Printed circuit board assembly and manufacturing method therefor

Abstract

A printed circuit board (PCB) assembly according to one embodiment comprises: a PCB including a plurality of pads and a dummy pad; and an electronic component including a plurality of contact points arranged on the lower side thereof, and mounted on the PCB by soldering the plurality of contact points. The dummy pad is provided on the PCB and can have an elongated portion spaced apart from an outer edge of the electronic component.

Description

Printed circuit board assembly and method for manufacturing the same

[0001] Various embodiments of the present disclosure relate to a printed circuit board assembly on which electronic components are mounted based on soldering and a method for manufacturing the same.

[0002] With the rapid development of the electronics industry and user demands, electronic devices are becoming increasingly miniaturized and multifunctional. Consequently, the need for miniaturization and multifunctionality in semiconductor devices is also increasing. Semiconductor devices use surface-mount technology to solder electronic components onto a substrate. This process may involve a reflow process, where solder paste is heated and melted. During the reflow process, the substrate is also heated, which can cause warping of certain areas.

[0003] Various embodiments of the present disclosure can maintain a connection between an electronic component and a substrate even if a portion of the substrate is warped during the reflow process.

[0004] Various embodiments of the present disclosure propose a printed circuit board assembly and a method of manufacturing the same, wherein dummy pads are provided to prevent solder cream (or solder paste) soldered for mounting electronic components from moving and being exposed to the outside of the electronic components.

[0005] Various embodiments of the present disclosure can prevent a short circuit between an electronic component and the substrate from occurring due to warping of the substrate during a reflow process when mounting an electronic component on the substrate through an SMT (Surface Mount Technology) process.

[0006] Various embodiments of the present disclosure can prevent a short circuit from occurring due to solder ball detachment caused by warping of the substrate during a reflow process when mounting electronic components on a substrate through an SMT process.

[0007] Various embodiments of the present disclosure can prevent short circuits between electronic components and the substrate, which may result in increased current consumption and reduced performance, even if a portion of the substrate is bent or sagged during the manufacturing process.

[0008] A printed circuit board assembly according to one embodiment may include a PCB including a plurality of pads and dummy pads, and an electronic component mounted on the PCB including a plurality of contact points disposed on a lower side thereof and soldering the plurality of contact points. The dummy pad may be provided on the PCB and may have an elongated portion spaced apart from an outer edge of the electronic component.

[0009] A method for manufacturing a printed circuit board assembly according to one embodiment may include the steps of: supplying dummy pads onto a PCB supported by a dummy substrate through a plurality of bridge sections and including a plurality of pads; applying a soldering material onto each of the plurality of pads on the PCB such that the soldering material is eccentrically disposed toward the dummy pad with respect to one of the plurality of pads; and mounting an electronic component including a plurality of contact points disposed underneath by soldering the plurality of pads onto the PCB. The dummy pad may be provided on the PCB and may have an elongated portion spaced apart from an outer edge of the electronic component for attaching the plurality of contact points of the electronic component and a portion of the soldering material that is detached during the soldering process of the plurality of pads of the PCB.

[0010] According to various embodiments proposed in the present disclosure, the printed circuit board assembly can reduce the manufacturing defect rate of the printed circuit board assembly by placing dummy pads around connection pads located in areas where warpage may occur during a reflow process.

[0011] According to various embodiments proposed in the present disclosure, a printed circuit board assembly can prevent a solder ball from coming off and short-circuiting other surrounding electronic components even if solder paste is over-applied on a single connection pad by arranging a dummy pad around the single connection pad.

[0012] According to various embodiments proposed in the present disclosure, a printed circuit board assembly can secure electrical performance of various electronic components (such as electronic components of the BGA (Ball Grid Array), LGA (Land Grid Array) or MIC (Micro Interconnection) type) placed near the edge of the board.

[0013] According to various embodiments proposed in the present disclosure, solder ball escape outside the connection pad can be prevented and short circuit between electronic components and a substrate can be prevented through soldering material distribution between the connection pad and the dummy pad.

[0014] The effects that can be obtained from the exemplary embodiments of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from implementing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0015] FIG. 1 is a perspective view of an exemplary printed circuit board assembly according to various embodiments.

[0016] Figure 2 is a plan view of part A of Figure 1.

[0017] Figure 3a is a plan view of part A of Figure 1 with the first electronic component omitted.

[0018] Figure 3b is a cross-sectional view taken along line B-B' of Figure 3a.

[0019] FIG. 4A is a plan view of an exemplary printed circuit board assembly according to various embodiments.

[0020] FIG. 4b is a drawing illustrating a state in which a first substrate is mounted on an electronic device according to various embodiments.

[0021] FIGS. 5A, 5B and 5C are drawings illustrating exemplary manufacturing processes of printed circuit board assemblies according to various embodiments.

[0022] FIGS. 6A, 6B, and 6C are drawings for explaining cases where warping occurs during reflow during the manufacturing process of a printed circuit board assembly according to various embodiments.

[0023] FIG. 7 is a flowchart of an exemplary printed circuit board assembly manufacturing method according to various embodiments.

[0024] FIG. 8 is a plan view of an exemplary substrate according to various embodiments.

[0025] FIG. 9 is a drawing for explaining various shapes of dummy pads in a printed circuit board assembly according to various embodiments.

[0026] FIGS. 10A and 10B are plan views of exemplary substrates according to various embodiments.

[0027] FIGS. 11A, 11B, and 11C are plan views of exemplary substrates according to various embodiments.

[0028] FIG. 12 is a plan view of an exemplary substrate according to various embodiments.

[0029] FIG. 13 is a side view of an exemplary printed circuit board assembly according to various embodiments.

[0030] FIG. 14 is a side view of an exemplary printed circuit board assembly according to various embodiments.

[0031] FIGS. 15A and 15B are cross-sectional views of exemplary substrates according to various embodiments.

[0032] Figures 16a to 16d are drawings of a printed circuit board assembly in which a dummy pad according to the prior art is omitted.

[0033] The following description refers to the attached drawings, and specific examples of implementations are illustrated within the drawings. Furthermore, other examples may be utilized and structural changes may be made without departing from the scope of the various examples.

[0034] The various embodiments used to illustrate the principles of the present disclosure, as illustrated in FIGS. 1 through 16d below and in this patent document, are for illustrative purposes only and should not be construed as limiting the scope of the present disclosure in any way. Those skilled in the art will appreciate that the principles of the present disclosure can be implemented in any appropriately arranged system or device.

[0035] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein. In connection with the description of the drawings, the same or similar reference numerals may be used for identical or similar components. Furthermore, in the drawings and related descriptions, descriptions of well-known functions and configurations may be omitted for clarity and conciseness.

[0036] FIG. 1 is a perspective view of an exemplary printed circuit board assembly according to various embodiments. FIG. 2 is a plan view of portion A of FIG. 1. FIG. 3a is a plan view of portion A of FIG. 1 with a first electronic component omitted. FIG. 3b is a cross-sectional view taken along line B-B' of FIG. 3a. FIGS. 16a to 16d are drawings of a printed circuit board assembly in which a dummy pad is omitted according to the prior art.

[0037] Referring to FIGS. 1 to 3B, a printed circuit board assembly (100) may include all or part of a PCB (110), an electronic component (120), a dummy substrate (140), and / or solder balls (150). The printed circuit board assembly (100) may be, for example, a module such as a solid state drive (SSD) module, a memory module, a computer system module, or a mobile system module, but is not limited thereto. The printed circuit board assembly (100) may be a semiconductor substrate. In the following description, the printed circuit board assembly (100) will be described specifically as a semiconductor substrate, but the proposed structure or its manufacturing method is not specifically applicable only to semiconductor substrates, but may be applied to all printed circuit board assemblies in which electronic components are prepared or mounted by a soldering process.

[0038] An electronic component (120) may be mounted on a PCB (110). The PCB (110) may be mounted on an electronic device (e.g., an electronic device (300) of FIG. 4B). An electronic component (120) may not be mounted on a dummy substrate (140). The dummy substrate (140) may be a portion removed at the final stage of the manufacturing process. The dummy substrate (140) may be provided to support or fix the PCB (110). The dummy substrate (140) may also be referred to as a support substrate. The PCB (110) and the dummy substrate (140) may be connected by at least one bridge section (130). The bridge section (130) may be a portion cut or removed at the final stage of the manufacturing process. By cutting or removing the bridge section (130), the PCB (110) may be separated from the dummy substrate (140).

[0039] When the bridge section (130) is cut or removed, dust (or fine dust) may be generated. The dust generated here may flow in or move between the PCB (110) and the electronic component (120) and cause defects. Therefore, by arranging an appropriate number of bridge sections (130) at appropriate (or fixed) locations, defects can be prevented or avoided. The bridge section (130) may also be referred to as a support member. The PCB (110) may be configured so that at least one electronic component (120) is mounted (or provided) on at least one of the upper surface (110a) and the lower surface (110b) by soldering. Various types of substrates well known in the art (e.g., ceramic substrates, printed circuit boards, flexible substrates, etc.) may be used as the PCB (110). Although not shown, a wiring pattern electrically connecting the connection pads (113) may be formed on at least one of the upper surface (110a) and lower surface (110b) of the PCB (110).

[0040] According to an example, the PCB (110) may include at least one of a body (111), a protective layer (112), a connection pad (113), a dummy pad (114), or a guide line (115). The PCB (110) may be classified into a single-layer PCB in which circuit wiring is formed on only one side, and a double-layer PCB in which circuit wiring is formed on both sides. In the case of the PCB (110) for double-layer PCB, the circuit wiring on the upper and lower sides may be electrically connected through a conductive via penetrating the body (111).

[0041] The body (111) may include glass epoxy (or FR-4) resin, phenol resin, or BT resin. The body (111) may include a body layer compressed to a certain thickness and circuit wiring formed on the body layer. The circuit wiring may be formed by patterning copper foil coated on the body layer.

[0042] The body (111) may have a structure in which the number of layers of copper foil is three or more using an insulator called prepreg, and circuit wiring is connected in three or more layers according to the number of layers of copper foil, but is not limited thereto.

[0043] The protective layer (112) may be formed of, for example, solder resist (SR) that covers the circuit wiring. The protective layer (112) may have a structure that covers the circuit wiring, but leaves the connection pad (113) portion open. The PCB (110) may be configured to be processed with solder resist around a dummy pad (114) to be described later.

[0044] The connection pad (113) may be a part of the circuit wiring or may be formed separately on the circuit wiring. The connection pad (113) may be referred to as an electrode pad, a substrate pad, a contact pad, a solder pad, or a soldering pad. The connection pad (113) may be formed of, for example, at least one of aluminum (Al), copper (Cu), nickel (Ni), tungsten (W), platinum (Pt), or gold (Au). A conductive layer used for fine bumps or wire bonding, etc., is referred to as a pad, and a conductive layer used for larger-sized solder balls, etc., is referred to as a land. However, hereinafter, they are collectively referred to as pads, i.e., connection pads.

[0045] A plurality of connection pads (113) may be provided to be electrically connected to the electronic component (120). The plurality of connection pads (113) may be arranged on the body (111). The plurality of connection pads (113) may be arranged on substantially the same plane as the protective layer (112), but is not limited thereto. The plurality of connection pads (113) may be arranged on at least one of the upper surface (110a) or the lower surface (110b) of the PCB (110). Although not illustrated, the plurality of connection pads (113) may also be provided to be electrically connected to other substrates in addition to the electronic component (120).

[0046] A plurality of connection pads (113) electrically connected to the electronic component (120) may be positioned on the lower side of the electronic component (120). The plurality of connection pads (113) may, for example, be arranged to overlap with respect to the electronic component (120). The plurality of connection pads (113) may be arranged so as not to be visually visible by the electronic component (120) when viewed in a direction from top to bottom (e.g., -z direction) as illustrated in FIG. 2. For example, the plurality of connection pads (113) electrically connected to the first electronic component (121) may be arranged so as not to protrude or extend outside the first electronic component (121) from the PCB (110).

