Method to enable double-side molded module with plated copper posts

Abstract

The present disclosure relates to a method of fabricating a double-side molded module, which starts with providing a laminate panel including a laminate body, pads on a bottom surface of the laminate body, and copper posts surrounding the pads and on the bottom surface of the laminate body. The copper posts with height variations are taller than each pad. Next, the laminate panel is placed on a support block, which includes cavities to accommodate the copper posts, and support mesas, each surrounded by certain ones of the cavities. A top surface of each support mesa has a vertical distance from the bottom surface of the laminate body to accommodate the pads. Vacuum holes are then formed through the support block, each of which is confined in a corresponding support mesa. The vacuum holes and the cavities are evacuated to ensure that the laminate panel sits flat on the support block.

Description

METHOD TO ENABLE DOUBLE-SIDE MOLDED MODULE WITH PLATED COPPER POSTSRelated Applications

[0001] This application claims the benefit of provisional patent application serial number 63 / 511 ,941 , filed July 5, 2023, the disclosure of which is hereby incorporated herein by reference in its entirety.Field of the Disclosure

[0002] The present disclosure relates to a method of fabricating a double-side molded module with plated copper posts in a reliable manner without deformation, die cracks, or component interconnect failures, and in particular enabling surface mounting / wire bonding processes and molding processes during fabrication of the double-side molded module.Background

[0003] With the popularity of portable consumer electronic products, such as smart phones, tablet computers, and so forth, double-sided assemblies are becoming more and more attractive in microelectronics devices to achieve electronics densification in a small footprint.

[0004] However, a conventional double-side molded module, which utilizes Ball Grid Array (BGA), may result in a relatively large thickness of the final product and have limitations for input / output (I / O) density. It is because each solder ball of the BGA has a relatively large size (in both horizontal and vertical dimensions). In order to achieve a desired performance, a thickness of a laminate substrate of the double-side molded module typically cannot be reduced. In some applications, to improve the double-side molded module’s performance, it is necessary to increase the thickness of the laminate substrate. The conventional double-side molded module with the BGA is limited to a decreased thickness of less than 0.7mm. In addition, the BGA is not superior for thermal dissipation, especially for high frequency and high-power applications.

[0005] Accordingly, to accommodate the low-profile requirements for portable products and to enhance thermal and electrical performance, it is therefore an object of the present disclosure to provide a fabricating method of improving a double-side molded module with a reduced thickness. It is also desirable to fabricate the improved double-side molded module in a reliable manner without deformation, die cracks, or component interconnect failures.

[0006] The present disclosure relates to a method of fabricating a double-side molded module with plated copper posts in a reliable manner without deformation, die cracks, or component interconnect failures, in particular enabling surface mounting / wire bonding processes and molding processes during fabrication of the double-side molded module. The disclosed method starts with providing a laminate panel that includes a laminate body, first pads on a first surface of the laminate body, second pads on a second surface of the laminate body, and copper posts surrounding the second pads and on the second surface of the laminate body. Herein, each of the second pads has a same thickness, while the copper posts are taller than each of the second pads and have height variations. In a horizontal aspect, the laminate panel includes multiple strips, and each of the first pads, each of the second pads, and each of the copper posts are confined within a corresponding strip. Next, the laminate panel is placed on a support block. The support block has a top surface in contact with the second surface of the laminate body, and includes one or more cavities underneath each of the strips of the laminate panel to accommodate one or more corresponding copper posts of the laminate panel. A depth of each of the one or more cavities is no smaller than a height of any one of the copper posts. The support block further includes a support mesa surrounded by the one or more cavities for each of the strips. A top surface of the support mesa is lower than the top surface of the support block and has a vertical distance from the second surface of the laminate body to accommodate the second pads.

[0007] In one embodiment of the method, the one or more cavities have a same depth. The support block further includes a soft padding layer at a bottom surface of each of the one or more cavities to compensate the height variation of the copper posts, such that each of the copper posts is in contact with the soft padding.

[0008] According to one embodiment, the method further includes, before placing the laminate panel on the support block, grinding the copper posts to have a same height. Herein, the one or more cavities have a same depth. After placing the laminate panel on the support block, each of the copper posts is in contact with a bottom surface of a corresponding one of the one or more cavities.

[0009] In one embodiment of the method, the support block further includes support pins in each of the one or more cavities. Each of the support pins has a same height as the copper posts after grinding, and extends directly between the second surface of the laminate body and the bottom surface of the corresponding one of the one or more cavities.

[0010] In one embodiment of the method, the laminate panel further includes a ring structure on the second surface of the laminate body for each of the strips. Herein, the ring structure is surrounded by corresponding ones of the copper posts for each of the strips. The ring structure has a same thickness as each of the second pads and is located vertically between the second surface of the laminate body and the top surface of the support mesa. The vertical distance difference between the top surface of the support mesa and the second surface of the laminate body is substantially the same as the thickness of the ring structure.

