TWI423407B - Integrated circuit micro-module - Google Patents

Description

Integrated circuit micromodule

The present invention generally relates to packaging of integrated circuits (ICs). More specifically, the present invention relates to an integrated circuit micromodule.

There are several conventional methods for packaging integrated circuit (IC) dies. Some packaging technologies create electronic modules for incorporating multiple electronic devices (for example, integrated circuits; passive devices such as inductors, capacitors, resistors, or ferromagnetic materials; etc.) In a single package. A package incorporating more than one integrated circuit die is often referred to as a multi-wafer module. Some multi-chip modules include a substrate or interposer to support various devices; while other multi-chip modules utilize wire frames, molds, or other structures to support various other packaged devices.

Several multi-wafer module packaging techniques have been identified, for example, to integrate multiple interconnect layers into the package using multiple stacked films or multiple stacked wafer carriers. Although there is nothing wrong with the existing arrangement and method for packaging electronic modules, efforts must continue to develop improved packaging techniques to provide a cost-effective way to meet the needs of a wide variety of packaging applications. .

The present invention describes various apparatus and methods for forming integrated circuit packages. One of the points of the present invention relates to a method for forming a microsystem And a method of forming one or more passive devices in the microsystem. A plurality of epoxy layers are sequentially deposited over a substrate to form a plurality of planarized epoxy layers over the substrate. The epoxy layers are deposited by spin coating. At least some of the epoxy layers are patterned in a photolithographic manner after at least some of the layers of epoxy are deposited and before the next layer of epoxy is deposited. An integrated circuit having a plurality of I/O solder contact pads is placed on an associated epoxy layer. At least one conductor interconnect layer is formed over an associated epoxy layer. A passive device is formed in at least one of the layers of epoxy. The passive device electrically couples the integrated circuit through at least one of the interconnect layers. A plurality of external package contacts are formed. The integrated circuit is electrically connected to the external package contacts at least in part via one or more of the conductor interconnect layers. The above operations can be performed at the wafer level to form multiple microsystems in a substantially simultaneous manner.

One or more passive devices can be placed in various locations within a microsystem. Passive devices can be formed for a variety of purposes. For example, the passive device may be a resistor, a capacitor, an inductor, a magnetic core, a MEMS device, a sensor, a photovoltaic cell, or any other suitable device.

Various techniques can be employed to form a passive device. For example, each passive device can be formed in substantially simultaneous manner with other portions of the microsystem, such as another passive device and/or one or more of the interconnect layers. In some embodiments, the thin film resistor can be formed by sputtering a metal over an epoxy layer. The inductor winding can be sputtered or plated with gold on at least one of the epoxy layers Formed by a layer. The capacitor can be formed by sandwiching a thin dielectric layer between metal plates deposited over the epoxy layer. A magnetic core for an inductor or sensor can be formed by sputtering or plating a ferromagnetic material over an epoxy layer.

In one of the views, the present invention is generally directed to integrated circuit (IC) packaging and, more specifically, to the IC micromodule technology. This view includes a micromodule composed of a plurality of layers made of a dielectric material, which is preferably photoimageable and easily planarized. The micromodule may contain a wide variety of devices including one or more integrated circuits, interconnect layers, heat sinks, conductor vias, passive devices, MEMS devices, sensors, heat pipes, etc. . The various devices can be arranged in a variety of different ways and stacked within the micromodule. The various layers and devices of the micromodule can be deposited and processed using various conventional wafer level processing techniques, such as spin coating techniques, spray coating techniques, lithography, and/or electroplating techniques. Another aspect of the present invention is directed to wafer level fabrication techniques and structures that integrate multiple active and/or passive devices into a single, low cost, high performance package.

Shown in Figure 1 is a package in accordance with an embodiment of the present invention. In the embodiment shown in the figures, a multi-layer package 100 includes a substrate 102, a heat sink 104, a plurality of stacked dielectric layers 106, integrated circuits 114a to 114c, and passive devices (not shown). Display, interconnect layers 122a through 122b, vias 125, and external contact pads 120. The heat sink 104 will be formed over the substrate 102, and the dielectric layers 106 will be stacked on the heat sink. The top of the piece. A plurality of interconnect layers are interposed between adjacent dielectric layers 106 as necessary. The integrated circuits may be embedded in a stacked dielectric layer 106 and may be electrically connected to other devices via suitable interconnections of the interconnect layers 122a-122b and the channels 125, for example. Said, other ICs, passive devices, external contact pads 120, ... and so on. In the embodiment shown in the figures, one of the integrated circuits (114a) is effectively placed over the heat sink 104 to provide a good heat dissipation.

The dielectric layers 106 can be made of any suitable dielectric material. In various preferred embodiments, the dielectric layers 106 are made of a material that is easily planarized and/or photoimageable. In a particularly preferred embodiment, the layers are made of photoimageable, planarized SU-8, although other suitable materials may be used. In some designs, the dielectric used for layer 106 is highly viscous when it is first applied and then partially or fully cured during the photolithography process. The layers 106 can be applied using a variety of suitable techniques, including spin coating techniques and spray coating techniques. The thickness of the individual dielectric layers can vary widely depending on the needs of the particular application, and the different layers need not have the same thickness (although they may also have the same thickness).

The integrated circuits 114a through 114c in the package 100 can be arranged in a variety of ways and can be placed at almost any location within the package. For example, different integrated circuits 114a-114c can be disposed within substrate 102, among different photoimageable layers, and/or within the same layer. In various embodiments, the integrated circuits 114a to 114c may be stacked, arranged side by side, placed in close proximity to each other, and/or separated to package 100. The overall size is a substantial distance from the baseline. The integrated circuits disposed in the different layers may be disposed directly or partially above each other, or they may be separated so that they do not overlap each other. The integrated circuits 114a through 114c may also have a wide variety of form factors, architectures, and configurations. For example, they may be in the form of relatively bare grains (for example, unpackaged grains, flip-chips, etc.), partially and/or fully encapsulated in the form of grains (for example, BGA, LGA, QFN, ..., etc.).

The electrical interconnects within package 100 can also be arranged in a variety of different ways. The embodiment shown in Figure 1 includes two interconnect (line) layers 122a and 122b. There may be more or fewer interconnect layers in different implementations. Each interconnect layer typically has at least one (but usually there are many) lines 123 that are used to help transmit electrical signals between different devices of the package. The interconnect layers 122a through 122b will typically be formed on top of an associated layer in the planarized layers 106. The circuit layer is then buried or covered by another dielectric layer. Thus, the interconnect layers typically extend in a plane parallel to the dielectric layers and embedded within the dielectric layers.

Because the interconnect layers (and other possible devices of the package) are formed on top of a dielectric layer, it may be desirable for the dielectric layers 106 to have a very flat and rigid surface thereon. Other devices (eg, lines, passive devices, etc.) may be formed or discrete devices (eg, ICs) may be placed. SU-8 is particularly suitable for this application because it can be easily automatically planarized when applied by conventional spin technology and spin coating techniques, and it will be very stiff after being cured. More precisely, The rotating SU-8 can be used to form a hard, flat surface without the need for any additional planarization prior to forming a high quality interconnect layer thereon using conventional sputtering/plating techniques (for example, , chemical mechanical polishing). A dielectric material that can be coated in this manner to form a very planar surface is referred to herein as a planarized dielectric.

Conductive vias 125 are provided to electrically connect devices resident at different layers of the package (eg, IC/line/contact/passive devices, etc.). The channels 125 will be arranged to extend through an associated dielectric layer 106. For example, the channels 125 can be used to couple lines from two different interconnect layers together, couple one die or another device to an interconnect layer, and couple a contact to A line, die or other device...etc. As explained in more detail below, a plurality of metallization vias can be formed simultaneously, such that an associated interconnect layer 122a-122b can be deposited by filling via vias previously formed in an associated dielectric layer 106. .

