Single step packaging

Abstract

The present invention discloses a single-step package. A semiconductor device includes a semiconductor wafer. A plurality of columnar bumps are formed on the semiconductor wafer. Solder is deposited on the columnar bumps. When the semiconductor wafer is on a carrier, after the columnar bumps are formed, the semiconductor wafer is singulated into a plurality of semiconductor dies. When the semiconductor dies are held on the carrier, a sealant is deposited around the semiconductor dies and the columnar bumps. The sealant covers the active surface of the semiconductor dies between the columnar bumps.

Description

[0001] This application is a divisional application. The invention name of the parent application is “Single-step Packaging”. The application date is August 9, 2017, and the application number is 201710675601.6.

[0002] Claiming national priority

[0003] This application claims the benefit of U.S. Provisional Application No. 62 / 372,720, filed August 9, 2016, which is incorporated herein by reference. Technical Field

[0004] The present invention relates generally to semiconductor devices, and more particularly to methods and semiconductor devices for packaging semiconductor dies using single-shot encapsulation. Background Art

[0005] Semiconductor devices are commonly found in modern electronic products. Semiconductor devices vary in the number and density of electrical components. Discrete semiconductor devices generally contain one type of electrical component, such as a light emitting diode (LED), a small signal transistor, a resistor, a capacitor, an inductor, and a power metal oxide semiconductor field effect transistor (MOSFET). Integrated semiconductor devices typically contain hundreds to millions of electrical components. Examples of integrated semiconductor devices include microcontrollers, microprocessors, charge coupled devices (CCDs), solar cells, and digital micromirror devices (DMDs).

[0006] Semiconductor devices perform a wide variety of functions, such as signal processing, high-speed computing, transmitting and receiving electromagnetic signals, controlling electronic devices, converting sunlight into electricity, and creating visual projections for television displays. Semiconductor devices are found in the fields of entertainment, communications, power conversion, networking, computers, and consumer products. Semiconductor devices are also found in military applications, aviation, automobiles, industrial controllers, and office equipment.

[0007] One goal of semiconductor manufacturing is to produce smaller semiconductor devices. Smaller devices and the resulting smaller end products typically consume less power, can be produced more efficiently, and have higher performance. Smaller semiconductor devices and smaller end products consume less material during manufacturing, which reduces environmental impact. In addition, smaller semiconductor devices have smaller footprints, which are desirable for crowded printed circuit boards and smaller end products. Smaller die size can be achieved by improvements in the front-end process that result in a die with smaller, higher density active and passive components. Back-end processes can result in semiconductor device packaging with a smaller footprint through improvements in electrical interconnects and packaging materials.

[0008] Semiconductor manufacturing can also be made more efficient by reducing the number of manufacturing steps. Manufacturers seek to streamline the process used to manufacture semiconductor devices so that fewer steps are required, less materials are used, and more environmentally friendly materials are used. Improving the manufacturing process can improve the time to market for new products and the cost of manufacturing.

[0009] It would be desirable to provide a semiconductor package having improved cost, manufacturing time, environmental impact, and parasitic characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1a-1e Figure 2 shows the formation of low profile bumps on a semiconductor wafer;

[0011] Figure 2a-2c The figure shows a low profile bump above the passivation layer opening;

[0012] Figure 3 Illustration of low profile bump and redistribution layer;

[0013] Figures 4a-4f The diagram shows packaging semiconductor dies from a wafer using a single-step packaging process;

[0014] Figure 5a-5d A semiconductor package manufactured using a single-step packaging process is shown;

[0015] Figure 6a-6b The figure shows a dual gang package manufactured using a single-step packaging process;

[0016] Figure 7a-7b The figure shows a three-combination package manufactured using a single-step packaging process;

[0017] Figures 8a-8d A second process flow for packaging a semiconductor die using a single-step packaging is illustrated;

[0018] Figures 9a-9f illustrates a third process flow for packaging a semiconductor die using a single-step packaging process; and

[0019] 10a-10b illustrate an electronic device utilizing a semiconductor package. DETAILED DESCRIPTION

[0020] The present invention is described in one or more embodiments in the following description with reference to the accompanying drawings, in which like numerals represent the same or similar elements. Although the present invention is described with respect to the best mode for carrying out the purposes of the present invention, those skilled in the art will appreciate that this description is intended to cover alternatives, modifications and equivalents as may be included in the spirit and scope of the present invention as defined by the appended claims and equivalents of the claims as supported by the following disclosure and drawings.