[0011] In one embodiment of the method, the ring structure surrounds corresponding ones of the second pads for each of the strips and has a continuous loop shape. The ring structure is not electrically connected to the first pads, the second pads, or the copper posts.

[0012] In one embodiment of the method, the ring structure surrounds corresponding ones of the second pads for each of the strips. The ring structure has a broken-up configuration and is composed of multiple individual segments.The ring structure is not electrically connected to the first pads, the second pads, or the copper posts.

[0013] According to one embodiment, the method further includes, after placing the laminate panel on the support block, forming one vacuum hole underneath each of the strips. Herein, the vacuum hole extends through the support block to expose certain ones of the second pads for each of the strips. The vacuum hole is formed and confined in the support mesa for a corresponding one of the strips and is capable of communicating with the one or more cavities underneath the corresponding one of the strips. In addition, the method also includes performing vacuuming to evacuate the vacuum hole and the one or more cavities for each of the strips.

[0014] According to one embodiment, the method further includes, after performing the vacuuming, mounting one or more first components to the first pads on the first surface of the laminate body.

[0015] According to one embodiment, the method further includes, after mounting the one or more first components to the first pads, applying a first mold compound over the first surface of the laminate body to encapsulate the one or more first components.

[0016] According to one embodiment, the method further includes, after applying the first mold compound, removing the support block and mounting one or more second components to the second pads on the second surface of the laminate body.

[0017] According to one embodiment, the method further includes, after mounting the one or more second components to the second pads, applying a second mold compound over the second surface of the laminate body to encapsulate the one or more second components, and each of the copper posts.

[0018] According to one embodiment, the method further includes grinding down the second mold compound until each of the copper posts is exposed.

[0019] In another aspect, any of the foregoing aspects individually or together, and / or various separate aspects and features as described herein, may be combined for additional advantage. Any of the various features and elements asdisclosed herein may be combined with one or more other disclosed features and elements unless indicated to the contrary herein.

[0020] Those skilled in the art will appreciate the scope of the present disclosure and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures.Brief Description of the Drawing Figures

[0021] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0022] Figure 1 provides a flow diagram that illustrates an exemplary process to provide a double-side molded module according to some embodiments of the present disclosure.

[0023] Figures 2A-2D, 3-4, 5A-5B, 6A-6B, and 7-13 illustrate the steps associated with the process shown in Figure 1 .

[0024] Figure 14 illustrates a block diagram of a communication device, which may include the double-side molded module provided by the process shown in Figure 1 according to some embodiments of the present disclosure.

[0025] It will be understood that for clarity of illustration, Figures 1 -14 may not be drawn to scale.Detailed Description

[0026] The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.

[0027] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0028] It will be understood that when an element such as a layer, region, or substrate is referred to as being "on" or extending "onto" another element, it can be directly on or extend directly onto the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or extending "directly onto" another element, there are no intervening elements present. Likewise, it will be understood that when an element such as a layer, region, or substrate is referred to as being "over" or extending "over" another element, it can be directly over or extend directly over the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly over" or extending "directly over" another element, there are no intervening elements present. It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

[0029] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe a relationship of one element, layer, or region to another element, layer, or region as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures.

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As usedherein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and / or "including" when used herein specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0031] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0032] Embodiments are described herein with reference to schematic illustrations of embodiments of the disclosure. As such, the actual dimensions of the layers and elements can be different, and variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and / or tolerances, are expected. For example, a region illustrated or described as square or rectangular can have rounded or curved features, and regions shown as straight lines may have some irregularity. Thus, the regions illustrated in the figures are schematic and their shapes are not intended to illustrate the precise shape of a region of a device and are not intended to limit the scope of the disclosure. Additionally, sizes of structures or regions may be exaggerated relative to other structures or regions for illustrative purposes and, thus, are provided to illustrate the general structures of the present subject matter and may or may not be drawn to scale. Common elements between figures may be shown herein with common element numbers and may not be subsequently redescribed.

[0033] The present disclosure relates to a method of fabricating a double-side molded module with plated copper posts in a reliable manner withoutdeformation, die cracks, or component interconnect failures, and in particular enabling surface mounting and wire bonding processes and a molding process during fabrication of the double-side molded module. Figure 1 provides a flow diagram that illustrates an exemplary process to provide a double-side molded module according to some embodiments of the present disclosure. Figures 2A- 13 illustrate the steps associated with the process shown in Figure 1. Although the flow diagram and the associated steps are illustrated in a series, they are not necessarily order dependent. Some steps may be done in a different order than that presented. Further, processes within the scope of this disclosure may include fewer or more steps than those illustrated in Figure 1 .