Package 100 may include many other types of devices than those shown in FIG. In the embodiment shown in the figures, only a few integrated circuits and interconnect layers are shown. However, package 100 may also contain almost any number of active and/or passive devices. Examples of such active and/or passive devices include resistors, capacitors, magnetic cores, MEMS devices, sensors, batteries (for example, encapsulated lithium batteries or other batteries), integrated thin film battery structures, inductors ,...Wait. The devices can be arranged and/or stacked in various locations within the package 100. These devices may be in the form of discrete devices fabricated in advance or may be formed in the field. One of the advantages of the lithography-based process for creating package 100 is that it can be formed in layers These and other devices are formed in the field during packaging. That is, discrete devices can be placed almost anywhere within the package 100 after being fabricated in advance, and the device can be fabricated directly on any suitable technology (eg, conventional sputtering and/or electroplating). Above the photoimageable layer 106. Due to this process characteristics, superior matching, accuracy, and control can be achieved, and low stress packages can be achieved on a variety of die and/or substrate sizes, including medium and large die and/or substrates. Effect.

Substrate 102 may be made of any suitable material including: tantalum, glass, steel, quartz, G10-FR4, any other FR4 family epoxy, ... and the like. Depending on the needs of the particular application, the substrate may be electrically conductive, electrically insulating and/or light transmissive. In some embodiments, the substrate is only used as a carrier during manufacture and thus will be removed prior to completion of the package. In other embodiments, the substrate will remain as an integrally formed part of the package. If desired, the substrate 102 can also be thinned after assembly by back grinding techniques or other suitable techniques. Also, in other embodiments, the substrate may be omitted altogether.

In some embodiments, the substrate 102 may incorporate one or more sensors (not shown). This approach achieves the goal of integrating the sensor device without having to package and without the reliability issues typically associated with the necessary conditions of the sensor to be exposed to the environment. The sensor can be placed on either side of the substrate 102 and can be embedded or exposed to the environment via an etched window or microchannel. Examples of suitable sensors include, but are not limited to, biosensors, gas sensors, chemical sensors, electromagnetic sensors, acceleration sensors, vibration sensors, temperature sensors ,wet Degree sensor, ...etc.

One such way is to integrate a sensing element to the back side of the substrate 102. The sensing element can be built into the interior of the substrate 102 that has been etched away from the back side of the substrate 102. For example, the sensing element may be a capacitor made of a plurality of plated Cu fingers. The capacitor can be connected to the contact pads on the front side of the substrate 102 via microchannels. A package 100 can be formed over the contact pads such that the capacitor is electrically coupled to at least a portion of the electrical devices and interconnect layers within the package 100. Sensing elements inside the cavity created on the back side of the wafer may be filled with gas sensitive material and may be automatically exposed to the environment, while active circuitry on the front side of substrate 102 may utilize conventional encapsulation techniques (eg, : Protected by the following discussion with Figure 5E).

The package 100 also includes a system for dissipating internally generated heat, which may include a heat pipe and a heat sink, such as a heat sink 104. This system may play an important role in the performance of package 100, as packages with high power density and multiple embedded devices may require good heat dissipation to function properly. The heat pipes and fins are typically formed substantially simultaneously with the interconnect layers 122a through 122b and using the same techniques. The heat pipes can pass through and/or bypass through one or more interconnect layers and/or photoimageable layers. Any single, continuous heat pipe, line, and/or channel can be split into a plurality of other lines and/or channels at almost any point of the location and can extend in more than one direction of the package, such as: Horizontal and / or vertical. The heat pipes can actually electrically couple any device within the package 100 to one or more heat sink pads located outside of the package 100 and/or heat sink.

The heat sink 104 may have a variety of different architectures. In the embodiment shown in the figures, the heat sink 104 will constitute a layer that covers a range that substantially matches the coverage of the photoimageable layer of the package 100. Alternatively, package 100 may include one or more heat sinks whose dimensions at least partially match the dimensions of the active device (eg, integrated circuit) above or below. In the embodiment shown in the figures, the heat sink may have the form of a layer or sheet 104 formed over the substrate and which may form a substrate for the dielectric layer 106. If desired, the integrated circuits 114a through 114c can be placed directly over the heat sink layer as shown by integrated circuit 114(a). Alternatively, a thermally conductive channel (not shown) may be used to improve the thermal path between the buried integrated circuit and the heat sink, as shown by integrated circuit 114(b). In some embodiments, the heat sink or fin layer may be exposed on the top or bottom surface of the package. In other embodiments, a substrate or other layer may cover the heat sink or heat sink layer such that the heat sink acts as a heat spreader. The fins 104 may be made of a variety of suitable conductor materials (e.g., copper) and may be constructed in the same manner as the interconnect layers.

Various embodiments of package 100 may also incorporate a wide variety of other features. For example, package 100 may incorporate high voltage (HV) isolation and embedded inductive galvanic capabilities. It may be characterized by a wireless interface, for example, RF antennas for wireless system IO, EM power scavenging, RF shielding for EMI sensitive applications, and the like. In various embodiments, package 100 may include a power management subsystem, for example, a supercharger, an integrated photovoltaic switch, etc. The package 100 can be formed over a wafer and encapsulated, for example, as shown in Figure 5E. The sensing surface and material can be integrated into the package 100 and other processing steps as described above and in conjunction with the wafers discussed in Figures 5A-5H, 6A-6C, and 7A-7C.

Next, a wafer level method 200 for forming an integrated circuit package 100 in accordance with an embodiment of the present invention will be described with reference to FIG. The steps of method 200 are illustrated in Figures 3A through 3L. The steps of method 200 may be performed repeatedly and/or in a different order than shown. It should be noted that the process illustrated in method 200 can be used to simultaneously construct many other structures than those shown in Figures 3A through 3L.

Initially, in step 202 of FIG. 2, an optional conductor layer 104 of FIG. 3A is formed over the substrate 102 using any of a variety of suitable techniques. For example, conventional plating after sputtering a seed layer is very suitable. Of course, other suitable conductor layer forming techniques can also be utilized. Conductor layer 104 acts as a heat sink and can be made of various materials such as copper or other suitable metal or metal layer stack. Substrate 102 may be a wafer and may be fabricated from a variety of suitable materials such as germanium, G10-FR4, steel, glass, plastic, and the like.

In FIG. 3B, a planarized, photoimageable epoxy 106 is deposited over the heat sink 104 (step 204 of FIG. 2). This can be done using a wide variety of techniques, such as spin coating, spray coating or sheet lamination. In the embodiment shown in the figures, the epoxy layer 106a is SU-8, although other suitable dielectric materials may be used. SU-8 is ideal for applications that utilize conventional spin coating techniques.

The SU-8 has a variety of superior features. It is a highly viscous, photoimageable, chemically inert polymer which, for example, can be cured when exposed to UV radiation during photolithography. SU-8 will provide mechanical strength greater than some other known photoresists, resist excessive grinding, and be mechanically stable and thermally stable at temperatures up to at least 300 °C. It can be easily and uniformly planarized by spin coating with respect to certain other photoimageable materials (eg, BCB), which makes it easy to fabricate interconnects or passive devices on it. A substrate, and an integrated circuit or other passive device can be placed thereon. It can be easily used to create dielectric layers ranging in thickness from 1 micron to 250 microns, and can produce thinner or thicker layers. In a particular embodiment, a plurality of openings having a large aspect ratio (for example, about 5:1 or greater) may be formed in the SU-8, which facilitates the formation of a large aspect ratio. Devices such as conductive channels or other structures. For example, an aspect ratio of 7:1 can be easily achieved. Compared to many other materials, the SU-8 layer can achieve better control, accuracy, and matching effects, which can result in higher density and improved performance. Other suitable dielectric materials having one or more of the above features may also be used in place of SU-8.

In step 206 of FIG. 2, the epoxy layer 106a is patterned using conventional photolithography techniques. In one embodiment, a mask is used to selectively expose portions of the epoxy layer 106a. The baking operation will be performed after the exposure. These operations enable cross-linking of the exposed portions of the epoxy layer 106a. During the photolithography process, the exposed portion of the epoxy layer 106a may be cured, partially cured (for example, B-stage) or may be modified or hardened relative to the unexposed portion to Helps remove the unexposed portion of the epoxy later.

In step 208 of Figures 2 and 3C, the unexposed portions of the epoxy layer 106a are removed to form one or more openings 306 in the epoxy layer 106a. This removal process can be implemented in a variety of ways. For example, the epoxy layer 106a can be developed in a developer solution, resulting in dissolution of the unexposed portions of the layer 106a. Hard baking may be performed after the development work.