[0047] The connection pad (113) may include a hollow circular first connection pad (113a) or a square second connection pad (113b), as illustrated. The first connection pad (113a) may have, for example, a ring shape. However, this is merely exemplary, and the shape of the connection pad (113) is not limited by the illustrated shape, and various shapes may be applied to the connection pad (113).

[0048] For example, the PCB (110) may include an opening (117) formed through a portion corresponding to a hollow portion in the first connection pad (113a). The opening (117) may be formed by penetrating the substrate vertically (e.g., in the z direction). For example, when the first electronic component (121) is a microphone element, sound may be introduced into the first electronic component (121) through the opening (117). The first electronic component (121) may have a groove formed inwardly at a portion corresponding to the opening (117) of the PCB (110). The groove of the first electronic component (121) may be formed to detect sound introduced through the opening (117).

[0049] For example, when one electronic component (e.g., a first electronic component (121)) is mounted on a PCB (110), a plurality of connection pads (113) to be electrically connected to the first electronic component (121) may be arranged on the inner side of the edge virtual line (E) based on the edge virtual line (E) of FIG. 3 indicating the edge of the electronic component (e.g., the first electronic component (121)). For example, the plurality of connection pads (113) to be electrically connected to the first electronic component (121) may be arranged so as not to protrude or extend from the edge virtual line (E). For example, the plurality of connection pads (113) to be electrically connected to the first electronic component (121) may be arranged so as not to cross or overlap the edge virtual line (E). That is, for example, the plurality of connection pads (113) may be arranged so as to remain within the boundary of the edge virtual line (E). Here, the area formed (or indicated) by the edge virtual line (E) may refer to the overlapping area of ​​the first electronic component (121) and the PCB (110).

[0050] A dummy pad (114) may be provided on the PCB (110). The dummy pad (114) may have a rectangular shape. The dummy pad (114) may be arranged on the outside of a structural boundary of the electronic component (120). The structural boundary of the electronic component (120) may mean a border, limit, or edge of the electronic component (120) when the electronic component (120) is viewed from above or downward (e.g., in the -z-axis direction). For example, the dummy pad (114) may be arranged spaced apart from the horizontal outer side of the structural boundary of the first electronic component (121). The dummy pad (114) may be arranged around (or close to) an electronic component (e.g., the first electronic component (121)) arranged next to or adjacent to an edge of the PCB (110). The dummy pad (114) may be positioned so as to be visible on the outside of the electronic component (120) when viewed from the top in a downward direction (e.g., -z direction).

[0051] The dummy pad (114) may be configured to extend in a direction parallel to one of the corners of the first electronic component (121). For example, a long side of the rectangular shape of the dummy pad (114) may be arranged parallel to a side surface of the first electronic component (121) on the PCB (110). For example, the dummy pad (114) may be configured to extend in a direction parallel to a side surface of the first electronic component (121) on the PCB (110). The corner of the first electronic component (121) may include, for example, a three-dimensional corner. The three-dimensional corner may be provided, for example, where the front surface and the side surface are in contact. The dummy pad (114) may have a certain length along the side surface of the first electronic component (121). The dummy pad (114) may have a relatively short width compared to the length. The dummy pad (114) may have, for example, a substantially rectangular shape, but is not limited thereto. The length of the dummy pad (114) may be 5% to 100% of the length of the side surface of the first electronic component (121) extending substantially parallel to the dummy pad (114). For example, the dummy pad (114) may be 15% to 35% of the length of the side surface of the first electronic component (121). For example, the dummy pad (114) may be 25% to 60% of the length of the side surface of the first electronic component (121).

[0052] For example, the dummy pad (114) may have a roughly rectangular shape extending in a direction substantially parallel to the longitudinal direction of the side surface of the first electronic component (121).

[0053] The dummy pad (114) may include a first dummy pad (114a) and a second dummy pad (114b). When the first dummy pad (114a) and the second dummy pad (114b) are arranged on the outside of the structural boundary of the first electronic component (121) as illustrated, they need to be arranged with an appropriate size in consideration of the gap with other adjacent electronic components. In particular, in order to mount electronic components on the PCB (110) at a high density, the dummy pad (114a) may be designed with an appropriate (e.g., predetermined) size.

[0054] The first dummy pad (114a) may extend in a direction substantially parallel to the side surface having the long side of the first electronic component (121). Two first dummy pads (114a) may be arranged spaced apart from each other on the two side surfaces having the long sides of the first electronic component (121). For example, the length (La) of the first dummy pad (114a) may be 0.88 mm to 1.32 mm, but is not limited thereto. As an example, the length (La) of the first dummy pad (114a) may be 1.10 mm. For example, the length (La) of the first dummy pad (114a) may have a length of 25% to 38% of the length of the side surface having the long side among the side surfaces of the first electronic component (121). For example, the width or thickness (Wa) of the first dummy pad (114a) may be, but is not limited to, 0.08 mm to 0.12 mm. As an example, the width or thickness (Wa) of the first dummy pad (114a) may be 0.10 mm.

[0055] The second dummy pad (114b) may extend in a direction substantially parallel to a side surface having a short side of the first electronic component (121). For example, the length (Lb) of the second dummy pad (114b) may be, but is not limited to, 1.24 mm to 1.86 mm. As an example, the length (Lb) of the second dummy pad (114b) may be 1.55 mm. For example, the length (Lb) of the second dummy pad (114b) may have a length of 46% to 70% of the length of the side surface having the short side of the first electronic component (121). For example, the width or thickness (Wb) of the second dummy pad (114b) may be, but is not limited to, 0.08 mm to 0.12 mm. As an example, the width or thickness (Wb) of the second dummy pad (114b) may be 0.10 mm.

[0056] As shown, by forming the width of the first dummy pad (114a) and the second dummy pad (114b) thin, the space of the PCB (110) can be efficiently secured even for high-density electronic component mounting.

[0057] The dummy pad (114) may be placed on the outer side of the edge virtual line (E). For example, the dummy pad (114) may be placed so as to be spaced apart from the edge virtual line (E) by a predetermined interval (or distance). In this case, the dummy pad (114) may not have an area that substantially overlaps the inner area of ​​the edge virtual line (E). For example, the dummy pad (114) may be placed so as to be spaced apart from the edge virtual line (E) by 0.01 mm or less. The distance (or width) between the dummy pad (114) and the edge virtual line (E) may be at most 0.01 mm. However, the present invention is not limited thereto, and the dummy pad (114) may be placed so as to be spaced apart from the edge virtual line (E) by 0.01 mm to 0.04 mm, or may be placed on the inner side of the edge virtual line (E). For example, the dummy pad (114) may be preferably placed between the connection pad (113) and the edge virtual line (E), even if it is placed inside the edge virtual line (E).

[0058] The dummy pad (114) may be positioned so as not to overlap the first electronic component (121). For example, the dummy pad (114) may be positioned so as not to overlap or cover an edge of the first electronic component (121). For example, the dummy pad (114) may be positioned so as not to overlap or cover an edge imaginary line (E). The dummy pad (114) may be positioned between a side surface of the first electronic component (121) and an edge of the PCB (110).

[0059] The dummy pad (114) may be positioned adjacent to one of the plurality of connection pads (113) (e.g., the first connection pad (113a)). For example, the one connection pad (e.g., the first connection pad (113a)) may refer to a connection pad that may cause a short circuit due to warpage (or deformation) of the PCB (110) during a reflow process. The distance (or width) between the one connection pad (e.g., the first connection pad (113a)) and the dummy pad (114) may be 0.2 mm to 0.8 mm. However, the present invention is not limited thereto.

[0060] The dummy pad (114) may be placed adjacent to an edge or corner of the PCB (110). When the reflow process is performed, the edge or corner of the PCB (110) may be bent or deformed due to high temperature. Therefore, the dummy pad (114) may be placed adjacent to the edge or corner of the PCB (110) to prevent or prevent a short circuit from occurring in the connection pad (e.g., the first connection pad (113a)) located at the corresponding portion or the solder ball (or solder cream) that is excessively supplied to the periphery from coming off. For example, the dummy pad (114) may be placed between the first electronic component (121) mounted near the edge or corner of the PCB (110) and the edge or corner of the PCB (110). For example, the dummy pad (114) may be placed outside the structural boundary of the first electronic component (121) and may be mounted near the edge or corner of the PCB (110) adjacent to the first electronic component (121). The dummy pad (114) may be positioned outside the edge or corner of the PCB (110) adjacent to the first electronic component (121). For example, the dummy pad (114) may be positioned between the edge virtual line (E) and the adjacent edge or corner of the PCB (110). However, the position of the dummy pad (114) is not limited thereto.

[0061] The surface of the dummy pad (114) can be soldered. The dummy pad (114) is electrically isolated from the connection pad (113) or contact point (1211), but can be soldered during the manufacturing process.

[0062] The dummy pad (114) may be formed of, for example, at least one of aluminum (Al), copper (Cu), nickel (Ni), tungsten (W), platinum (Pt), or gold (Au), but is not limited thereto. For example, the dummy pad (114) may have a material substantially the same as or similar to the connection pad (113).

[0063] A dummy pad (114) may be provided to attach a portion of the soldering material that has detached during the process of soldering a plurality of contact points (1211) of the first electronic component (121) and a plurality of pads (113) of the PCB (110). The dummy pad (114) may have an elongated portion spaced apart from an outer edge of the first electronic component (121). For example, the dummy pad (114) may have an elongated shape.

[0064] The PCB (110) may include at least one dummy pad (114) arranged in different directions with respect to one connection pad (e.g., the first connection pad (113a)). For example, at least one dummy pad (114) may be provided in each of an upper direction (e.g., -y direction), a right direction (e.g., +x direction), and a lower direction (e.g., +y direction) with respect to the first connection pad (113a) as illustrated. Each of the at least one dummy pad (114) may be formed to extend in a direction parallel to an edge of the electronic component (120). For example, unlike the illustrated example, only one dummy pad (114) may be provided, arranged in one of an upper direction (e.g., -y direction), a right direction (e.g., +x direction), or a lower direction (e.g., +y direction) with respect to the first connection pad (113a).

[0065] The dummy pad (114) can be electrically or independently separated from the connection pad (113). The dummy pad (114) can be electrically separated from an electronic component (e.g., a first electronic component (121)). For example, the dummy pad (114) may be free of circuit wiring for electrical connection. The dummy pad (114) may be configured as a pad that is electrically independent from the connection pad (113). For example, the dummy pad (114) may have an electrical or circuit blocking design structure.

[0066] The solder ball (150) may include a first solder ball (150a) and a second solder ball (150b). The first solder ball (150a) may refer to a solder ball placed on a connection pad (113). The second solder ball (150b) may refer to a solder ball placed on a dummy pad (114). The first solder ball (150a) and the second solder ball (150b) may be placed on the connection pad (113) and the dummy pad (114) by a SMT (Surface Mount Technology) process to be described later.

[0067] The second solder ball (150b) arranged on the dummy pad (114) can prevent external water, dust or foreign matter (D) from flowing into the space between the first electronic component (121) and the PCB (110). Since the second solder ball (150b) forms a wall, it is possible to prevent water, dust or foreign matter (D) from flowing into the area around the connection pad (113) and causing a short circuit. For example, as described below, dust is generated during the process of cutting the bridge section (130), and this dust can fly toward the first electronic component (121) arranged adjacent to the edge. The second solder ball (150b) can act as a wall that prevents this dust from flowing into the lower side of the first electronic component (121).

[0068] The area (or surface area) of the dummy pad (114) may be smaller than the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)). For example, the area (or surface area) of the dummy pad (114) may be 30% or less of the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)), but is not limited thereto. For example, the area of ​​the dummy pad (114) may be 10% or more of the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)), but is not limited thereto. Accordingly, the size of the first solder ball (150a) provided on one connection pad (e.g., the first connection pad (113a)) may be larger than the size of the second solder ball (150b) provided on the dummy pad (114). A first solder ball (150a) provided on one connection pad (113) may be formed to electrically connect between the connection pad (113) and a contact point (1211), which is an electrical terminal provided on the electronic component (120). Here, the contact point (1211) may include a pad.