[0034] Initially, a laminate panel 10 with copper posts 12 is provided as illustrated in Figures 2A and 2B (step 102). Figure 2A is a bottom view of the laminate panel 10, and Figure 2B is a cross-sectional view of a portion of the laminate panel 10 along a dashed line A-A’. The laminate panel 10 includes a laminate body 14, first pads 16, second pads 20, a ring structure 22, and the copper posts 12 (for clarification, only some first pads, some second pads, and some copper posts are labeled with reference numbers). The first pads 16 are formed on a first surface of the laminate body 14 and configured to accommodate electronic components (more details are described below) on the first surface of the laminate body 14. Each first pad 16 may have a same size and a same shape, such as a circle, square, etc. (not shown). The second pads 20 are formed on a second surface of the laminate body 14 and configured to accommodate electronic components (more details are described below) on the second surface of the laminate body 14. Each second pad 20 may have a same size and a same shape, such as a circle, square, etc. The ring structure 22 is also formed on the second surface of the laminate body 14 and may surround the second pads 20. The copper posts 12 are formed on the second surface of the laminate body 14 and surround the ring structure 22. Each copper post 12 is taller than the second pads 20 and the ring structure 22. Herein, the first surface and the second surface of the laminate body 14 are a top surface and a bottom surface of the laminate body 14, respectively.

[0035] Viewed in a plane, the laminate panel 10 can be divided into multiple strips 24 with strip margins 26 therebetween, such that the strips 24 are separate from each other. For the purpose of this illustration, the laminate panel 10 includes 3X2 strips 24. In different applications, the laminate panel 10 may include fewer or more strips with different layout configurations. Each of the first pads 16, each of the second pads 20, the ring structure 22, and each of the copper posts 12 are confined within a corresponding strip 24.

[0036] The laminate body 14 has a thickness between 100 pm and 400 pm and is formed from alternating prepreg (PPG) layers and metal layers in a vertical direction (not shown). The first pads 16 and the second pads 20 are formed of a metal material, such as copper. Each of the first pads 16 and the second pads 20 may be electrically connected to a corresponding metal layer within the laminate body 14 (not shown). There may be some connecting lines (not shown) formed on the first surface of the laminate body 14 to electrically connect certain first pads 16, and some connecting lines (not shown) formed on the second surface of the laminate body 14 to electrically connect certain second pads 20.

[0037] Each of the copper posts 12 has a height between 100 pm and 150 pm, and a diameter between 150 pm and 250 pm. In some embodiments, the copper posts 12 may have a height variation due to a formation process of the copper posts 12 (e.g., an electrolytic copper plating process). For instance, the copper posts 12 in outer portions of the laminate panel 10 will be taller than the copper posts 12 in a middle portion of the laminate panel 10. The height variation of the copper posts may be 125 pm + / - 25 pm. For the purpose of this illustration, a first copper post 12-1 located close to the point A (i.e., close to one outer edge of the laminate panel 10) is taller than a second copper post 12-2 located away from the point A (i.e., away from the outer edge of the laminate panel 10).

[0038] The ring structure 22 is formed of a conduct material such as copper and is not electrically connected to any of the first pads 16, the second pads 20, the metal layer within the laminate body 14, or the copper posts 12. The ring structure 22 is merely configured to provide mechanical support to the laminatepanel 10 in subsequent fabrication steps (e.g., a molding step). The ring structure 22 and each of the second pads 20 have a substantially same thickness.

[0039] In one embodiment, the ring structure 22 is continuous, as illustrated in Figure 2A. In one embodiment, the ring structure 22 has a broken-up configuration and is composed of multiple individual segments 28, as illustrated in Figure 2C (only a portion of the laminate panel 10 including one strip 24 is shown for simplicity). In one embodiment, the ring structure 22 is omitted in the laminate panel 10, as illustrated in Figure 2D (only a portion of the laminate panel 10 including one strip 24 is shown for simplicity). In different applications, the ring structure 22 may have a different configuration and / or a different shape. In some cases, the ring structure 22 may not be a loop, but an arbitrary shape based on the application. In addition, the ring structure 22 may be located in different areas within each strip 24, and do not need to surround the second pads 22. Regardless of the configuration of the ring structure 22 and / or the presence or absence of the ring structure 22, each of the second pads 20 has a certain distance DD from its nearest copper post 12. The certain distance DD is at least 50 pm, or between 50 pm and 200 pm.

