WO2024023980A1 - Component mounting substrate - Google Patents

Component mounting substrate Download PDF

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Publication number
WO2024023980A1
WO2024023980A1 PCT/JP2022/028988 JP2022028988W WO2024023980A1 WO 2024023980 A1 WO2024023980 A1 WO 2024023980A1 JP 2022028988 W JP2022028988 W JP 2022028988W WO 2024023980 A1 WO2024023980 A1 WO 2024023980A1
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WO
WIPO (PCT)
Prior art keywords
pad
solder
component mounting
copper
mounting board
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PCT/JP2022/028988
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French (fr)
Japanese (ja)
Inventor
光昭 戸田
光生 岩本
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株式会社メイコー
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Priority to PCT/JP2022/028988 priority Critical patent/WO2024023980A1/en
Publication of WO2024023980A1 publication Critical patent/WO2024023980A1/en

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering

Definitions

  • the present invention relates to a component mounting board.
  • a circuit board generally connects a plurality of electronic components mounted on the board, such as semiconductor chips, resistors, and capacitors, to each other via a wiring layer provided on the surface of an insulating layer.
  • a wiring pattern formed on the wiring layer is narrower than the electrode terminal of the electronic component to be mounted, a conductive pad with a secured area is provided at a position corresponding to the electrode terminal of the electronic component.
  • the electrode terminal of the electronic component and the conductive pad of the wiring layer can be soldered while being in surface contact with each other, and the two can be stably connected.
  • the wiring layer described above is generally made of copper
  • the conductive pads to which soldering is performed are made of gold, nickel, or palladium, which have higher solder wettability and smoother surfaces than copper.
  • the surface treatment is performed using a surface treatment material consisting of , or a combination thereof.
  • the conductive pad is composed of a copper pad that is continuous with the wiring pattern, and a surface pad that is laminated on the surface of the copper pad. Therefore, the solder applied to the conductive pads during the mounting of the electronic component spreads over the entire surface of the surface pad in the reflow process, thereby increasing the cross-sectional area of the connection with the electrode terminal of the electronic component.
  • the reflow process for soldering the electrode terminals of electronic components to the conductive pads may be performed multiple times, so for example, the solder connections formed in the first reflow process may be soldered in the second reflow process. may become unstable. For this reason, it is common to use so-called high-temperature solder, which has a relatively high solid phase melting point temperature, in the primary reflow process, and to use ordinary solder, which has a relatively low solid phase melting point temperature, in the secondary reflow process.
  • the present invention has been made in view of this situation, and its purpose is to provide a component mounting board that suppresses remelting of solder.
  • the component mounting board of the present invention is a component mounting board on which electronic components are mounted, and includes a wiring layer in which a copper pad is provided at a position corresponding to an electrode terminal of the electronic component; A surface pad formed on a part of the surface of the copper pad and made of a surface treatment material for soldering, and a solder for connecting the electrode terminal to the surface pad, the edge of the surface pad being A component mounting board spaced apart from the copper pad.
  • FIG. 2 is a cross-sectional view of the component mounting board according to the first embodiment.
  • FIG. 3 is a cross-sectional view of a substrate showing a step of forming a surface pad on a wiring layer.
  • FIG. 3 is a cross-sectional view of a board showing a process of mounting and embedding components.
  • FIG. 3 is a cross-sectional view of a component mounting board according to a second embodiment.
  • FIG. 1 is a cross-sectional view of a component mounting board 1 according to the first embodiment.
  • the component mounting board 1 according to the present embodiment is a so-called component-embedded board in which an electronic component 12 is built into an insulating layer 11 having wiring layers 10 on both sides. Further, as will be described in detail below, in the component mounting board 1, a surface pad 13 for soldering is formed on a copper pad 10p formed as a part of the wiring layer 10, and an electronic component 12 is attached via a solder 14. is connected to the surface pad 13.
  • the component mounting board 1 has various other components (not shown) mounted on the wiring layers 10 on both sides of the board.
  • the component mounting board 1 is not limited to the above configuration, and may be a multilayer board in which a plurality of wiring layers 10 and a plurality of insulating layers 11 are laminated, for example. An example of a method for manufacturing the component mounting board 1 according to the first embodiment of the present invention will be described below with reference to FIGS. 2 and 3.
  • FIG. 2 is a cross-sectional view of the substrate showing the process of forming the surface pad 13 on the wiring layer 10.
  • a dry film 20 is laminated on a copper foil for forming a wiring layer 10, as shown in FIG. 2(A).
  • the dry film 20 has an opening V formed at the electrode position of the electronic component 12 to be mounted in a later step. More specifically, a mask (not shown) is provided on the surface of the dry film 20 other than the area where the openings V are formed, and the portions corresponding to the openings V are dissolved by supplying a developer. At this time, the opening V is formed in the dry film 20 so that the corner portion 20a of the bottom surface slightly remains as a rounded surface. In the drawing, the size of the corner portion 20a is emphasized.
  • the surface pad 13 is formed in the opening V of the dry film 20 by plating.