[0021] Semiconductor devices are generally manufactured using two complex manufacturing processes: front-end manufacturing and back-end manufacturing. Front-end manufacturing involves the formation of multiple dies on the surface of a semiconductor wafer. Each die on the wafer contains active and passive electrical components that are electrically connected to form a functional electrical circuit. Active electrical components, such as transistors and diodes, have the ability to control the flow of electrical current. Passive electrical components, such as capacitors, inductors, and resistors, create the relationship between voltage and current necessary to perform the electrical circuit function.

[0022] Active and passive components are formed on the surface of a semiconductor wafer through a series of process steps including doping, deposition, lithography, etching, and planarization. Doping introduces impurities into the semiconductor material through techniques such as ion implantation or thermal diffusion. The doping process modifies the conductivity of the semiconductor material in the active device by dynamically changing the conductivity of the semiconductor material in response to an electric field or base current. The transistor contains regions of different doping types and doping levels, which are arranged as necessary to enable the transistor to promote or restrict the flow of current when an electric field or base current is applied.

[0023] Active and passive components are formed by layers of materials having different electrical properties. Each layer can be formed by various deposition techniques, which are determined in part by the type of material being deposited. For example, thin film deposition can include chemical vapor deposition (CVD), physical vapor deposition (PVD), electrolytic plating, and electroless plating processes. Each layer is generally patterned to form an active component, a passive component, or part of an electrical connection between components.

[0024] Back-end manufacturing refers to dicing or singulating the finished wafer into individual semiconductor die and packaging the semiconductor die for structural support, electrical interconnection, and environmental isolation. The finished package is then inserted into an electrical system, and the functionality of the semiconductor device is made available to other system components.

[0025] Figure 1aA semiconductor wafer 120 is shown having a base substrate material 122 such as silicon, germanium, aluminum phosphide, aluminum arsenide, gallium arsenide, gallium nitride, indium phosphide, silicon carbide, or other bulk semiconductor material for structural support. A plurality of semiconductor dies or components 124 are formed on the wafer 120 and separated by non-active, inter-die wafer regions or saw streets 126. The saw streets 126 provide dicing areas for singulating the semiconductor wafer 120 into individual semiconductor dies 124. In one embodiment, the semiconductor wafer 120 has a width or diameter of 100-450 millimeters (mm).

[0026] Figure 1b A cross-sectional view of a portion of a semiconductor wafer 120 is shown. Each semiconductor die 124 has a back or inactive surface 128 and an active surface 130 that contains analog or digital circuits implemented as active devices, passive devices, conductive layers, and dielectric layers formed within the die and electrically interconnected according to the electrical design and function of the die. For example, the circuit may include one or more transistors, diodes, and other circuit elements formed within the active surface 130 to implement analog or digital circuits, such as digital signal processors (DSPs), ASICs, MEMS, memories, or other signal processing circuits. Semiconductor die 124 may also include integrated passive devices (IPDs) such as inductors, capacitors, and resistors for RF signal processing. In one embodiment, semiconductor die 124 includes a single active component, such as a diode or a power MOSFET.

[0027] Conductive layer 132 is formed over active surface 130 using PVD, CVD, electrolytic plating, chemical plating process, or other suitable metal deposition process. Conductive layer 132 includes one or more layers of aluminum (Al), copper (Cu), tin (Sn), nickel (Ni), gold (Au), silver (Ag), or other suitable conductive materials. Conductive layer 132 operates as a contact pad electrically connected to the circuit on active surface 130.