In step 210 of FIGS. 2 and 3D, an integrated circuit 114a is placed in the opening 306 and placed over the heat sink 104. The integrated circuit 114a can be configured in a variety of ways. For example, the integrated circuit 114a may be a bare die or flip chip, or it may have a BGA, LGA, and/or other suitable external pin configuration. In the embodiment shown in the figures, the thickness of the integrated circuit 114a may be greater than the thickness of the epoxy layer 106a in which it is initially buried; however, in other embodiments, the die may also The epoxy layer that is initially embedded therein has substantially the same or a thin thickness. The active surface of the integrated circuit 114a may face up or face down. In a particular embodiment, the integrated circuit 114a can be attached with an adhesive and thermally coupled to the heat sink 104.

After the integrated circuit 114a has been disposed in the opening 306 and attached to the heat sink, a second epoxy layer 106b is applied over the integrated circuit 114a and the epoxy layer 106a. (Step 204 of Figure 2), as shown in Figure 3E. Like the first epoxy layer 106a, the second epoxy layer 106b can be deposited by any convenient method (for example, spin coating). In the embodiment shown in the figures, the epoxy layer 106b is located directly above the integrated circuit 114a and the epoxy layer 106a, in close proximity to and/or in direct contact with the integrated circuit 114a and the epoxy layer 106a. The integrated circuit 114a and the epoxy layer 106a; however, other arrangements are also possible. The epoxy layer 106b may completely or partially cover the active surface of the integrated circuit 114a.

After the epoxy layer 106b has been coated, it can be patterned and developed using any suitable technique (steps 206 and 208), which are typically used to pattern the first epoxy layer 106a. For the same technology. In the embodiment shown in the figures, a plurality of channel openings 312 are formed over the integrated circuit 114a to expose I/O solder contact pads on the active surface of the integrated circuit 114a (not shown). . The resulting structure is shown in Figure 3F.

After any suitable via openings 312 have been formed, a seed layer 319 is deposited over openings 312 and epoxy layer 106b, as shown in Figure 3G. The seed layer 319 may be made of any suitable material (which includes a stack of a plurality of sequentially applied sub-layers (for example, Ti, Cu, and Ti)) and may utilize a wide variety of materials. The process is deposited (for example, by sputtering a thin metal layer on the exposed surfaces). A feature of the foregoing is that the sputtered seed layer has a tendency to coat all exposed surfaces that include the sidewalls and bottom of the passage opening 312. The deposition of the seed layer 319 may also be limited to only a portion of the exposed surfaces.

In Figure 3H, a photoresist 315 is applied over the seed layer 319. The photoresist 315 may be either positive or negative, which will cover the seed layer 319 and fill the opening 312. In FIG. 3I, the photoresist is patterned and developed to form an open region 317 that exposes the seed layer 319. The open areas will be patterned to reflect the desired layout of the interconnect layers, including any desired conductor traces and heat pipes, as well as any desired channels in the underlying epoxy layer 106(b). After the desired open regions have been formed, the exposed portions of the seed layer are then electroplated to form the desired interconnect layer structure. In some embodiments, a portion of the seed layer (eg, Ti) is etched prior to electroplating. During electroplating, a voltage is applied to the seed layer 319 to help plate a conductor material (e.g., copper) into the open regions 317. After the interconnect layer has been formed, the photoresist 315 and seed layer 319 in the field will then be stripped.

Therefore, the interconnect layer 122a will be formed over the epoxy layer 106b as shown in FIG. 3J (step 212). The plating operation described above for filling the opening of the passage with metal thereby forms a metal passage 313 in the space defined before the opening of the passage. The metal vias 313 can be arranged to electrically couple the I/O pads of the integrated circuit 114a and the corresponding traces 316 of the interconnect layer 122a. Since the seed layer 319 has been deposited on both the sidewalls and the bottom of the opening 312, the conductor material will accumulate substantially simultaneously on the sidewalls and the bottoms, thereby causing the opening 312 to fill faster. The seed layer is only applied over the bottom of the opening 312.

Although not shown in the epoxy layers 106a and 106b; other channels may also be formed through one or more epoxy layers for devices (eg, lines, passive devices, External contact pads, ICs, ..., etc.) are coupled together. Moreover, in other arrangements, a plurality of conductor paths may be formed between a surface of the bottom (or other) surface of the integrated circuit and the fin layer 104 to achieve current carrying even without metallization. The load function still provides a good thermal path to the heat sink. In general, interconnect layer 122a will have any number of associated lines and metal vias and will wrap the conductors in any manner suitable for the associated packaged devices used to electrically couple them.

It is to be noted that a particular sputtering/electrodeposition process that is well suited for forming a line over an associated epoxy layer 106 and forming a channel therein is formed at substantially the same time; however, it should be understood Yes, a variety of other conventional or newly developed processes can be used to separate or form the channels and lines together.

After the interconnect layer 122a has been formed, it is generally suitable to form an additional epoxy layer, an interconnect layer, and a suitable device for placing or embedding a suitable device therein or thereon. Steps 204, 206, 208, 210, and/or 212 are repeated in any order to form a particular package 100, such as the package shown in FIG. 3K. For example, in the embodiment shown in the figures, additional layers of epoxy 106c to 106f will be applied over layer 106b (which will actually repeat step 204 as necessary). The integrated circuits 114b and 114c are embedded in the epoxy layers 106d and 106e (steps 206, 208, and 210). Another interconnect layer 122b will be formed in the top epoxy layer 106f (steps 206, 208, and 212), and so on.

It should be understood that the integrated circuitry and interconnect layers in package 100 can be arranged in a variety of ways, depending on the needs of the particular application. For example, in the embodiment shown in the figures, the active faces of some integrated circuits are stacked directly above each other (for example, integrated circuits 114a and 114b). Some integrated circuits may be embedded in the same epoxy layer or in multiple identical epoxy layers (for example, integrated circuits 114b and 114c). The integrated circuit may be embedded in an epoxy layer different from the epoxy layer in which the interconnect layer is buried (for example, interconnect layer 318a and electrical circuits 114a and 114b). ("Different" epoxy layer means that each of the layers and other layers are sequentially deposited in a single, adhesive coating, such as epoxy layers 106a through 106e. Situation.) Integrated circuits may be stacked on top of each other and/or in close proximity to each other. The integrated circuit can also be electrically coupled (e.g., integrated circuits 114b and 114c) through electrical interconnect layers, vias, and/or lines that extend substantially to the nearest or outer contour of any single integrated circuit.

In step 214 of FIGS. 2 and 3L, an optional external contact pad 120 may be added to the top surface of the package 100. The external contact pads 120 can be placed over other surfaces and formed in a variety of ways. For example, the top epoxy layer 106f can be patterned and developed using the techniques described above to expose a portion of the electrical interconnect layer 122b. Any suitable metal (e.g., copper) can be plated into the holes in the epoxy layer 106f to form the conductor vias and the external contact pads 120. Accordingly, at least some of the external contact pads 120 can be electrically coupled to the electrical interconnect layers 122a-122b and/or the integrated circuits 114a-114c.

The features of package 100 can be modified in a variety of ways. For example, it may contain more or fewer integrated circuits and/or interconnect layers. It may also contain a number of additional devices such as: sensors, MEMS devices, resistors, capacitors, thin film battery structures, photovoltaic cells, RF wireless antennas and/or inductors. In some embodiments, the substrate 102 can be concealed or disposed of. Substrate 102 may have any suitable thickness. For example, a thickness ranging from about 100 to 250 microns is well suited for many applications. The thickness of the package 100 may vary widely. For example, a thickness ranging from about 0.5 to 1 mm is well suited for many applications. The thickness of the electrical interconnect layers 122a and 122b may also vary widely as the needs of a particular application. For example, it is believed that a thickness of about 50 microns is well suited for many applications.

Figure 4A is a cross-sectional view showing another embodiment of the present invention. Similar to the package 100 of FIG. 1, the package 400 of FIG. 4A includes integrated circuits 401 and 403, an epoxy layer 410, and a plurality of interconnect layers. Package 400 also includes some additional non-essential features not shown in package 100.