[0040] Next, the laminate panel 10 with the copper posts 12 is placed on a support block 30 (step 104), as illustrated in Figure 3. The support block 30 includes a number of cavities 32, and there might be one or more cavities 32 underneath each strip 24. Each cavity 32 is configured to accommodate one or more corresponding copper posts 12. In view of cost and manufacturing complexities, each cavity 32 is typically formed to have a same depth D1 , which is measured from a top surface of the support block 30 to a bottom surface of one cavity 32. As described above, the copper posts 12 may have a height variation due to the plating process (e.g., the first copper post 12-1 is taller than the second copper post 12-2). Therefore, to accommodate all of the copper posts 12, the depth D1 of the cavities 32 is desired to be no smaller than a height of the tallest copper post 12. Otherwise, the taller copper posts 12 may be compressed in subsequent fabrication steps (e.g., a molding step), which will cause sideeffects on the final product (such as, deflection / deformation of the laminate panel 10, component interconnect failures).

[0041] However, if the depth D1 of the cavities 32 can accommodate the taller copper posts 12, the shorter copper posts 12 will float in the corresponding cavities 32. In one embodiment, the support block 30 may further include a soft padding layer 34 at the bottom surface of each cavity 32 to compensate for the height variation of the copper posts 12. Herein, each copper post 12 will be in contact with a corresponding soft padding layer 34. The soft padding layer 34 protects the taller copper posts 12 (e.g., the first copper post 12-1 ) from deformation, and supports the shorter copper posts 12 (e.g., the second copper post 12-2) to prevent floating in the cavities 32. The cavities 32 with the soft padding layers 34 in combination with the copper posts 12 provide mechanical support to the laminate panel 10, keep horizontal balance of the laminate panel 10 in the subsequent molding step, and also prevent the laminate panel 10 from bending over while proceeding with a high molding pressure. The soft padding layer 34 may be formed of a soft material that does not damage the copper posts 12 under pressure, such as tape, rubber, silicon membrane, or any polymer material. The soft padding layer 34 has a thickness less than a height of the shortest copper post 12 and may be between 25 pm and 100 pm.

[0042] In addition, for each of the strips 24, the support block 30 includes at least one support mesa 36 surrounded by the cavities 32. For the purpose of this illustration, the support block 30 only includes one support mesa 36 for each of the strips 24. In different applications, the support block 30 may include more support mesas for each of the strips 24. Herein, the support mesa 36 has a height H1 , which is measured from the bottom of one cavity 32 to a top surface of the support mesa 36. A height difference H2 between the top surface of the support mesa 36 and the top surface of the support block 30 is substantially the same as the thickness of each second pad 20 / the ring structure 22. For each of the strips 24, the second pads 20 and the ring structure 22 are confined within the support mesa 36. As such, each second pad 20 and the ring structure 22 are in contact with the top surface of the support mesa 36. The support mesa 36 incombination with the second pads 20 and the ring structure 22 provides mechanical support to the laminate panel 10, keeps the horizontal balance of the laminate panel 10 in the subsequent molding step, and also prevents the laminate panel 10 from bending over while proceeding with a high molding pressure.

[0043] Furthermore, the top surface of the support block 30 is in contact with the second surface of the laminate body 14 to provide further mechanical support to the laminate panel 10. The top surface of the support block 30, the top surface of each support mesa 36, the bottom surface of each cavity 32, and the first and second surfaces of the laminate body 14 are substantially flat.

[0044] In some applications, the ring structure 22 is omitted. Regardless of the configuration of the ring structure 22 and / or the presence or absence of the ring structure 22, each of the second pads 20 is confined within the corresponding support mesa 36. Sharp edges of the support mesa 36 do not touch any of the second pads 20. Otherwise, pad damage may occur and lead to side effects such as non-wet defects and bump cracks in subsequent fabrication steps (e.g., a surface mounting step).

[0045] Alternatively, to remove the height variation of the copper post 12, an optional grinding step (optional step 104A) is applied before placing the laminate panel 10 on the support block 30 (step 104), as illustrated in Figure 4. After the grinding step, each ground copper post 12G has a same height H3 and has a bottom surface at a same plane (e.g., a first ground copper post 12G-1 is ground from the first copper post 12-1 , a second ground copper post 12G-2 is ground from the second copper post 12-2, and the first ground copper post 12G-1 and the second ground copper post 12G-2 have the same height H3). Then, the laminate panel 10 with the planarized copper posts 12 is placed on the support block 30 (step 104), as illustrated in Figure 5A. Herein, the depth D1 of the cavities 32 is substantially the same as the height H3 of the ground copper posts 12G. As such, each ground copper post 12G is in contact with the bottom surface of a corresponding cavity 32 and the second surface of the laminate body 14. The cavities 32 in combination with the ground copper posts 12G providemechanical support to the laminate panel 10, keep a horizontal balance of the laminate panel 10 in the subsequent molding step, and also prevent the laminate panel 10 from bending over while proceeding with a high molding pressure.