[0069] The guide line (115) may be a marking line that guides the electronic component (120) to be mounted in the correct position. The guide line (115) positioned outside the structural boundary of the electronic component (120) may be positioned, for example, outside the corner portion of the edge virtual line (E), but is not limited thereto.

[0070] The electronic component (120) may be mounted on at least one of the upper surface (110a) or the lower surface (110b) of the PCB (110). Here, the upper surface (110a) of the PCB (110) may refer to a surface in the direction toward the electronic component (120) in the drawing (e.g., +z direction). Here, the lower surface (110b) of the PCB (110) may refer to a surface in the opposite direction toward the electronic component (120) (e.g., -z direction). In FIG. 1, an example in which the electronic component (120) is mounted on the upper surface (110a) of the PCB (110) is illustrated. However, the present invention is not limited thereto, and the electronic component (120) may also be mounted on the lower surface (110b) of the PCB (110). Electronic components (120), unlike those shown, may vary in size and shape, and may be arranged in various forms on both sides of the PCB (110) depending on the design of the printed circuit board assembly (100). Electronic components (120) include various components such as passive components and active components, and any component that can be mounted on the PCB (110) can be used as an electronic component.

[0071] The electronic component (120) may include a first electronic component (121) or a second electronic component (122). The first electronic component (121) may be a component that is positioned relatively closer to the edge of the PCB (110) than the second electronic component (122). For example, the first electronic component (121) may be a component that is positioned relatively closer to the corner portion of the PCB (110) than the second electronic component (122). According to an example, the dummy pad (114) may be preferably provided around the first electronic component (121) rather than the second electronic component (122). The first electronic component (121) may be a component that is positioned at a portion of the PCB (110) where warping occurs during a reflow process during the manufacturing process of the printed circuit board assembly (100) described below. The second electronic component (122) may be an element that is placed in a portion of the PCB (110) where warping does not occur during the reflow process during the manufacturing process of the printed circuit board assembly (100) described later. The first electronic component (121) may be placed in a portion where warping occurs when high heat is applied to the PCB (110). The second electronic component (122) may be placed in a portion where warping does not occur when high heat is applied to the PCB (110).

[0072] The electronic component (120) may include at least one contact point (1211). The at least one contact point (1211) may be a portion configured to be electrically connected to a plurality of connection pads (113) via at least one solder ball (150).

[0073] The electronic component (120) may be a chip package including at least one semiconductor chip therein. For example, the electronic component (120) may include at least one memory chip or logic chip therein. For example, when the electronic component (120) includes a memory chip, the electronic component (120) may be a memory device including memory such as DRAM, SRAM, flash memory, EEPROM, PRAM, MRAM, or RRAM. When the electronic component (120) includes a logic chip, the electronic component (120) may be a logic device including a logic chip of a relatively small size.

[0074] The electronic component (120) may include elements such as a connector, a controller, or an electrolytic cap. Here, the electrolytic cap is a unipolar capacitor, has a large electrostatic capacitance, and can be used for a low-frequency filter or bypass.

[0075] The electronic component (120) may generally include a chip package such as a large-sized microprocessor, central processing unit (CPU), controller, or application specific integrated circuit (ASIC).

[0076] The electronic component (120) may include an AP (Application Processor) of the SoC (System on Chip) type used in a mobile electronic device.

[0077] The types of electronic components (120) are not limited to the above-described elements.

[0078] Electronic components (120) may be mounted on a PCB (110) through a Surface Mount Technology (SMT) process. The SMT process may refer to a so-called soldering technology that mounts and attaches electronic device components to the surface of a PCB (110) using a solder material (or solder paste). For example, the SMT process may refer to a technology that automatically mounts electronic components, such as semiconductors, diodes, and chips, on a substrate using a chip mounter or a multi-mounter and hardens them using a solder material. In this SMT process, heat and pressure may be applied to facilitate bonding of the electronic components with the solder material. Reflow, in which the solder material is melted, may occur due to the applied heat and pressure. Accordingly, the SMT process may include a reflow process.

[0079] For example, the first electronic component (121) may be a microphone (MIC) element. The microphone element may be arranged adjacent to the edge of the PCB (110). When the first electronic component (121), which is a microphone element, is mounted on the board, the first electronic component (121) may receive sound or sound from the outside through the opening (117) of the PCB (110). If a portion of the soldering portion between the first electronic component (121), which is a microphone element, and the first connection pad (113a) is short-circuited (or separated), a space is formed by the short-circuit. External sound or sound may be introduced into the space formed by the short-circuit, which may act as noise. According to various embodiments of the present document, as will be described later, a short-circuit between the first electronic component (121), which is a microphone element, and the first connection pad (113a) can be prevented.

[0080] The first electronic component (121) can be mounted on a PCB (110) using a Surface Mount Technology (SMT) process by soldering a plurality of contact points (1211) arranged on the lower surface of the first electronic component (121) and a plurality of pads (113) arranged on the upper surface of the PCB (110). A dummy pad (114) can be configured to attach a soldering material detached during the process of mounting the first electronic component (121) on the PCB (110).

[0081] A printed circuit board assembly (100) may include at least one solder ball (150). The solder ball (150) may include a first solder ball (150a) disposed on a connection pad (113) and a second solder ball (150b) disposed on a dummy pad (114).

[0082] The first solder ball (150a) may be positioned between a contact point (1211) of an electronic component (120) and a connection pad (113) of a PCB (110). The first solder ball (150a) may be configured to electrically connect the contact point (1211) and the connection pad (113). The first solder ball (150a) may be positioned on the lower side of the electronic component (120). The first solder ball (150a) may be positioned so as not to be visually visible when the printed circuit board assembly (100) is viewed from above in a downward direction (e.g., in the -z direction).

[0083] The second solder ball (150b) may be placed on the dummy pad (114). The second solder ball (150b) may be placed so as to be spaced apart from the contact point (1211) by a predetermined distance or a predetermined width. The second solder ball (150b) may be placed so as not to be connected to an electronic component (e.g., the first electronic component (121)). The second solder ball (150b) may be placed so as to be visually visible when the printed circuit board assembly (100) is viewed from above in a downward direction (e.g., -z direction), but is not limited thereto. The second solder ball (150b) may have a substantially semicircular shape. For example, the upper (e.g., +z axis) surface of the second solder ball (150b) may be curved.

[0084] The second solder ball (150b) may be positioned outside the structural boundary of the first solder ball (150a), as illustrated in FIG. 3b, wherein the first solder ball (150a) may be positioned inside the structural boundary of the electronic component (120), thereby preventing foreign substances or dust from entering the inside. The second solder ball (150b) may prevent foreign substances or dust from entering the space formed between the electronic component (120) and the PCB (110).

[0085] The printed circuit board assembly (100) may further include a bridge section (130) for supporting the PCB (110). The bridge section (130) may be connected to an edge of the PCB (110) to support or secure the PCB (110). The bridge section (130) may also be integrally connected to the PCB (110). The bridge section (130) may be cut after component mounting on the PCB (110) is completed.

[0086] Referring to FIGS. 16A to 16D, a conventional printed circuit board assembly structure without a dummy pad is illustrated. FIG. 16A is a perspective view illustrating a state in which a solder ball detachment phenomenon has occurred, FIG. 16B is a plan view illustrating a state in which a solder ball detachment phenomenon has occurred, (a), (b), and (c) of FIG. 16C are actual examples in which a solder ball detachment phenomenon has occurred, and FIG. 16D is an actual example in which a short circuit has occurred. The electronic component (2) illustrated here may be a microphone element in which a roughly circular groove is formed in a portion of the area.

[0087] Referring to FIGS. 16a, 16b, and 16c, an electronic component (2) is mounted on a substrate (1) using the SMT method, and the substrate (1) and the electronic component (2) are electrically connected by solder balls (3). After the electronic component (2) is mounted on the substrate (1) while a semi-liquid soldering material is applied, soldering is performed through a high-temperature reflow process. At this time, gas (G), etc., is generated and a part of the substrate (1) is warped, deformed, or sagged, so that some of the solder balls (4) detach from the electronic component (2), reducing the amount of solder on the actual pad, which may potentially cause a short circuit due to poor interconnection. In the present disclosure, as illustrated in FIGS. 1 to 3b and FIGS. 5a to 15b, a dummy pad (e.g., a dummy pad (114) of FIG. 2) is provided to prevent detachment of the solder balls, thereby preventing wiring defects that may cause a short circuit.

[0088] Referring to FIG. 16d, an example in which a short circuit occurs between an electronic component (2) and a connection pad (11) of a substrate (1) is illustrated. When the substrate (1) is exposed to a high-temperature environment during a reflow step for soldering, warping may occur, resulting in a short circuit in an area (O) adjacent to the edge. In the case of an electronic component (2), which is a microphone element, it is configured to detect sound introduced through a through-hole (12) formed in the substrate (1), but as illustrated, if a short circuit occurs in a portion, sound may also be introduced through the short-circuited portion rather than the through-hole (12), thereby generating noise. In the present disclosure, as illustrated in FIGS. 1 to 3b and FIGS. 5a to 15b, a dummy pad (e.g., a dummy pad (114) of FIG. 2) is provided, and a soldering material (solder adhesive or solder paste) is excessively applied to the connection pad (11), thereby preventing a short circuit that may occur due to poor wiring between the electronic component and the pad.

[0089] FIG. 4A is a plan view of an exemplary printed circuit board assembly according to various embodiments.

[0090] The printed circuit board assembly (200) illustrated in FIG. 4a is an exemplary embodiment of the printed circuit board assembly (100) described above with reference to FIGS. 1 to 3b. Since the printed circuit board assembly (200) illustrated in FIG. 4a is an exemplary embodiment, the scope of the present document is not limited by the illustrated shape and arrangement relationship.

[0091] Referring to FIG. 4A, the printed circuit board assembly (200) may include a PCB (210), an electronic component (220), a bridge section (230), or a dummy substrate (240). The PCB (210) and the dummy substrate (240) may be connected by the bridge section (230). The PCB (210) may correspond to the PCB (110) of FIGS. 1 to 3B. The electronic component (220) may correspond to the electronic component (120) of FIGS. 1 to 3B. The bridge section (230) may correspond to the bridge section (130) of FIGS. 1 to 3B. The dummy substrate (240) may correspond to the dummy substrate (140) of FIGS. 1 to 3B. Descriptions of overlapping components are omitted below.

[0092] According to an example, an electronic component (220) may be mounted on a PCB (210). The electronic component (220) may include a first electronic component (221) and a second electronic component (222) positioned relatively farther from the edge than the first electronic component (221). The first electronic component (221) may be, for example, a microphone element.

[0093] A bridge section (230) may be provided around the first electronic component (221). The bridge section (230) may be provided to prevent a portion of the PCB (210) from being bent or deformed in a high-temperature environment during the reflow step described later during the manufacturing process of the printed circuit board assembly (200). However, with only the bridge section (230), warping may still occur in the edge portion, which is relatively more vulnerable to bending in a high-temperature environment.

[0094] The bridge section (230) may be a component that is cut or removed when separating the PCB (210) from the dummy substrate (240) during the manufacturing process of the printed circuit board assembly (200). When the bridge section (230) is cut or removed, dust (or fine dust) is generated. In order to prevent warping due to a high-temperature environment at the edge of the PCB (210), there is a method of providing additional bridge sections (230) around the edge of the PCB (210). However, if the number of bridge sections (230) increases, a large amount of dust (or fine dust) may be generated during the cutting or removal step of the bridge sections (230). This fine dust may flow into the inside of the first electronic component (221), which is a microphone element, through the through-hole portion of the PCB (210) at the lower side of the first electronic component (221). As a result, there is a problem that the occurrence rate of defects increases. Therefore, in addition to providing an additional bridge section (230) around the first electronic component (221), it is necessary to use a method other than that to prevent solder ball detachment or wiring defects that may cause a short circuit between the first electronic component (221) and the PCB (210).

[0095] In the present disclosure, the above problem can be solved by configuring a dummy pad (e.g., a dummy pad (114) of FIG. 2) as described in FIGS. 1 to 3b and as described later in FIG. 5a.

