Connecting array device with support structure, electronic package and method for manufacturing an electronic assembly

Abstract

A connecting array device (110a) comprising: a substrate (120) with a substrate body (122) and a main surface (124); an array of solder joint elements (130) formed on the main surface; and a support structure (140, 240a, 240b, 340) formed on the main surface (124), wherein the support structure (140, 240a, 240b, 340) is configured to maintain a predefined distance between the main surface (124) of the substrate (120) and another main surface of a component carrier on which the interconnect array device (110a) is mounted during a soldering process, and the support structure (140, 240a, 240b, 340) comprises at least one support element (140, 240a, 240b, 340); wherein the support structure (140, 240a, 240b, 340) comprises a plurality of support elements (140, 240a, 240b, 340) that are spatially separated from each other; at least one support element (240a) from the plurality of support elements (140, 240a, 240b, 340) has the following characteristics: a base section (242a) adjacent to the substrate (120); a tip section (244a) facing away from the substrate (120); and a middle section (246a) formed between the base section (242a) and the tip section (244a); wherein the base section (242a) and the tip section (244a) are made of or comprise a solderable material and wherein the middle section (246a) is made of or comprises an electrically conductive material that remains solid at reflow temperatures; and at least one support element (240a) from the plurality of support elements (140, 240a, 240b, 340) further comprising an insulating jacket (248a) that surrounds a side wall of the middle section (246a).

Description

Technical field

[0001] The present disclosure relates generally to the field of electronic assemblies in which a packaged (enclosed) electronic component is mounted on a component carrier. The present disclosure also relates to an electronic assembly with an electronic component packaged in a interconnect array package (e.g., a ball grid array package (BGA)) mounted on a component carrier. The present disclosure also relates to a method for manufacturing an electronic assembly. State of the art

[0002] Electronic packages or chip carriers are used to mount integrated circuits (ICs) or chips, such as microprocessors, memory, analog components, etc., onto a component carrier, e.g., a printed circuit board (PCB). A BGA generally contains spherical electrical connectors or contacts arranged in a two-dimensional array on the underside of the package. The entire underside of the component can be used, not just the edge or perimeter. Spherical connectors are often referred to simply as "balls."

[0003] Due to small distances between adjacent connecting elements, electrical bridging can lead to a short circuit between neighboring spheres. Such a short circuit can be caused or at least exacerbated by unwanted distortion of the package, particularly in a reflow oven where an assembly comprising the package and a component carrier is heated above a specific solder reflow temperature.

[0004] JP H11-214585A discloses an IC chip that is sealed on one side of a package assembly with a sealing element, for example made of ceramic, thus forming an IC package. Furthermore, a pad for electrically connecting the IC chip to a column-shaped bump is arranged on the rear side of the package assembly. On one side where the pads are arranged, a projection is formed by which a pad located on one side of a mounting plate is separated from the pad of the IC package when the column-shaped bump is fused, in order to ensure a predetermined distance between the pad and the pad.

[0005] US 2021 / 0082798A1 discloses an electronic assembly comprising a first substrate, a second substrate, and an arrangement of connecting elements that electrically connect the first substrate to the second substrate. The arrangement of connecting elements includes first connections, wherein the first connections have a first volume and a first material composition, and second connections, wherein the second connections have a second volume and a second material composition, and wherein the first volume differs from the second volume and / or the first material composition differs from the second material composition.

[0006] JP 2007 - 324 418 A discloses a semiconductor device in which several first electrodes formed on the main surface of the first substrate plate and several second electrodes formed correspondingly to the first electrodes on the main surface of the second substrate plate are connected opposite each other by solder beads and the space between the main surfaces of the first and second substrate plates is filled with a backfill material, wherein the semiconductor devices each have a column-shaped structure made of an insulating material between the solder beads.

[0007] JP H10 - 84 011 A discloses a semiconductor device in which several spherical conductors are mounted on the mounting surface of a package equipped with a semiconductor chip and these spherical conductors are surface-mounted via a printed circuit board, wherein several spacers are mounted on the mounting surface of the package, adjacent to the printed circuit board and keeping the height of the package constant. Summary

[0008] According to a first aspect, an interconnection array device with the features of claim 1 is provided, comprising (a) a substrate with a substrate body and a main surface; (b) an array of solder connection elements formed on the main surface; and (c) a support structure formed on the main surface. The support structure is configured to maintain a predefined distance between the main surface of the substrate and another main surface of a component carrier on which the interconnection array device is mounted during a soldering process. The support structure comprises at least one support element.The support structure is non-collapsible during expected use and processes, resists distortion, or in some embodiments is rigid against compressive forces.

[0009] In some embodiments, a ball grid array (BGA) device uses a support structure that (i) is positioned between a BGA substrate and a component carrier and (ii) is made of a material that structurally withstands solder melting temperatures and prevents undesired collapse of at least one solder joint during a (reflow) soldering process by which the BGA device is permanently mounted to a component carrier with appropriate electrical contacts. The mounting process can be a surface mount process, in which, in some embodiments, the ball grid array is applied to the upper (further) main surface of the component carrier. The BGA device can be at least part of a surface mount device (SMD), i.e., a packed or packaged electronic component configured for surface mounting. Surface mounting can be performed, for example, using pick-and-place machines of any type (e.g.,Pick-and-place assembly machines).