  • the surface pad 13 is made of a surface treatment material for soldering, and more specifically contains at least one of gold, nickel, and palladium, which has higher solder wettability and surface smoothness than copper. Formed from material.
  • the surface pad 13 is formed from a nickel material that does not contain phosphorus, which lowers the solid phase melting point temperature of the solder in contact with it by several degrees centigrade.
  • the surface pad 13 has an edge portion 13a shaped along the corner portion 20a of the opening V.
  • a laminate of the wiring layer 10 and the surface pad 13 is formed.
  • the edge portion 13a of the surface pad 13 is separated from the wiring layer 10, and a step of, for example, 0.1 to 5.0 ⁇ m is formed between the center portion of the surface pad 13 and the edge portion 13a.
  • the exposed surface of the wiring layer 10 is roughened so that even if solder 14 used in a later process overflows from the surface pad 13, it will not spread over the surface. You can stay there.
  • FIG. 3 is a cross-sectional view of the board showing the process of mounting and embedding components.
  • solder 14 is first applied to the surface of the surface pad 13 formed on the wiring layer 10.
  • the solder 14 is a so-called high-temperature solder that does not contain a copper component, has a composition of, for example, Sn-Sb, and has a relatively high solid phase melting point temperature of, for example, 246° C.
  • the electronic component 12 is, for example, a semiconductor chip, a resistor, or a capacitor with a size of [1005] (1 mm x 0.5 mm), and has a rectangular parallelepiped component body 12A, and a cross section covering both sides of the component body 12A is U.
  • This is a chip component including a letter-shaped electrode terminal 12B and an electrode terminal 12C.
  • the solder 14 spreads over the surface of the surface pad 13 and forms a so-called solder fillet between the bottom and side surfaces of the electrode terminals 12B and 12C.
  • the surface pad 13 has a step formed between the center portion and the edge portion 13a. Therefore, the solder 14 that spreads on the upper surface of the surface pad 13 is dammed so that it does not overflow onto the surface of the wiring layer 10, and the separation between the solder 14 and the wiring layer 10 reduces the possibility that the two will come into contact with each other. .
  • the electronic components 12 mounted on the wiring layer 10 are buried in the insulating layer 11, and a new wiring layer 10 is provided on the surface of the insulating layer 11 to form a double-sided board.
  • the insulating layer 11 is made of a resin material having insulating properties.
  • a prepreg is placed around the electronic component 12 and heated, and a new wiring layer 10 made of copper is placed on the surface and pressed in the thickness direction. It can be formed by
  • the wiring layer 10 on both sides is patterned to form a wiring pattern while providing copper pads 10p at positions corresponding to the electrode terminals 12B and 12C of the electronic component 12, thereby forming the component shown in FIG.
  • a mounting board 1 is formed.
  • various other components are mounted on the wiring layers 10 on both sides.
  • the mounting is performed in a secondary reflow process using a normal solder having a relatively low solid phase melting point temperature of, for example, 217°C, and at a reflow temperature of, for example, 240°C. Therefore, the solder 14 that has hardened after the first reflow process is not remelted in the second reflow process, and is also prevented from coming into contact with the copper pad 10p, which would cause a decrease in the solid phase melting point temperature, so the solder 14 is hardened after the first reflow process. This reduces the risk of instability.
  • the edge portion of the surface pad 13 laminated on the copper pad 10p 13a is spaced apart from the copper pad 10p, and a step is formed between the center portion of the surface pad 13 and the edge portion 13a. Therefore, the solder 14 spreading on the upper surface of the front pad 13 is dammed so that it does not overflow onto the surface of the copper pad 10p, and the possibility of contacting the copper pad 10p is reduced. Therefore, the component mounting board 1 according to the first embodiment can suppress remelting of the solder 14 due to a decrease in the solid phase melting point temperature.
  • a component mounting board 2 according to a second embodiment differs from the first embodiment in that electronic components are surface mounted on the board, unlike the component built-in board of the component mounting board 1 of the first embodiment described above.
  • parts that are different from the first embodiment will be explained, and constituent elements common to the first embodiment will be given the same reference numerals and detailed explanations will be omitted.
  • FIG. 4 is a cross-sectional view of the component mounting board 2 according to the second embodiment.
  • the component mounting board 2 according to the second embodiment has copper pads 10p at positions corresponding to the electrode terminals 12B and 12C of the electronic component 12 by patterning the wiring layer 10 provided on both sides of the insulating layer 11. While providing the wiring pattern, the wiring pattern is formed. Further, a surface pad 13 is formed on a portion of the surface of the copper pad 10p. At this time, the surface pad 13 is formed by the same procedure as in the first embodiment so that the edge portion 13a is spaced apart from the copper pad 10p, so that a step is created between the center portion and the edge portion 13a. It is formed. Then, the electronic component 12 is mounted on the wiring layer 10 via the solder 14 provided on the surface pad 13.
  • the solder joints of the electronic components 12 after mounting with a known undercoat, overcoat, or side coat. Further, the wiring layer 10 is insulated and protected by applying a solder resist.