[0096] FIG. 4b is a drawing illustrating a state in which a first substrate is mounted on an electronic device according to various embodiments.

[0097] FIG. 4b is an internal plan view illustrating a state in which a PCB (310) is arranged within an electronic device (300). Here, the PCB (310) may correspond to the PCB (210) of FIG. 4a. The PCB (310) illustrated in FIG. 4b is an exemplary embodiment, and therefore the scope of the present document is not limited by the illustrated shape and arrangement relationship. The PCB (310) may have various shapes depending on the type and / or structure of the electronic device (300).

[0098] The PCB (310) may be placed within an area defined by a first side member (301), a second side member (302) extending in a vertical direction from one end of the first side member (301), and a third side member (303) extending in a vertical direction from the other end of the first side member (301). The PCB (310) may be placed such that the electronic component (320), which is a microphone element, is positioned adjacent to one side of the electronic device (300). For example, the PCB (310) may be placed such that the electronic component (320), which is a microphone element, is adjacent to the first side member (301). Accordingly, when the electronic component (320), which is a microphone element, is mounted on the PCB (310), it may be mounted adjacent to an edge.

[0099] When manufacturing a printed circuit board assembly (e.g., printed circuit board assembly (100) of FIG. 1 or printed circuit board assembly (200) of FIG. 4a), the electronic component (320), which is a microphone element that must be placed adjacent to an edge, and its surroundings may be vulnerable to short circuits or solder ball formation during the reflow process. Therefore, in the present disclosure, as described in FIGS. 1 to 3b and described in FIG. 5a and below, by providing a dummy pad (e.g., a dummy pad (114) of FIG. 2) around the electronic component (320), it is possible to prevent short circuits or solder ball separation between the electronic component (320) and the PCB (310) due to warpage.

[0100] FIGS. 5A, 5B and 5C are drawings illustrating exemplary manufacturing processes of printed circuit board assemblies according to various embodiments.

[0101] The configurations illustrated in FIGS. 5A, 5B, and 5C may be substantially the same as or similar to the configurations illustrated in FIGS. 1 to 3B, and the same reference numerals are used for configurations that are substantially the same or similar. The manufacturing process of the printed circuit board assembly illustrated in FIGS. 5A, 5B, and 5C can be applied not only to the printed circuit board assembly (100) illustrated in FIGS. 1 to 3B, but also to various embodiments to be described later. FIGS. 5A, 5B, and 5C describe some processes in the manufacturing process of the printed circuit board assembly. FIGS. 5A, 5B, and 5C describe a manufacturing process of mounting electronic components on a board using an SMT process. Hereinafter, a process of mounting a first electronic component (121) will be described as an example, but is not limited thereto.

[0102] In FIGS. 5A to 5C, the portion where the first connection pad (113a) is arranged is exemplified as the portion where warping or deformation of the PCB (110) occurs during the reflow process. Since this is an exemplary embodiment, the manufacturing process described below can be applied not only to the first connection pad (113a) but also to the connection pads arranged in the portion where warping of the PCB (110) occurs. For the convenience of explanation, the following description will be made using an example in which only one dummy pad (114) is provided.

[0103] Referring to FIG. 5A, a printed circuit board assembly manufacturing process may include a step of applying a solder material (S) (e.g., solder adhesive, solder paste, or solder cream) onto a PCB (110). To apply the solder material (S) onto the connection pads (113), a metal mask (M) having an open pattern corresponding to the pattern of the connection pads (113) may be used. After the solder material (S) is applied onto the PCB (110), for example, the solder material (S) may be applied onto the connection pads (113).

[0104] According to one example, the metal mask (M) may be formed or prepared in such a way that a soldering material (S) is over-applied on the first connection pad (113a). The size of the opening of the portion of the opening of the metal mask (M) corresponding to the first connection pad (113a) may be larger than the size of the first connection pad (113a). Here, the over-applied soldering material (S) may mean that an amount exceeding an appropriate amount (or a specific amount) for soldering the connection pad (113) to the contact point (1211) of the electronic component (120) (e.g., the first electronic component (121)) is applied. The amount of the soldering material (S) applied on the first connection pad (113a) may be over-applied by approximately 20% to 30% more than the existing amount. The specific gravity of the over-applied soldering material (S) is not limited thereto.

[0105] When soldering material (S) is over-applied on the connection pad (113), the over-applied portion may partially detach during the reflow process, thereby short-circuiting peripheral components. In various embodiments disclosed in this document, a dummy pad is provided to prevent solder balls from detaching to peripheral components or peripheral connection pads. In various embodiments disclosed in this document, the dummy pad serves to distribute a portion of the over-applied soldering material (S), thereby preventing solder balls from detaching.

[0106] The over-coated soldering material (S) may be applied so as to extend or protrude from the first connection pad (113a) (e.g., not included within the surface area of ​​the pad) as illustrated in (b) of FIG. 5a. For example, the soldering material (S) applied on the first connection pad (113a) may partially overlap the first connection pad (113a) and partially not overlap the first connection pad (113a). The over-coated soldering material (S) on the first connection pad (113a) may be applied so as to extend or protrude toward the dummy pad (114). For example, the over-coated soldering material (S) on the first connection pad (113a) may be applied so as to extend or protrude along one surface (e.g., the upper surface (110a)) of the PCB (110) toward the dummy pad (114). For example, the soldering material (S) over-coated on the first connection pad (113a) may be applied so as to extend or protrude in the right direction (e.g., +x direction) as illustrated, but is not limited thereto, and the overflow direction may vary depending on the arrangement position of the dummy pad (114). For example, when a plurality of dummy pads (114) are provided, unlike as illustrated, the soldering material (S) over-coated on the first connection pad (113a) may be formed so as to extend or protrude in a plurality of directions.

[0107] When the soldering material (S) is applied on the first connection pad (113a), it may be applied so as not to overlap with the dummy pad (114) as shown. However, this is not limited thereto, and the soldering material (S) may also be applied so as to overlap with the first connection pad (113a) and the dummy pad (114).

[0108] Referring to FIG. 5B, the printed circuit board assembly manufacturing process may include a step of mounting or settling an electronic component (120) (e.g., a first electronic component (121)) after applying a soldering material (S). For example, the electronic component (120) (e.g., the first electronic component (121)) may be mounted or settled on the soldering material (S) applied to the connection pad (113). When the electronic component (120) (e.g., the first electronic component (121)) is mounted or settled on the soldering material (S), the soldering material (S) may be pressed and spread in a horizontal direction (e.g., a direction including the x-axis and / or the y-axis). For example, when an electronic component (120) (e.g., a first electronic component (121)) is mounted on a PCB (110), the soldering material (S) may spread due to the load of the electronic component (120) (e.g., the first electronic component (121)).

[0109] The soldering material (S) may be in a semi-liquid state. The semi-liquid state may correspond to a state in which the shape can be changed by an external force, for example. For example, the semi-liquid state may be a state intermediate between a solid state and a liquid state.

[0110] The soldering material (S) over-applied on the first connection pad (113a) may extend or protrude toward the dummy pad (114), so that when the electronic component (120) (e.g., the first electronic component (121)) is seated, the soldering material (S) may touch the dummy pad (114) or may spread horizontally to cover at least a portion of the dummy pad (114). If the gap between the dummy pad (114) and the first connection pad (113a) is large, the soldering material (S) that is pressed and spread by the electronic component (120) (e.g., the first electronic component (121)) may not reach the dummy pad (114). Therefore, an appropriate gap is required between the first connection pad (113a) and the dummy pad (114). For example, the dummy pad (114) may be configured to be positioned within 0.01 mm from the edge virtual line (E) as described above, but is not limited thereto. For example, the dummy pad (114) may be configured to be positioned within 0.01 mm in the horizontal direction from the edge of the electronic component (120) (e.g., the first electronic component (121)), but is not limited thereto.

[0111] Referring to FIG. 5c, the printed circuit board assembly manufacturing process may include a reflow process for melting and reflowing the soldering material (S). The reflow process may refer to a process of exposing the printed circuit board assembly in the state of FIG. 5b to a high-temperature environment to melt and reflow the soldering material (S).

[0112] In a high temperature environment, the soldering material (S) is melted to form surface tension, and the soldering material (S) positioned on the protective layer (112) on which the solder resist is formed by the surface tension can be positioned or attached on a pad (e.g., a connection pad (113) or a dummy pad (114)). In the reflow process, the soldering material (S) covering a part of the first connection pad (113a) and the dummy pad (114) is melted by high heat (or high temperature). At this time, the flux component included in the soldering material (S) is melted to coat the surface of the pad (e.g., a connection pad (113) or a dummy pad (114)) and an alloy layer can be formed. While the alloy layer is formed, gas may be generated from the soldering material (S) and discharged to the outside. The gas generated from the soldering material (S) applied to the lower side of the first electronic component (121) is discharged to the outside, and thus at least a portion of the soldering material (S) over-applied on the first connection pad (113a) may move toward the dummy pad (114). The narrower the gap between the first electronic component (121) and the PCB (110), the greater the likelihood that the soldering material (S) will be scattered to the outside by the flux and gas generated when the soldering material (S) is melted.

[0113] The soldering material (S) covering a part of the dummy pad (114) and the first connection pad (113a) by mounting the first electronic component (121) can be distributed onto each pad (e.g., the connection pad (113) or the dummy pad (114)) by forming surface tension as the soldering material (S) melts during the reflow process. Since the protective layer (112) is formed of a solder resist material, the molten soldering material (S) is not distributed onto the protective layer (112). The molten soldering material (S) can form an attractive force due to surface tension. By the tension formed in each of the first solder ball (150a) positioned on the first connection pad (113a) and the second solder ball (150b) positioned on the dummy pad (114), the first solder ball (150a) and the second solder ball (150b) can pull the soldering material (S) positioned on the protective layer (112). The connection between the first solder ball (150a) and the second solder ball (150b) can be severed by the tension.

[0114] A solder ball (150) can be formed on each of the first connection pad (113a) and the dummy pad (114). The first solder ball (150a) melted and reflowed on the connection pad (113) can electrically connect the connection pad (113) and the contact point (1211). The second solder ball (150b) melted and reflowed on the dummy pad (114) can be spaced apart from the electronic component (120) (e.g., the first electronic component (121)).

[0115] FIGS. 6A, 6B, and 6C are drawings for explaining cases where warping occurs during reflow during the manufacturing process of a printed circuit board assembly according to various embodiments.

[0116] The drawings shown in FIGS. 6a, 6b and 6c illustrate the shapes of the substrate that may occur in the reflow process of FIG. 5c.

[0117] In the reflow process, a portion of the PCB (110) may be deformed or maintained as illustrated in one of FIG. 6A, FIG. 6B, or FIG. 6C. For example, referring to FIGS. 6A and 6C, in a high-temperature environment of the reflow process, a phenomenon in which a portion of the PCB (110) is bent or deformed may occur. For example, a phenomenon in which an edge portion of the PCB (110) is bent or deformed may occur in the reflow process. For example, a phenomenon in which a corner portion of the PCB (110) is bent may occur in the reflow process. When a portion of the PCB (110) is bent in a high-temperature environment, the PCB (110) may be bent in a direction away from the first electronic component (121) as illustrated in FIG. 6A. When a portion of the PCB (110) is bent in a high-temperature (or high-temperature) environment, the PCB (110) may be bent in a direction toward the first electronic component (121) as shown in FIG. 6c.

[0118] Referring to FIG. 6a, in a high-temperature environment of a reflow process, a warping phenomenon may occur at the edge side of the PCB (110). As illustrated, due to the high temperature, some of the edges of the PCB (110) may warp away from the electronic component (120) (e.g., the first electronic component (121)). In this case, the gap between the contact point (1211) and the first connection pad (113a) increases, and the quantity or size of the first solder ball (150a) required for connection between the contact point (1211) and the first connection pad (113a) also increases.

[0119] In the present disclosure, by over-dosing a soldering material (e.g., the soldering material (S) of FIG. 5a) on the first connection pad (113a), a first solder ball (150a) having a sufficient quantity or size to fill the space between the contact point (1211) and the first connection pad (113a) can be formed even if the PCB (110) is warped. Accordingly, even if warping occurs in the PCB (110) during the reflow process, a short circuit can be prevented from occurring between the contact point (1211) and the first connection pad (113a).