[0010] In some embodiments, the solder joint elements are solder balls. However, other geometries besides the spherical shape can also be used to realize the solder joint element(s). Other possible geometries are ellipsoidal, conical, cylindrical, cuboidal, or combinations thereof.

[0011] In some embodiments, the connection device can significantly increase the process reliability of a (surface) assembly process for an electronic component in a simple and effective manner. In some embodiments, maintaining the predefined distance prevents severe compression of a solder joint due to the (high) weight of the connection device and any additional elements mounted on it. This effectively prevents unwanted short circuits between adjacent solder joints. Furthermore, solder joints can also be subjected to high compression when an additional element, particularly a heat sink, is attached to the package with additional pressure, for example, to achieve good thermal contact between the package and the additional element / heat sink.For such applications, the described support structure or the at least one support element should have a mechanical stability that, in some embodiments, can withstand very high compressive forces.

[0012] A component carrier can be a mounting support structure capable of accommodating one or more components on and / or within it for mechanical support and / or electrical connection. In other words, a component carrier can be configured as a mechanical and / or electronic support for electronic (BGA) components. Specifically, a component carrier can be a printed circuit board (PCB), an interposer, or an integrated circuit (IC) substrate. A component carrier can also be a hybrid board that combines various types of component carriers mentioned above.

[0013] The described support structure does not collapse during a surface-mount soldering reflow process of a BGA package on, for example, a printed circuit board. Therefore, in some embodiments, the molten solder elements, such as solder balls, are not further compressed at temperatures above their melting point. The support structure can be so stable that it does not collapse even under comparatively strong compressive forces, which can arise, for example, from a relatively high weight of the BGA package.

[0014] The reflow process is carried out in a reflow oven, the interior of which is heated by appropriately controlled heating elements. Reflow temperatures can exceed 183 °C and, in some embodiments, 220 °C. In some applications, the reflow temperature can exceed 245 °C and, in particular, 300 °C.

[0015] The support structure comprises a number of support elements that are spatially separated from one another. This use of support elements reduces the area occupied by the support structure, so that for most applications a sufficiently high number of (spherical) solder pads are still available for contacting an electronic circuit with at least one component mounted on the substrate on a surface opposite the main surface. The number of support elements, e.g., two, three, four, five, or even more, allows the solder pads to be spatially distributed on the main surface in such a way as to provide stable mechanical support.In some embodiments, the support elements can be distributed such that even in a non-uniform reflow soldering process, where some solder joints melt earlier than others, the main surface of the substrate body remains aligned parallel to the main surface of the component carrier. A suitable height is selected for each support element based on system parameters and design criteria. In some embodiments, all support elements have at least approximately the same height.

[0016] According to some embodiments, at least some of the support elements are arranged at least approximately on a diagonal line (of two diagonal lines) connecting opposite corners of the substrate body. This makes it possible to easily specify suitable positions for the support elements. Furthermore, when forming the support elements on the main surface of the substrate, the support elements can be placed precisely and easily reproducibly at the predefined positions.

[0017] It should be noted that diagonal lines are not limited to square-shaped substrate bodies. Diagonal lines can also be present for other shapes such as a rectangle, a parallelogram, a rhombus, etc. In such shapes, two diagonal lines intersect at the geometric center of the substrate body. However, in other embodiments, substrate bodies with a more asymmetrical shape and / or with more than four corners can also be used. In such embodiments, more than two diagonal lines and / or at least one center point can be present, with the at least one center point being located at or outside the geometric center of the substrate body.

[0018] According to some embodiments, the support element is a central support element located (at least approximately) in the center of the main surface of the substrate. This can be particularly advantageous for BGA devices with concave distortion, which is caused, for example, during a (hot) reflow process due to a mismatch in the coefficient of thermal expansion (CTE) between different materials of the BGA device and, in particular, a BGA package comprising the described BGA device, whereby, after assembly of the BGA device, the center of the substrate (body) is closest to the further main surface of the component carrier.

[0019] For substrates with a rectangular or even square main surface, the center or a central position of the main surface can be defined by the intersection of two diagonal lines connecting opposite corners of the substrate body. In some embodiments and other geometries, the center point can be defined in other ways. In any case, the central support element can be placed at a position that is closest to the main surface of a component carrier after assembly.

[0020] In some embodiments with a central support element, at least one other "off-center" support element can also be used to provide additional compression protection in at least one other area of ​​the substrate body. At least one further support element can be used to prevent unwanted tilting of the BGA device / BGA package relative to the substrate.

[0021] In some embodiments, at least one of the support elements is a corner support element that is arranged (at least approximately) at a corner of the main surface of the substrate. This can be particularly advantageous for BGA devices with a convex distortion or a complex distortion, whereby, in the assembled state, the respective edge has the smallest distance to the rest of the main surface of the component carrier.

[0022] Advantageously, three or four corner support elements can be provided for stable support. In some embodiments, at least one of the support elements is an edge support element that is arranged (at least approximately) along an edge of the main surface of the substrate. The described at least one edge support element can also be advantageous for a BGA device that has a convex shape. In other words, the support element(s) is arranged along the substrate edges, which may be desirable in some examples where the risk of a short circuit between different solder joints is higher in outer rows due to higher compressive forces acting on the solder joints during reflow soldering.