  • the component mounting board 2 according to the second embodiment similarly to the first embodiment, the solder 14 spreading on the upper surface of the surface pad 13 is dammed so that it does not overflow onto the surface of the copper pad 10p. The risk of contact with is reduced. Therefore, the component mounting board 2 according to the second embodiment can suppress remelting of the solder 14, as in the first embodiment, even when the electronic component 12 is surface mounted.
  • a component mounting board is a component mounting board on which an electronic component is mounted, and includes a wiring layer in which a copper pad is provided at a position corresponding to an electrode terminal of the electronic component, and a wiring layer provided with a copper pad at a position corresponding to an electrode terminal of the electronic component.
  • the edge of the surface pad laminated on the copper pad is spaced apart from the copper pad, and the surface pad is separated from the copper pad.
  • a step is formed between the center portion and the edge portion of the pad. Therefore, the solder spreading on the upper surface of the surface pad is dammed so that it does not overflow onto the surface of the copper pad, and the risk of contacting the copper pad is reduced. Therefore, the component mounting board according to the first embodiment can suppress remelting caused by a decrease in the solid phase melting point temperature of the solder.
  • the solder is made of Sn--Sb that does not contain copper, and the surface pad is made of nickel that does not contain phosphorus. This is a component mounting board.
  • the component mounting board according to the second embodiment of the present invention it is possible to suppress remelting of the solder due to a decrease in the solid phase melting point temperature of the solder in contact with the surface pad by several degrees Celsius.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Electric Connection Of Electric Components To Printed Circuits (AREA)

Abstract

The present invention provides a component mounting substrate (1) on which an electronic component (12) is to be mounted, and which is provided with: a wiring layer (10) that is provided with a copper pad (10p) at a position which corresponds to an electrode terminal (12B, 12C) of the electronic component (12); a surface pad (13) that is formed in a part of the surface of the copper pad (10p) and is formed of a surface treated material for soldering; and a solder (14) that connects the electrode terminal (12B, 12C) to the surface pad (13). With respect to this component mounting substrate (1), the peripheral edge of the surface pad (13) is apart from the copper pad (10p).

Description

部品実装基板Component mounting board
　本発明は、部品実装基板に関する。 The present invention relates to a component mounting board.
　回路基板は、絶縁層の表面に設けられた配線層を介して、基板に実装される複数の半導体チップ、抵抗器、及びコンデンサ等の電子部品を互いに接続するのが一般的である。このとき、当該配線層に形成される配線パターンは、実装される電子部品の電極端子よりも幅が狭いため、電子部品の電極端子に対応する位置において面積を確保した導電パッドが設けられる。これにより、電子部品の電極端子と配線層の導電パッドとは、互いに面接触した状態で半田付けを行うことができ、両者を安定的に接続することができる。 A circuit board generally connects a plurality of electronic components mounted on the board, such as semiconductor chips, resistors, and capacitors, to each other via a wiring layer provided on the surface of an insulating layer. At this time, since the wiring pattern formed on the wiring layer is narrower than the electrode terminal of the electronic component to be mounted, a conductive pad with a secured area is provided at a position corresponding to the electrode terminal of the electronic component. Thereby, the electrode terminal of the electronic component and the conductive pad of the wiring layer can be soldered while being in surface contact with each other, and the two can be stably connected.
　また、上記のような配線層は、一般的に銅で形成されるが、半田付けが行われる導電パッドにおいては、銅よりも半田の濡れ性が高く表面の平滑度が高い金、ニッケル、パラジウム、又はこれらの組み合わせからなる表面処理材により表面処理が行われる。つまり、導電パッドは、配線パターンと一続きの銅パッド、及び当該銅パッドの表面に積層される表面パッドから構成されることになる。このため、電子部品の実装時に導電パッドに塗布された半田は、リフロー工程において表面パッドの全面に広がり、電子部品の電極端子との間の接続断面積を増大させることができる。 In addition, although the wiring layer described above is generally made of copper, the conductive pads to which soldering is performed are made of gold, nickel, or palladium, which have higher solder wettability and smoother surfaces than copper. The surface treatment is performed using a surface treatment material consisting of , or a combination thereof. In other words, the conductive pad is composed of a copper pad that is continuous with the wiring pattern, and a surface pad that is laminated on the surface of the copper pad. Therefore, the solder applied to the conductive pads during the mounting of the electronic component spreads over the entire surface of the surface pad in the reflow process, thereby increasing the cross-sectional area of the connection with the electrode terminal of the electronic component.
ここで、電子部品を実装する際のリフローにおいて、溶融した半田が表面パッドから銅パッドへ溢れた場合には、当該半田が銅パッドの表面を伝って広がってしまい、短絡に繋がるなどの品質低下を招来する虞が生じる。そこで、特許文献１に係る従来技術では、表面パッドの側縁に接する位置まで銅パッドの表面を粗化することで、部品や配線の高密度化を妨げることなく半田の広がりを抑制している。 During reflow when mounting electronic components, if molten solder overflows from the surface pad to the copper pad, the solder will spread along the surface of the copper pad, leading to short circuits and other quality deterioration. There is a risk that this may lead to Therefore, in the prior art according to Patent Document 1, the surface of the copper pad is roughened to the position where it touches the side edge of the surface pad, thereby suppressing the spread of solder without hindering the high density of components and wiring. .