[0120] For example, if the first electronic component (121) is a microphone element, if a short circuit occurs between the contact point (1211) and the first connection pad (113a), noise may be generated as sound is introduced through the short-circuited space as described above. In the present disclosure, by preventing such a short circuit, it is possible to contribute to improving the sound quality of the microphone element. As the quantity or size of the first solder ball (150a) increases, the size of the second solder ball (150b) may decrease.

[0121] Referring to Fig. 6b, warpage may not occur despite the high-temperature environment of the reflow process. In this case, the excess portion of the soldering material (S) over-applied on the first connection pad (113a) may be transferred (applied or transferred) onto the dummy pad (114) during the melting and reflow process.

[0122] Referring to FIG. 6c, in a high-temperature environment of the reflow process, a warping phenomenon may occur at the edge side of the PCB (110). As illustrated, some of the edges of the PCB (110) may be warped toward the electronic component (120) (e.g., the first electronic component (121)) due to the high temperature. In this case, the gap between the contact point (1211) and the first connection pad (113a) becomes closer, and the amount or size of the first solder ball (150a) required for connecting the contact point (1211) and the first connection pad (113a) also decreases. In the case of soldering the space between the contact point (1211) and the first connection pad (113a), the remaining (or excess) soldering material (S) may be moved or applied onto the dummy pad (114). The space between the contact point (1211) and the first connection pad (113a) is soldered, and the remaining soldering material (S) can be pulled by the tension of the molten soldering material (S) positioned on the dummy pad (114). In the present disclosure, even if the PCB (110) is bent toward the electronic component (120) (e.g., the first electronic component (121)), the dummy pad (114) can prevent the solder ball from coming off, thereby preventing a short circuit from occurring.

[0123] Likewise, even if the PCB (110) is bent toward the electronic component (120) (e.g., the first electronic component (121)) during the reflow process, the excess portion of the over-applied soldering material (S) can be transferred (applied or transferred) onto the dummy pad (114).

[0124] Therefore, even if the soldering material (S) is over-applied during the reflow process, the dummy pad (114) can limit the movement of the excess soldering material (S), thereby preventing the excess soldering material (S) from moving (applying or transferring) to other surrounding electronic components or other surrounding connection pads.

[0125] FIG. 7 is a flowchart of an exemplary printed circuit board assembly manufacturing method according to various embodiments.

[0126] Hereinafter, a method for manufacturing a printed circuit board assembly is described using the printed circuit board assembly (100) illustrated in FIGS. 1 to 6c as an example. The manufacturing method described below can also be applied to the embodiments described below. The flowchart in FIG. 7 illustrates a portion of the manufacturing process of a printed circuit board assembly.

[0127] Referring to FIG. 7, a method for manufacturing a printed circuit board assembly (100) may include a step (710) of supplying or placing a dummy pad (114) on a PCB (110). The dummy pad (114) may be mounted on the PCB (110). Here, the PCB (110) may be supported by a dummy substrate (140) via a plurality of bridge sections (130). For example, the PCB (110) may be connected to and supported by the dummy substrate (140) by the bridge sections (130). The PCB (110) may include a plurality of connection pads (113).

[0128] A method for manufacturing a printed circuit board assembly (100) may include a step (720) of applying a soldering material (S) to a plurality of connection pads (113) arranged on a PCB (110). For a first connection pad (113a), which is one of the plurality of connection pads (113), the soldering material (S) may be applied so as to protrude (or overflow) toward a dummy pad (114) arranged around the first connection pad (113a). Step 720 may correspond to the manufacturing process of FIG. 5A.

[0129] A method for manufacturing a printed circuit board assembly (100) may include a step (730) of mounting a first electronic component (121) on a PCB (110) (or a first connection pad (113a)). When the first electronic component (121) is mounted, the first electronic component (121) may pressurize a soldering material (S) to spread in a horizontal direction. At this time, the first electronic component (121) may be mounted while pressing the soldering material (S) so that the soldering material (S) applied on the first connection pad (113a) may be positioned or attached to at least a portion of a dummy pad (114). In response to the first electronic component (121) being mounted on the first connection pad (113a), the soldering material (S) applied on the first connection pad (113a) may come into contact with a portion of the dummy pad (114). Step 730 may correspond to the manufacturing process of FIG. 5b.

[0130] A method for manufacturing a printed circuit board assembly (100) may include a step (740) of melting and reflowing a soldering material (S) positioned between a first electronic component (121) and a PCB (110) (or a first connection pad (113a)). During the process of melting the soldering material (S), the surface tension of the soldering material (S) increases, so that the soldering materials (S) positioned on the protective layer (112) may gather on the pad (e.g., the connection pad (113) or the dummy pad (114)). When the soldering material (S) melts, the weight of the first electronic component (121) is supported by the tension of the melted soldering material (S), so that an appropriate gap (e.g., a specific gap) may be maintained between the first electronic component (121) and the PCB (110). In this way, the soldering material (S) can be reflowed to form a first solder ball (150a) on the connection pad (113) and a second solder ball (150b) on the dummy pad (114). Step 740 can correspond to the manufacturing process of FIG. 5c.

[0131] A method for manufacturing a printed circuit board assembly (100) may include a step (750) of cutting a bridge section (130). Once the bridge section (130) is cut, the PCB (110) may be separated from the dummy substrate (140).

[0132] FIG. 8 is a plan view of an exemplary substrate according to various embodiments.

[0133] The PCB (110-1) illustrated in FIG. 8 may be included in the printed circuit board assembly (100) of FIG. 1. In the PCB (110-1) illustrated in FIG. 8, the same reference numbers are assigned to components that are substantially the same or similar to the PCB (110) illustrated in FIGS. 1 to 3b.

[0134] Referring to FIG. 8, the PCB (110-1) may include a dummy pad (114-1). The dummy pad (114-1) may be positioned outside the structural boundary of the electronic component (120). For example, the dummy pad (114-1) may be positioned outside the structural boundary of the first electronic component (121). The dummy pad (114-1) may be positioned around an electronic component (e.g., the first electronic component (121)) positioned adjacent to a corner of the PCB (110-1). The dummy pad (114-1) may be positioned so as to be visible outside the structural boundary of the electronic component (120) when viewed from above in a downward direction (e.g., -z direction). The dummy pad (114-1) may be positioned between the outside of the boundary of the electronic component (121) and a corner or edge of the substrate.

[0135] The dummy pad (114-1) may be positioned adjacent to one of the plurality of connection pads (113) (e.g., the first connection pad (113a)). For example, the one connection pad (e.g., the first connection pad (113a)) may refer to a connection pad that may cause a short circuit due to warping or deformation of the PCB (110-1) during the reflow process.

[0136] The dummy pad (114-1) may be configured to extend in a direction parallel to one of the edges of the first electronic component (121). The dummy pad (114-1) may have a shape in which one side protrudes (e.g., extends or protrudes in a specific direction). For example, the dummy pad (114-1) may be formed such that a portion thereof protrudes or extends in the direction of the first electronic component (121). For example, the dummy pad (114-1) may be configured such that a portion thereof extends in the direction of the edge virtual line (E). For example, the dummy pad (114-1) may be configured to extend in the direction of the first connection pad (113a).

[0137] The dummy pad (114-1) may be positioned outside the edge virtual line (E). For example, the dummy pad (114-1) may be positioned to be spaced apart from the edge virtual line (E) by a predetermined distance (or width). For example, the dummy pad (114-1) may be positioned to be spaced apart from the edge virtual line (E) by 0.01 mm or less. The distance between the dummy pad (114-1) and the edge virtual line (E) may be at most 0.01 mm. For example, the dummy pad (114-1) may be positioned to be spaced apart from the edge of the first electronic component (121) by 0.01 mm or less in the horizontal direction outward. However, the present invention is not limited thereto, and the dummy pad (114-1) may also be positioned inside the edge virtual line (E). According to one example, the protrusion protruding or extending from the dummy pad (114-1) toward the first connection pad (113a) may be positioned to overlap or span the edge virtual line (E), unlike as shown.

[0138] The dummy pad (114-1) may be positioned so as not to overlap with the first electronic component (e.g., the electronic component (121) of FIG. 3B). For example, the dummy pad (114-1) may be positioned so as not to overlap with or cross over an edge of the first electronic component (121). The edge of the first electronic component (121) may include, for example, a three-dimensional edge. The three-dimensional edge may be provided such that, for example, the front and the side are in contact with each other. For example, the dummy pad (114-1) may be positioned so as not to overlap with or cross over an edge virtual line (E). According to one example, the dummy pad (114-1) may be positioned so that a portion of a protrusion that protrudes or extends in the direction of the first connection pad (113a), unlike as illustrated, overlaps with the first electronic component (121).

[0139] The surface of the dummy pad (114-1) can be soldered. The dummy pad (114-1) is electrically isolated (or independent) from the connection pad (113) or contact point (1211), but can be soldered during the manufacturing process.

[0140] The dummy pad (114-1) may be configured to be electrically isolated from the connection pad (113). The dummy pad (114-1) may be configured to be electrically isolated from an electronic component (e.g., the first electronic component (121) of FIG. 3B). For example, circuit wiring for electrical connection may be omitted from the dummy pad (114-1).

[0141] The area of ​​the dummy pad (114-1) may be smaller than the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)). For example, the area of ​​the dummy pad (114-1) may be 30% or less of the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)), but is not limited thereto. For example, the area of ​​the dummy pad (114-1) may be 10% or more of the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)), but is not limited thereto. Accordingly, the size of a solder ball (e.g., the first solder ball (150a) of FIG. 3B) provided on a connection pad (e.g., the first connection pad (113a)) may be larger than the size of a solder ball provided on the dummy pad (114-1).

[0142] FIG. 9 is a drawing for explaining various shapes of dummy pads in a printed circuit board assembly according to various embodiments.

[0143] The various shapes of dummy pads (910, 920, 930) illustrated in FIG. 9 are exemplary, and the illustrated shapes do not limit the scope of the present disclosure. At least one dummy pad among the various shapes of dummy pads (910, 920, 930) illustrated in FIG. 9 can replace the dummy pad (114-1) of the PCB (110-1) illustrated in FIG. 8. At least one dummy pad among the various shapes of dummy pads (910, 920, 930) illustrated in FIG. 9 can be included in the PCB (110-1) illustrated in FIG. 8.

[0144] According to an example, the various shaped dummy pads (910, 920, 930) illustrated in FIG. 9 may have a shape that protrudes or extends to one side. The protrusions of the dummy pads (910, 920, 930) may protrude, for example, toward the first connection pad (e.g., the connection pad (113a) of FIG. 8) as described in FIG. 8.

[0145] The dummy pad (910) illustrated in (a) to (f) of FIG. 9 may include a body portion (911) and a protrusion portion (912). The body portion (911) may refer to a roughly rectangular pad extending to one side. The body portion (911) may include a first end portion (911a) and a second end portion (911b), which are opposite ends along the length direction. The protrusion portion (912) may extend or protrude toward the first connection pad (113a). The protrusion portion (912) may extend or protrude toward the first electronic component (e.g., the electronic component (121) of FIG. 3b). The protrusion portion (912) may extend from the body portion (911) along the surface of a PCB (e.g., the PCB (110-1) of FIG. 8). The protrusion portion (912) may be, for example, triangular. The protrusion (912) may have, for example, a shape whose width decreases as it moves away from the body (911). The body (911) and the protrusion (912) may be formed integrally.

[0146] The dummy pad (910-1) illustrated in (a) of FIG. 9 may have a shape substantially identical to or similar to the dummy pad (114-1) of FIG. 8.

[0147] In (b) of Fig. 9, the protrusion (912-2) may extend from a portion adjacent to the second end (911b) of the body portion (911). In (c) of Fig. 9, the protrusion (912-3) may extend from a portion adjacent to the center of the body portion (911). In (d) of Fig. 9, the protrusion (912-3) may extend from a portion adjacent to the first end (911a) of the body portion (911). The position of the protrusion may vary, for example, depending on the position of the first connection pad (113a).