[0023] In some embodiments, at least two edge support elements are provided, located at opposite edges. In other embodiments, at least four edge support elements are provided, of which at least two are located at two opposite edges and at least two further edge support elements are arranged at two other opposite edges of the substrate. Since the edges of the substrate are generally geometrically well-defined, the edge support elements can be easily and reproducibly applied to suitable positions on the main surface for a batch of BGA devices.

[0024] According to another embodiment, the array of solder connection elements forms a regular pattern of array node positions and at least one support element is formed at an array node position.

[0025] In the case of multiple support elements, each occupying an array node position, in some embodiments each of the multiple support elements is located at its own array node position. This means that an array node position can only be occupied by a single support element. In some embodiments, a single support element can occupy more than one array node position if its size (e.g., diameter) is larger than the plumb bob diameter.

[0026] In some embodiments, at least one of the solder joint elements is replaced by a support element. Therefore, during the fabrication of the described BGA device, the formation of the support elements can occur simultaneously with, or at least close to, the conventional formation of the solder joint elements on the main substrate surface. Due to the thermally stable structure of the support elements, they are formed before the solder joint elements. A "solder joint replacement" can thus be used to implement the described BGA device in a simple and effective manner.

[0027] According to a further embodiment, the at least one support element at an array node position is designed as an electrically conductive support element. This can offer the advantage that not only the (unreplaced) solder joint elements, but also the at least one electrically conductive support element can contribute to high and / or highly flexible connectivity between the described BGA array and the external circuit formed on or in the component carrier.

[0028] According to another embodiment, the array of solder connection elements forms a regular pattern of array node positions and at least one support element is formed between two adjacent array node positions.

[0029] In this configuration, the support structure can be formed without loss of electrical connection, as no "soldered connection element replacement" is required. Therefore, in some embodiments, the connectivity of the ball grid array device with external circuits, which may be located on or within the component carrier, is not affected.

[0030] In some embodiments, the intermediate solder joint element or the intermediate ball support is small (e.g., narrow enough) so as not to interfere with a reflow soldering process. In some embodiments, if the at least one support element contains an electrically insulating material, then even if the solder material of a solder joint element reaches the respective support element, there is no or a reduced risk of a short circuit of adjacent solder joint elements by a support element.

[0031] At least one support element comprises, among other things, (a) a base section adjacent to the substrate; (b) a tip section facing away from the substrate; and (c) a middle section formed between the base section and the tip section. The base section and the tip section are made of, or contain, a solderable material. Furthermore, the middle section is made of, or contains, an electrically conductive material that remains solid at reflow temperatures.

[0032] The solderable material of the two end sections, i.e., the base section and the tip section, allows the BGA component to be permanently electrically connected to external circuits on or in the component carrier not only via the solder joints but also via the respective support element using one and the same (reflow) soldering process. This enables high electrical conductivity to be achieved efficiently.

[0033] At least one support element from the plurality of support elements also includes an insulating jacket that surrounds (at least partially) a side wall of the middle section.

[0034] The described insulating sheath can electrically isolate the inherently conductive support element from adjacent (also conductive) solder joint elements. This effectively prevents unwanted short circuits between at least one such adjacent (also conductive) solder joint element and the respective conductive support element.

[0035] It should be noted that the provision of an insulating sheath can be particularly advantageous when an adjacent compressed solder joint changes its shape to a rounded or bulbous form during a (reflow) soldering process. With the described insulating sheath, the expanded area of ​​such a bulbous solder joint, which without such a sheath would have the highest probability of causing or at least contributing to a short circuit, is insulated. The described insulating sheath thus effectively prevents unwanted short circuits.

[0036] The electrically insulating material exhibits sufficient mechanical stability even at high (reflow) soldering temperatures to provide the desired collapse-resistant support for the solderable joint elements in some embodiments. In some embodiments, the electrically insulating material is a high-temperature plastic or Teflon.

[0037] According to a further embodiment, the electrically insulating material of at least one support element from the plurality of support elements is attached to the main surface of the substrate by means of an adhesive. This can make it possible to attach the respective support element to the substrate in a simple and effective manner.

[0038] According to a further embodiment, at least one support element from the plurality of support elements is or comprises an electronic component. This can offer the advantage that the described support effect can be combined with the possibility of providing electronic functionality even in a spatial area between the substrate of the BGA component and the component carrier.

[0039] To comply with the standard height of a BGA solder pad, the described electronic component should be very small and, in particular, very flat. This requirement can easily be met with a passive electronic component, which typically has only two electrical connections. In this context, a passive component is one that has no power source and / or cannot amplify an electrical signal and / or control another circuit. Examples of passive components include diodes, resistors, inductors (coils), and capacitors.

[0040] According to another embodiment, the electronic component is a capacitor.

[0041] The combination of the described support function of the support structure with a capacitive function that capacitively couples two solder joint elements can improve signal integrity even at a location close to the substrate of the described BGA device. In particular, when, as described in more detail below, an electronic / semiconductor component is mounted on the substrate on a different main surface (opposite) the main surface of the substrate, the electrical (signal) path between the mounted component and the capacitor can be kept very short. This can be especially true when the support capacitor is mounted on the substrate opposite the position of the mounted component.

[0042] According to another aspect of the described technology, an electronic package having the features of claim 12 is provided, comprising, among other things: (a) a ball grid array device according to any aspect or embodiment described above; and (b) a semiconductor chip mounted on another principal surface of the substrate and electrically connected to at least two of the solder joint elements, the other principal surface being opposite the principal surface.

