Surface mounting techniques using support members
By using support members and adhesive layers in electronic assembly, the problem of BGA welded joints being prone to break under stress is solved, and the strengthening of welded joints and the stability of electronic assembly is achieved.
Patent Information
- Application Number
- CN202380015694.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-10-09
- Publication Date
- 2025-06-13
AI Technical Summary
Ball Grid Array (BGA) welded joints are prone to breaking under mechanical and thermal stresses, resulting in failure of electronic assembly.
Using a support member, including a support frame, a first adhesive layer and a second adhesive layer, the support member is attached to the component through a first adhesive layer, the support member is mounted to the substrate through a second adhesive layer, and reflow soldering and adhesive curing are performed at a temperature higher than the melting point of the solder ball.
The strength of the welded joint is enhanced, the mechanical and thermal stability of electronic assembly is improved, and the risk of welded joint breaking under stress is avoided.
Smart Images
Figure CN120153766A_ABST
Abstract
Description
Background Art
[0001] Surface Mount Technology (SMT) is a technology used for manufacturing electronic assemblies, where components are directly mounted onto the surface of a substrate such as a printed circuit board (PCB). For the vast majority of electronic devices, components are specifically designed to be directly mounted onto the substrate rather than hardwired to it. SMT enables increased manufacturing automation, thereby reducing costs and improving quality, such as higher component density and smaller components for mounting, while having better performance under stress.
[0002] Ball Grid Array (BGA) technology is a surface mount method mainly used for flip chips with the increasing demand for high-density mounting. BGA includes an array of small-sized metal solder balls arranged on the bottom surface of a component. Correspondingly, the substrate includes an array of contact pads having the same pattern that matches the solder balls. Placing the component on the substrate is achieved through a reflow soldering process, in which the solder balls are heated, for example, using a reflow oven or through an infrared heater, to melt. Surface tension causes the melted solder balls to hold the component aligned with the substrate at a certain separation distance. After the solder balls cool and solidify, a solder joint is formed between the component and the substrate.
[0003] The solder balls connecting the substrate and the component are prone to breakage when subjected to mechanical and thermal stresses, which in turn may cause the failure of the entire device. For example, bending, flexing, vibration between the substrate and the BGA, as well as differences in the coefficient of thermal expansion, may potentially cause the solder joint to break. There is a need to develop viable and effective technologies to strengthen the solder joint to prevent failure. Summary of the Invention
[0004] The present Summary of the Invention is provided to introduce a series of concepts further described in the detailed description below. The present Summary of the Invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to help limit the scope of the claimed subject matter.
[0005] In some aspects, the technologies described herein relate to a method of manufacturing an electronic assembly, the method comprising: forming a support member by applying a first adhesive layer to an inner surface of a support frame and a second adhesive layer to a bottom surface of the support frame; attaching the support member to a component including a ball grid array of solder balls through the first adhesive layer such that the inner surface of the support frame covers a portion of a first side surface of the component and a portion of the bottom surface of the component; mounting the support member to a substrate including an array of contact pads, the pattern of the contact pads matching the ball grid array on the component, through the second adhesive layer; and curing the second adhesive layer, wherein the curing includes: connecting the solder balls to the contact pads by reflow soldering the solder balls at a temperature higher than the melting point of the solder balls.
[0006] In some aspects, the techniques described herein relate to a method in which an inner surface of a support frame covers a portion of a second side surface of a component, the second side surface being adjacent to a first side surface and a bottom surface of the component.
[0007] In some aspects, the techniques described herein relate to a method in which an inner surface of a support frame covers a portion of a top surface of a component.
[0008] In some aspects, the techniques described herein relate to a method that further includes attaching a support member to a corner of a component.
[0009] In some aspects, the techniques described herein relate to a method that further includes attaching additional support members to one or more corners and / or one or more edges of a component.
[0010] In some aspects, the techniques described herein relate to a method that further includes semi-curing at least one of a first adhesive layer and a second adhesive layer before mounting a support member to a substrate.
[0011] In some aspects, the techniques described herein relate to a method in which a support frame is made of a metal or a metal alloy.