[0046] In one embodiment, the support block 30 may further include one or more support pins 38 in each cavity 32, as illustrated in Figure 5B (only one support pin is labeled with the reference number for clarity). The one or more support pins 38 located in a spare space in each cavity 32 (e.g., located between one ground copper post 12G and walls of each cavity 32). Each support pin 38 also has the same height H3 as the ground copper posts 12G (i.e., substantially the same as the depth D1 of the cavities 32). Therefore, each support pin 38 is in contact with the bottom surface of the corresponding cavity 32 and the second surface of the laminate body 14. The one or more support pins 38 in each cavity 32 provide extra mechanical support to the laminate panel 10, keep the horizontal balance of the laminate panel 10 in the subsequent molding step, and also prevent the laminate panel 10 from bending over while proceeding with a high molding pressure. The support pins 38 may be formed of metal, or a hard material like metal. The support pins 38 may be in contact with either the PPG layers or the metal layers within the laminate body 14.

[0047] Typically, bonding quality of electrical components on the laminate panel 10 depends on whether the laminate panel 10 is lying flat enough. In order to enable the laminate panel 10 to sit flat on the support block 30, a vacuum hole 40 is formed underneath each strip 24 (step 106), as illustrated in Figures 6A and 6B. Figure 6A is a cross-sectional view of a portion of the laminate panel 10 with a portion of the support block 30 along the dashed line A-A’, and Figure 6B is a bottom view of the support block 30. Herein, the vacuum hole 40 is formed based on the configuration shown in Figure 3, but not limited to. The vacuum hole 40 can also be formed based on the configurations shown in Figures 5A and 5B.

[0048] For each strip 24, the vacuum hole 40 extends through the support block 30 to expose certain second pads 20 on the second surface of the laminate body 14. Herein, the vacuum hole 40 is formed and confined in the support mesa 36 for a corresponding strip 24 and capable of communicating with certaincavities 32 surrounding the support mesa 36 (due to the vertical distance between the second surface of the laminate panel 10 and the top surface of the support mesa 36). As such, when the vacuum hole 40 is vacuumed, each cavity 32 underneath and confined within the corresponding strip 24 will be vacuumed as well. And in consequence, the laminate panel 10 will be secured flat on the support block 30, and the laminate panel 10 will not bounce back when electrical components are mounted on the laminate panel 10.

[0049] For the purpose of this illustration, the vacuum hole 40 is located at a center of each strip 24 and has a cylindrical shape. In different applications, the vacuum hole 40 may be located at a random location within the corresponding support mesa 36, and may have a different shape, such as a cube, cuboid, triangular prism, etc. It is desired that sharp edges of the vacuum hole 40 do not touch any of the second pads 20 to avoid pad damage in the subsequent fabrication steps (e.g., a molding step). If the ring structure 22 exists, the vacuum hole 40 may be confined within the ring structure 22. In addition, the vacuum hole 40 may not expose all of the second pads 20 for each strip 24 and may be smaller than an electrical component that is subsequently mounted on the second pads 20.

[0050] Next, a vacuuming step (step 108) is performed to evacuate each vacuum hole 40 and the cavities 32 for each strip 24. Once the laminate panel 10 is secured flat on the support block 30, one or more first components 42 are mounted to the first pads 16 on the first surface of the laminate body 14 for each strip 24 (step 110), as illustrated in Figure 7. For the purpose of this illustration, the one or more first components 42 include a first surface mounted device (SMD) 42-1 , a second SMD 42-2, a first flip-chip die 42-3 with die copper pillars, and a second flip-chip die 42-4 with die solder balls. Each first component 42 is confined within a corresponding strip 24. In different applications, there might be fewer or more first components 42 mounted on the first surface of the laminate body 14. The first components 42 may be other electrical components, such as filters, Silicon (Si) devices, power amplifiers (PAs), and passive components. The first components 42 are mounted to the first pads 16 with or without adhesivematerial. The first components 42 may also be electrically connected to corresponding metal layers within the laminate body 14, respectively (not shown). Due to the air vacuuming through the vacuum hole 40, the laminate panel 10 will not bounce back when the first components 42 are mounted.

[0051] Next, a first mold compound 46 is applied over the first surface of the laminate body 14 to provide a single-side molded precursor 48 (step 112), as illustrated in Figure 8. The first mold compound 46 encapsulates each first component 42. The first mold compound 46 may be an organic epoxy resin system or the like, and may be applied by various procedures, such as sheet molding, overmolding, compression molding, transfer molding, dam fill encapsulation, or screen print encapsulation. In a typical molding step (e.g., a compression molding), a molding pressure used for applying the first mold compound 46 is between 100 psi and 1000 psi.

[0052] Herein, if the support block 30 includes the soft padding layer 34 at the bottom surface of each cavity 32 to compensate the height variation of the copper posts 12, no copper post 12 will float in the cavity 32. As such, the support block 30 in combination with the copper posts 12 provides mechanical support to the laminate panel 10 during the molding step, and in consequence prevents deformation of the laminate panel 10, cracks of the first components 42, or connection failures for the first components 42.