[0043] The electronic package described above is also based on the idea that the support structure of the BGA component described above effectively prevents unwanted (gravity-related) collapse or strong compression of at least one solder joint element during a (reflow) soldering process, with which the BGA electronic package is permanently mounted on a component carrier with corresponding electrical contacts.

[0044] In some embodiments, the semiconductor chip can be arranged in the center or off-center of the substrate body. Furthermore, an electronic package according to the described technology can also contain more than one semiconductor chip. At least one of the at least two chips can be supported at its corners.

[0045] The semiconductor chip spatially occupies a mounting area of ​​the other main surface of the substrate, with the mounting area forming only a portion of the other main surface. Furthermore, the support structure comprises four support elements, each of which is located at an inner corner position of the main surface of the substrate, the inner corner position being opposite a corner of the mounting area with respect to the substrate body.

[0046] Placing the support elements near a corner of the mounting surface or a corner of the mounted semiconductor chip can offer two advantages in some embodiments. A first advantage is that the position of the support elements is precisely defined, which can facilitate the process of forming the support structure. A second advantage is based on simulations performed by the inventor, which surprisingly revealed that, at least for typical dimensions of the substrate and the semiconductor chip (parallel to the plane of the main surface), the inner corner positions provide good support, regardless of whether the ball grid array device or the larger electronic package has a convex, concave, or more complex distortion.Therefore, even without prior knowledge of a possible (undesired) distortion, the described inner corner positions are suitable substrate positions to enable a reliable (reflow) soldering process that leads to a correct and reliable electrical connection.

[0047] According to another embodiment, at least one of the four support elements is a capacitor or contains one.

[0048] By connecting at least one capacitor near the body of the semiconductor chip within the chip's electrical contact structure, high signal integrity can be achieved in the immediate vicinity of the semiconductor chip. This high signal integrity results from the fact that there are no long signal paths to and / or from the semiconductor chip that are not capacitively protected and therefore could be disrupted, for example, by a sudden increase in the supply voltage.

[0049] In some embodiments, the electronic package further comprises a heat spreader formed on the other main surface of the substrate, the heat spreader at least covering the semiconductor chip. The described heat spreader can dissipate heat from the semiconductor chip and protect it from the environment, thus enabling the semiconductor chip to operate reliably. Furthermore, the heat spreader can improve the mechanical stability of the entire electronic package.

[0050] According to further aspects, methods with the features of claim 14 and claim 16, respectively, are provided for manufacturing an electronic assembly. The methods provided include, among others, (a) manufacturing an electronic package as described above; (b) mounting the ball grid array device of the electronic package to another main surface of a component carrier such that at least some of the solder joint elements are in contact with a respective connection pad on the other main surface of a component carrier; (c) heating at least the ball grid array device so that the solder of the solder joint elements becomes liquid (and bonds with connection pads of the component carrier); and (d) cooling at least the ball grid array device so that the liquid solder of the solder joint elements solidifies.

[0051] The described manufacturing processes are also based on the idea that by providing the support structure of the BGA component, an undesirable (gravity-related) excessive compression of at least one solder joint element during a (reflow) soldering process can be effectively prevented.

[0052] The fabrication of an electronic package includes (a) forming the support structure on the main surface; and (b) forming the solder joint elements on the main surface.

[0053] As briefly mentioned above, in some embodiments the support structure is formed before the solder joint elements are formed. This can offer the advantage that the support structure, and in particular the majority of support elements, which must remain stable even at typical reflow soldering temperatures, can be formed at temperatures that are (significantly) higher than a typical reflow temperature. This can make it possible to produce or form a support structure with exceptionally high thermal stability. Since, in this particular embodiment, the solder joint elements are formed after the support structure, they can be formed at a suitable temperature using known and proven sphere formation methods.

[0054] It should be noted that in other embodiments, the solder joint elements are formed before the support structure is formed. In other embodiments, the solder joint elements are formed together with the support structure.

[0055] It should be noted that the embodiments have been described with reference to different subject matter. In particular, some embodiments have been described with reference to process-related claims, while other embodiments have been described with reference to device-related claims. However, the person skilled in the art will understand from the above and the following description that, unless otherwise disclosed, in addition to any combination of features belonging to one type of subject matter, any combination of features relating to different subject matter, in particular features of the process-related claims and features of the device-related claims, is also deemed to be disclosed in this document.

[0056] The aspects defined above and further aspects of the present technology are evident from the exemplary embodiments described below and are explained with reference to these embodiments. The invention is described in more detail below with reference to some exemplary embodiments, to which, however, the invention is not limited. Brief description of the drawing

[0057] Various objects, aspects, features, and benefits of the disclosure are more clearly and better understood by referring to the detailed description in conjunction with the accompanying drawings, in which the same reference numerals consistently denote corresponding elements. In the drawings, identical reference numerals generally denote identical, functionally similar, and / or structurally similar elements. Fig. Figure 1a shows an electronic package with a semiconductor chip, wherein, according to a first embodiment, support elements are arranged below the corners of the semiconductor chip. Fig. Figure 1b shows an electronic package with a substrate, wherein, according to a second embodiment, support elements are arranged below the corners of the substrate. Fig. Figure 1c shows a top view of possible positions for support elements formed on the substrate of an electronic package. Fig. Figure 2a shows an electrically conductive support element with an insulating sheath. Fig. Figure 2b shows an electrically insulating support element according to a comparative example. Fig. Figure 3 shows a detail of a BGA component with a capacitor as a support element. Fig. Figure 4 shows a flowchart of a process for manufacturing an electronic assembly according to one embodiment. Detailed description

[0058] The representation in the drawing is schematic. It should be noted that in different figures, similar or identical elements or features are designated with the same reference numerals or with reference numerals that differ only in the first digit from the corresponding reference numerals. To avoid unnecessary repetition, elements or features that have already been explained in relation to a previously described embodiment will not be explained again later in this description.