ところで、上記のような回路基板においては、電子部品の電極端子を導電パッドに半田付けするリフロー工程が複数回行われることがあるため、例えば一次リフロー工程で形成された半田接続が二次リフロー工程で不安定化する可能性がある。このため、一次リフロー工程では固相融点温度が比較的高い所謂高温半田を使用し、二次リフロー工程では固相融点温度が比較的低い通常の半田を使用するのが一般的である。 By the way, in the above-mentioned circuit boards, the reflow process for soldering the electrode terminals of electronic components to the conductive pads may be performed multiple times, so for example, the solder connections formed in the first reflow process may be soldered in the second reflow process. may become unstable. For this reason, it is common to use so-called high-temperature solder, which has a relatively high solid phase melting point temperature, in the primary reflow process, and to use ordinary solder, which has a relatively low solid phase melting point temperature, in the secondary reflow process.
国際公開２０１２／０３２６５４号公報International Publication No. 2012/032654
　しかしながら、上記の従来技術では、銅パッドへ溢れた半田の広がりを抑制することはできるものの、一次リフロー工程で溢れた高温半田が銅パッドの銅成分を含有することにより、当該高温半田の固相融点温度が二次リフロー温度以下まで低下し、半田が再溶融し易くなる虞が生じる。 However, with the above conventional technology, although it is possible to suppress the spread of solder overflowing to the copper pad, the solid phase of the high-temperature solder overflows in the primary reflow process because it contains the copper component of the copper pad. There is a risk that the melting point temperature will drop to below the secondary reflow temperature and the solder will be more likely to re-melt.
　本発明は、このような状況に鑑みてなされたものであり、その目的とするところは、半田の再溶融を抑制する部品実装基板を提供することにある。 The present invention has been made in view of this situation, and its purpose is to provide a component mounting board that suppresses remelting of solder.
　上記した目的を達成するため、本発明の部品実装基板は、電子部品が実装される部品実装基板であって、前記電子部品の電極端子に相当する位置に銅パッドが設けられる配線層と、前記銅パッドの表面上の一部に形成され、半田付けのための表面処理材からなる表面パッドと、前記電極端子を前記表面パッドに接続する半田と、を備え、前記表面パッドの端縁部が前記銅パッドから離間している、部品実装基板である。 In order to achieve the above object, the component mounting board of the present invention is a component mounting board on which electronic components are mounted, and includes a wiring layer in which a copper pad is provided at a position corresponding to an electrode terminal of the electronic component; A surface pad formed on a part of the surface of the copper pad and made of a surface treatment material for soldering, and a solder for connecting the electrode terminal to the surface pad, the edge of the surface pad being A component mounting board spaced apart from the copper pad.
　本発明によれば、半田の再溶融を抑制する部品実装基板を提供することができる。 According to the present invention, it is possible to provide a component mounting board that suppresses remelting of solder.
第１実施形態に係る部品実装基板の断面図である。FIG. 2 is a cross-sectional view of the component mounting board according to the first embodiment. 配線層に表面パッドを形成する工程を示す基板断面図である。FIG. 3 is a cross-sectional view of a substrate showing a step of forming a surface pad on a wiring layer. 部品を実装及び埋設する工程を示す基板断面図である。FIG. 3 is a cross-sectional view of a board showing a process of mounting and embedding components. 第２実施形態に係る部品実装基板の断面図である。FIG. 3 is a cross-sectional view of a component mounting board according to a second embodiment.
　以下、図面を参照し、本発明の実施の形態について詳細に説明する。尚、本発明は、以下に説明する内容に限定されるものではなく、その要旨を変更しない範囲において任意に変更して実施することが可能である。また、実施の形態の説明に用いる図面は、いずれも構成部材を模式的に示すものであって、理解を深めるべく部分的な強調、拡大、縮小、または省略などを行っており、構成部材の縮尺や形状等を正確に表すものとはなっていない場合がある。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the content described below, and can be implemented with arbitrary changes within the scope of not changing the gist. In addition, the drawings used to explain the embodiments schematically show the constituent members, and parts of the drawings are emphasized, enlarged, reduced, or omitted for better understanding. It may not accurately represent the scale, shape, etc.
＜第１実施形態＞
　図１は、第１実施形態に係る部品実装基板１の断面図である。本実施形態に係る部品実装基板１は、両面に配線層１０を備える絶縁層１１に電子部品１２が内蔵された所謂部品内蔵基板である。また、部品実装基板１は、以下に詳細を説明するように、配線層１０の一部として形成された銅パッド１０ｐに半田付け用の表面パッド１３が形成され、半田１４を介して電子部品１２が表面パッド１３に接続されている。 <First embodiment>
FIG. 1 is a cross-sectional view of a component mounting board 1 according to the first embodiment. The component mounting board 1 according to the present embodiment is a so-called component-embedded board in which an electronic component 12 is built into an insulating layer 11 having wiring layers 10 on both sides. Further, as will be described in detail below, in the component mounting board 1, a surface pad 13 for soldering is formed on a copper pad 10p formed as a part of the wiring layer 10, and an electronic component 12 is attached via a solder 14. is connected to the surface pad 13.