[0028] exist Figure 1c In the embodiment of the present invention, an insulating or dielectric layer 134 is formed on the semiconductor wafer 120. The insulating layer 134 includes one or more layers of silicon dioxide (SiO2), silicon nitride (Si3N4), silicon oxynitride (SiON), tantalum pentoxide (Ta2O5), aluminum oxide (Al2O3), solder resist, or other materials with similar insulating and supporting properties. Portions of the insulating layer 134 are removed by laser direct ablation (LDA), etching, or other processes suitable for exposing the conductive layer 132 on the semiconductor die 124.

[0029] exist Figure 1dIn, an electroplating process is used to grow the low-profile columnar bump 140 upward from the conductive layer 132. The low-profile columnar bump 140 is manufactured directly from the tube core pad upward. In some embodiments, electrolytic plating, chemical plating, or other suitable deposition processes are used to form the columnar bump 140 from Al, Cu, Sn, Ni, Au, Ag, titanium (Ti), tungsten (W), another suitable conductive material or alloys thereof. In other embodiments, a photolithographic mask is used to form the columnar bump 140. In one embodiment, the low-profile columnar bump 140 is approximately 0.5 mm×0.5 mm in a plan view with a height of approximately 50 micrometers (µm). In Figure 1e In FIG. 1 , solder cap 142 is deposited over bump 140 .

[0030] The solder cap 142 is formed by electroplating or otherwise depositing Ni, Au, Sn, Ag, or a combination thereof over the bump 140. In one embodiment, a single masking layer is used to form the stud bump 140 and the solder cap 142. In some embodiments, the solder cap 142 comprises lead-free solder.

[0031] Figure 2a-2c The diagram shows a low profile bump 140 formed over an opening in a polyimide (PI) passivation layer. Figure 2a In the embodiment, PI layer 150 is formed on insulating layer 134. In other embodiments, other passivation materials are used. During subsequent manufacturing steps, PI layer 150 protects insulating layer 134. Figure 2b In the embodiment of the present invention, the conductive layer 132 is exposed by LDA or suitable for use in Figure 2c The opening 152 is formed through the PI layer 150 by another etching process used to form the bump 140 and the solder cap 142 .

[0032] Figure 3 A redistribution layer (RDL) is shown formed over semiconductor die 124 prior to forming bumps 140. An insulating or dielectric layer 160 is formed over insulating layer 134 and conductive layer 132. Insulating layer 160 includes one or more layers of SiO2, Si3N4, SiON, Ta2O5, Al2O3, or other materials having similar insulating and structural properties. Insulating layer 160 extends completely across semiconductor wafer 120. Portions of insulating layer 160 are removed by LDA, etching, or other processes suitable for exposing conductive layer 132 for subsequent electrical interconnection.

[0033] Conductive layer 162 is formed on insulating layer 160 using PVD, CVD, electrolytic plating, chemical plating or other suitable metal deposition processes. Conductive layer 162 includes one or more layers of Al, Cu, Sn, Ni, Au, Ag or other suitable conductive materials. In one embodiment, conductive layer 162 includes an adhesion or seed layer of Ti / Cu, TiW / Cu or coupling agent / Cu. Optionally, another material such as Ni, Au or Ag with good wet etch selectivity is added to the seed layer. The seed layer is deposited by sputtering, chemical plating or by depositing laminated Cu foil combined with chemical plating. Conductive layer 162 is electrically connected to conductive layer 132 of semiconductor die 124 through an opening in insulating layer 160. Conductive layer 162 is patterned into a fan-out or fan-in configuration to position low-profile bump 140 on semiconductor die 124 as desired. In some embodiments, additional insulating layers and conductive layers are interwoven on insulating layer 160 and conductive layer conductive layer 162 to implement more advanced signal routing.

[0034] An insulating or passivation layer 164 similar to insulating layer 160 or PI layer 150 is formed over insulating layer 160 and conductive layer 162. An opening is formed in passivation layer 164 over conductive layer 162. Figure 1d and 1e As in FIG. 1 , low-profile bumps 140 and solder caps 142 are formed on conductive layer 162 through openings in passivation layer 164 .