[0059] Furthermore, spatially relative terms such as "front" and "back," "top" and "bottom," "left" and "right," etc., are used to describe the relationship of one element to another element or elements, as depicted in the figures. These spatially relative terms can therefore refer to orientations that differ from the orientation shown in the figures. Of course, all these spatially relative terms refer to the orientation shown in the figures only for the sake of simplicity and are not necessarily restrictive, since a device according to one embodiment of the invention can assume different orientations in use than those shown in the figures.

[0060] The systems and methods described here can be used to reduce the possibility of "poor" electrical contacts (e.g., a short circuit between adjacent spherical connectors or a lack of electrical contact between at least one spherical connector and the corresponding contact pad on the component carrier) due to small distances between adjacent spherical connectors. In some embodiments, the systems and methods can be used with large BGA packages, which have an area of, for example, 55 mm x 55 mm or even larger and can be particularly susceptible to electrical bridging with solder material, leading to a short circuit between adjacent spheres.In some embodiments, the systems and methods can be used to reduce undesirable distortion of the BGA package, particularly in a reflow oven in which an assembly comprising the BGA package and a component carrier is heated above a specific reflow soldering temperature.

[0061] In some embodiments, the systems and methods can be used to reduce distortion caused by the corners or edges of the package being lifted during reflow soldering relative to the central area. This distortion results in the balls in the center of the BGA package exhibiting the greatest deformation and / or the balls at the corners or edges not making proper contact. In some embodiments, the systems and methods can be used to reduce distortion caused by the central area being lifted, resulting in an open connection for the central balls and / or deformation-induced short circuits between the ball contacts at the corners or edges of the package. In some embodiments, the systems and methods can be used to reduce the risk of short circuits between adjacent solder balls due to highly compressed balls.

[0062] In some embodiments, the systems and methods can be used to prevent bridging between adjacent solder balls in the liquid state (e.g., during the reflow process) in packages with integrated heat spreaders. The molten solder balls must be able to support the entire weight of the package, including the integrated heat spreader, without collapsing, which significantly increases the package's weight. In some embodiments, the systems and methods are advantageously used in flip-chip BGA packages with copper heat spreader structures that are, for example, 1 mm thick or more. To prevent bridging between adjacent solder balls in their liquid state, e.g., when subjected to a reflow process, the systems and methods, in some embodiments, assist the molten solder balls in supporting the entire weight of the package without collapsing.In some embodiments, the systems and methods are used in BGA packages where an external heat sink is to be attached for heat dissipation. The systems and methods are used to reduce problems associated with the high clamping force required to attach the heat sink and the time-dependent phenomenon of solder ball deformation known as solder creep.

[0063] Fig. Figure 1a shows an electronic package 100a according to a first embodiment. The electronic package 100a comprises a interconnect array device (e.g., a ball grid array (BGA) device 110a) and a semiconductor chip 180. The BGA device 110a comprises a substrate 120 and a number of solder connection elements 130 formed on the lower main surface 124 of the substrate 120. The semiconductor chip 180 is mounted on another main surface 126 of the substrate 120, which is located in Fig. 1a is an upper surface and is opposite the main surface 124.

[0064] According to the embodiment described here, the solder connection elements are solder balls 130. Depending on the application, the substrate 120 can be any suitable support (base) for the semiconductor chip 180, which allows the chip leads 181 of the semiconductor chip 180 to be electrically connected to at least one solder connection element 130 each, in a manner not shown. The substrate 120, embedded in a substrate body 122, can have an electrical circuit forming a so-called redistribution structure. The electrical circuit can include (horizontal) conductor tracks parallel to the main surface 124 and (vertical) vias perpendicular to the main surface 124. The redistribution structure can enable a spatial distribution of the solder connection elements 130 with respect to the chip leads 181.The substrate 120 can, for example, consist of or comprise a printed circuit board (PCB), in particular a multilayer PCB made of organic or ceramic materials.

[0065] As from Fig. As can be seen in Figure 1a, the electronic package 100a further comprises a heat spreader 190, which facilitates heat dissipation from the semiconductor chip 180 and protects the semiconductor chip 180 from environmental influences. The heat spreader 190 can be made of or comprise any suitable thermally conductive material, such as copper, its alloys, or other metals. According to the embodiment described here, the heat spreader 190 is mechanically connected to both the substrate 120 or its top surface 126 and to the top surface of the semiconductor chip 180 by means of an adhesive material 192. In some embodiments, the adhesive material 192 is also made of or comprises a suitable thermally conductive material. Furthermore, the semiconductor chip 180 is mechanically connected to the substrate 120 by means of an underfill material 182.

[0066] According to one aspect of the technology described in this document, the BGA device 110a includes not only the spherical solder joint elements 130 formed on the main surface 124. In order to avoid undesirable excessive compression of the then liquid solder joint elements 130 during a (reflow) soldering process for the permanent assembly and electrical connection of the electronic package 100a to another main surface of a component carrier not shown, e.g. a printed circuit board, a plurality of support elements 140 are formed on the main surface 124 of the substrate 120.