[0012] In some aspects, the techniques described herein relate to an electronic assembly that includes: a component including a ball grid array of solder balls; a substrate including an array of contact pads, the pattern of the array of contact pads matching the ball grid array on the component; and a support member between the component and the substrate, wherein the support member includes: a support frame; a first adhesive layer on an inner surface of the support frame; and a second adhesive layer on a bottom surface of the support frame, wherein the inner surface of the support frame covers a portion of a first side surface and a portion of a bottom surface of the component, and wherein the support member is attached to the component through the first adhesive layer and to the substrate through the second adhesive layer.
[0013] In some aspects, the techniques described herein relate to an electronic assembly in which an inner surface of a support frame covers a second side surface of a component, the second side surface being adjacent to a first side surface and a bottom surface of the component.
[0014] In some aspects, the techniques described herein relate to an electronic assembly in which an inner surface of a support frame covers a portion of a top surface of a component.
[0015] In some aspects, the techniques described herein relate to an electronic assembly in which a support frame is attached to a corner of a component.
[0016] In some aspects, the techniques described herein relate to an electronic assembly in which additional support members are attached to one or more corners and / or one or more edges of a component.
[0017] In some aspects, the techniques described herein relate to an electronic assembly in which a support frame is made of metal or a metal alloy.
[0018] Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 A cross-sectional view of an electronic assembly in accordance with one or more embodiments of the present disclosure is shown.
[0020] Figure 2 An arrangement of support members in accordance with one or more embodiments of the present disclosure is shown.
[0021] Figures 3A to 3F A support member in accordance with one or more embodiments of the present disclosure is shown.
[0022] Figure 4 A cross-sectional view of an electronic assembly in accordance with one or more embodiments of the present disclosure is shown.
[0023] Figure 5 is a flow chart of a surface mounting method for an electronic assembly in accordance with one or more embodiments of the present disclosure. DETAILED DESCRIPTION
[0024] The detailed embodiments of the present disclosure will now be described below with reference to the accompanying drawings. For consistency, the same elements in the various figures are denoted by the same reference numerals.
[0025] In the following detailed description of embodiments of the present disclosure, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.
[0026] One or more embodiments of the present disclosure relate to a support member, an electronic assembly including the support member, and a surface mounting method for an electronic assembly including the support member. Embodiments of the present disclosure provide advantageous effects in strengthening solder joints, enhancing the resistance of the electronic assembly, and absorbing the thermal expansion mismatch between components and the substrate in the electronic assembly, thereby avoiding breakage when subjected to mechanical and thermal stresses. Additionally, embodiments of the present disclosure enable one-step reflow soldering and adhesive curing, including an electronic assembly and method using a support member with double-sided coating between components and the substrate.
[0027] In the present disclosure, the thickness direction of the substrate is defined as the vertical direction Z. One direction perpendicular to the vertical direction Z represents the direction X, and the other direction perpendicular to the two directions of the vertical direction Z and the direction X represents the direction Y. Along the vertical direction Z, the component side and the substrate side are respectively referred to as the upper (top) side and the lower (bottom) side. The horizontal plane refers to any plane along the directions X and Y, such as a plane parallel to the top surface of the substrate. The vertical plane refers to any plane along the direction Z, such as a plane perpendicular to the top surface of the substrate. In addition, the plan view means viewing the target object from the vertical direction Z. The sectional view refers to the sectional view of the target object when cut along a plane in the vertical direction Z.
[0028] "Electronic assembly" in the present disclosure refers to the process of collecting, soldering, and / or integrating electronic components and circuits to perform one or more tasks, and the product manufactured through such a process. Figure 1 An electronic assembly 100 according to one or more embodiments of the present disclosure is shown. The electronic assembly 100 includes a component 110, a substrate 120, and a support member 130.
[0029] The component 110 may be an electronic component, which may be any basic discrete device or physical entity in an electronic system for influencing electrons and / or their associated fields, or may be an integrated circuit (IC) component, which is an assembly of electronic components on a flat semiconductor material (e.g., a silicon wafer) connected together to achieve a common goal. Examples of the component 110 may include resistors, capacitors, inductors, discrete semiconductors, and integrated circuits. In one or more embodiments, the component 110 may be a microprocessor, such as a central processing unit.