[0035] Figures 4a-4f The diagram shows the use of a single-step packaging process to package Figure 1a-1e If a PI layer or RDL is desired, then Figure 2c or Figure 3 A similar process is performed on the semiconductor wafer 120 in FIG. Figure 4a In the embodiment of the present invention, trenches are dug into the wafer 120 between the semiconductor die 124. The trenches 170 are formed in the saw streets 126 through the insulating layer 134 and only partially through the wafer 120 using a laser cutting tool or a saw blade 172. In one embodiment, the trenches 170 are formed using deep reactive ion etching (DRIE). In some embodiments, the trenches 170 are formed to a depth between 60 and 200 μm, including the height of the bumps 140 and the solder caps 142.

[0036] exist Figure 4bIn the embodiment of the present invention, the wafer 120 is flipped over and mounted on a substrate support 174 and a back grinding tape 176, wherein the active surface 130 and the grooves 170 are oriented toward the substrate support. The wafer 120 is back ground using a back grinding tool 180 using a mechanical grinding or etching process to remove portions of the substrate material 122 and reduce the thickness of the semiconductor wafer 120. The semiconductor wafer 120 is thinned using the back grinding tool 180 to form a new back surface 178 of the semiconductor wafer. Figure 4b In the embodiment shown in , trenches 170 are formed to be at least as deep as the desired final thickness for semiconductor die 124. The back grinding operation separates semiconductor die 124 from one another by removing any remaining semiconductor material in saw streets 126.

[0037] Figure 4c-4d An alternative embodiment is shown in which trenches 170 are not formed completely through the desired final thickness of semiconductor die 124. Back grinding tool 180 removes portions of semiconductor wafer 120 but does not fully thin the semiconductor wafer into separate semiconductor die 124. In some embodiments, the thickness of semiconductor die 124 after back grinding, including bumps 140-142, ranges between 80 and 220 μm, with approximately 20 μm of semiconductor wafer thickness remaining in saw streets 126 after back grinding is complete. Figure 4d Semiconductor die 124 are singulated by removing the remaining portions of semiconductor wafer 120 within saw streets 126 using a laser cutting tool or saw blade 182. In some embodiments, semiconductor die 124 are singulated using DRIE or another suitable etching process after back grinding.

[0038] Optionally, for example by sputtering, Figure 4b or Figure 4d The semiconductor die 124 in an alternative embodiment of is exposed to the oxide coating after singulation. Figure 4e In the embodiment of the present invention, sealant or molding compound 186 is deposited on semiconductor die 124 and low profile bump 140 as insulating material using paste printing, compression molding, transfer molding, liquid sealant molding, vacuum lamination, spin coating or other suitable applicator. In particular, sealant 186 covers the side surface, active surface 130 and back surface 178 of semiconductor die 124. Sealant 186 also extends completely around each bump 140, leaving solder cap 142 exposed from sealant. Sealant 186 can be a polymer composite material, such as epoxy resin with filler, epoxy acrylate with filler or polymer with appropriate filler. Sealant 186 is non-conductive and protects semiconductor device from external elements and pollutants in the environment. Sealant 186 also protects semiconductor die 124 from degradation caused by exposure to light.

[0039] In some embodiments, the surface of encapsulant 186 is coplanar with the surface of solder cap 142. In other embodiments, solder cap 142 is recessed within encapsulant 186 or extends out of encapsulant. Semiconductor die 124 and encapsulant 186 are removed from carrier 174 as a plate and subjected to an optional post-mold curing (PMC) process, for example, in an oven. Encapsulant 186 maintains the relative position of each semiconductor die 124, approximately as if the semiconductor die remained as part of semiconductor wafer 120. Semiconductor die 124 are connected to each other through encapsulant 186 rather than substrate material 122.