[0067] According to the embodiment described here, the electronic package 100a comprises four support elements 140 located in the areas directly below the corners of the semiconductor chip 180. In the cross-sectional view of Fig. In 1a only two of these “inside corner” support elements 140 can be seen.

[0068] As from Fig. As can be seen in Figure 1a, the support elements 140 and 130 are located at the grid position instead of a solder joint element. This means that in the manufacture of the BGA device 110a, four solder joint elements must each be replaced by a support element 140. However, it should be noted that in other embodiments, at least one support element 140 is arranged between two adjacent solder joint elements 130.

[0069] The support elements 140 have a height that is smaller than the diameter of the spherical solder joint elements 130. Therefore, during a reflow soldering process, the solder joint elements 130 can only be compressed to a height equal to the height of the solder joint elements 130 due to pressure caused, for example, by the weight of the electronic package 110b. When selecting a suitable height for the support elements 140, it should be taken into account that during the soldering process (i) the compression should be strong enough to form a reliable electrical connection, and (ii) the compression should not be so strong that a solder joint element 130 collapses completely. Such complete collapse could, for example, lead to a short circuit due to spherical bridging.

[0070] As mentioned above, the (lateral) position of the support elements 140, at least approximately at the corners of the semiconductor chip 180, can provide effective and suitable support for many different distortion characteristics of the BGA package. In particular, regardless of whether the BGA component 110a exhibits convex or concave distortion, which is caused, for example, during the soldering process due to a CTE mismatch within the electronic package 100a, adequate support can always be provided.

[0071] Fig. Figure 1b shows an electronic package 100b with a BGA device 110b according to another embodiment of the described technology. The electronic package 100b essentially corresponds to the one shown in Figure 1. Fig. The electronic package 100a shown in Figure 1a. The only difference is that on the lower main surface 124 of the substrate 120 of the BGA device 110b, the four support elements 140 are arranged at the four corners of the substrate 120. Here too, due to the cross-sectional view of Fig. 1b only two of the four “outer corner” support elements 140 are shown.

[0072] Fig. Figure 1c shows in a top view areas for support elements on the lower main surface of the substrate 120 of an electronic package according to the described technology.

[0073] In many applications, areas for support elements are located along two diagonal lines connecting opposite corners of the substrate 120. Fig. 1c is a first diagonal line designated by reference numeral 120a and the second diagonal line by reference numeral 120b. Along these diagonal lines 120a, 120b, (a) four inner corner regions 154, used for the support elements 140 of the BGA device 110a, and four outer corner regions 152, used for the support elements 140 of the BGA device 110b, can be arranged. To illustrate the location of the four inner corner regions 154, in Fig. Figure 1c sketches an outline 180a of the semiconductor chip 180. The support elements 140 can have a square, rectangular, hexagonal, pentagonal, oval or circular cross-sectional area.

[0074] It is noted that in BGA packages where the semiconductor chip 180 is not centered on the substrate 120, the four inner corner areas 154 follow the corners of the semiconductor chip 180 and cannot be located on or near the diagonal substrate lines 120a and 120b.

[0075] Other possible areas for the arrangement of (additional) support elements are edge areas 156 near each edge of the substrate 120 and a central area 158 in the (geometric) center of the substrate 120. The edge areas 156 can be located midway between two adjacent corners of the substrate 120. If there is more than one edge area between two adjacent corners, the respective two or more edge areas can be evenly distributed along the respective edge.

[0076] Fig. Figure 2a shows an electrically conductive support element 240a. The support element 240a comprises a base section 242a. The base section 242a comprises a solderable material that makes it possible to electrically connect the support element 240a to a conductor pad (not shown) on the lower main surface 124 of the substrate 120.

[0077] The support element 240a further comprises a conductive central section 246a. The central section 246a is made of, or comprises, a material that is mechanically stable at typical reflow temperatures. Therefore, the central section 246a essentially performs the entire support function during a reflow soldering process.

[0078] Furthermore, the support element 240a includes a tip section 244a, which also comprises a solderable material. This allows the electrically conductive support element 240a to be electrically connected to a conductor pad (not shown) of a component carrier (also not shown), on which the respective electronic package is permanently mounted in the reflow soldering process. The electrically conductive and geometrically stable middle section 246a is, in simplified terms, "clamped" between the two solderable parts 242a and 244a.

[0079] As from Fig. As can be seen in Figure 2a, the conductive support element 240a further comprises a sheath 248a made of an electrically insulating material. The insulating material can be a high-temperature-resistant plastic such as Teflon. The insulating sheath 248a, which surrounds the outer side wall of the central section 246a, enables electrical insulation of the conductive central section 246a from adjacent (also conductive) solder joint elements. Thus, unwanted short circuits between at least one such adjacent (also conductive) solder joint element and the respective conductive support element can be effectively prevented.

[0080] Fig. Figure 2b shows an electrically insulating support element 240b according to a comparative example. Due to its electrical insulating properties, the support element 240b cannot contribute to electrical connections between a semiconductor chip and a component carrier on which the respective electronic package is mounted. An advantage is that the support element 240b does not pose a risk of a short circuit between two solder joint elements.