[0148] In FIG. 9 (e) and FIG. 9 (f), a plurality of protrusions (912-5, 912-6) may be provided. As shown in FIG. 9 (e), a plurality of protrusions (912-5) may be arranged adjacent to each other. As shown in FIG. 9 (f), a plurality of protrusions (912-6) may be arranged spaced apart from each other by a predetermined distance. As shown in FIG. 9 (f), a plurality of protrusions (912-6) may be positioned adjacent to the first end (911a) or the second end (911b), respectively.

[0149] The dummy pad (920) illustrated in (g) of FIG. 9 may include a first pad (921) and a second pad (922). The first pad (921) and the second pad (922) may have their respective ends joined to form an approximate 'V' shape. The dummy pad (920) may be arranged such that the portion where the first pad (921) and the second pad (922) are joined or in contact protrudes toward the first connection pad (e.g., the first connection pad (113a) of FIG. 8). The first pad (921) and the second pad (922) may be formed integrally.

[0150] The dummy pad (930) illustrated in (h) to (l) of FIG. 9 may include a body portion (931) and a protrusion portion (932). The body portion (931) may refer to a roughly rectangular pad extending to one side. The body portion (931) may include a first end portion (931a) and a second end portion (931b), which are opposite ends along the length direction. The protrusion portion (932) may extend or protrude toward the first connection pad (113a). The protrusion portion (932) may extend or protrude toward the first electronic component (e.g., the electronic component (121) of FIG. 3b). The protrusion portion (932) may extend from the body portion (931) along the surface of a PCB (e.g., the PCB (110-1) of FIG. 8). The protrusion portion (932) may be, for example, rectangular. The protrusion (932) may have a shape extending from the body portion (931) while maintaining the width, for example. The body portion (931) and the protrusion (932) may be formed integrally.

[0151] In (h) of Fig. 9, the protrusion (932-1) may extend from a portion adjacent to the center of the body portion (931). In (i) of Fig. 9, the protrusion (932-2) may extend from a portion adjacent to the first end (931a) of the body portion (931). In (j) of Fig. 9, the protrusion (932-3) may extend from a portion adjacent to the second end (931b) of the body portion (931). The position of the protrusion may vary, for example, depending on the position of the first connection pad (113a).

[0152] In FIG. 9 (k) and FIG. 9 (l), a plurality of protrusions (932-4, 932-5) may be provided. As shown in FIG. 9 (k), a plurality of protrusions (932-4) may be arranged adjacent to each other. As shown in FIG. 9 (l), a plurality of protrusions (932-5) may be arranged spaced apart from each other by a predetermined distance. As shown in FIG. 9 (l), a plurality of protrusions (932-5) may be positioned adjacent to the first end (931a) or the second end (931b), respectively.

[0153] Although not shown, the protrusion shape may have a semicircle, or may have various other shapes.

[0154] FIGS. 10A and 10B are plan views of exemplary substrates according to various embodiments.

[0155] The PCBs (110-2, 110-3) illustrated in FIGS. 10a and 10b may be included in the printed circuit board assembly (100) of FIG. 1. Components in the PCBs (110-2, 110-3) illustrated in FIGS. 10a and 10b that are substantially the same or similar to the PCBs (110) illustrated in FIGS. 1 to 3b are given the same reference numerals.

[0156] Referring to FIGS. 10A and 10B, the PCB (110-2, 110-3) may include dummy pads (115-2, 115-3). The dummy pads (115-2, 115-3) may be positioned on the outside of an electronic component (e.g., an electronic component (120) of FIG. 3B). For example, the dummy pads (115-2, 115-3) may be positioned on the outside of a first electronic component (e.g., a first electronic component (121) of FIG. 3B). The dummy pads (115-2, 115-3) may be positioned adjacent to a corner portion of an edge virtual line (E). The dummy pads (115-2, 115-3) can serve to distribute the over-coated soldering material (S) to the first connection pad (113a) as described above, and can also serve to guide the position where an electronic component (e.g., an electronic component (120) of FIG. 1) is mounted.

[0157] Dummy pads (115-2, 115-3) may be arranged around an electronic component (e.g., a first electronic component (121)) positioned adjacent to an edge of a PCB (110-2, 110-3). The dummy pads (115-2, 115-3) may be arranged so as to be visible on the outside of the electronic component (120) when viewed from above in a downward direction (e.g., in the -z direction).

[0158] The dummy pads (115-2, 115-3) may be positioned adjacent to one of the plurality of connection pads (113) (e.g., the first connection pad (113a)). For example, the one connection pad (e.g., the first connection pad (113a)) may refer to a connection pad that may cause a short circuit due to warping of the PCB (110-2, 110-3) during the reflow process.

[0159] The surfaces of the dummy pads (115-2, 115-3) can be soldered. The dummy pads (115-2, 115-3) are electrically isolated from the connection pads (113) or contact points (e.g., contact points (1211) in FIG. 3b), but can be soldered during the manufacturing process.

[0160] The dummy pads (115-2, 115-3) may be configured to be electrically isolated from the connection pad (113). The dummy pads (115-2, 115-3) may be configured to be electrically isolated from an electronic component (e.g., a first electronic component (121)). For example, circuit wiring for electrical connection may be omitted from the dummy pads (115-2, 115-3).

[0161] The area of ​​the dummy pads (115-2, 115-3) may be smaller than the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)). For example, the area of ​​the dummy pads (115-2, 115-3) may be 30% or less of the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)), but is not limited thereto. For example, the area of ​​the dummy pads (115-2, 115-3) may be 10% or more of the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)), but is not limited thereto. Accordingly, the size of a solder ball (e.g., the first solder ball (150a) of FIG. 3b) provided on one connection pad (e.g., the first connection pad (113a)) may be larger than the size of a solder ball provided on a dummy pad (115-2, 115-3).

[0162] Referring to FIG. 10A, the dummy pad (115-2) may be positioned outside the edge virtual line (E). For example, the dummy pad (115-2) may be positioned so as to be spaced apart from the edge virtual line (E) by a predetermined interval (or distance). For example, the dummy pad (115-2) may include two elongated portions. The two elongated portions may be combined and positioned adjacent to the corner of the electronic component (121).

[0163] The dummy pad (115-2) may be formed by connecting the ends of two elongated sections to form a substantially right angle. The dummy pad (115-2) may have an “ㄱ” shape. However, the present invention is not limited thereto, and the dummy pad (115-2) may be formed by connecting two elongated sections to form an angle corresponding to the angle of the corner portion of the electronic component (121).

[0164] For example, the dummy pad (115-2) may be positioned so as to be spaced apart from the edge virtual line (E) by 0.01 mm or less. The distance between the dummy pad (115-2) and the edge virtual line (E) may be at most 0.01 mm. For example, the dummy pad (115-2) may be positioned so as to be spaced apart from the edge of the electronic component (e.g., the first electronic component (121)) by 0.01 mm or less in the horizontal direction outward.

[0165] The dummy pad (115-2) may be positioned so as not to overlap or cover the first electronic component (121). For example, the dummy pad (115-2) may be positioned so as not to overlap or cross an edge of the first electronic component (121). For example, the dummy pad (115-2) may be positioned so as not to overlap or cross an edge virtual line (E). According to one example, the dummy pad (115-2) may be positioned so that a portion of a protrusion protruding or extending in the direction of the first connection pad (113a), unlike as illustrated, overlaps the first electronic component (121).

[0166] Referring to FIG. 10B, the dummy pad (115-3), unlike the dummy pad (115-2) of FIG. 10A, may include a protrusion (1151-3) that protrudes or extends on one side. For example, the dummy pad (115-3) may be formed such that a portion thereof protrudes or extends toward the first electronic component (e.g., the first electronic component (121) of FIG. 3B). For example, the dummy pad (115-3) may be formed such that a portion thereof protrudes or extends toward the first connection pad (113a). For example, the dummy pad (115-3) may be configured such that the protrusion (1151-3) protrudes or extends toward the edge virtual line (E). The protrusion (1151-3) of the dummy pad (115-3) may be positioned to span the edge virtual line (E). Some of the protrusions (1151-3) of the dummy pad (115-3) may be formed to protrude or extend inwardly of the edge virtual line (E). Some of the protrusions (1151-3) of the dummy pad (115-3) may be positioned to overlap the first electronic component (121).

[0167] The gap between the first connection pad (113a) and the dummy pad (115-3) is reduced by the shape of the protrusion (1151-3), and as a result, the soldering material (e.g., the soldering material (S) of FIG. 5a) over-applied to the first connection pad (113a) can be more easily distributed to the dummy pad (115-3).

[0168] FIGS. 11A, 11B, and 11C are plan views of exemplary substrates according to various embodiments.

[0169] The PCBs (110-4, 110-5, 110-6) illustrated in FIGS. 11a, 11b, and 11c may be included in the printed circuit board assembly (100) of FIG. 1. Components in the PCBs (110-4, 110-5, 110-6) illustrated in FIGS. 11a, 11b, and 11c that are substantially the same or similar to those in the PCB (110) illustrated in FIGS. 1 to 3b are given the same reference numerals.

[0170] Referring to FIGS. 11A, 11B, and 11C, the PCBs (110-4, 110-5, 110-6) may include dummy pads (114-4, 114-5, 114-6). The dummy pads (114-4, 114-5, 114-6) may be positioned inside an electronic component (e.g., an electronic component (120) of FIG. 3B). For example, the dummy pads (114-4, 114-5, 114-6) may be positioned inside a first electronic component (e.g., a first electronic component (121) of FIG. 3B). The dummy pads (114-4, 114-5, 114-6) may be positioned adjacent to an edge virtual line (E). Dummy pads (114-4, 114-5, 114-6) may be placed on the inner side of the edge virtual line (E). The dummy pads (114-4, 114-5, 114-6) may serve to distribute the soldering material (S) over-applied to the first connection pad (113a) as described above.

[0171] Dummy pads (114-4, 114-5, 114-6) may be positioned on the lower side of an electronic component (e.g., a first electronic component (121)) positioned adjacent to an edge of a PCB (110-4, 110-5, 110-6). The dummy pads (114-4, 114-5, 114-6) may be positioned so as to be visually invisible when viewed in a direction facing downward from the top (e.g., in the -z direction).

[0172] The dummy pads (114-4, 114-5, 114-6) may be positioned adjacent to one of the plurality of connection pads (113) (e.g., the first connection pad (113a)). For example, the one connection pad (e.g., the first connection pad (113a)) may refer to a connection pad that may cause a short circuit due to warping or deformation of the PCB (110-4, 110-5, 110-6) during the reflow process.

[0173] The surfaces of the dummy pads (114-4, 114-5, 114-6) can be soldered. The dummy pads (114-4, 114-5, 114-6) are electrically isolated from the connection pad (113) or the contact point (e.g., the contact point (1211) in FIG. 3b), but can be soldered during the manufacturing process.

[0174] The dummy pads (114-4, 114-5, 114-6) may be configured to be electrically isolated from the connection pad (113). The dummy pads (114-4, 114-5, 114-6) may be configured to be electrically isolated from an electronic component (e.g., a first electronic component (121)). For example, circuit wiring for electrical connection may be omitted from the dummy pads (114-4, 114-5, 114-6).

[0175] The area of ​​the dummy pads (114-4, 114-5, 114-6) may be smaller than the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)). For example, the area of ​​the dummy pads (114-4, 114-5, 114-6) may be 30% or less of the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)), but is not limited thereto. For example, the area of ​​the dummy pads (114-4, 114-5, 114-6) may be 10% or more of the area of ​​an adjacent connection pad (e.g., the first connection pad (113a)), but is not limited thereto. Accordingly, the size of a solder ball (e.g., the first solder ball (150a) of FIG. 3b) provided on one connection pad (e.g., the first connection pad (113a)) may be larger than the size of a solder ball provided on a dummy pad (114-4, 114-5, 114-6).