[0040] After PMC, semiconductor die 124 within encapsulant 186 are mounted onto carrier 190 and thermal or UV release tape 192 for singulation. Semiconductor die 124 are singulated into single step encapsulation (SSE) packages 200 between semiconductor dies using a saw blade, laser cutting tool, or water cutting tool 194. Singulated SSE packages 200 are thermally released from carrier 190 or released from carrier 190 by UV irradiation and packaged into, for example, tape and reel for delivery to a customer who will integrate the package into an electronic device. In some embodiments, SSE packages 200 are sent for testing operations.

[0041] Figure 5a-5d SSE package 200 is illustrated from various perspectives. Figure 5a Shown in Figures 4a-4f FIG. 2 is a cross-section of an SSE package 200 in FIG. Figure 5b The SSE package 200 is shown relative to Figure 5a A cross-sectional view rotated ninety degrees to the left or right. Figure 5a-5d The semiconductor die 124 in FIG. 1 is a two-terminal device, such as a diode, but in other embodiments a more complex semiconductor die 124 with additional terminals and additional bumps 140 is similarly packaged. The semiconductor die 124 may be a two-terminal device, a three-terminal device such as a power MOSFET, or have more terminals, such as an ASIC with address and data buses.

[0042] Figure 5c and 5d A perspective view of an SSE package 200 is shown. Figure 5c is the external view, and Figure 5d Encapsulant 186 is shown as transparent to reveal the structure of semiconductor die 124 and bumps 140 within the encapsulant. Figure 5d The dashed lines in are lines that are visible only because the sealant 186 is transparent.

[0043] The SSE package 200 is formed without the need for a base frame or substrate (which remains as part of the final package), which allows for a reduced package thickness. In some embodiments, the thickness of the SSE package 200 is approximately 0.150 mm or less. The relatively low thickness of the SSE package 200 meets the needs of manufacturers of increasingly smaller devices, especially wearable and Internet of Things (IoT) devices. The construction of the SSE package 200, which allows the elimination of internal substrates and wire bonds, improves package reliability, increases product performance, and simplifies the assembly process. Parasitic electrical characteristics, such as resistance, inductance, and capacitance, are also reduced.

[0044] The construction of the SSE package 200 without internal solder joints allows the use of lead-free solder for the solder cap 142, which melts at a higher temperature relative to conventional tin-lead solder. In other package types, internal solder joints, such as for coupling the semiconductor die 124 to the frame using a ball grid array or wire bonding connection, can melt when the final package is mounted to a printed circuit board (PCB) or other substrate. The SSE package 200 can be mounted to the substrate at a higher temperature required for lead-free solder without risking the integrity of the package. The columnar bumps 140 and solder caps 142 can be formed at the wafer level and not reflowed until the SSE package 200 is attached to the consumer's PCB using the solder cap. Due to the simplified process flow, the SSE package 200 is thin and lightweight, with improved second-level board reliability and time to market.

[0045] Figure 6a-6b The diagram shows a dual package 220 formed to include two semiconductor dies 124 in the same package. The semiconductor dies 124 are singulated using a sawing tool 194, such as in Figure 4f However, for some of the semiconductor die pairs, the adjacent semiconductor die 124 are not singulated. The dual combination package 220 includes two semiconductor die 124, which may be connected to a pair of conductive traces on a PCB. Figure 7a-7b Semiconductor die 124 is shown singulated into groups of three semiconductor dies to form tri-package 230. Semiconductor die 124 may be singulated into any desired configuration for the number of devices to be used together on a circuit board.

[0046] Figures 8a-8d As shown in Figures 4a-4f A single-step packaging process is an alternative to the process in Figure 8a In the embodiment, the semiconductor wafer 120 is arranged with the active surface 130 oriented toward the carrier 174, as in Figure 4c As in the example above, but without the previous formation of trench 170. If a PI layer and / or RDL layer is desired, the Figure 2cor 3 semiconductor wafer 120. Figure 8b In, as in Figure 4d As in FIG. 1 , semiconductor die 124 is singulated using a saw blade or laser cutting tool 182. In some embodiments, DRIE is used. Figure 8c In, as in Figure 4e As in the example, sealant 186 is deposited and in Figure 8d In Figure 4f The encapsulated semiconductor die 124 is singulated into SSE package 250 as in FIG. SSE package 250 is similar to SSE package 200, but the process is performed without the formation of trench 170.