[0081] As from Fig. As can be seen from Figure 2b, the electrically insulating support element 240b comprises an insulating section 247b, which is made of, or at least includes, a material that is mechanically stable even at typical reflow temperatures. Here too, a high-temperature-resistant plastic or Teflon can be used as such a material. During a reflow soldering process, the insulating part 247b essentially performs the entire support function.

[0082] According to the comparative example described here, the support element 240b or the insulating section 247b is attached to the lower main surface 124 of the substrate 120 by means of a suitable adhesive 243b. In some embodiments, the adhesive 243b is also stable at reflow soldering temperatures.

[0083] Fig. Figure 3 shows a detail of a BGA component with a capacitor 340 serving as a support element. The capacitor 340 should be dimensioned and / or oriented such that its support height is less than the height of the spherical solder joint elements 130.

[0084] As mentioned above, a capacitor, when appropriately connected as a decoupling element, can perform two functions. The first function is decoupling, which is the main aspect of the described technology. The second function is to prevent electrical noise from the power supply from entering the system. In some embodiments, this can ensure high-quality power supply to the semiconductor chip.

[0085] Fig.Figure 4 shows a flowchart for a method for manufacturing an electronic assembly according to one embodiment. According to the embodiment described here, the method is described with six main operations. It should be clear to those skilled in the art that, upon closer examination, the manufacturing method can be described with more operations than those described here. Suitable additional operations can be performed before, between, and / or after the main operations described.

[0086] In a first step S10, an electronic package is provided, which is a precursor to, for example, the BGA electronic packages 100a or 100b. In particular, the provided electronic package does not yet include the spherical solder joint elements 130 and the support elements 140, compared to the electronic packages 100a / 100b.

[0087] In a second step (S20), a support structure with a suitable number and type of support elements is formed on the lower main surface of the substrate of the respective BGA component. This formation can take place at temperatures that, at least for a certain period, are higher than a typical reflow soldering temperature. This allows for the production of very stable support elements.

[0088] In a third step (S30), spherical solder joint elements (around the support elements) are also formed on the lower main surface of the substrate. The usual methods for forming solder balls can be used.

[0089] In a fourth step, S40, the BGA component or the larger electronic package is mounted onto a component carrier. A standard SMD placement machine can be used for this assembly process.

[0090] In a fifth step, S50, a reflow soldering process is performed. The BGA component or larger electronic package is heated to a temperature above the melting point of the solder material used for the solder joints. This process can be carried out in a standard reflow oven.

[0091] As described in detail above, the support elements prevent the spherical solder joint elements from collapsing.

[0092] In a sixth step, S60, the reflow soldering process is stopped by lowering the temperature of the BGA component / electronic package. This temperature reduction can be achieved by cooling the oven. However, in some embodiments, the temperature reduction is simply accomplished by moving / transporting the BGA component / electronic package out of the reflow oven.

