed, for example, by the aforementioned manner. Subsequently, an assembly including the area of electrically insulating encapsulant material 110 and the semiconductor die 102 is placed on the transfer laminate 126. The orientation of the assembly is inverted so that the back surface 103 of the semiconductor die faces away from the substrate. Subsequently, as shown in fig. 3D-3F, gaps 112 are formed in regions of the electrically insulating encapsulant material 110, regions of the electrically conductive material 114 are formed, and a singulation process is performed, for example, in a similar manner as previously described.

The semiconductor package may be produced using the method described with reference to fig. 3, wherein the back surface 103 of the semiconductor die 102 is exposed at the bottom surface of the encapsulant body. Such a package configuration may be preferred in some applications, for example, in applications with backside cooling and/or vertical device configurations. The semiconductor package may be produced using the method described with reference to fig. 1-2, wherein the back surface 103 of the semiconductor die 102 is covered by the encapsulant body. In some applications, such a package configuration may be preferred, for example, in a lateral device configuration.

Referring to fig. 4, a semiconductor package 200 is depicted, in accordance with an embodiment. The semiconductor package 200 may be formed according to any of the techniques described with reference to fig. 1-3. The semiconductor package 200 includes an encapsulant body 202 having sidewalls 204 extending between a top surface 206 of the encapsulant body 202 and a back surface (not shown) of the encapsulant body 202. In this context, the terms "top surface" and "back surface" are used for explanatory purposes only to describe the opposite faces of the enclosure body 202. In practice, the semiconductor package 200 may be arranged in different orientations such that the "top surface" may face upward, downward, and sideways. The encapsulant body 202 may include a laser-activatable molding compound. Semiconductor package 200 includes a number of major surface-facing terminals 116 disposed on a top surface 206 of encapsulant body 202 and a number of sidewall-facing terminals 118 disposed on sidewalls 204 of encapsulant body 202. In an embodiment, the rear surface of the enclosure body 202 includes conductive terminals having the same configuration as the terminals 116 facing the major surface. In that case, both the top surface 206 of the encapsulant body 202 and the back surface of the encapsulant body 202 may serve as an interface surface with another object, such as a printed circuit board or another packaged device. This configuration can be obtained by the following further process step: removing areas of the electrically insulating encapsulant material 110 from the carrier 100 or from the temporary carrier 122; and performing another laser activation and plating step according to the techniques described herein.

In the illustrated embodiment, the sidewall-facing terminals 118 extend completely between the top surface 206 of the enclosure body 202 and the back surface of the enclosure body 202. That is, the sidewall-facing terminals 118 extend along the entire thickness of the encapsulant body 202. This terminal configuration has significant advantages. In particular, the sidewall-facing terminals 118 are well-suited for LTI (lead tip inspection). The LTI feature allows for optical inspection of the solder joints when the semiconductor package 200 is mounted and electrically connected to an external device, such as a printed circuit board. Because the sidewall-facing terminals 118 extend along the entire thickness of the encapsulant body 202, there is a large area available for lead tip inspection of solder joints extending up the sides of the package. In addition, the side-facing terminals 118 provide additional electrical contact points that may be directly accessed for electrical connection when mounting and electrically connecting the semiconductor package 200 to an external device, such as a printed circuit. Examples of these configurations will be described in more detail below with reference to fig. 6 and 7.

In the illustrated embodiment, the sidewall-facing terminals 118 and the major surface-facing terminals 116 are portions of one conductive structure that extends continuously from the sidewalls of the enclosure body 202 to the major surface 101 of the enclosure body 202. As a result, this one conductive structure provides I/O terminals at two different sides of the semiconductor package 200.

Referring to fig. 5, a semiconductor package 200 is depicted in accordance with another embodiment. The semiconductor package 200 is configured as a discrete switching device, e.g., a power transistor such as a MOSFET, an IGBT, or the like. In this case, the semiconductor package 200 includes first terminals 208 collectively provided by one of the terminals 116 facing the main surface and one of the terminals 118 facing the side wall, second terminals 210 and third terminals 212 each provided by one of the terminals 118 facing the side wall. By forming the second and third terminals 210, 212 only on the sidewalls, the first terminal 208 can be made very large, which is beneficial for cooling and/or conducting electricity. Conversely, the second and third terminals 210, 212 may be smaller terminals having lower conduction requirements. To this end, the first terminal 208 may be a high current carrying or heat generating terminal (e.g., source or drain), while the second and third terminals 210, 212 may be the remaining gate, source or drain terminals of the device.

Referring to fig. 6, an assembly 300 including two semiconductor packages 200 mounted on a printed circuit board 302 is depicted in accordance with an embodiment. These semiconductor packages 200 may be formed according to any of the techniques described with reference to fig. 1-3. Although the two packages 200 are identical to each other in the illustrated embodiment, in principle, this concept applies to any two semiconductor packages having sidewall-facing terminals 118 formed by the techniques described with reference to fig. 1-3.

In the embodiment of fig. 6, each of the semiconductor packages 200 is mounted such that the terminals 116 facing the main surface face the printed circuit board 302. The terminals 116 facing the main surface are electrically connected to the bonding pads of the printed circuit board 302 by solder joints 304. Further, the assembly 300 includes direct electrical connections 306 between the sidewall-facing terminals 118 of two adjacent semiconductor packages 200. In the illustrated embodiment, such direct electrical connection 306 is provided by an area of solder material. More generally, the direct electrical connection 306 may be provided by any of a variety of electrical connectors (e.g., wires, clamps, etc.). Advantageously, by providing a direct electrical connection 306 between two adjacent semiconductor packages 200 above the printed circuit board 302, the need for conductive traces within the circuit board to make such connections is eliminated. Thus, I/O connection density of the assembly 300 is advantageously improved.

Referring to fig. 7, an assembly 300 including two semiconductor packages 200 mounted on a printed circuit board 302 is depicted in accordance with an embodiment. The semiconductor package 200 may be formed according to any of the techniques described with reference to fig. 1-3. In the present embodiment, the semiconductor packages 200 are mounted with one of the side walls 204 facing the printed circuit board 302, and the side-wall facing terminals 118 of each semiconductor package 200 are vertically spaced apart from each other. In this configuration, the terminals 116 of two adjacent semiconductor packages 200 facing the main surfaces face each other. The terminals 116 of two adjacent semiconductor packages 200 facing the major surfaces are electrically connected to each other by direct electrical connections 306. This configuration provides electrical interconnection over the printed circuit board 302, thereby alleviating the need for interconnection capacity of conductive tracks within the printed circuit board.

Terms such as "first," "second," and the like, are used to describe various elements, regions, sections, etc. and are not intended to be limiting. Like terms refer to like elements throughout the specification.

As used herein, the terms "having," "including," and the like are open-ended words that indicate the presence of stated elements or features, but do not exclude additional elements or features. The articles "a" and "the" are intended to include the plural and singular, unless the context clearly indicates otherwise.

Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.