　尚、部品実装基板１は、上記した主要構成の他、基板両面の配線層１０に図示しない他の各種部品が実装されている。また、部品実装基板１は、上記の構成に限定されるものではなく、例えば複数の配線層１０、及び複数の絶縁層１１が積層された多層基板であってもよい。以下において、図２及び図３を参照しつつ本発明の第１実施形態に係る部品実装基板１の製造方法の一例について説明する。 In addition to the main components described above, the component mounting board 1 has various other components (not shown) mounted on the wiring layers 10 on both sides of the board. Furthermore, the component mounting board 1 is not limited to the above configuration, and may be a multilayer board in which a plurality of wiring layers 10 and a plurality of insulating layers 11 are laminated, for example. An example of a method for manufacturing the component mounting board 1 according to the first embodiment of the present invention will be described below with reference to FIGS. 2 and 3.
　図２は、配線層１０に表面パッド１３を形成する工程を示す基板断面図である。本工程においては、まず、図２（Ａ）に示すように配線層１０を形成するための銅箔にドライフィルム２０が積層される。 FIG. 2 is a cross-sectional view of the substrate showing the process of forming the surface pad 13 on the wiring layer 10. In this step, first, a dry film 20 is laminated on a copper foil for forming a wiring layer 10, as shown in FIG. 2(A).
　また、ドライフィルム２０は、図２（Ｂ）に示すように、後の工程で実装される電子部品１２の電極位置において開口部Ｖが形成される。より具体的には、ドライフィルム２０は、開口部Ｖを形成する領域以外の表面に図示しないマスクが設けられ、現像液が供給されることにより開口部Ｖの相当する部分が溶解される。このとき、ドライフィルム２０は、底面の角部分２０ａがＲ面として僅かに残るように開口部Ｖが形成される、尚、図面においては、角部分２０ａの大きさを強調して示している。 Furthermore, as shown in FIG. 2(B), the dry film 20 has an opening V formed at the electrode position of the electronic component 12 to be mounted in a later step. More specifically, a mask (not shown) is provided on the surface of the dry film 20 other than the area where the openings V are formed, and the portions corresponding to the openings V are dissolved by supplying a developer. At this time, the opening V is formed in the dry film 20 so that the corner portion 20a of the bottom surface slightly remains as a rounded surface. In the drawing, the size of the corner portion 20a is emphasized.
　次に、図２（Ｃ）に示すように、ドライフィルム２０の開口部Ｖにおいてメッキ処理により表面パッド１３が形成される。表面パッド１３は、半田付けのための表面処理材からなり、より具体的には、銅よりも半田の濡れ性が高く表面の平滑度が高い、金、ニッケル、パラジウムのうち少なくとも一つを含む材料から形成される。尚、表面パッド１３は、接触した半田の固相融点温度を数℃低下させるリンを含まないニッケル材料から形成される。そして、表面パッド１３は、端縁部１３ａが開口部Ｖの角部分２０ａに沿った形状となる。 Next, as shown in FIG. 2C, the surface pad 13 is formed in the opening V of the dry film 20 by plating. The surface pad 13 is made of a surface treatment material for soldering, and more specifically contains at least one of gold, nickel, and palladium, which has higher solder wettability and surface smoothness than copper. Formed from material. Note that the surface pad 13 is formed from a nickel material that does not contain phosphorus, which lowers the solid phase melting point temperature of the solder in contact with it by several degrees centigrade. The surface pad 13 has an edge portion 13a shaped along the corner portion 20a of the opening V.
　続いて、図２（Ｄ）に示すように、配線層１０からドライフィルム２０を除去することにより、配線層１０と表面パッド１３との積層体が形成される。これにより、表面パッド１３の端縁部１３ａが配線層１０から離間し、表面パッド１３の中央部と端縁部１３ａとの間に例えば0.1～5.0μｍの段差が形成されることになる。尚、配線層１０の露出面は、後の工程で使用される半田１４が、万が一、表面パッド１３から溢れた場合であっても、表面上を拡散することが無いよう表面を粗化しておいてもよい。 Subsequently, as shown in FIG. 2(D), by removing the dry film 20 from the wiring layer 10, a laminate of the wiring layer 10 and the surface pad 13 is formed. As a result, the edge portion 13a of the surface pad 13 is separated from the wiring layer 10, and a step of, for example, 0.1 to 5.0 μm is formed between the center portion of the surface pad 13 and the edge portion 13a. The exposed surface of the wiring layer 10 is roughened so that even if solder 14 used in a later process overflows from the surface pad 13, it will not spread over the surface. You can stay there.