[0053] Alternatively, if each copper post 12 has a same height (e.g., optional grinding step 104A is applied), each copper post 12 may sit on the bottom surface of the corresponding cavity 32 and the laminate body 14 will lie on the top surface of the support block 30. Thus, during the molding step, the support block 30 in combination with the copper posts 12 provides mechanical support to the laminate panel 10 without the deformation of the laminate panel 10, the cracks of the first components 42, or the connection failures for the first components 42. In addition, if the support block 30 further includes the support pins 38 in each cavity 32, the support pins 38 will provide extra support to the laminate panel 10. A curing process (not shown) is then used to harden the first mold compound 46. The curing temperature is between 100QC and 320QCdepending on which material is used as the first mold compound 46. A planarization process may also be applied to planarize a top surface of the first mold compound 46 (not shown).

[0054] The support block 30 is then removed and the single-side molded precursor 48 is flipped (step 114), as illustrated in Figure 9. The second surface of the laminate body 14, and the copper posts 12, the second pads 20, and the ring structure 22 on the second surface of the laminate body 14 are exposed. Next, at least one second component 50 is mounted to the exposed second pads 20 on the second surface of the laminate body 14 (step 1 16), as illustrated in Figure 10. For the purpose of this illustration, the at least one second component 50 includes a flip-chip die with die solder balls. In different applications, there might be more second components 40 mounted on the second surface of the laminate body 14. The at least one second component 50 may be one of other electrical components, such as filters, low noise amplifiers (LNAs), passive components, integrated passive devices (IPDs), PAs, Si caps, controllers, and antenna switches (ASWs). The at least one second component 50 is confined within a corresponding strip 24. The at least one second component 50 is mounted to the exposed second pads 20 with or without adhesive material. The at least one second component 50 may be electrically connected to the first components 42 via the corresponding metal layers within the laminate body 14 (not shown). In one embodiment, each copper post 12 may extend vertically beyond a backside of the at least one second component 50 (i.e., each copper post 12 may be taller than the at least one second component 50, not shown). In one embodiment, each copper post 12 does not extend vertically beyond the backside of the at least one second component 50 but extends vertically beyond an active device region of the at least one second component 50.

[0055] A second mold compound 52 is applied over the second surface of the laminate body 14 to provide a double-side molded package 54 (step 118), as illustrated in Figure 1 1 . The second mold compound 52 encapsulates the at least one second component 50, each copper post 12, and the ring structure 22 (if one exists). The second mold compound 52 may be an organic epoxy resin system orthe like and may be formed of a same or different material from the first mold compound 46. The second mold compound 52 may be applied by various procedures, such as sheet molding, overmolding, compression molding, transfer molding, dam fill encapsulation, or screen print encapsulation. Herein, the planarized first mold compound 46 provides mechanical support to the laminate panel 10, such that during the second molding step, there will be no vertical deformations occurring to the laminate panel 10, no die cracks occurring to the second components 50, and no connection failures for the second component 50.

[0056] Figure 12 illustrates an additional grinding step (step 120) of the second mold compound 52 of the double-side molded package 54. The second mold compound 52 is ground until each copper post 12 is exposed. If each copper post 12 is taller than the at least one second component 50, the at least one second component 50 is still fully encapsulated by the second mold compound 52 after the grinding (not shown). If some copper posts 12 are lower than the at least one second component 50, a portion of the at least one second component 50 (e.g., die substrate) might be ground to expose each copper post 12. Since each copper post 1 always extends vertically beyond the active device region of the at least one second component 50, the grinding process will not affect the active device region of the at least one second component 50. In some applications, an additional metal pad 58 is formed over the exposed surface of each copper post 12.

[0057] The double-side molded package 54 is then singulated into individual double-side molded modules 56 (step 122), as illustrated in Figure 13. The strip margins 26 of the laminate panel 10 may not be included in the final individual double-side molded module 56. Each individual double-side molded module 56 includes the one or more first components 42, the first mold compound 46, the at least one second component 50, the second mold compound 52, and a portion of the laminate panel 10 within a corresponding strip 24. Since the copper posts 12 are connected to the first components 42 and / or the second component 50, the copper posts 12 will also help to conduct heat generated from the firstcomponents 42 and / or the second component 50. Since each copper post 12 has a height only between 100 pm and 150 pm, the double-side molded module 56 may have a thickness less than 0.7 mm.