For example, the package 400 is characterized in that the integrated circuit 401 is thermally coupled to a heat sink 402. In the embodiment shown in the figures, certain dimensions of the heat sink 402 are substantially the same as those of the thermal coupling device. In a particular embodiment, the heat sink 402 may be larger or smaller than the device below it. The heat sink 402 may be disposed on the top or bottom surface of the integrated circuit 401 and/or directly contact the top or bottom surface of the integrated circuit 401. It may be directly adjacent to an outer surface of the package 400 (as is the case with the embodiment shown in the figures) or may be connected to the outer surface through one or more hot channels. The heat sink 402 is thermally coupled to a conductor layer, such as layer 104 of FIG. In the preferred embodiment where the epoxy layer 410 is made of SU-8, the presence of a heat sink 402 directly beneath the integrated circuit 401 can be particularly helpful because heat is not fully conducted through the SU-8.

The package 400 is also characterized by various passive components such as inductors 406 and 408, resistor 404, and capacitor 407. The passive devices may be located in any epoxy layer or location within the package 400. They can be formed using a variety of suitable techniques, depending on the needs of the particular application. For example, inductor winding 412 and inductor cores 410a and 410b may be formed by depositing a conductor material and a ferromagnetic material, respectively, over at least one of the epoxy layers 410. The thin film resistor may be formed by sputtering or coating any suitable resistive material (eg, ruthenium chromium, nickel chromium, and/or chromium tantalum carbide) over one of the epoxy layers 410. The capacitor may be formed by sandwiching a thin dielectric layer between metal plates deposited over the one or more epoxy layers. Pre-fabricated resistors, inductors, and capacitors can also be placed over one or more epoxy layers 410. Conductor, ferromagnetism, and other materials can be deposited by any convenient method known in the art, such as electroplating or sputtering.

The package 400 also includes an optional BGA type contact pad 411 located over the front surface 416. The substrate 414 can be made of various materials such as G10-FR4, steel, and glass because of the positional contact of the contact pads 411. In a particular embodiment where the contact pads are located on the back surface 418, the base The plate 414 may be made of tantalum and is characterized by a through passage that is electrically connectable to the contact pads. In another embodiment, the substrate is primarily used as a build platform for forming the package 400 and will eventually be removed.

Shown in Figure 4B is another embodiment of the present invention having many of the features shown in Figure 4A. This embodiment includes additional devices including: precision adjustable capacitor 430 and resistor 432, micro-relay 434, low-cost configurable precision passive feedback network 436, FR-4 base 438, and photovoltaic cells 440. Battery 440 may be covered by a layer of transparent material (eg, transparent SU-8). In other embodiments, photovoltaic cell 440 can be replaced by a window glass sensor, a wireless phase antenna array, a heat sink, or another suitable device. Package 400 may include a number of additional structures including: a power inductor array, an RF-enabled antenna, a heat pipe, and an external contact pad for dissipating heat from the interior of package 400.

Shown in Figures 4C and 4D are two additional embodiments having a heat pipe. 4C illustrates a package 479 that includes an integrated circuit 486 that is embedded in a multi-layer planarized, photoimageable epoxy 480. A plurality of metal interconnects 484 are coupled to solder contact pads (not shown) on the active surface of integrated circuit 486. The back side of the integrated circuit 486 is placed over a heat transfer tube 488a and 488b that includes a thermally conductive line 488a and a thermally conductive path 488b. The heat pipes 488a and 488b are made of any suitable material that would properly conduct heat, such as copper. As indicated by the dashed line 489, heat from the integrated circuit 486 is transferred through the back side of the integrated circuit 486, in the thermal path. The vicinity of 488a flows and passes upward through the heat transfer passage 488b, so the heat flows to the outer top end surface of the package 479. The embodiment shown in Figure 4B can be fabricated using a variety of techniques, such as the techniques discussed in connection with Figures 3A through 3K.

Figure 4D shows another embodiment of the present invention. This embodiment includes an integrated circuit 114a whose bottom surface is thermally coupled to the heat pipes 470a to 470d. The heat pipes 470a to 470d are made of a heat conductive material such as copper, and transfer heat from the integrated circuit 114a to the external heat flux portion 472 of the package 100. For packages with multiple integrated circuits and high power density, heat dissipation can cause problems. Heat pipes 470a through 470d that can couple one or more devices within package 100 can transfer internally generated heat to one or more exterior surfaces of package 100. In FIG. 4C, for example, heat is conducted away from the integrated circuit 114a to the top end surface of the package 100, the bottom surface, and the heat flux 472 on the plurality of side surfaces.

A plurality of fins may also be placed on the top, bottom, side, and/or substantially any exterior surface of the package 100. In the embodiment shown in the figures, for example, the heat spreader plate 101 on the bottom surface of the package 100 thermally couples the heat pipes 470a through 470d and dissipates heat to the entire bottom surface area of the package 100. In one embodiment, all of the heat pipes in the package 100, which are thermally coupled to a plurality of embedded integrated circuits, are also thermally coupled to the heat spreader plate 101. In a variation of this embodiment, some of the heat pipes may also couple heat sinks on the top surface of the package 100. The heat pipes 470a to 470d may be formed using a process similar to that used to fabricate the interconnect layers 122a to 122b. They may be coupled to the inside of the package 100 Multiple passive and/or active devices can be extended in almost any direction within the package 100. In the embodiment shown in the figures, for example, the heat pipes 470a through 470d may extend in a direction parallel and perpendicular to certain planes in the plane formed by the photoimageable layers 106. As shown in FIG. 4C, the heat pipes 470a through 470d may include thermally conductive lines 470b and 470d and/or channels 470a and 470c that pass through one or more interconnect layers 122a-122b and/or photoimageable layer 106. The heat pipes 470a to 470d may be configured to dissipate heat, conduct electrical signals, or both. In one embodiment, an interconnect layer for transmitting electrical signals and a heat pipe unsuitable for transmitting electrical signals are embedded in the same epoxy layer.

Another embodiment of the invention is illustrated in Figure 4E. Package arrangement 450 includes a microsystem 452 formed on top surface 460 of substrate 456. Microsystem 452 may include multiple dielectric layers, interconnect layers, active and/or passive devices, and may have any of the features described in conjunction with package 100 of FIG. 1 and/or package 400 of FIG. 4A. The top surface 460 of the microsystem 452 and substrate 456 will be encapsulated in a molding material 464 (which may be made of any suitable material, such as a thermoset plastic). A plurality of metal channels 458 are electrically coupled to an external contact pad (not shown) at the bottom of the microsystem 452 and a bottom surface 461 of the substrate 456. The channels 458 terminate at non-essential solder balls 462, which may be made of various conductor materials. For example, solder balls 462 can be placed over a printed circuit board to achieve an electrical connection between microsystem 452 and various external components.

5A through 5H are cross-sectional views of a wafer level process for establishing a package identical to the arrangement 450 of FIG. 4D. FIG. 5A depicts a wafer 500 having a top end surface 502 and a bottom surface 504. Only a small portion of the wafer 500 is shown. Shown by the dashed vertical line is the projected cut line 508. In the embodiment shown in the figures, the substrate 500 may be made from a wide variety of suitable materials, such as: 矽.

In FIG. 5B, the top end surface 502 of the wafer 500 is etched away to form the holes 506. This etching process can be implemented using a wide variety of techniques, such as plasma etching techniques. Metal is then deposited in the holes to form an electrical system. This deposition can be carried out using any convenient method, such as electroplating. For example, a seed layer (not shown) may be deposited over the top surface 502 of the wafer 500. Next, a metal (e.g., copper) can be used to electroplate the seed layer. The electroplating process produces a metal via 510 and a contact pad 512 on the top surface 502 of the wafer 500.

In FIG. 5D, the microsystem 513 is formed on the top end surface 502 of the wafer 500 using the same steps as those described in connection with FIGS. 2 and 3A through 3L. In the embodiment shown in the figures, the microsystems 513 do not have external contact pads formed on their top end surfaces 515 because the top surface 515 will be overmolded in a later operation. In another embodiment, a plurality of external contact pads may be formed on the top surface 515 for wafer level functional testing prior to cladding molding. Microsystems 513 have external contact pads on their bottom surface 517 that align with contact pads 512 on top surface 502 of wafer 500. This facilitates an electrical connection between the metal vias 510 and the interconnect layers within the microsystems 513.