[0030] An array of solder balls 111 (also known as BGA) can be soldered to the bottom surface of component 110 facing substrate 120. The solder balls 111 are solid metal spheres, the diameter of which varies based on the component design, depending on the desired separation distance to prevent bridging defects or short circuits and / or the desired electron density to ensure high performance. The diameter of the solder balls 111 can range from about 100 μm to about 1000 μm, or from about 200 μm to about 800 μm. The solder balls 111 can be made of metal or metal alloy and can include, for example, tin (Sn), silver (Ag), copper (Cu), bismuth (Bi), or combinations thereof.
[0031] Substrate 120 includes an array of contact pads 121 having the same pattern as the solder balls 111. The contact pads 121 can be made of metal or metal alloy such as tin (Sn), silver (Ag), gold (Au), copper (Cu), nickel (Ni), palladium (Pd), or combinations thereof.
[0032] Component 110 and substrate 120 are connected by a reflow soldering process in which the solder balls 111 are heated to melting, for example, using a reflow oven or by an infrared heater, so that surface tension holds component 110 aligned with substrate 120 at a separation distance defined by the size of the solder balls 111. After the solder balls cool and solidify, each contact pad 121 is connected to the corresponding solder ball 111, such that component 110 and substrate 120 are electrically connected through the solder balls 111 and contact pads 121.
[0033] Support member 130 includes a support frame 131, a first adhesive layer 133, and a second adhesive layer 134. The support frame 131 includes a bottom horizontal portion disposed between the bottom surface of component 110 and the top surface of substrate 120, and a vertical portion covering a part of the side surface of component 110. The support frame 131 can be made of a rigid material. In one or more embodiments, the support frame 131 can be made of metal or metal alloy (such as aluminum, magnesium, and stainless steel) or polymer.
[0034] The first adhesive layer 133 is disposed at the inner surface of the support frame 131 facing the component 110. The inner surface covers a part of the bottom surface of the component 110 and a part of the side surface of the component 110. The second adhesive layer 134 is disposed at the bottom surface of the support frame 131, between the support frame 131 and the top surface of the substrate 120. An adhesive can be used for the first adhesive layer 133 and / or the second adhesive layer 134, and has fluidity at room temperature or low temperature and cures at an elevated temperature to form a uniform and void-free layer. The adhesives used for the first adhesive layer 133 and the second adhesive layer 134 can be the same or can be different. The adhesive can be a polymer, such as epoxy resin, silicone resin, and acrylic acid. In one or more embodiments, the adhesives used for the first adhesive layer 133 and the second adhesive layer 134 can be heat-curable one-component adhesives, such as epoxy resin. In other embodiments, one of the adhesives used for the first adhesive layer and the second adhesive layer is a heat-curable and semi-curable two-component adhesive under ultraviolet light or heat, while the other adhesive used for the first adhesive layer and the second adhesive layer is a heat-curable one-component adhesive. For example, the first adhesive used in the first adhesive layer can be composed of acrylic acid, and the second adhesive used in the second adhesive layer can be composed of epoxy resin.
[0035] As Figure 1 shown, the component 110 and the substrate 120 are electrically connected through solder balls 111 and contact pads 121, and are structurally supported by the support member 130. The support member 130 can be disposed, for example, at the edge and / or corner of the component because the edge and / or corner may experience higher mechanical or thermal stress. Figure 2 The setting of the support member 130 at the edge and corner of the component is shown.
[0036] As Figure 2 shown, the component 210 can include an array of solder balls 211 at the bottom surface of the component 210. The support member can be disposed at the corner of the component 210, such as the support member 230a, or at the edge of the component, such as the support member 230b. The support member can be disposed without disturbing the solder balls and can be adjusted based on the design of the electronic device. In one or more embodiments, a single-piece support member can be disposed to cover one or more corners and edges of the component 210. For example, a single-piece support member can cover all four corners and four edges of the component 210. In one or more embodiments, multiple support members can be dispersedly disposed at each corner and / or each edge of the component 210, and the number of support members can be adjusted as needed.