[0176] Referring to FIG. 11a, the dummy pad (114-4) may include at least one of a first pad (114a-4), a second pad (114b-4), or a third pad (114c-4). The second pad (114b-4) may extend from an end of the first pad (114a-4) in a direction perpendicular to the first pad (114a-4). The third pad (114c-4) may extend from an end of the second pad (114b-4) in a direction perpendicular to the second pad (114b-4). The first pad (114a-4) and the third pad (114c-4) may extend parallel to each other.

[0177] The dummy pad (114-4) may be arranged around the first connection pad (113a). The first pad (114a-4) may be arranged in a first direction (downward direction or +y direction) with respect to the first connection pad (113a). The second pad (114b-4) may be arranged in a second direction (rightward direction or +x direction) perpendicular to the first direction with respect to the first connection pad (113a). The third pad (114c-4) may be arranged in a third direction (upward or -y direction) opposite to the first direction with respect to the first connection pad (113a).

[0178] The first pad (114a-4), the second pad (114b-4), and the third pad (114c-4) may be formed integrally as illustrated, but are not limited thereto. The first pad (114a-4), the second pad (114b-4), and the third pad (114c-4) may be spaced apart from each other, unlike as illustrated.

[0179] The width or thickness of the dummy pad (114-4) may be, but is not limited to, 0.1 mm to 0.9 mm. For example, the width or thickness of the first pad (114a-4) may be 0.1 mm to 0.9 mm. For example, the thickness of the second pad (114b-4) may be 0.1 mm to 0.9 mm. For example, the thickness of the third pad (114c-4) may be 0.1 mm to 0.9 mm. The thicknesses of the first pad (114a-4), the second pad (114b-4), and the third pad (114c-4) may be the same or different from each other. The length of the first pad (114a-4), the second pad (114b-4), or the third pad (114c-4) may have a length corresponding to 5% to 100% of the length of the side surface of the first electronic component (121) extending substantially parallel to the dummy pad (114). For example, the dummy pad (114-4) may have a length corresponding to 15% to 35% of the length of the side surface of the first electronic component (121). For example, the dummy pad (114-4) may have a length corresponding to 25% to 60% of the length of the side surface of the first electronic component (121).

[0180] For example, each of the first pad (114a-4), the second pad (114b-4), or the third pad (114c-4) may have a roughly rectangular shape extending in a direction substantially parallel to the longitudinal direction of one side of the first electronic component (121).

[0181] Each of the first pad (114a-4), the second pad (114b-4), or the third pad (114c-4) may be positioned within 0.01 mm from the adjacent edge virtual line (E). However, this is not limited thereto, and each of the first pad (114a-4), the second pad (114b-4), or the third pad (114c-4) may be positioned within 0.01 mm to 0.04 mm from the adjacent edge virtual line (E).

[0182] Referring to FIG. 11b, the dummy pad (114-5) may be arranged to surround the first connection pad (113a). The dummy pad (114-5) may be arranged spaced apart from the first connection pad (113a). The dummy pad (114-5) may have a cylindrical shape as illustrated, but is not limited thereto.

[0183] Referring to FIG. 11c, the dummy pad (114-6) may include at least one of a first pad (114a-6), a second pad (114b-6), or a third pad (114c-6). The second pad (114b-6) may extend from an end of the first pad (114a-6). The third pad (114c-6) may extend from an end of the second pad (114b-6). For example, the first pad (114a-6) and the second pad (114b-6) may extend to form an obtuse angle. For example, the second pad (114b-6) and the third pad (114c-6) may extend to form an obtuse angle.

[0184] The dummy pad (114-6) may be arranged around the first connection pad (113a). The first pad (114a-6) may be arranged in a first direction (downward direction or +y direction) with respect to the first connection pad (113a). The second pad (114b-6) may be arranged in a second direction (rightward direction or +x direction) perpendicular to the first direction with respect to the first connection pad (113a). The third pad (114c-6) may be arranged in a third direction (upward or -y direction) opposite to the first direction with respect to the first connection pad (113a).

[0185] The first pad (114a-6), the second pad (114b-6), and the third pad (114c-6) may be formed integrally as illustrated, but are not limited thereto. The first pad (114a-6), the second pad (114b-6), and the third pad (114c-6) may be spaced apart from each other, unlike as illustrated.

[0186] The width or thickness of the dummy pad (114-6) may be, but is not limited to, 0.1 mm to 0.9 mm. For example, the width or thickness of the first pad (114a-6) may be 0.1 mm to 0.9 mm. For example, the thickness of the second pad (114b-6) may be 0.1 mm to 0.9 mm. For example, the thickness of the third pad (114c-6) may be 0.1 mm to 0.9 mm. The thicknesses of the first pad (114a-6), the second pad (114b-6), and the third pad (114c-6) may be the same or different. The length of the second pad (114b-6) may have a length corresponding to 5% to 100% of the length of the side surface of the first electronic component (121) extending substantially parallel to the dummy pad (114). For example, the second pad (114b-6) may have a length of 15% to 35% of the length of the side surface of the first electronic component (121). For example, the second pad (114b-6) may have a length of 25% to 60% of the length of the side surface of the first electronic component (121).

[0187] For example, each of the first pad (114a-6), the second pad (114b-6), or the third pad (114c-6) may have a roughly rectangular shape of the first electronic component (121). For example, the second pad (114b-6) may extend in a direction substantially parallel to the longitudinal direction of one side of the first electronic component (121).

[0188] As explained with examples in FIGS. 11a, 11b, and 11c, when the dummy pads (114-4, 114-5, 114-6) are positioned inside the edge virtual line (E), it may be advantageous for high-density mounting when designing component mounting.

[0189] FIG. 12 is a plan view of an exemplary substrate according to various embodiments.

[0190] The PCB (110-7) illustrated in FIG. 12 may be included in the printed circuit board assembly (100) of FIG. 1. In the PCB (110-7) illustrated in FIG. 12, the same reference numbers are assigned to components that are substantially the same or similar to the PCB (110) illustrated in FIGS. 1 to 3b.

[0191] Referring to FIG. 12, the PCB (110-7) may include a first dummy pad (114a-7) and a second dummy pad (114b-7).

[0192] The first dummy pad (114a-7) may be positioned outside the edge virtual line (E). The first dummy pad (114a-7) may be positioned spaced apart from the edge virtual line (E). The first dummy pad (114a-7) may be formed with a protrusion that protrudes or extends toward the first connection pad (113a), but is not limited thereto. The first dummy pad (114a-7) may have one of the shapes of the various dummy pads (910, 920, 930) illustrated in FIG. 9.

[0193] The second dummy pad (114b-7) may be arranged on the inner side of the edge virtual line (E). The second dummy pad (114b-7) may be arranged adjacent to the first connection pad (113a) on the inner side of the edge virtual line (E). The second dummy pad (114b-7) may be arranged between the first connection pad (113a) and another connection pad (e.g., the second connection pad (113b)) adjacent to the first connection pad (113a). The second dummy pad (114b-7) may prevent a solder ball melted on the first connection pad (113a) from being separated toward another adjacent connection pad (e.g., the second connection pad (113a)) during a reflow process of melting and reflowing a soldering material (e.g., the soldering material (S) of FIG. 5a). The second dummy pad (114b-7) can form a protrusion protruding toward the first connection pad (113a).

[0194] The second dummy pad (114b-7) may be positioned to overlap with the first electronic component (e.g., the first electronic component (121) of FIG. 3b). The second dummy pad (114b-7) may be positioned so as to be visually invisible when viewed from above in a downward direction (e.g., in the -z direction).

[0195] FIG. 13 is a side view of an exemplary printed circuit board assembly according to various embodiments.

[0196] The PCB (110) or electronic component (120) illustrated in FIG. 13 may be included in the printed circuit board assembly (100) of FIG. 1. In the PCB (110) illustrated in FIG. 13, the same reference numerals are assigned to components that are substantially the same or similar to the PCB (110) illustrated in FIGS. 1 to 3b.

[0197] Referring to FIG. 13, the electronic component (120) (e.g., the first electronic component (121)) may further include a component dummy pad (1212). The component dummy pad (1212) may have the same function as the dummy pad described in FIGS. 1 to 5C (e.g., the dummy pad (114) of FIG. 3B). The component dummy pad (1212) may be disposed on the outside of the contact point (1211). The component dummy pad (1212) may be disposed on the lower side of the electronic component (120) (e.g., the first electronic component (121)). The component dummy pad (1212) may be disposed adjacent to an edge of the electronic component (120) (e.g., the first electronic component (121)). By placing the element dummy pad (1212) on the edge side of the electronic component (120) (e.g., the first electronic component (121)), the solder ball can be prevented from being separated from the outside of the electronic component (120) (e.g., the first electronic component (121)) when the soldering material (e.g., the soldering material (S) of FIG. 5A) connected to the contact point (1211) is melted.

[0198] Referring to FIG. 13, as illustrated, the dummy pad (114) may be omitted from the PCB (110). Instead of the dummy pad (114) provided on the PCB (110), a component dummy pad (1212) may perform the role of the existing dummy pad (114).

[0199] When electronic components (120) are mounted at high density on a substrate, it may be difficult to place dummy pads (e.g., dummy pads (114) of FIG. 3b) outside the structural boundary of the electronic components (120) due to the spatial structure. In this case, by providing the element dummy pads (1212) on the electronic components (120) side rather than the PCB (110), the dummy pads (1212) can be configured even when mounting high-density components.

[0200] FIG. 14 is a side view of an exemplary printed circuit board assembly according to various embodiments.

[0201] The PCB (110) or electronic component (120) illustrated in FIG. 14 may be included in the printed circuit board assembly (100) of FIG. 1. In the PCB (110) illustrated in FIG. 14, the same reference numerals are assigned to components that are substantially the same or similar to the PCB (110) illustrated in FIGS. 1 to 3b.

[0202] The electronic component (120) illustrated in FIG. 14 (e.g., the first electronic component (121)) may be substantially the same as or similar to the electronic component (120) illustrated in FIG. 13 (e.g., the first electronic component (121)). The PCB (110) illustrated in FIG. 14 may be substantially the same as or similar to the PCB (110) illustrated in FIG. 3b.

[0203] Unlike the PCB (110) illustrated in FIG. 13, the PCB (110) of FIG. 14 may have a dual structure with a dummy pad (1212) of an electronic component (120) (e.g., a first electronic component (121)) by including a dummy pad (114).

[0204] FIGS. 15A and 15B are cross-sectional views of exemplary substrates according to various embodiments.

[0205] The PCB (110) or electronic component (120) illustrated in FIGS. 15a and 15b may be included in the printed circuit board assembly (100) of FIG. 1. In the PCB (110-7) illustrated in FIGS. 15a and 15b, the same reference numerals are given to components that are substantially the same or similar to the PCB (110) illustrated in FIGS. 1 to 3b.

[0206] Referring to FIGS. 15a and 15b, the PCB (110) may include connection pads (113) (e.g., first connection pad (113a)) and dummy pads (114) arranged at different heights.

[0207] The PCB (110) may have a top-down design structure designed such that the height of the dummy pad (114) is lower than the connection pad (113) (e.g., the first connection pad (113a)), as illustrated in FIG. 15A. The dummy pad (114) may be positioned relatively inner than the connection pad (113) (e.g., the first connection pad (113a)) with respect to the body (111). The dummy pad (114) may be positioned lower (e.g., in the -z direction) than the connection pad (113) (e.g., the first connection pad (113a)), as illustrated. By designing such a top-down design structure, solder balls can be more efficiently distributed toward the dummy pad (114) during the reflow process.

[0208] The PCB (110) may have a bottom-up design structure designed so that the height of the dummy pad (114) is higher than the connection pad (113) (e.g., the first connection pad (113a)), as illustrated in FIG. 15b. The dummy pad (114) may be positioned relatively outside the connection pad (113) (e.g., the first connection pad (113a)) with respect to the body (111). The dummy pad (114) may be positioned above (e.g., in the +z direction) the connection pad (113) (e.g., the first connection pad (113a)) as illustrated. By designing this bottom-up design structure, it is possible to more efficiently prevent external foreign substances, dust, or substances such as water from entering the space between the electronic component (120) (e.g., the first electronic component (121)) and the PCB (110).