In the drawing, a suitable molding material 520 is applied over the microsystems 513 and the top surface 502 of the wafer 500. The molding process can be carried out using a variety of suitable techniques and materials. As a result, a molded wafer structure 522 is formed. In some designs, the molding material 520 will completely cover and encapsulate the microsystem 513 and/or the entire tip surface 502. The application of the molding material 520 can provide additional mechanical support to the microsystem 513, which can be quite practical when the microsystem 513 is very bulky.

Shown in FIG. 5F is a molded wafer structure 522 after the bottom surface 504 of the wafer 500 is partially removed using any of a variety of suitable techniques (eg, backgrinding techniques). As a result, part of the metal passage 510 is exposed. In Figure 5G, solder balls 524 are applied to portions of the bare metal channels 510. In FIG. 5H, the cast wafer structure 522 is then singulated along the projected cut line 508 to create a plurality of individual package arrangements 526. The singulation process can be carried out using a variety of suitable methods (eg, cutting or laser cutting).

6A to 6C are cross-sectional views showing a wafer level process for establishing a package in accordance with another embodiment of the present invention. Shown in FIG. 6A is a substrate 600 in which a plurality of perforations 602 have been previously fabricated. Shown in Figure 6B is the deposition of metal in the holes 602 to form a plurality of metal channels 604. The deposition of metal can be carried out using any suitable technique, such as electroplating techniques. In some embodiments, the substrate 600 will be fabricated with perforations 602 and/or metal channels 604 in advance, thereby obscuring one or more processing steps. In FIG. 6C, a plurality of microsystems 606 are formed over the metal vias 604 and the substrate 600 using any of the foregoing techniques. Then, the solder bumping operation and singulation can be performed as shown in Figs. 5G and 5H. The embodiment shown in the figures may include the same various features as those described in connection with Figures 5A through 5H.

7A through 7C are cross-sectional views showing a wafer leveling process for establishing a package in accordance with another embodiment of the present invention. A substrate 700 will be provided initially. A plurality of copper contact pads 702 are then formed over the top surface of the substrate 700. In FIG. 7B, a plurality of microsystems 704 are formed over the copper contact pads 702 and the substrate 700 using any of the foregoing techniques. The microsystems 704 and the top surface of the substrate 700 are then encapsulated in a suitable mold molding material 706. Next, in FIG. 7C, the substrate 700 will be completely removed or removed. A plurality of solder bumps are then attached to the copper contact pads 702. The embodiment shown in the figures may include the same various features as those described in connection with Figures 5A through 5H.

Additional embodiments of the invention are illustrated in Figures 8-10. These embodiments are directed to integrated circuit packages that embed one or more integrated circuits in a substrate (e.g., a germanium substrate). The buried integrated circuit is covered by a photoimageable epoxy layer. An interconnect layer will be formed over the epoxy layer and electrically coupled to the integrated circuit via one or more channels in the epoxy layer.

Embedding one or more integrated circuits in a substrate provides a number of advantages. For example, various embodiments of the present invention include a buried integrated circuit that uses the substrate as a heat sink, an electrical conductor, and/or a medium for optical communication. When a tantalum wafer is used as the substrate, the same thermal expansion of the embedded integrated circuit and the tantalum substrate is a number that can help reduce the risk of delamination. In some implementations, embedding the integrated circuit in the substrate rather than in the epoxy layer can help minimize the thickness of the epoxy layer and reduce the size of the package.

Various examples of integrated circuit packages including substrates having one or more buried integrated circuits will now be described with reference to FIGS. 8A and 8B. 8A is an integrated circuit package 800 comprising a substrate 804, an integrated circuit 802, an epoxy layer 806, and an interconnect layer 812. Substrate 804 is preferably a enamel wafer that is readily handled by existing semiconductor packaging equipment. However, depending on the intended use of the package 800, other suitable materials (for example, glass, quartz, ..., etc.) may be used. The integrated circuit 802 is disposed within the cavity 808 in the top surface of the substrate 804. The active surface of the integrated circuit 802 and the top surface of the substrate 804 are covered by an epoxy layer 806. The epoxy layer 806 is made of a planarized, photoimageable epoxy resin (e.g., SU-8). The interconnect layer 812 will be formed over the epoxy layer 806. The interconnect layer 812 includes a conductor line 812b and a conductor channel 812a that extend to the opening 810 in the epoxy layer 806 and that couples the transistor to the I/O contact on the active side of the integrated circuit 802. pad. A dielectric layer can be applied over the interconnect layer 812 without regard to various implementations of adding more epoxy layers, integrated circuits, and electrical devices. Solder contact pads may be formed on the outside of the package 800 that electrically couple the integrated circuits 802 and the interconnect layer 812 via openings in the dielectric layer.

Shown in FIG. 8B is another embodiment of the present invention that includes providing an additional layer of epoxy, integrated circuitry, and interconnect layers over substrate 804. The integrated circuit package 801 includes a plurality of adjacent epoxy layers 822, interconnect layers 818, and integrated circuits 816 which are stacked on the interconnect layer 812, the epoxy layer 806, the integrated circuit 802, and the substrate. Above the 804. Each of the integrated circuits 816 will be disposed in at least one of the epoxy layers 822. The interconnect layer 818 is interspersed between the respective integrated circuits 816 and the epoxy layer 822. The interconnect layers 818 electrically connect the respective integrated circuits 802 and 816 to each other and electrically connect the integrated circuits 802 and 816 to the I/O pads 824 formed on the top surface of the integrated circuit package 801.

It should be understood that Figures 8A and 8B represent particular embodiments from which many variations can be made. For example, there may be one or almost any number of integrated circuits disposed on or in the substrate 804. The arrangement of the conductor channels and lines, the placement and dimensions of the cavities and/or the thickness of the interconnect layers and the epoxy layer may be different than those shown. In addition, any of the features and arrangements described with respect to Figures 1 through 7C can be combined with almost any of the views of Figures 8A and 8B or used to modify almost any of the views of Figures 8A and 8B.

An exemplary method for forming the integrated circuit package of FIGS. 8A and 8B will now be described with reference to FIGS. 9A through 9G. A substrate 902 is provided in FIG. 9A. In a preferred embodiment, the substrate 902 is a germanium wafer because this can help maximize the operation of Figures 9A through 9F and the compatibility of semiconductor wafer-based processing equipment. In an alternate embodiment, the substrate 902 may be made from a wide variety of materials including: tantalum, glass, steel, G10-FR4, quartz, ..., etc., depending on the needs of the particular application. set.

In FIG. 9B, a plurality of cavities 904 are formed in the substrate 902. Cavity 904 can be formed using wet or plasma etching, although other suitable techniques can be utilized. The chemical used in the etching process and the crystalline structure of the germanium in the substrate 902 can help control the angle of the sidewalls of the cavity 904. For example, it has been discovered that the [1,1,0] germanium crystal structure can help more straight sidewalls and/or help form a sidewall that is approximately perpendicular to the bottom surface of its corresponding cavity. A die attach adhesive 903 is applied to the bottom of the cavity 904 to help adhere the integrated circuit 906 to the bottom surface of the cavity 904, as shown in Figure 9C. In an alternate embodiment, the die attach adhesive 903 is first applied to the integrated body in an individual manner or in the wafer level prior to placing the integrated circuit 906 in the cavity 904. The back surface of circuit 906. Depending on the needs of the particular application, the die attach adhesive may be conductive or non-conductive. In some embodiments, two types of adhesives are used in the same package at the same time, such that one of the integrated circuits is electrically coupled to a conductive substrate via its bottom surface, while the other integrated circuit is Will be electrically isolated from the substrate (the various applications of conductive substrates are discussed below).

In FIG. 9D, a planarized, photoimageable epoxy layer 908 is deposited over the cavities 904, the substrate 902, and the integrated circuits 906. The epoxy layer 908 is preferably SU-8, although other suitable materials may be used. The epoxy layer can extend over the active surface of the integrated circuit 906 and directly contact the active surface of the integrated circuit 906 and can be filled into the cavity 904 in the substrate 902. As previously mentioned, one of the advantages of using photoimageable epoxy resins (e.g., SU-8) is that it provides better control than photolithography.

In FIG. 9E, one or more openings 910 may be formed in the epoxy layer 908. The openings 910 can be produced in a variety of ways known to those skilled in the art of semiconductor processing. For example, the epoxy layer 908 may be photolithographically patterned and a portion of the epoxy layer 908 may be dissolved using a developer solution. The openings 910 are capable of exposing I/O pads on the active surface of the integrated circuit 906 that are embedded within the epoxy layer 908.