[0037] The support member 230a can include a support frame 231a, a first adhesive layer ( Figure 2not shown) and a second adhesive layer 234. The support frame 231a may include a first vertical sheet 235a covering a portion of the first side surface of the component 210, a second vertical sheet 236a covering a portion of the second side surface of the component 210, and a bottom horizontal sheet 237a covering a portion of the bottom surface of the component 210. The first side surface, the second side surface, and the bottom surface of the component 210 are adjacent to each other at the corners of the component 210. The upper edge of the first vertical sheet 235a and / or the upper edge of the second vertical sheet 236a may be aligned with the top surface of the component 210. Alternatively, in some implementations, the upper edges of the first vertical sheet 235a and the second vertical sheet 236a may extend above or below the top surface of the component 210. The bottom horizontal sheet 237a may be coupled to the first vertical sheet 235a at the lower edge of the first vertical sheet 235a. The lower edge of the second vertical sheet 236a may be aligned with the bottom surface of the component 210. Alternatively, in some implementations, the lower edge of the second vertical sheet 236a may extend above or below the bottom surface of the component 210. The first vertical sheet 235a, the second vertical sheet 236a, and the bottom horizontal sheet 237a may be manufactured by bending a single piece of sheet or by molding multiple sheets together. As Figure 2 shown, the connection between any two sheets may have a rounded edge. Alternatively, in other implementations, the connection between the sheets may have an acute edge or a right-angled edge. As Figure 2 shown, the second vertical sheet 236a and the bottom horizontal sheet 237a may be separated from each other and may be coupled to each other in other implementations.
[0038] The support member 230a may be attached to the component 210 through a first adhesive layer (not shown) and to a substrate (not shown) through the second adhesive layer 234. For Figure 2 the support member 230a shown, the first adhesive layer is applied to the inner surface of the support frame 231a. The inner surface includes the surfaces of the first vertical sheet 235a, the second vertical sheet 236a, and the bottom horizontal sheet 237a facing the component. That is, the inner surface of the support frame 231a covers a portion of the first side surface, a portion of the second side surface, and the bottom surface of the component 210. Although the first side surface and the second side surface of the component are shown as vertical in Figure 2 this is not intended to be restrictive. In some implementations, the side surfaces of the component may be angled or have other shapes, and the support frame may be modified to accommodate the shape of the component.
[0039] The support member 230b may include a support frame 231b, a first adhesive layer ( Figure 2(not shown in the figure) and a second adhesive layer 234. The support frame 231b may include a first vertical sheet 235b covering a part of the first side surface of the component 210, and a bottom horizontal sheet 237b covering a part of the bottom surface of the component 210. The upper edge of the first vertical sheet 235b may be aligned with the top surface of the component 210. Alternatively, in some implementations, the upper edge of the first vertical sheet 235b may extend above or below the top surface of the component 210. The bottom horizontal sheet 237b may be coupled to the first vertical sheet 235b at the lower edge of the first vertical sheet 235b. The first vertical sheet 235a and the bottom horizontal sheet 237a may be manufactured by bending a single piece of sheet or by molding multiple sheets together. As Figure 2 shown, the connection between the sheets may have rounded edges. Alternatively, in other implementations, the connection between the sheets may have acute and / or right-angled edges.
[0040] The support member 230b may be attached to the component 210 through a first adhesive layer (not shown) and to the substrate (not shown) through the second adhesive layer 234. For Figure 2 the support member 230b shown, the first adhesive layer is applied to the inner surface of the support frame 231b. The inner surface includes the surfaces of the first vertical sheet 235b and the bottom horizontal sheet 237b facing the component. That is, the inner surface of the support frame 231b covers the bottom surface of the component 210 and a part of the first side surface. In one or more embodiments, the first side surface is vertical such that the first vertical sheet 235a is vertically arranged.