[0047] Figures 9a-9f The third process flow for single-step packaging is shown in the figure. Figure 9a In, as in Figure 8a The semiconductor wafer 120 is back ground as in FIG. Figure 9b In the embodiment of the present invention, semiconductor wafer 120 is mounted on thermal release tape 260 with back surface 178 oriented toward the thermal release tape. Saw blade or laser cutting tool 262 is used to singulate semiconductor die 124 through saw streets 126. After singulation, semiconductor die 124 are transferred and mounted on support substrate or carrier 264, such as in Fig.9c Prior to mounting semiconductor die 124, UV or thermal transfer tape 266 is disposed on carrier 264. In one embodiment, tape 260 is a thermal tape and tape 266 is a UV tape. Figure 9d In the embodiment, the thermal release tape 260 is removed using an elevated temperature without the release UV tape 266. In another embodiment, the tape 266 is a thermal release tape and the tape 260 is a UV release tape.

[0048] exist Fig.9e In, as in Figure 4e As in the example, sealant 186 is deposited and in Figure 9f In Figure 4f The sealed semiconductor die 124 is singulated into SSE package 270 as in FIG. SSE package 270 is similar to SSE package 200, but the process is as in FIG. Figures 9a-9f Do as in.

[0049] FIG. 10 a illustrates one of the SSE packages mounted on a PCB or other substrate 360. The substrate 360 ​​includes a conductive layer or trace 362 formed on the surface of the substrate. The conductive layer 362 is patterned as desired to implement the intended function of the electronic device. FIG. 10 a shows the SSE package 230 as an example, but any disclosed SSE package is similarly mounted. The SSE package 230 is disposed on 360, wherein the sealant 186 contacts the substrate. The solder cap 142 contacts the conductive layer 362. In some embodiments, there is an offset between the SSE package 230 and the substrate 360, for example due to an adhesive layer for attachment, additional solder paste provided on the conductive layer 362, or other logistical realities of device manufacturing. The solder cap 142 is reflowed onto the conductive layer 362 to mechanically bond and electrically connect the SSE package 230 to the substrate 360. The solder 142 is substantially contained within the opening of the sealant 186.

[0050] 10b illustrates SSE package 230 mounted on PCB 360 as part of electronic device 370 having multiple semiconductor packages mounted on the surface of the PCB along with the SSE package. Electronic device 370 may have one type of semiconductor package or multiple types of semiconductor packages depending on the application.

[0051] Electronic device 370 may be a stand-alone system that uses a semiconductor package to perform one or more electrical functions. Alternatively, electronic device 370 may be a subcomponent of a larger system. For example, electronic device 370 may be part of a tablet computer, a cellular phone, a digital camera, a communication system, or other electronic device. Electronic device 370 may also be a graphics card, a network interface card, or other signal processing card that may be integrated into a computer. The semiconductor package may include a microprocessor, a memory, an ASIC, a logic circuit, an analog circuit, an RF circuit, a discrete device, or other semiconductor die or electrical component.

[0052] In FIG. 10 b, PCB 360 provides a general substrate for structural support and electrical interconnection of semiconductor packages mounted on the PCB. Conductive signal traces 362 are formed on the surface of PCB 360 or within the layers of PCB 360 using evaporation, electrolytic plating, chemical plating, screen printing or other suitable metal deposition processes. Signal traces 362 provide electrical communication between each of the semiconductor package, mounting components, and other external system components. Traces 362 also provide power and ground connections to the semiconductor package as needed.