Claims

[1] A connecting array device (110a) comprising: a substrate (120) with a substrate body (122) and a main surface (124); an array of solder joint elements (130) formed on the main surface; and a support structure (140, 240a, 240b, 340) formed on the main surface (124), wherein the support structure (140, 240a, 240b, 340) is configured to maintain a predefined distance between the main surface (124) of the substrate (120) and another main surface of a component carrier on which the interconnect array device (110a) is mounted during a soldering process, and the support structure (140, 240a, 240b, 340) comprises at least one support element (140, 240a, 240b, 340); wherein the support structure (140, 240a, 240b, 340) comprises a plurality of support elements (140, 240a, 240b, 340) that are spatially separated from each other; at least one support element (240a) from the plurality of support elements (140, 240a, 240b, 340) has the following characteristics: a base section (242a) adjacent to the substrate (120); a tip section (244a) facing away from the substrate (120); and a middle section (246a) formed between the base section (242a) and the tip section (244a); wherein the base section (242a) and the tip section (244a) are made of or comprise a solderable material and wherein the middle section (246a) is made of or comprises an electrically conductive material that remains solid at reflow temperatures; and at least one support element (240a) from the plurality of support elements (140, 240a, 240b, 340) further comprising an insulating jacket (248a) that surrounds a side wall of the middle section (246a). [2] The connecting array device (110a) according to claim 1, wherein at least some of the support elements (140, 240a, 240b, 340) are arranged at least approximately on a diagonal line connecting opposite corners of the substrate body (122). [3] The connecting array device (110a) according to claim 1, wherein the support element (140, 240a, 240b, 340) is a central support element located at least approximately in the middle of the main surface (124) of the substrate (120). [4] The connecting array device (110a) according to claim 2, wherein at least one of the support elements (140, 240a, 240b, 340) is a corner support element located at a corner of the main surface (124) of the substrate (120). [5] The connecting array device (110a) according to claim 1, wherein at least one of the support elements (140, 240a, 240b, 340) is an edge support element located along an edge of the main surface (124) of the substrate (120). [6] The connection array device (110a) according to claim 1, wherein the array of solder connection elements (130) forms a regular pattern of array node positions and wherein at least one support element (140, 240a, 240b, 340) is formed at an array node position, wherein the at least one support element (140, 240a, 240b, 340) formed at an array node position is preferably an electrically conductive support element. [7] The connection array device (110a) according to claim 1, wherein the array of solder connection elements (130) forms a regular pattern of array node positions and wherein at least one support element (140, 240a, 240b, 340) is formed between two adjacent array node positions. [8] The connecting array device (110a) according to claim 1, wherein at least one support element from the plurality of support elements (140, 240a, 240b, 340) has an electrically insulating material or consists only of such material. [9] The interconnect array device (110a) according to claim 8, wherein the electrically insulating material of the at least one support element from the plurality of support elements (140, 240a, 240b, 340) is attached to the main surface (124) of the substrate (120) by means of an adhesive. [10] The interconnect array device (110a) according to claim 1, wherein at least one support element from the plurality of support elements (140, 240a, 240b, 340) is or comprises an electronic component. [11] The interconnect array device (110a) according to claim 10, wherein the electronic component is a capacitor. [12] An electronic package (100a) comprising: a ball grid array device (110a) comprising the following a substrate (120) with a substrate body (122) and a main surface (124); an array of solder joint elements (130) formed on the main surface (124); and a support structure (140, 240a, 240b, 340) formed on the main surface (124), wherein the support structure (140, 240a, 240b, 340) is configured to maintain a predefined distance between the main surface (124) of the substrate (120) and another main surface of a component carrier on which the ball grid array (110a) is mounted during a soldering process, and the support structure (140, 240a, 240b, 340) comprises at least one support element (140, 240a, 240b, 340); and a semiconductor chip (180) mounted on another main surface (126) of the substrate (120) and electrically connected to at least two of the solder connection elements (130), wherein the other main surface (126) is opposite the main surface (124); wherein the semiconductor chip (180) spatially occupies a mounting area of ​​the other main surface (126) of the substrate (120), the mounting area forming only a part of the other main surface (126), and the support structure (140, 240a, 240b, 340) comprises four support elements (140), each of the four support elements (140) being formed at an inner corner position of the main surface (124) of the substrate (120), the inner corner position being opposite a corner of the mounting area. [13] The electronic package (100a) according to claim 12, wherein at least one of the four support elements (140) has or consists of a capacitor. [14] A method for manufacturing an electronic assembly, the method comprising: Manufacturing an electronic package (100a) comprising the following: a connecting array device (110a), comprising: a substrate (120) with a substrate body (122) and a main surface (124); an array of solder joint elements (130) formed on the main surface (124); and a support structure (140, 240a, 240b, 340) formed on the main surface (124), wherein the support structure (140, 240a, 240b, 340) is configured to maintain a predefined distance between the main surface (124) of the substrate (120) and another main surface of a component carrier on which the interconnect array device is mounted during a soldering process; and a semiconductor chip (180) mounted on another main surface (126) of the substrate (120) and electrically connected to at least two of the solder connection elements (130), the other main surface (126) being opposite the main surface (124); Mounting the connection array device (110a) of the electronic package (100a) on another main surface of a component carrier, such that at least some of the solder connection elements (130) are in contact with a respective connection pad on the other main surface of a component carrier; Heating at least the connection array device (110a) so that the solder of the solder joint elements (130) becomes liquid; and Cooling at least of the interconnect array device (110a), so that the liquid solder of the solder joint elements (130) becomes solid; the support structure (140, 240a, 240b, 340) comprises a plurality of support elements (140, 240a, 240b, 340) that are spatially separated from each other; at least one support element (240a) from the plurality of support elements (140, 240a, 240b, 340) has the following characteristics: a base section (242a) adjacent to the substrate (120); a tip section (244a) facing away from the substrate (120); and a middle section (246a) formed between the base section (242a) and the tip section (244a); wherein the base section (242a) and the tip section (244a) are made of or comprise a solderable material and wherein the middle section (246a) is made of or comprises an electrically conductive material that remains solid at reflow temperatures; and at least one support element (240a) from the plurality of support elements (140, 240a, 240b, 340) further comprising an insulating jacket (248a) that surrounds a side wall of the middle section (246a). [15] The method for manufacturing an electronic assembly according to claim 14, wherein manufacturing an electronic package (100a) comprises: Forming the support structure (140, 240a, 240b, 340) on the main surface (124); and Forming the solder joint elements (130) on the main surface (124). [16] A method for manufacturing an electronic assembly, the method comprising: Manufacturing an electronic package (100a) comprising the following: a connecting array device (110a), comprising: a substrate (120) with a substrate body (122) and a main surface (124); an array of solder joint elements (130) formed on the main surface (124); and a support structure (140, 240a, 240b, 340) formed on the main surface (124), wherein the support structure (140, 240a, 240b, 340) is configured to maintain a predefined distance between the main surface (124) of the substrate (120) and another main surface of a component carrier on which the interconnect array device is mounted during a soldering process; and a semiconductor chip (180) mounted on another main surface (126) of the substrate (120) and electrically connected to at least two of the solder connection elements (130), the other main surface (126) being opposite the main surface (124); Mounting the connection array device (110a) of the electronic package (100a) on another main surface of a component carrier, such that at least some of the solder connection elements (130) are in contact with a respective connection pad on the other main surface of a component carrier; Heating at least the connection array device (110a) so that the solder of the solder joint elements (130) becomes liquid; and Cooling at least of the interconnect array device (110a), so that the liquid solder of the solder joint elements (130) solidifies; wherein the semiconductor chip (180) spatially occupies a mounting area of ​​the other main surface (126) of the substrate (120), the mounting area forming only a part of the other main surface (126), and the support structure (140, 240a, 240b, 340) comprises four support elements (140), each of the four support elements (140) being formed at an inner corner position of the main surface (124) of the substrate (120), the inner corner position being opposite a corner of the mounting area.

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