　図３は、部品を実装及び埋設する工程を示す基板断面図である。当工程においては、図３（Ｅ）に示すように、まず配線層１０に形成された表面パッド１３の表面に半田１４が塗布される。本実施形態においては、半田１４は、銅成分を含有せず組成が例えばＳｎ－Ｓｂであり、固相融点温度が例えば２４６℃と比較的高い所謂高温半田が採用される。 FIG. 3 is a cross-sectional view of the board showing the process of mounting and embedding components. In this step, as shown in FIG. 3E, solder 14 is first applied to the surface of the surface pad 13 formed on the wiring layer 10. In this embodiment, the solder 14 is a so-called high-temperature solder that does not contain a copper component, has a composition of, for example, Sn-Sb, and has a relatively high solid phase melting point temperature of, for example, 246° C.
　また、図３（Ｆ）に示すように、半田１４を介して表面パッド１３に電子部品１２を実装する一次リフロー工程が行われる。ここで、電子部品１２は、例えばサイズが[1005]（1mm×0.5mm）の半導体チップ、抵抗器、又はコンデンサであり、直方体状の部品本体１２Ａ、部品本体１２Ａの両側面を覆う断面がＵ字形状の電極端子１２Ｂ、及び電極端子１２Ｃを含むチップ部品である。 Further, as shown in FIG. 3(F), a primary reflow process is performed in which the electronic component 12 is mounted on the surface pad 13 via the solder 14. Here, the electronic component 12 is, for example, a semiconductor chip, a resistor, or a capacitor with a size of [1005] (1 mm x 0.5 mm), and has a rectangular parallelepiped component body 12A, and a cross section covering both sides of the component body 12A is U. This is a chip component including a letter-shaped electrode terminal 12B and an electrode terminal 12C.
　そして、半田１４は、一次リフロー工程により、表面パッド１３の表面に広がると共に、電極端子１２Ｂ及び電極端子１２Ｃの底面及び側面との間に所謂半田フィレットを形成する。ここで、表面パッド１３は、上記したように中央部と端縁部１３ａとの間に段差が形成されている。このため、表面パッド１３の上面に広がる半田１４は、配線層１０の表面に溢れないよう堰き止められると共に、配線層１０との間が離間することにより両者が互いに接触する虞が低減されている。 Then, through the primary reflow process, the solder 14 spreads over the surface of the surface pad 13 and forms a so-called solder fillet between the bottom and side surfaces of the electrode terminals 12B and 12C. Here, as described above, the surface pad 13 has a step formed between the center portion and the edge portion 13a. Therefore, the solder 14 that spreads on the upper surface of the surface pad 13 is dammed so that it does not overflow onto the surface of the wiring layer 10, and the separation between the solder 14 and the wiring layer 10 reduces the possibility that the two will come into contact with each other. .
　次に、図３（Ｇ）に示すように、配線層１０に実装した電子部品１２を絶縁層１１で埋設すると共に、絶縁層１１の表面に新たに配線層１０を設けることにより両面板を構成する。ここで、絶縁層１１は、絶縁性を有する樹脂材料からなり、例えば電子部品１２の周囲にプリプレグを配置して加熱すると共に、銅からなる新たな配線層１０を表面に重ねて厚み方向に押圧することにより形成することができる。 Next, as shown in FIG. 3(G), the electronic components 12 mounted on the wiring layer 10 are buried in the insulating layer 11, and a new wiring layer 10 is provided on the surface of the insulating layer 11 to form a double-sided board. do. Here, the insulating layer 11 is made of a resin material having insulating properties. For example, a prepreg is placed around the electronic component 12 and heated, and a new wiring layer 10 made of copper is placed on the surface and pressed in the thickness direction. It can be formed by
　そして、両面の配線層１０は、電子部品１２の電極端子１２Ｂ及び電極端子１２Ｃに相当する位置に銅パッド１０ｐを設けつつ、配線パターンを形成するようにパターニングされることにより、図１に示す部品実装基板１が形成される。 Then, the wiring layer 10 on both sides is patterned to form a wiring pattern while providing copper pads 10p at positions corresponding to the electrode terminals 12B and 12C of the electronic component 12, thereby forming the component shown in FIG. A mounting board 1 is formed.
　図１に示す部品実装基板１には、両面の配線層１０に図示しない他の各種部品が実装される。当該実装は、固相融点温度が例えば２１７℃と比較的低い通常の半田が採用され、リフロー温度を例えば２４０℃とする二次リフロー工程で行われる。このため、一次リフロー工程の後に硬化した半田１４は、二次リフロー工程において再溶融せず、また、固相融点温度の低下を招来する銅パッド１０ｐとの接触も妨げられるため、二次リフロー工程により不安定化する虞が低減される。 In the component mounting board 1 shown in FIG. 1, various other components (not shown) are mounted on the wiring layers 10 on both sides. The mounting is performed in a secondary reflow process using a normal solder having a relatively low solid phase melting point temperature of, for example, 217°C, and at a reflow temperature of, for example, 240°C. Therefore, the solder 14 that has hardened after the first reflow process is not remelted in the second reflow process, and is also prevented from coming into contact with the copper pad 10p, which would cause a decrease in the solid phase melting point temperature, so the solder 14 is hardened after the first reflow process. This reduces the risk of instability.