Illustrated in Figure 9F is the formation of interconnect layer 912, which can be implemented using various suitable techniques known in the art. One of the methods similar to the steps described in connection with FIGS. 3F to 3J includes: depositing a seed layer and a photoresist layer; patterning the photoresist layer; and plating a metal to form a conductor in the openings 910 Line 912a and conductor channel 912b. In various embodiments, the interconnect layer 912 electrically connects a plurality of integrated circuit dies 906 that are embedded in the substrate 902.

Additional epoxy layer 918, integrated circuit 922, and/or interconnect layer 916 can then be formed over substrate 902, integrated circuit 906, epoxy layer 908, and interconnect layer 912. The layers and devices can be arranged in a wide variety of ways, and any of the permutations and features discussed in connection with Figures 1 through 7C can be utilized to modify any of the aspects of the embodiments shown. For example, the one or more interconnect layers 912 and/or 916 can be used to electrically connect the integrated circuit 906 disposed within the substrate 902 and any embedded within the epoxy layer 918. Or all of the integrated circuits 922. A heat pipe suitable or unsuitable for transmitting electrical signals may extend from the substrate-based integrated circuit die 906 to any external surface of the integrated circuit package 921. As described previously, various passive devices and active devices, heat pipes, heat sinks, sensors, etc. can be formed or placed in almost any position of the integrated circuit package 921 (for example, Among the substrates 902, on the substrate 902, embedded between the epoxy resin layers 918, etc.). The substrate 902 may also be subjected to back grinding or any other operation suitable for reducing the thickness of the substrate 902. Shown in FIG. 9G is an additional epoxy layer, interconnect layer, and integrated body of FIG. 9F after the integrated circuit is applied over the substrate 902, the integrated circuit 906, the epoxy layer 908, and the interconnect layer 912. An example of a circuit package.

Shown in Figures 10A through 10D are additional embodiments of the present invention, each of which also includes a substrate having one or more buried integrated circuits. 10A is an integrated circuit package 1000 comprising: a conductive and thermally conductive substrate 1002 having a buried integrated circuit 1004; a planarized, photoimageable epoxy layer 1006; and an interconnect layer 1008. The integrated circuit package 1000 can be formed using any of the techniques described in conjunction with Figures 9A through 9F.

The integrated circuit 1004b is disposed on the bottom surface of the cavity 1005 in the substrate 1002 using the conductive adhesive 1012b. Thus, integrated circuit 1004b can electrically couple the substrate 1002 and/or can dissipate heat to the exterior surface of the package using the substrate 1002. Some implementations also include an integrated circuit 1004a that is electrically isolated from the conductor substrate 1002 by a non-conductive adhesive 1012a. In the embodiment shown in the figures, only two integrated circuits are shown; however, fewer or more integrated circuits may be disposed in the substrate 1002, each of which is electrically coupled to the substrate 1002 or It is electrically insulated from the substrate 1002.

In various embodiments, the substrate 1002 can serve as a conduit for achieving an electrical ground connection. The package 1000 includes a ground interconnect 1020 that is formed over the epoxy layer 1006 and extends through the epoxy layer 1006 and is electrically coupled to a ground contact region 1014 of the substrate 1002. Ground interconnect 1020 is made of a conductive material (e.g., copper) and may have been formed at least partially during formation of the interconnect layer 1008, as previously described in connection with Figure 9F.

The ground contact regions 1014 and other portions of the substrate 1002 in the substrate 1002 are made of tantalum and may be doped to improve their electrical conductivity. To facilitate electrical connection between the substrate 1002 and the ground interconnect 1020, the doping concentration of the ground contact region 1014 is substantially higher than one or more other portions of the substrate 1002. In various implementations, the substrate 1002 is made of a p-type semiconductor material and the ground contact region 1014 is a p++ doped region; however, any suitable material known to those skilled in the art and/or may be utilized. The substrate 1002 and the ground contact region 1014 are doped or concentrated. Thus, when the ground interconnect 1020 is electrically grounded, the integrated circuit 1004b, the substrate 1002, and the ground contact region 1014 can be electrically coupled to the ground interconnect 1020 and will also be electrically grounded.

FIG. 10B provides an enlarged view of region 1010 of FIG. 10A in accordance with one embodiment of the present invention. The figure includes a substrate 1002 having a ground contact region 1014, an interlayer dielectric 1016, a passivation layer 1018, a conductive plug 1022, electrical interconnect lines 1024 and 1020, an epoxy layer 1006, and a ground interconnect 1020. Various techniques known to those skilled in the art of semiconductor fabrication can be used to deposit, pattern, and/or develop interlayer dielectric 1016 and passivation layer 1018, and form plugs 1022 and electrical interconnects 1024. Plug 1022 and electrical interconnect 1024 may be made of a variety of suitable electrically conductive materials, including tungsten and aluminum, respectively. Epoxy layer 1006 and interconnect 1020 can be formed using a variety of techniques including the techniques described in conjunction with Figures 9D through 9F.

The technique used to form the interlayer dielectric 1016 and passivation layer 1018 of FIG. 10B can be integrated into the technique used to form the cavity 1005 of FIG. 10A. For example, during formation of cavity 1005, interlayer dielectric 1016 will be deposited across top surface 1003 of substrate 1002. The interlayer dielectric is patterned and etched to not only create space for the plugs 1022, but also to form a mask to form the cavity 1005 in the substrate 1002. This approach can help reduce the number of processing steps used to fabricate the integrated circuit package 1000.

Another embodiment of the invention is illustrated in Figure 10C. Figure 10C includes an integrated circuit package 1030 that forms an integrated circuit, a planarized photoimageable epoxy layer, and an interconnect layer over both sides of a substrate. In the embodiment shown in the figures, integrated circuit 1036, epoxy layer 1040, and interconnect layer 1038 are formed over top surface 1034 of substrate 1032. Integrated circuit 1042, epoxy layer 1044, and interconnect layer 1046 are formed over the opposite bottom surface 1046 of substrate 1032. One of the ways to form the integrated circuit package 1030 is to apply the techniques discussed in connection with Figures 9A through 9F over both the top and bottom surfaces of the substrate 1032.

One particular implementation of the integrated circuit package 1030 includes arranging a plurality of integrated circuits to optically communicate with one another via a light transmissive substrate. In the embodiment shown in the figures, for example, the integrated circuits 1036a and 1042a are vertically aligned with each other and include a plurality of optical devices, such as: laser diodes, optical detectors, etc. (again In another embodiment, a plurality of optical devices (eg, optical sensors, optical detectors, laser diodes, etc.) may be used in place of integrated circuits 1036a and/or 1042a). Portions 1034 of the substrate at least between integrated circuits 1036a and 1042a are transmissive and are arranged to permit optical communication between integrated circuits 1036a and 1042a. The light transmissive substrate may be made of various materials including glass and quartz. Some modes of operation include a substrate 1032 that is entirely made of a single light transmissive material and/or that has a uniform composition.

Another way includes a substrate 1032 made of tantalum. The enamel substrate 1032 can electrically insulate the integrated circuits 1036a and 1042a; however, for example, they are allowed to communicate optically using ultraviolet light (which can travel through the cymbal).

Again, another embodiment of the present invention is illustrated in Figure 10D. Shown in FIG. 10D is an integrated circuit package 1050 having features for mitigating stresses embedded in one or more integrated circuits 1054 inside the package substrate 1052. The integrated circuit package 1050 includes a substrate 1052 having a lower surface: a cavity 1060, an integrated circuit 1054, a photoimageable epoxy layer 1056, and an interconnect layer 1058. Each cavity 1060 includes an air gap 1062 between a sidewall 1064 of the cavity 1060 and the integrated circuit 1054.

During the test and operation, the integrated circuit 1054 and the package 1050 perform a temperature cycling operation. The increase in temperature may cause the integrated circuit 1054 to expand with other devices in the package 1050. If the integrated circuit 1054 is encapsulated in a resilient material, this expansion may impose additional stress on the integrated circuit 1054. The air gap 1062 can provide space for the integrated circuit 1054 to expand and thereby help to reduce this stress. Accordingly, the epoxy layer 1056, while covering the cavity 1060, does not substantially extend into the cavity 1060.