[0041] The support members 230a and 230b are mounted to the substrate ( Figure 2 (not shown in the figure)) through the second adhesive layer 234. The adhesive for the second adhesive layer 234 may be fluid at room temperature or low temperature and cure at an elevated temperature to form a uniform and void-free layer. The second adhesive layer 234 is shown as droplets in Figure 2 the figure. However, those of ordinary skill in the art will recognize that the configuration of the second adhesive layer 234 is not limited by the drawings. The second adhesive layer 234 may be droplets, a film, or any other configuration known in the art. In some implementations, the adhesive in the liquid phase may be applied by drop casting, spraying, or electrodeposition. In some implementations, the adhesive may be applied by dipping the support frame into an adhesive solution and then performing a semi-curing process to fix the adhesive. In some implementations, the adhesive is applied only by dispensing droplets on the surface of the sheet.
[0042] Each of the support members 230a and 230b represents one or more embodiments of the present disclosure. Although Figure 2Only two configurations are shown, but those of ordinary skill in the art will recognize that many modifications can be made in the exemplary embodiments without materially departing from the present invention, and various shapes, sizes, materials, and arrangements of the support members can be applied.
[0043] Figures 3A to 3F Various configurations for supporting a frame are shown. According to one or more embodiments, the support member can be disposed at a corner or an edge of the component. Thus, the support frame can be designed to have a plurality of sheets having a shape adapted to the corner or the edge. For example, Figure 3A The support member shown includes two vertical sheets and a bottom horizontal sheet. When the support member is disposed in the electronic assembly described herein and cut by Plane I, the cross-sectional view of the support member can have a cross-sectional view as Figure 1 shown. Figure 3A The support member of Figure 2 has the same configuration as the support member 230a disposed at the corner of the component shown in
[0044] In one or more embodiments, the support member includes a vertical sheet and a bottom horizontal sheet, as Figure 3B shown. The support member has the same configuration as the support member 230b disposed at the edge shown in Figure 2 shown.
[0045] Although the sheets forming Figure 3A and Figure 3B of the support frame have a rectangular shape, this is not intended to be limiting in this regard. According to one or more embodiments, as Figure 3C shown, the support member can have two vertical sheets having a rectangular shape and a bottom horizontal sheet having a polygonal shape.
[0046] In one or more embodiments, the support frame includes a top sheet covering the top surface of the component. For example, Figure 3D shown is a support frame having two vertical sheets, a bottom horizontal sheet, and a top horizontal sheet. The top horizontal sheet is coupled to the upper edges of the two vertical sheets. Figure 3E shown is a support frame having a vertical sheet, a bottom horizontal sheet, and a top horizontal sheet coupled to the upper edge of the vertical sheet. Figure 3F shown is a support frame having two vertical sheets, a bottom horizontal sheet, and a top horizontal sheet. Both the bottom horizontal sheet and the top horizontal sheet have a polygonal shape.
[0047] The cross-sectional view of the support member having a top horizontal sheet can have a configuration as Figure 4 shown. For example, when the electronic assembly includes Figure 3D the support member and is cut by Plane II, the cross-sectional view of the electronic assembly can be atFigure 4 is shown in Figure 4 FIG. shows an electronic assembly 400 that includes a support frame having a top horizontal sheet. One or more identical elements in the figures are represented by the same reference numerals and will not be described again here.
[0048] The electronic assembly 400 includes a component 410, a substrate 420, and a support member 430. An array of solder balls 411 is soldered to the bottom surface of the component 410 facing the substrate 420. An array of contact pads 421 is provided on the substrate 420 having the same pattern as the solder balls 411. The component 410 and the substrate 420 are connected by a reflow soldering process. After the solder balls 411 are cooled and solidified, each contact pad 421 is connected to a corresponding solder ball 411 such that the component 410 and the substrate 120 are electrically connected through the solder balls 411 and the contact pads 421.
[0049] The support member 430 includes a support frame 431, a first adhesive layer 433, and a second adhesive layer 434. The support frame 431 has a bottom horizontal portion disposed between the bottom surface of the component 410 and the top surface of the substrate 420, a top horizontal portion disposed on the top surface of the component 410, and a vertical portion covering a part of the side surface of the component 410.