　以上のように、本発明の第１実施態様に係る部品実装基板１は、電子部品１２を配線層１０に実装するための導電パッドにおいて、銅パッド１０ｐに積層される表面パッド１３の端縁部１３ａが銅パッド１０ｐから離間しており、表面パッド１３の中央部と端縁部１３ａとの間に段差が形成されている。このため、表面パッド１３の上面に広がる半田１４は、銅パッド１０ｐの表面に溢れないよう堰き止められると共に、銅パッド１０ｐと接触する虞が低減される。従って、第１実施態様に係る部品実装基板１は、半田１４の固相融点温度の低下に伴う再溶融を抑制することができる。 As described above, in the component mounting board 1 according to the first embodiment of the present invention, in the conductive pad for mounting the electronic component 12 on the wiring layer 10, the edge portion of the surface pad 13 laminated on the copper pad 10p 13a is spaced apart from the copper pad 10p, and a step is formed between the center portion of the surface pad 13 and the edge portion 13a. Therefore, the solder 14 spreading on the upper surface of the front pad 13 is dammed so that it does not overflow onto the surface of the copper pad 10p, and the possibility of contacting the copper pad 10p is reduced. Therefore, the component mounting board 1 according to the first embodiment can suppress remelting of the solder 14 due to a decrease in the solid phase melting point temperature.
＜第２実施形態＞
　続いて、第２実施形態に係る部品実装基板２について説明する。第２実施形態に係る部品実装基板２は、上記した第１実施形態の部品実装基板１の部品内蔵基板とは異なり、電子部品が基板に表面実装されている点において第１実施形態と異なる。以下、第１実施形態と異なる部分について説明することとし、第１実施形態と共通する構成要素については、同じ符号を付して詳細な説明を省略する。 <Second embodiment>
Next, a component mounting board 2 according to a second embodiment will be described. The component mounting board 2 according to the second embodiment differs from the first embodiment in that electronic components are surface mounted on the board, unlike the component built-in board of the component mounting board 1 of the first embodiment described above. Hereinafter, parts that are different from the first embodiment will be explained, and constituent elements common to the first embodiment will be given the same reference numerals and detailed explanations will be omitted.
　図４は、第２実施形態に係る部品実装基板２の断面図である。第２実施形態に係る部品実装基板２は、絶縁層１１の両面に設けられた配線層１０をパターニングすることにより、電子部品１２の電極端子１２Ｂ及び電極端子１２Ｃに相当する位置に銅パッド１０ｐを設けつつ、配線パターンが形成される。また、銅パッド１０ｐの表面上の一部に表面パッド１３が形成される。このとき、表面パッド１３は、第１実施形態と同様の手順により、端縁部１３ａが銅パッド１０ｐから離間するように形成されることで、中央部と端縁部１３ａとの間に段差が形成される。そして、表面パッド１３に設けられる半田１４を介して配線層１０に電子部品１２が実装される。 FIG. 4 is a cross-sectional view of the component mounting board 2 according to the second embodiment. The component mounting board 2 according to the second embodiment has copper pads 10p at positions corresponding to the electrode terminals 12B and 12C of the electronic component 12 by patterning the wiring layer 10 provided on both sides of the insulating layer 11. While providing the wiring pattern, the wiring pattern is formed. Further, a surface pad 13 is formed on a portion of the surface of the copper pad 10p. At this time, the surface pad 13 is formed by the same procedure as in the first embodiment so that the edge portion 13a is spaced apart from the copper pad 10p, so that a step is created between the center portion and the edge portion 13a. It is formed. Then, the electronic component 12 is mounted on the wiring layer 10 via the solder 14 provided on the surface pad 13.
　尚、第２実施形態に係る部品実装基板２においては、実装後の電子部品１２の半田接合部に対して公知のアンダーコート、オーバーコート、又はサイドコートにより封止するのが好適である。また、配線層１０は、ソルダーレジストが塗布されることにより絶縁保護される。 In the component mounting board 2 according to the second embodiment, it is preferable to seal the solder joints of the electronic components 12 after mounting with a known undercoat, overcoat, or side coat. Further, the wiring layer 10 is insulated and protected by applying a solder resist.
　そして、第２実施形態に係る部品実装基板２は、第１実施形態と同様に、表面パッド１３の上面に広がる半田１４が、銅パッド１０ｐの表面に溢れないよう堰き止められると共に、銅パッド１０ｐと接触する虞が低減されている。従って、第２実施形態に係る部品実装基板２は、電子部品１２が表面実装される場合であっても、第１実施形態と同様に半田１４の再溶融を抑制することができる。 In the component mounting board 2 according to the second embodiment, similarly to the first embodiment, the solder 14 spreading on the upper surface of the surface pad 13 is dammed so that it does not overflow onto the surface of the copper pad 10p. The risk of contact with is reduced. Therefore, the component mounting board 2 according to the second embodiment can suppress remelting of the solder 14, as in the first embodiment, even when the electronic component 12 is surface mounted.