[0058] The systems and methods for enabling surface mounting / wire bonding processes and molding processes of fabricating a double-side molded module without deformation, die cracks, or component interconnect failures, according to aspects disclosed herein, may be provided in fabricating any processor-based device. Examples, without limitation, include a set-top box, an entertainment unit, a navigation device, a communications device, a fixed location data unit, a mobile location data unit, a global positioning system (GPS) device, a mobile phone, a cellular phone, a smartphone, a session initiation protocol (SIP) phone, a tablet, a phablet, a server, a computer, a portable computer, a mobile computing device, a wearable computing device (e.g., a smartwatch, a health or fitness tracker, eyewear, etc.), a desktop computer, a personal digital assistant (PDA), a monitor, a computer monitor, a television, a tuner, a radio, a satellite radio, a music player, a digital music player, a portable music player, a digital video player, a video player, a digital video disc (DVD) player, a portable digital video player, an automobile, a vehicle component, avionics systems, a drone, and a multicopter.

[0059] With reference to Figure 14, the concepts described above may be utilized in fabricating various types of communication devices 100, such as those listed in the previous paragraph. The communication device 100 will generally include a control system 102, a baseband processor 104, transmit circuitry 106, receive circuitry 108, antenna switching circuitry 110, multiple antennas 112, and user interface circuitry 1 14. Herein, at least one or any combination of the control system 102, the baseband processor 104, the transmit circuitry 106, and the receive circuitry 108 may be implemented in the double-side molded module 56 (e.g. implemented in the first flip-chip die 42-3, the second flip-chip 42-4, and / or the flip-chip die 50) shown in Figure 13 using the manufacturing process described above.

[0060] In a non-limiting example, the control system 102 can be a field- programmable gate array (FPGA) or an application-specific integrated circuit(ASIC), as an example. In this regard, the control system 102 can include at least a microprocessor(s), an embedded memory circuit(s), and a communication bus interface(s). The receive circuitry 108 receives radio frequency signals via the antennas 1 12 and through the antenna switching circuitry 110 from one or more base stations. A low noise amplifier and a filter of the receive circuitry 108 cooperate to amplify and remove broadband interference from the received signal for processing. Down conversion and digitization circuitry (not shown) will then down convert the filtered, received signal to an intermediate or baseband frequency signal, which is then digitized into one or more digital streams using an analog-to-digital converter(s) (ADC).

[0061] The baseband processor 104 processes the digitized received signal to extract the information or data bits conveyed in the received signal. This processing typically comprises demodulation, decoding, and error correction operations, as will be discussed in greater detail below. The baseband processor 104 is generally implemented in one or more digital signal processors (DSPs) and ASICs.

[0062] For transmission, the baseband processor 104 receives digitized data, which may represent voice, data, or control information, from the control system 102, which it encodes for transmission. The encoded data is output to the transmit circuitry 106, where a digital-to-analog converter(s) (DAC) converts the digitally encoded data into an analog signal and a modulator modulates the analog signal onto a carrier signal that is at a desired transmit frequency or frequencies. A power amplifier will amplify the modulated carrier signal to a level appropriate for transmission and deliver the modulated carrier signal to the antennas 1 12 through the antenna switching circuitry 110. The multiple antennas 1 12 and the replicated transmit and receive circuitries 106, 108 may provide spatial diversity. Modulation and processing details will be understood by those skilled in the art.

[0063] It is contemplated that any of the foregoing aspects, and / or various separate aspects and features as described herein, may be combined for additional advantage. Any of the various embodiments as disclosed herein maybe combined with one or more other disclosed embodiments unless indicated to the contrary herein.

[0064] Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow.

Claims

ClaimsWhat is claimed is:1 . A method comprising:• providing a laminate panel that includes a laminate body, first pads on a first surface of the laminate body, second pads on a second surface of the laminate body, and copper posts surrounding the second pads and on the second surface of the laminate body, wherein:• each of the second pads has a same thickness, while the copper posts are taller than each of the second pads and have height variations;• in a horizontal aspect, the laminate panel includes multiple strips, and each of the first pads, each of the second pads, and each of the copper posts are confined within a corresponding strip; and• placing the laminate panel on a support block, wherein:• the support block has a top surface in contact with the second surface of the laminate body, and includes one or more cavities underneath each of the strips of the laminate panel to accommodate one or more corresponding copper posts of the laminate panel, wherein a depth of each of the one or more cavities is no smaller than a height of any one of the copper posts;• the support block further includes a support mesa surrounded by the one or more cavities for each of the strips, wherein a top surface of the support mesa is lower than the top surface of the support block and has a vertical distance from the second surface of the laminate body to accommodate the second pads.

2. The method of claim 1 wherein:• the one or more cavities have a same depth; and• the support block further includes a soft padding layer at a bottom surface of each of the one or more cavities to compensate the height variation ofthe copper posts, such that each of the copper posts is in contact with the soft padding layer.

3. The method of claim 1 further comprising, before placing the laminate panel on the support block, grinding the copper posts to have a same height, wherein:• the one or more cavities have a same depth; and• after placing the laminate panel on the support block, each of the copper posts is in contact with a bottom surface of a corresponding one of the one or more cavities.