[0209] A printed circuit board assembly according to one embodiment may include a PCB (110) including a plurality of pads (113) and dummy pads (114, 910, 920, 930), and an electronic component (121) mounted on the PCB (110) (PCB substrate) by soldering the plurality of contact points (1211) disposed on a lower side. The dummy pads (114, 910, 920, 930) may be provided on the PCB (110) and may have an elongated portion spaced apart from an outer edge of the electronic component (121).

[0210] According to one embodiment, the dummy pads (114, 910, 920, 930) may be provided on the PCB (110) to attach a portion of the soldering material that has detached during the process of soldering the plurality of contact points (1211) of the electronic component (121) and the plurality of pads (113) of the PCB (110).

[0211] According to one embodiment, the dummy pad (114, 910, 920, 930) may be configured to extend in a direction parallel to the side surface of the electronic component (121).

[0212] According to one embodiment, the dummy pad (114, 910, 920, 930) may have a length of 15% to 35% of the length of the side of the adjacent electronic component (121).

[0213] According to one embodiment, the dummy pads (114, 910, 920, 930) may be configured to be electrically isolated from the plurality of pads (113).

[0214] According to one embodiment, the dummy pad (114, 910, 920, 930) may have a length of 25% to 60% of the length of the side of the adjacent electronic component (121).

[0215] According to one embodiment, the PCB assembly may further include a dummy substrate (140) and a plurality of bridge sections (130) disposed between the PCB (110) and the dummy substrate (140). While the PCB (110) is attached to the dummy substrate (140) via the plurality of bridge sections (130), soldering of the plurality of contact points (1211) of the electronic component (121) to the plurality of pads (113) of the PCB (110) may be performed.

[0216] According to one embodiment, the printed circuit board assembly (100) may further include at least one bridge section (130) configured to extend outwardly from an edge of the PCB (110) and support the PCB (110).

[0217] According to one embodiment, another electronic component (122) may be further mounted on the PCB (110). The electronic component (121) may be positioned relatively closer to the edge of the PCB (110) than the other electronic component (122).

[0218] According to one embodiment, the plurality of pads (113) may be arranged to overlap the electronic component (121).

[0219] According to one embodiment, one of the plurality of connection pads (113) may be positioned adjacent to the dummy pad (114, 910, 920, 930).

[0220] According to one embodiment, one pad (113a) of the plurality of connection pads (113) may have a ring shape for connection with an electronic component (121) including a microphone. The dummy pads (114, 910, 920, 930) may be arranged adjacent to the one pad (113a) having a ring shape.

[0221] According to one embodiment, the area of ​​the dummy pad (114, 910, 920, 930) may be configured to be smaller than the area of ​​one connection pad (113a) adjacent to the dummy pad (114, 910, 920, 930) among the plurality of connection pads (113).

[0222] According to one embodiment, the dummy pad (910, 920, 930) may include a body portion (911, 921, 931) and at least one protrusion (912, 922, 932) extending toward the electronic component (121).

[0223] According to one embodiment, the protrusions (912, 922, 932) may extend from the body portion (911, 921, 931) along the surface of the PCB (110).

[0224] According to one embodiment, the at least one protrusion (912, 922, 932) may be triangular, square or semicircular.

[0225] According to one embodiment, the dummy pad (115-2) includes two elongated portions, and the two elongated portions can be combined and positioned adjacent to a corner of the electronic component (121).

[0226] According to one embodiment, the electronic component (121) may be configured to be mounted on the PCB (110) using a Surface Mount Technology (SMT) process by soldering a plurality of contact points (1211) arranged on the lower surface of the electronic component (121) and a plurality of pads (113) arranged on the upper surface of the PCB (110). The dummy pads (114, 910, 920, 930) provided on the PCB (110) may be configured to attach a soldering material detached during the process of mounting the electronic component (121) on the PCB (110) using the SMT process.

[0227] According to one embodiment, the PCB (110) may be configured to have solder resist processed around the dummy pads (114, 910, 920, 930).

[0228] According to one embodiment, the dummy pad (114, 910, 920, 930) may further include a solder ball (150b) positioned so as to be spaced apart from the electronic component (121).

[0229] A method for manufacturing a printed circuit board assembly (100) according to one embodiment may include the steps of supplying dummy pads (114, 910, 920, 930) onto a PCB (110) supported by a dummy substrate (140) via a plurality of bridge sections (130) and including a plurality of pads (113), applying a soldering material onto each of the plurality of pads (113) on the PCB (110) such that the soldering material is eccentrically disposed toward one of the plurality of pads (113) toward the dummy pad (114, 910, 920, 930), and mounting an electronic component (121) including a plurality of contact points (1211) disposed on a lower side onto the plurality of pads (113). The above dummy pads (114, 910, 920, 930) are provided on the PCB (110) and may have an elongated portion spaced apart from an outer edge of the electronic component (121) to attach a portion of soldering material detached during the soldering process of the plurality of contact points (1211) of the electronic component (121) and the plurality of pads of the PCB (110).

[0230] According to one embodiment, the plurality of pads (113) and the dummy pads (114, 910, 920, 930) may be configured to be electrically isolated.

[0231] According to one embodiment, one pad (113a) of the plurality of pads (113) may have a ring shape for connecting the electronic component (121) including the microphone.

[0232] According to one embodiment, a solder ball (150b) can be formed on the dummy pad (114, 910, 920, 930) by a step in which the soldering material (S) is melted and reflowed.

[0233] According to one embodiment, the method for manufacturing a printed circuit board assembly may further include the step of separating the PCB (110) from the dummy substrate (140) by cutting the bridge section (130).

[0234] The terminology used herein is merely used to describe specific embodiments and is not intended to limit the present disclosure. For example, a singular element should be understood to include plural elements unless the context clearly indicates only a singular element. As used herein, phrases such as "A or B," "at least one of A and B," "at least one of A or B," "A, B, or C," "at least one of A, B, and C," and "at least one of A, B, or C" can each include any one of the items listed together in that phrase, or all possible combinations thereof. It should be understood that the term "and / or" as used herein encompasses any and all possible combinations of one or more of the listed items. The terms "include," "have," "comprise," and the like used in this disclosure are intended to specify only the presence of a feature, component, part, or combination thereof described in this disclosure, and the use of these terms does not exclude the possibility of the presence or addition of one or more other features, components, parts, or combinations thereof. The expressions "first," "second," and the like used in this disclosure can modify various components regardless of order and / or importance, and are only used to distinguish one component from another, without limiting the components.

[0235] The expression "configured to" used in the present disclosure can be appropriately used interchangeably with, for example, "suitable for," "capable of," "designed to," "modified to," "made to," or "capable of." The term "configured to" may not necessarily mean only something "specially designed" in terms of hardware. Instead, in some situations, the expression "a device configured to" may mean that the device is "capable of" doing something together with other devices or components. For example, the phrase "a device configured (or set) to perform A, B, and C" may mean a dedicated device for performing the corresponding operations, or a general-purpose device that can perform various operations including the corresponding operations.

[0236] Meanwhile, the terms “upper side,” “lower side,” and “front-rear direction” used in the present disclosure are defined based on the drawings, and the shape and position of each component are not limited by these terms.

[0237] Although the foregoing description in this disclosure has focused on specific embodiments, it should be understood that this disclosure is not limited to such specific embodiments, but rather encompasses various modifications, equivalents, and / or alternatives of the various embodiments.

Claims

1. PCB (110) including a plurality of pads (113) and dummy pads (114, 910, 920, 930); and It includes a plurality of contact points (1211) arranged on the lower side and an electronic component (121) mounted on the PCB (110) by soldering the plurality of contact points (1211). The above dummy pad (114, 910, 920, 930) is provided on the PCB (110) and has an elongated portion spaced from the outer edge of the electronic component (121). Printed circuit board assembly.

2. In paragraph 1, The above dummy pads (114, 910, 920, 930) are A printed circuit board assembly provided on the PCB (110) to attach a portion of the soldering material detached during the process of soldering the plurality of contact points (1211) of the electronic component (121) and the plurality of pads (113) of the PCB (110).

3. In paragraph 1 or 2, The above dummy pads (114, 910, 920, 930) are A printed circuit board assembly configured to extend in a direction parallel to the side surface of the above electronic component (121).

4. In one of paragraphs 1 to 3, The above dummy pads (114, 910, 920, 930) are A printed circuit board assembly having a length of 15% to 35% or a length of 25% to 60% of the length of the side of the adjacent electronic component (121).

5. In one of paragraphs 1 to 4, dummy substrate (140); and It further includes a plurality of bridge sections (130) arranged between the above PCB (110) and the above dummy substrate (140), While the PCB (110) is attached to the dummy substrate (140) through the plurality of bridge sections (130), soldering of the plurality of contact points (1211) of the electronic component (121) to the plurality of pads (113) of the PCB (110) is performed. Printed circuit board assembly.

6. In one of paragraphs 1 to 5, It further includes another electronic component (122) mounted on the above PCB (110), The above electronic component (121) is A printed circuit board assembly positioned relatively adjacent to an edge of the PCB (110) relative to the other electronic component (122).

7. In one of paragraphs 1 to 6, The above multiple pads (113) are, A printed circuit board assembly arranged to overlap the above electronic component (121).

8. In one of paragraphs 1 to 7, One pad (113a) of the above plurality of connection pads (113) has a ring shape for connection with an electronic component (121) including a microphone. The above dummy pads (114, 910, 920, 930) are arranged adjacent to the one pad (113a) having a ring shape. Printed circuit board assembly.

9. In one of paragraphs 1 to 8, A printed circuit board assembly, wherein the area of ​​the above dummy pad (114, 910, 920, 930) is configured to be smaller than the area of ​​one pad (113a) adjacent to the above dummy pad (114, 910, 920, 930) among the plurality of pads (113).

10. In one of the clauses 1 to 9, The above dummy pads (910, 920, 930) are Body parts (911, 921, 931); and Including at least one protrusion (912, 922, 932) extended toward the electronic component (121), The above protrusions (912, 922, 932) are A printed circuit board assembly extending along the surface of the PCB (110) from the body portion (911, 921, 931).

11. In one of the clauses 1 to 9, A printed circuit board assembly, wherein the above dummy pad (115-2) includes two elongated parts, and the two elongated parts are combined and placed adjacent to the corner of the electronic component (121).

12. In one of paragraphs 1 to 11, The above electronic component (121) is It is configured to be mounted on the PCB (110) by using the SMT (Surface Mount Technology) process by soldering a plurality of contact points (1211) arranged on the lower surface of the electronic component (121) and a plurality of pads (113) arranged on the upper surface of the PCB (110). The dummy pads (114, 910, 920, 930) provided on the PCB (110) are configured to attach the soldering material detached during the process of mounting the electronic component (121) on the PCB (110) using the SMT process. Printed circuit board assembly.

13. In one of paragraphs 1 to 12, A printed circuit board assembly further comprising a solder ball (150b) arranged spaced apart from the electronic component (121) on the dummy pad (114, 910, 920, 930).

14. A step of supplying dummy pads (114, 910, 920, 930) electrically separated from the plurality of pads (113) on a PCB (110) supported by a dummy substrate (140) through a plurality of bridge sections (130) and including a plurality of pads (113); A step of applying a soldering material onto each of the plurality of pads (113) on the PCB (110) so that the soldering material is eccentrically arranged in a direction toward the dummy pad (114, 910, 920, 930) for one of the plurality of pads (113); and A step of mounting an electronic component (121) including a plurality of contact points (1211) arranged on the lower side by soldering it to the plurality of pads (113) and forming a solder ball (150b) on the dummy pad (114, 910, 920, 930), The above dummy pad (114, 910, 920, 930) is provided on the PCB (110) and has an elongated portion spaced from an outer edge of the electronic component (121) to attach a portion of soldering material detached during the soldering process of the plurality of contact points (1211) of the electronic component (121) and the plurality of pads of the PCB (110). A method for manufacturing a printed circuit board assembly.

15. In paragraph 14, A method for manufacturing a printed circuit board assembly, wherein one pad (113a) among the plurality of pads (113) has a ring shape for connecting the electronic component (121) including a microphone.

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