＜本発明の実施態様＞
　本発明の第１実施態様に係る部品実装基板は、電子部品が実装される部品実装基板であって、前記電子部品の電極端子に相当する位置に銅パッドが設けられる配線層と、前記銅パッドの表面上の一部に形成され、半田付けのための表面処理材からなる表面パッドと、前記電極端子を前記表面パッドに接続する半田と、を備え、前記表面パッドの端縁部が前記銅パッドから離間している、部品実装基板である。 <Embodiments of the present invention>
A component mounting board according to a first embodiment of the present invention is a component mounting board on which an electronic component is mounted, and includes a wiring layer in which a copper pad is provided at a position corresponding to an electrode terminal of the electronic component, and a wiring layer provided with a copper pad at a position corresponding to an electrode terminal of the electronic component. a surface pad made of a surface treatment material for soldering; and solder for connecting the electrode terminal to the surface pad; This is a component mounting board that is separated from the pad.
　本発明の第１実施態様に係る部品実装基板は、電子部品を配線層に実装するための導電パッドにおいて、銅パッドに積層される表面パッドの端縁部が銅パッドから離間しており、表面パッドの中央部と端縁部との間に段差が形成されている。このため、表面パッドの上面に広がる半田は、銅パッドの表面に溢れないよう堰き止められると共に、銅パッドと接触する虞が低減される。従って、第１実施態様に係る部品実装基板は、半田の固相融点温度の低下に伴う再溶融を抑制することができる。 In the component mounting board according to the first embodiment of the present invention, in the conductive pad for mounting electronic components on the wiring layer, the edge of the surface pad laminated on the copper pad is spaced apart from the copper pad, and the surface pad is separated from the copper pad. A step is formed between the center portion and the edge portion of the pad. Therefore, the solder spreading on the upper surface of the surface pad is dammed so that it does not overflow onto the surface of the copper pad, and the risk of contacting the copper pad is reduced. Therefore, the component mounting board according to the first embodiment can suppress remelting caused by a decrease in the solid phase melting point temperature of the solder.
　本発明の第２実施態様に係る部品実装基板は、上記した本発明の第１実施態様において、前記半田は、銅を含まないＳｎ－Ｓｂからなり、前記表面パッドは、リンを含まないニッケルからなる、部品実装基板である。 In the component mounting board according to the second embodiment of the present invention, in the first embodiment of the present invention described above, the solder is made of Sn--Sb that does not contain copper, and the surface pad is made of nickel that does not contain phosphorus. This is a component mounting board.
　本発明の第２実施態様に係る部品実装基板によれば、表面パッドに接触した半田の固相融点温度が数℃低下することによる半田の再溶融を抑制することができる。 According to the component mounting board according to the second embodiment of the present invention, it is possible to suppress remelting of the solder due to a decrease in the solid phase melting point temperature of the solder in contact with the surface pad by several degrees Celsius.
　　１～２　部品実装基板
　１０　配線層
　１０ｐ　銅パッド
　１１　絶縁層
　１２　電子部品
　１３　表面パッド
　１３ａ　端縁部
　１４　半田 1-2 Component mounting board 10 Wiring layer 10p Copper pad 11 Insulating layer 12 Electronic component 13 Surface pad 13a Edge portion 14 Solder

Claims (2)

  1. 　電子部品が実装される部品実装基板であって、
    　前記電子部品の電極端子に相当する位置に銅パッドが設けられる配線層と、
    　前記銅パッドの表面上の一部に形成され、半田付けのための表面処理材からなる表面パッドと、
    　前記電極端子を前記表面パッドに接続する半田と、を備え、
    　前記表面パッドの端縁部が前記銅パッドから離間している、部品実装基板。     A component mounting board on which electronic components are mounted,
    a wiring layer in which copper pads are provided at positions corresponding to electrode terminals of the electronic component;
    a surface pad formed on a part of the surface of the copper pad and made of a surface treatment material for soldering;
    solder connecting the electrode terminal to the surface pad,
    A component mounting board, wherein an edge portion of the surface pad is spaced apart from the copper pad.
  2. 　前記半田は、銅を含まないＳｎ－Ｓｂからなり、
    　前記表面パッドは、リンを含まないニッケルからなる、請求項１に記載の部品実装基板。     The solder is made of Sn-Sb containing no copper,
    2. The component mounting board according to claim 1, wherein the surface pad is made of nickel that does not contain phosphorus.
PCT/JP2022/028988 2022-07-27 2022-07-27 Component mounting substrate WO2024023980A1 (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001015539A (en) * 1999-07-02 2001-01-19 Fujitsu Ltd Semiconductor and its manufacture
JP2017073497A (en) * 2015-10-08 2017-04-13 イビデン株式会社 Printed wiring board and method for manufacturing the same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001015539A (en) * 1999-07-02 2001-01-19 Fujitsu Ltd Semiconductor and its manufacture
JP2017073497A (en) * 2015-10-08 2017-04-13 イビデン株式会社 Printed wiring board and method for manufacturing the same

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