[0050] The first adhesive layer 433 is disposed at the inner surface of the support frame 431 facing the component 410. The inner surface covers a part of the bottom surface of the component 410, a part of the top surface of the component 410, and a part of the side surface of the component 410. The second adhesive layer 434 is disposed at the bottom surface of the support frame 431 between the support frame 431 and the top surface of the substrate 420. One or more adhesives can be used for the first adhesive layer 433 and / or the second adhesive layer 434, which have fluidity at room temperature or low temperature and cure at elevated temperature to form a uniform and void-free layer.
[0051] The component 410 and the substrate 420 are electrically connected through the solder balls 411 and the contact pads 421 and are structurally supported by the support member 430. The support member 430 can be disposed, for example, at the edges and / or corners of the component 410 because the edges and / or corners may experience higher mechanical or thermal stresses.
[0052] Although Figures 1 to 4 only several configurations are shown in, those of ordinary skill in the art will recognize that the top horizontal sheet, the bottom horizontal sheet, and one or more vertical sheets of the support frame can have other shapes and sizes. The sheets in the support frame can be integrated into one piece, for example, by bending a single piece of sheet or by welding multiple sheets.
[0053] The thickness of each sheet in the support frame depends on the design of the electronic assembly and can range from about 100 μm to about 1000 μm or from about 200 μm to about 600 μm. The thickness of the first adhesive layer can range from about 20 μm to about 200 μm. The thickness of the second adhesive layer can range from about 20 μm to about 200 μm.
[0054] The electronic assembly described in one or more embodiments can be manufactured by Figure 5 the surface mounting method shown in the flowchart of. The surface mounting method can include step S501 of forming a support member by applying a first adhesive layer to the inner surface of the support frame and a second adhesive layer to the bottom surface of the support frame.
[0055] The adhesive for the first adhesive layer and the adhesive for the second adhesive layer can be the same or can be different. In some implementations, the adhesive in a liquid phase can be applied by drop casting, spraying, or electrodeposition. In some implementations, the adhesive can be applied by dipping the support frame into an adhesive solution and then performing a semi-curing process to fix the adhesive and prevent the adhesive from falling off or misaligning during the assembly process. In some implementations, the adhesive is applied only by dispensing droplets on the surface of the support frame. The first adhesive layer and the second adhesive layer can be applied one after another or can be applied simultaneously.
[0056] Figure 5The surface mounting method may include step S502 of attaching a support member to a component including a ball grid array with solder balls through a first adhesive layer such that the inner surface of the support frame covers a part of the first side surface and a part of the bottom surface of the component. In some implementations, the inner surface of the support frame also covers a part of the second side surface and / or a part of the top surface of the component. The inner surface of the support frame may include all surfaces of the sheet facing the component. The support member may be attached to one or more corners and / or one or more edges of the component because these areas may experience higher mechanical or thermal stresses. In one or more embodiments, multiple support members may be attached to the corners (e.g., all four corners) and / or edges of the component. For example, four support members may be attached to the four corners of the component, and a desired number (e.g., one, two, three, etc.) of support members may be attached to each edge of the component. The shape, size, arrangement, and number of the support members may vary in practical applications. The support frame may be an integrated structure including multiple sheets. One or more sheets may be vertical to cover a part of the side surface of the component, or may be horizontal to cover a part of the bottom surface and / or the top surface of the component. In one or more embodiments, the attachment may include aligning the support member and the component using any known technique in the art. In one or more embodiments, the attachment may include a pick-and-place process known in the art.
[0057] Figure 5 The surface mounting method may include step S503 of mounting the support member to a substrate including a contact pad array, the pattern of which matches the ball grid array on the component, through a second adhesive layer. In one or more embodiments, the mounting may be performed in a manner similar to attaching the support member to the component.
[0058] During the attachment in S502 and the mounting in S503, the adhesive in the first adhesive layer and / or the second adhesive layer has fluidity to fill the gaps between the component and the support member and between the substrate and the support member, respectively. In one or more embodiments, before mounting the support member to the substrate, at least one of the first adhesive layer and the second adhesive layer may be semi-cured such that the adhesive is fixed on the surface of the support frame but still has the fluidity to fill the gaps. Figure 5 The surface mounting method may include step S504 of curing the first adhesive layer and the second adhesive layer. The curing of the first adhesive layer and the second adhesive layer may be performed simultaneously with the reflow soldering of the solder balls. The heating system may include a reflow oven and an infrared lamp to provide an elevated temperature for curing and reflow soldering.