There are various ways in which the features of the integrated circuit package 1050 can be formed. For example, forming cavity 1060 in substrate 1052 and placing integrated circuit 1054 in cavity 1060 can be implemented as previously described in connection with Figures 9A-9C. A pre-fabricated photoimageable epoxy resin (e.g., SU-8) can then be applied to cover the cavity 1060 and the substrate 1052. In various embodiments, the epoxy layer 1056 is not sprayed and spin coated over the cavities 1060, but is stacked over the substrate 1052. This approach helps to retain the air gap 1062 between each integrated circuit 1054 and the sidewall 1064 of the corresponding cavity 1060. Next, the formation of an opening in the epoxy resin layer 1056 and the interconnect layer 1058 can be performed in the same manner as the operation described in connection with Figs. 9E to 9F. For example, photolithography can be utilized to pattern the epoxy layer 1056, which can result in curing and/or removal of a portion of the epoxy layer 1056.

Although the present invention has been described in detail herein, it is understood that the invention may be embodied in many other forms without departing from the spirit or scope of the invention. For example, the various embodiments described herein sometimes illustrate unique and distinct features; however, the invention encompasses a wide variety of integrated circuit packages, each of which may contain substantially all of the features described herein. Any combination is formed using almost any combination of the processes described herein. Taking the substrate 804 of the integrated circuit package 800 of FIG. 8A including one or more buried integrated circuits 802 as an example, it may also include a plurality of metal vias that pass through the substrate 804 and electrically interconnect the interconnect layer 812 Connecting the contacts on the outer surface of the substrate 804. These metal channels are described in conjunction with Figure 4E. The process for fabricating the metal channels is as described with respect to Figures 5A through 5H and can also be applied to the substrate 804 of Figure 8A. Therefore, the embodiments of the present invention should be construed as illustrative and not limiting, and the invention is not limited to the details disclosed herein. Make corrections.

100‧‧‧Package

101‧‧‧Hot Dispersion Plate

102‧‧‧Substrate

104‧‧‧ Heat sink

106‧‧‧Epoxy layer

106a‧‧‧Epoxy layer

106b‧‧‧Epoxy layer

106c‧‧‧Epoxy layer

106d‧‧‧Epoxy layer

106e‧‧‧Epoxy layer

106f‧‧‧Epoxy layer

106g‧‧‧Epoxy layer

114a‧‧‧ integrated circuit

114b‧‧‧ integrated circuit

114c‧‧‧ integrated circuit

120‧‧‧External contact pads

122a‧‧‧Interconnect layer

122b‧‧‧Interconnect layer

123‧‧‧ lines

125‧‧‧ channel

200‧‧‧ method

202-214‧‧‧Steps in Method 200

306‧‧‧ openings

312‧‧‧ passage opening

313‧‧‧ channel

315‧‧‧Light resistance

316‧‧‧ lines

317‧‧‧Open area

319‧‧‧ seed layer

400‧‧‧Package

401‧‧‧ integrated circuit

402‧‧‧ Heat sink

403‧‧‧Integrated circuit

404‧‧‧Resistors

406‧‧‧Inductors

407‧‧‧ capacitor

408‧‧‧Inductors

410‧‧‧Epoxy layer

410a‧‧‧Inductor core

410b‧‧‧Inductor core

411‧‧‧Contact pads

412‧‧‧Inductor winding

414‧‧‧Substrate

416‧‧‧ front surface

418‧‧‧Back surface

430‧‧‧ capacitor

432‧‧‧Resistors

434‧‧‧Micro Relay

436‧‧‧passive feedback network

438‧‧‧FR-4 base

440‧‧‧Photovoltaic battery

450‧‧‧Package arrangement

452‧‧‧Microsystem

456‧‧‧Substrate

458‧‧‧ channel

460‧‧‧ top surface

461‧‧‧ bottom surface

462‧‧‧ solder balls

464‧‧‧Mold molding materials

470a‧‧‧Heat pipe/channel

470b‧‧‧heat pipe / heat conduction line

470c‧‧‧Heat pipe/channel

470d‧‧‧Heat pipe / heat conduction line

472‧‧‧External heat transfer parts

479‧‧‧Package

480‧‧‧Epoxy layer

484‧‧‧Metal interconnect

486‧‧‧ integrated circuit

488a‧‧‧Heat pipe / heat conduction line

488b‧‧‧heat pipe / heat conduction channel

489‧‧‧The direction of heat flow

500‧‧‧ wafer

502‧‧‧ top surface

504‧‧‧ bottom surface

506‧‧‧ hole

508‧‧‧Projected cutting line

510‧‧‧Metal channel

512‧‧‧Contact pads

513‧‧‧Microsystem

515‧‧‧ top surface

517‧‧‧ bottom surface

520‧‧‧Mold molding materials

522‧‧‧Molded wafer structure

524‧‧‧ solder balls

526‧‧‧Package arrangement

600‧‧‧Substrate

602‧‧‧Perforation

604‧‧‧ channel

606‧‧‧Microsystem

700‧‧‧Substrate

702‧‧‧Bronze touch pad

704‧‧‧Microsystem

706‧‧‧Mold molding materials

800‧‧‧Integrated circuit package

801‧‧‧Integrated circuit package

802‧‧‧ integrated circuit

804‧‧‧Substrate

806‧‧‧Epoxy layer

808‧‧‧ cavity

810‧‧‧ openings

812‧‧‧Interconnect layer

812a‧‧‧ conductor channel

812b‧‧‧Conductor line

816‧‧‧ integrated circuit

818‧‧‧Interconnect layer

822‧‧‧Epoxy layer

824‧‧‧I/O touch pad

902‧‧‧Substrate

903‧‧‧ die attach adhesive

904‧‧‧ cavity

906‧‧‧Integrated circuit

908‧‧‧Epoxy layer

910‧‧‧ openings

912‧‧‧Interconnection layer

912a‧‧‧ conductor lines

912b‧‧‧ conductor channel

916‧‧‧Interconnect layer

918‧‧‧Epoxy layer

921‧‧‧Integrated circuit package

922‧‧‧Integrated circuit

1000‧‧‧Package

1002‧‧‧Substrate

1003‧‧‧ top surface

1004‧‧‧ integrated circuit

1004a‧‧‧ integrated circuit

1004b‧‧‧ integrated circuit

1005‧‧‧ cavity

1006‧‧‧Epoxy layer

1008‧‧‧Interconnect layer

1010‧‧‧Area

1012a‧‧‧Non-conductor adhesive

1012b‧‧‧Electrostatic adhesive

1014‧‧‧Ground contact zone

1016‧‧‧Interlayer dielectric

1018‧‧‧ Passivation layer

1020‧‧‧Interconnection line

1022‧‧‧conductive plug

1024‧‧‧interconnection line

1030‧‧‧Package

1032‧‧‧Substrate

1034‧‧‧ top surface

1036‧‧‧ integrated circuit

1036a‧‧‧ integrated circuit

1036b‧‧‧ integrated circuit

1038‧‧‧Interconnect layer

1040‧‧‧Epoxy layer

1042‧‧‧Integrated circuit

1042a‧‧‧ integrated circuit

1042b‧‧‧Integrated circuit

1044‧‧‧Epoxy layer

1046‧‧‧Interconnect layer

1050‧‧‧Package

1052‧‧‧Substrate

1054‧‧‧Integrated circuit

1056‧‧‧Epoxy layer

1058‧‧‧Interconnect layer

1060‧‧‧ Cavity

1062‧‧‧Air gap

1064‧‧‧ side wall

The invention and its advantages are best understood by reference to the accompanying drawings in which: FIG. 1 shows a plurality of integrated circuits and interconnect layers in accordance with an embodiment of the present invention. A cross-sectional view of the package.

2 is a process flow diagram of a wafer level process for packaging integrated circuits in accordance with an embodiment of the present invention.

3A to 3L are cross-sectional views showing selected steps in the process of Fig. 2.

4A through 4E are cross-sectional views of a package in accordance with various alternative embodiments of the present invention.

5A through 5H are selected steps in a wafer level process for packaging integrated circuits in accordance with another embodiment of the present invention.

Figures 6A through 6C illustrate selected steps in a wafer leveling process for packaging integrated circuits in accordance with another embodiment of the present invention.