4. The method of claim 3 wherein the support block further includes support pins in each of the one or more cavities, wherein each of the support pins has a same height as the copper posts after grinding and extends directly between the second surface of the laminate body and the bottom surface of the corresponding one of the one or more cavities.

5. The method of claim 1 wherein the laminate panel further comprises a ring structure on the second surface of the laminate body for each of the strips, wherein• the ring structure is surrounded by corresponding ones of the copper posts for each of the strips;• the ring structure has a same thickness as each of the second pads and is located vertically between the second surface of the laminate body and the top surface of the support mesa; and• the vertical distance difference between the top surface of the support mesa and the second surface of the laminate body is substantially the same as the thickness of the ring structure.

6. The method of claim 5 wherein:• the ring structure surrounds corresponding ones of the second pads for each of the strips and has a continuous loop shape; and• the ring structure is not electrically connected to the first pads, the second pads, or the copper posts.

7. The method of claim 5 wherein:• the ring structure surrounds corresponding ones of the second pads for each of the strips;• the ring structure has a broken-up configuration and is composed of multiple individual segments; and• the ring structure is not electrically connected to the first pads, the second pads, or the copper posts.

8. The method of claim 1 further comprising:• after placing the laminate panel on the support block, forming one vacuum hole underneath each of the strips, wherein:• the vacuum hole extends through the support block to expose certain ones of the second pads for each of the strips; and• the vacuum hole is formed and confined in the support mesa for a corresponding one of the strips and is capable of communicating with the one or more cavities underneath the corresponding one of the strips; and• performing vacuuming to evacuate the vacuum hole and the one or more cavities for each of the strips.

9. The method of claim 8 wherein:• the one or more cavities of the support block have a same depth; and• the support block further includes a soft padding layer at a bottom surface of each of the one or more cavities to compensate the height variation ofthe copper posts, such that each of the copper posts is in contact with the soft padding layer.

10. The method of claim 8 further comprising, before placing the laminate panel on the support block, grinding the copper posts to have a same height, wherein:• the one or more cavities have a same depth; and• after placing the laminate panel on the support block, each of the copper posts is in contact with a bottom surface of a corresponding one of the one or more cavities.1 1 . The method of claim 10 wherein the support block further includes support pins in each of the one or more cavities, wherein each of the support pins has a same height as the copper posts after grinding, such that each of the support pins extends between the second surface of the laminate body and the bottom surface of the corresponding one of the one or more cavities for mechanical support.

12. The method of claim 8 wherein the laminate panel further comprises a ring structure on the second surface of the laminate body for each of the strips, wherein:• the ring structure is surrounded by corresponding ones of the copper posts for each of the strips;• the ring structure has a same thickness as each of the second pads and is located vertically between the second surface of the laminate body and the top surface of the support mesa; and• the vertical distance difference between the top surface of the support mesa and the second surface of the laminate body is substantially the same as the thickness of the ring structure.

13. The method of claim 12 wherein:• the ring structure surrounds corresponding ones of the second pads for each of the strips and has a continuous loop shape; and• the ring structure is not electrically connected to the first pads, the second pads, or the copper posts.

14. The method of claim 12 wherein:• the ring structure surrounds corresponding ones of the second pads for each of the strips;• the ring structure has a broken-up configuration and is composed of multiple individual segments; and• the ring structure is not electrically connected to the first pads, the second pads, or the copper posts.

15. The method of claim 12 further comprising before placing the laminate panel on the support block, grinding the copper posts to have a same height, wherein:• the one or more cavities have a same depth; and• after placing the laminate panel on the support block, each of the copper posts is in contact with a bottom surface of a corresponding one of the one or more cavities.

16. The method of claim 15 wherein the support block further includes support pins in each of the one or more cavities, wherein each of the support pins has a same height as the copper posts after grinding, such that each of the support pins extends between the second surface of the laminate body and the bottom surface of the corresponding one of the one or more cavities for mechanical support.

17. The method of claim 12 wherein:• the one or more cavities of the support block have a same depth; and• the support block further includes a soft padding layer at a bottom surface of each of the one or more cavities to compensate the height variation of the copper posts, such that each of the copper posts is in contact with the soft padding layer.

18. The method of claim 8 further comprising, after performing the vacuuming, mounting one or more first components to the first pads on the first surface of the laminate body.

19. The method of claim 18 further comprising, after mounting the one or more first components to the first pads, applying a first mold compound over the first surface of the laminate body to encapsulate the one or more first components.

20. The method of claim 19 further comprising:• after applying the first mold compound, removing the support block; and• mounting one or more second components to the second pads on the second surface of the laminate body.21 . The method of claim 20 further comprising, after mounting the one or more second components to the second pads, applying a second mold compound over the second surface of the laminate body to encapsulate the one or more second components, and each of the copper posts.

22. The method of claim 22 further comprising grinding down the second mold compound until each of the copper posts is exposed.

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