[0053] The SSE package 372 is an ASIC packaged using one of the single-step packaging processes disclosed above. The SSE package 230 is a three-combination package and is soldered in series with three adjacent conductive traces. For illustration purposes, several types of first-level packages are shown on the PCB 360, including a bonded lead package 390 and a flip chip 382. In addition, several types of second-level packages, including a ball grid array (BGA) 384, a bump chip carrier (BCC) 392, a land grid array (LGA) 394, a multi-chip module (MCM) 388, a quad flat package (QFN) 396, an embedded wafer-level ball grid array (eWLB) 386, and a wafer-level chip size package (WLCSP) 380 are shown mounted on the PCB 360. In one embodiment, the eWLB 386 is a fan-out wafer-level package (Fo-WLP) or a fan-in wafer-level package (Fi-WLP). Any combination of semiconductor packages (configured with any combination of first and second level packaging styles) and other electronic components may be connected to PCB 360 depending on system needs.

[0054] In some embodiments, electronic device 370 includes a single attached semiconductor package, while other embodiments require multiple interconnected packages. By combining one or more semiconductor packages on a single substrate, manufacturers can incorporate pre-manufactured components into electronic devices and systems. Because semiconductor packages include complex functions, electronic devices can be manufactured using less expensive components and streamlined manufacturing processes. The resulting device is less prone to failure and less expensive to manufacture, resulting in lower costs to the consumer.

[0055] While one or more embodiments of the present invention have been described in detail, those skilled in the art will appreciate that modifications and adaptations may be made to those embodiments without departing from the scope of the invention as set forth in the appended claims.

Claims

1. A semiconductor device comprising: Semiconductor die; stud bumps formed over the semiconductor die; a solder cap formed over the pillar bump; as well as An encapsulant is deposited over the semiconductor die, columnar bumps, and solder cap, wherein a surface of the encapsulant is coplanar with a surface of the solder cap, and the encapsulant contacts a back surface of the semiconductor die opposite the columnar bump, and wherein the volume of the space directly above the surface of the solder cap and the surface of the encapsulant remains free of solid matter attached to the solder cap and the encapsulant. 2 . The semiconductor device of claim 1 , further comprising a plurality of semiconductor dies mechanically connected to each other by the encapsulant.

3. The semiconductor device according to claim 1, further comprising: A first insulating layer is formed over the semiconductor die, wherein the stud bump extends into an opening of the first insulating layer.

4. The semiconductor device according to claim 3, further comprising: A second insulating layer is formed over the first insulating layer, wherein an opening of the second insulating layer is aligned with the opening of the first insulating layer. The semiconductor device according to claim 3 , wherein the first insulating layer comprises polyimide.

6. The semiconductor device according to claim 1, further comprising: A redistribution layer connects the stud bumps to the semiconductor die.

7. A semiconductor device comprising: a first semiconductor die; stud bumps formed over the first semiconductor die; a solder cap formed over the pillar bump; as well as An encapsulant deposited over the first semiconductor die, the columnar bumps, and the solder cap, wherein the encapsulant contacts an active surface of the first semiconductor die and a back surface of the first semiconductor die opposite the active surface, wherein a surface of the encapsulant is coplanar with a surface of the solder cap, and wherein a volume of space directly above the surface of the solder cap remains free of electrical components attached to the solder cap.

8. The semiconductor device according to claim 7, further comprising: A second semiconductor die is disposed in the encapsulant, wherein the encapsulant extends continuously from the first semiconductor die to the second semiconductor die.

9. A semiconductor device comprising: Semiconductor die; stud bumps formed over the semiconductor die; a solder cap formed over the pillar bump; as well as An encapsulant is deposited over the semiconductor die, stud bumps, and solder cap, wherein a surface of the encapsulant is coplanar with a surface of the solder cap, and wherein the surface of the solder cap remains free of electrical components electrically coupled to the solder cap. 10 . The semiconductor device of claim 9 , further comprising a redistribution layer formed between the semiconductor die and the stud bumps.

11. The semiconductor device of claim 9, further comprising a plurality of semiconductor dies mechanically connected to each other by the encapsulant.

12. The semiconductor device of claim 11, further comprising a substrate, wherein the plurality of semiconductor dies are mechanically bonded to the substrate by solder.

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