7A through 7C are selected steps in a wafer level process for packaging integrated circuits in accordance with yet another embodiment of the present invention.

8A through 8B are cross-sectional views of packages in accordance with various embodiments of the present invention, each package including a substrate having a buried integrated circuit.

9A through 9G illustrate selected steps in a wafer leveling process for forming a package, each package including a substrate having a buried integrated circuit, in accordance with another embodiment of the present invention.

10A through 10D are cross-sectional views of package arrangements in accordance with various embodiments of the present invention.

In the drawings, the same component symbols are sometimes used to denote the same structural elements. It should also be understood that the figures are only schematic and not drawn to scale.

400‧‧‧Package

401‧‧‧ integrated circuit

402‧‧‧ Heat sink

403‧‧‧Integrated circuit

404‧‧‧Resistors

406‧‧‧Inductors

407‧‧‧ capacitor

408‧‧‧Inductors

410‧‧‧Epoxy layer

410a‧‧‧Inductor core

410b‧‧‧Inductor core

411‧‧‧Contact pads

412‧‧‧Inductor winding

414‧‧‧Substrate

416‧‧‧ front surface

418‧‧‧Back surface

Claims (20)

A wafer level method for packaging an integrated circuit, the method comprising: sequentially depositing a plurality of epoxy layers over a substrate to form a plurality of planarized epoxy layers over the substrate Wherein the epoxy layers are deposited by spin coating; at least some of the epoxy layers are deposited and photolithographically patterned at least some of the epoxy layers are deposited before the next epoxy layer is deposited Some of the epoxy layers; placing an integrated circuit on an associated epoxy layer, wherein the integrated circuit has a plurality of I/O solder contact pads; forming at least one conductor interconnect layer, wherein Each of the interconnect layers is formed over an associated epoxy layer; a first passive device is formed in at least one of the plurality of epoxy layers, wherein the first passive device Electrically coupling the integrated circuit through at least one of the interconnect layers; and forming a plurality of external package contacts, wherein the integrated circuit is at least partially via at least one of the conductive interconnect layers One of them is powered Connected to a plurality of such external package contacts. The method of claim 1, wherein at least a portion of the formation of the first passive device and at least a portion of the formation of one of the interconnect layers are performed in a substantially simultaneous manner. The method of claim 1, wherein the first passive device is one of the group consisting of: a resistor, a capacitor, Inductors, magnetic cores, MEMS devices, sensors, and photovoltaic cells. The method of claim 2, wherein the first passive device is a thin film resistor, and the first passive device is formed by sputtering over at least one of the epoxy layers A conductor metal is implemented to form the thin film resistor. The method of claim 1, wherein the first passive device is a capacitor, and the forming of the first passive device comprises forming a plurality of metal layers and a dielectric layer, so that the dielectric layer is sandwiched Between the first metal layer and the second metal layer. The method of claim 1, wherein the first passive device is a magnetic core, and the forming of the first passive device comprises sputtering a ferromagnetic layer on at least one of the epoxy layers Material to form a magnetic core. The method of claim 1, wherein: the substrate has a first surface and a reverse second surface; the stacked epoxy layers are deposited over the first surface of the substrate; The method includes: etching the second surface of the substrate to form a cavity; plating a conductor metal into the cavity to form a capacitor; and forming a plurality of conductors in the substrate Channels, such that at least some of the channels are electrically coupled to the capacitor. For example, the method of claim 1 of the patent scope includes forming a second The movable device, wherein: the first passive device is disposed in a first epoxy layer of the sequentially deposited epoxy layers; and the second passive device is disposed on the sequentially deposited epoxy The resin layer is inside the second layer different from the first layer. The method of claim 1, which forms a second passive device, wherein the first passive device and the second passive device are disposed in the sequentially deposited epoxy layer An epoxy layer inside. The method of claim 8, wherein: the first passive device does not overlap the second passive device; and at least one of the interconnect layers is disposed in the first passive device Between the second passive device. A wafer level method for packaging integrated circuits, comprising forming a plurality of micro-modules, each micro-module being formed by using the first step of the patent application scope, wherein each micro-module At least a portion will be formed simultaneously with at least a portion of another micromodule. The method of claim 1, wherein the forming of the first passive device comprises: sputtering a ferromagnetic material on a first epoxy layer of the sequentially deposited epoxy layers, Forming a magnetic core; depositing a second epoxy layer of the sequentially deposited epoxy layer over the magnetic core; A conductor material is sputtered over the second epoxy layer to form an inductor winding configured to magnetically couple the magnetic core. A wafer level method for packaging an integrated circuit, the method comprising: sequentially depositing a plurality of planarized, photoimageable epoxy layers over a substrate to form a plurality of layers over the substrate a planarized epoxy layer, wherein the epoxy layers are deposited by spin coating; after at least some of the epoxy layers are deposited and before the next epoxy layer is deposited Patterning at least some of the epoxy layers, wherein the photolithographic patterning results in at least partial cross-linking of each of the plurality of exposed portions of the patterned epoxy layer; at least some of the rings After the oxyresin layer is patterned, a plurality of openings are formed in at least some of the patterned epoxy layers by removing portions of the patterned epoxy that are not exposed; forming a plurality of conductor interconnect layers, Wherein each interconnect layer is formed directly over an associated epoxy layer and is at least partially formed by electroplating; an integrated circuit is placed in an associated opening in the openings , The integrated circuit has a plurality of I/O solder contact pads, and at least one of the epoxy layers is deposited after the integrated circuit is placed to cover the integrated circuit; Conductor channels, wherein each of the conductor channels is associated with an associated interconnect layer and an associated epoxy layer, and one of the openings is formed in the associated epoxy layer Related open And forming at least partially during plating of the associated interconnect layer; sputtering a conductive material over at least one of the epoxy layers to form at least one thin film resistor; Depositing a ferromagnetic material over at least one of the epoxy layers to form at least one magnetic core; plating a conductive material over at least one of the epoxy layers to form At least one inductor is wound, wherein each of the at least one thin film resistor, the at least one magnetic core, and the at least one inductor winding are formed between the sequentially deposited epoxy layers and sequentially Depositing an epoxy layer to encapsulate and electrically couple at least one of the interconnect layers; and forming a plurality of external package contacts, wherein the integrated circuit will at least partially interconnect via the conductors At least one of the ones and at least one of the conductor channels are electrically connected to a plurality of the external package contacts. An integrated circuit package comprising: a plurality of closely adjacent stacked cured, planarized photoimageable epoxy layers; at least one interconnect layer, each interconnect layer being embedded in an associated ring Inside the oxy-resin layer and comprising a plurality of interconnecting lines; a plurality of I/O pads, which are exposed on a first surface of the package; and an integrated circuit disposed at least in the epoxy layer One of them has an active surface, wherein the epoxy layers are At least one of the plurality of passive devices extending over the active surface of the integrated circuit and the integrated circuit electrically coupled to the at least one interconnect layer; and a plurality of passive devices, each of the plurality of passive devices The at least one associated epoxy layer is disposed within the epoxy layer and electrically coupled to the first integrated circuit. The integrated circuit package of claim 14, wherein the plurality of passive devices comprise at least one of the group consisting of: a resistor, a capacitor, an inductor, a magnetic core, a MEMS device, and a sense Detector and photovoltaic special battery. The integrated circuit package of claim 14, comprising: a substrate having a first surface, a reverse second surface, and a plurality of extending between the first surface and the second surface a substrate conductor channel, wherein the epoxy layers are stacked over the first surface of the substrate; and a sensing device that is one of the group consisting of: a photovoltaic cell, a sense And a wireless phase antenna disposed in a cavity in the second surface of the substrate and supported by the cavity, wherein the sensing device electrically couples at least some of the substrate conductors aisle. The integrated circuit package of claim 14, wherein each of the epoxy layers is made of SU-8. The integrated circuit package of claim 14, wherein the plurality of passive devices comprise a magnetic core, an inductor winding, and a thin film resistor, wherein the magnetic core is disposed on the epoxy layer middle In one of the cases, the inductor is wound in a different epoxy layer in the epoxy layer and overlying the magnetic core. The integrated circuit package of claim 14, which comprises at least one thin film battery structure. The integrated circuit package of claim 14, wherein the plurality of passive devices comprise a capacitor formed by a dielectric layer interposed between the plurality of metal layers.