[0059] The heating curve for curing and reflow soldering can include a first stage (when the temperature increases from about room temperature to an elevated temperature above the melting point of the solder balls), a second stage (when the temperature is maintained at the elevated temperature for a period of time), and a third stage (cooling). In the first stage, the temperature can increase at a rate of about 1 °C to 5 °C per second or about 1 °C to 3 °C per second. The elevated temperature can be in the range of about 140 °C to about 250 °C. The solder balls can melt at the elevated temperature, and surface tension causes the molten solder balls to hold the component in alignment with the substrate at a certain separation distance. After the solder balls cool and solidify, each contact pad is connected to the corresponding solder ball, such that the component and the substrate are electrically connected through the solder balls and the contact pads. At the same time, the second adhesive layer is cured, fixing the support member to both the component and the substrate, thereby providing beneficial effects in terms of strengthening the solder joints, enhancing the resistance of the electronic assembly, and absorbing the thermal expansion mismatch between the component and the substrate, thus avoiding breakage when subjected to mechanical and thermal stresses.
[0060] Although only several configurations are shown in the drawings, those of ordinary skill in the art will recognize that many modifications can be made in the exemplary embodiments without materially departing from the invention. Accordingly, all such modifications are intended to be included within the scope of the present disclosure as defined by the appended claims.
Claims
1. A method of manufacturing an electronic assembly, comprising: forming a support member by applying a first adhesive layer to an inner surface of a support frame and a second adhesive layer to a bottom surface of the support frame; attaching the support member to a component of a ball grid array including solder balls through the first adhesive layer such that the inner surface of the support frame covers a part of a first side surface of the component and a part of a bottom surface of the component; mounting the support member to a substrate including a contact pad array through the second adhesive layer, the pattern of the contact pad array matching the pattern of the ball grid array; and curing the first adhesive layer and the second adhesive layer, wherein the curing includes: connecting the solder balls to the contact pads by reflow soldering the solder balls at a temperature higher than the melting point of the solder balls.
2. The method according to claim 1, wherein the inner surface of the support frame covers a part of a second side surface of the component, the second side surface being adjacent to the first side surface and the bottom surface of the component.
3. The method according to claim 1 or 2, wherein the inner surface of the support frame covers a part of a top surface of the component.
4. The method according to any one of claims 1 to 3, further comprising: attaching the support member to a corner or an edge of the component.
5. The method according to any one of claims 1 to 4, further comprising: attaching additional support members to one or more corners and / or one or more edges of the component.
6. The method according to any one of claims 1 to 5, further comprising: semi - curing at least one of the first adhesive layer and the second adhesive layer before mounting the support member to the substrate.
7. The method according to any one of claims 1 to 6, wherein the support frame is made of metal or metal alloy.
8. An electronic assembly, comprising: a component of a ball grid array including solder balls; a substrate including a contact pad array, the pattern of the contact pad array matching the ball grid array on the component; and a support member between the component and the substrate, wherein the support member includes: a support frame; a first adhesive layer on an inner surface of the support frame; and a second adhesive layer on a bottom surface of the support frame, wherein the inner surface of the support frame covers a part of a first side surface of the component and a part of a bottom surface of the component, and wherein the support member is attached to the component through the first adhesive layer and attached to the substrate through the second adhesive layer.
9. The electronic assembly according to claim 8, wherein the inner surface of the support frame covers a second side surface of the component, the second side surface being adjacent to the first side surface and the bottom surface of the component.
10. The electronic assembly according to claim 8 or 9, wherein the inner surface of the support frame covers a part of a top surface of the component.
11. The electronic assembly according to any one of claims 8 to 10, wherein The support frame is attached to a corner or an edge of the component.
12. The electronic assembly according to any one of claims 8 to 11, wherein, additional support members are attached to one or more corners and / or one or more edges of the component.
13. The electronic assembly according to any one of claims 8 to 12, wherein, the support frame is made of metal or a metal alloy.