Classifications

• • 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
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/0274—Optical details, e.g. printed circuits comprising integral optical means
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/50—Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the groups H01L21/18 - H01L21/326 or H10D48/04 - H10D48/07 e.g. sealing of a cap to a base of a container
  • H01L21/56—Encapsulations, e.g. encapsulation layers, coatings
  • H01L21/563—Encapsulation of active face of flip-chip device, e.g. underfilling or underencapsulation of flip-chip, encapsulation preform on chip or mounting substrate
• • 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
  • H05K3/3452—Solder masks
• • 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
  • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
  • H05K2201/09—Shape and layout
  • H05K2201/09145—Edge details
• • 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
  • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
  • H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
  • H05K2201/10007—Types of components
  • H05K2201/10121—Optical component, e.g. opto-electronic component
• • 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
  • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
  • H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
  • H05K2201/10431—Details of mounted components
  • H05K2201/10439—Position of a single component
  • H05K2201/10446—Mounted on an edge
• • 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
  • H05K3/341—Surface mounted components
  • H05K3/3431—Leadless components
  • H05K3/3436—Leadless components having an array of bottom contacts, e.g. pad grid array or ball grid array components

Definitions

• This disclosure relates to a wiring board and a mounting structure using the same.
• a wiring board having a processor die mounted on the top surface and an optical module mounted on the outer periphery to connect to an optical connector (Patent Documents 1 and 2).
• the optical module includes a photonics die.
• underfill (sealing resin) is filled between the photonics die and the wiring board. Some of the filled underfill (sealing resin) may overflow onto the outer side of the board, causing connection problems with the optical connector. Underfill (sealing resin) is particularly likely to overflow when the edge of the solder resist located on the top surface of the wiring board is chipped. The outer edge of the wiring board is easily subjected to impacts during transportation, and the relatively fragile edge of the solder resist is easily chipped by the impact.
• the wiring board according to the present disclosure includes an insulating substrate having a first surface and a second surface located opposite the first surface, and a solder resist located on the first surface.
• the insulating substrate includes at least one recess recessed from the periphery of the insulating substrate toward the center in a plan view, and a plurality of electrodes located on the first surface along the recess.
• the solder resist has an opening that exposes the electrode.
• the periphery of the solder resist includes a first periphery along the recess, and a second periphery along the periphery of the insulating substrate other than the recess.
• the first periphery overlaps with the periphery of the recess, and the second periphery includes a first region that connects to the first periphery. In a plan view, the first region is located toward the center from the periphery of the insulating substrate.
• the mounting structure according to the present disclosure includes the above-mentioned wiring board, an adapter located in the recess, and an electronic component connected to the adapter and to a plurality of electrodes located on the first surface of the insulating substrate, and a sealing resin is located between the underside of the electronic component and the solder resist.
• FIG. 1 is an explanatory diagram showing a mounting structure including a wiring board according to an embodiment of the present disclosure.
• FIG. 2 is an explanatory diagram illustrating a wiring board according to an embodiment of the present disclosure.
• FIG. 3 is a plan view of a region X shown in FIG. 2 .
• 2 is an enlarged explanatory view showing a connection portion between an adapter and an optical connector in the mounting structure shown in FIG. 1 .
• 2 is an enlarged explanatory view showing a state of a sealing resin at a connection portion between an adapter and an optical connector in the mounting structure shown in FIG. 1 .
• the wiring board and mounting structure disclosed herein have the configuration described in the section on means for solving the above problems, and therefore, even if some of the filled sealing resin overflows, it can be prevented from overflowing onto the outer peripheral side surface of the wiring board.
• FIG. 1 is an explanatory diagram showing a mounting structure 10 including a wiring board 1 according to an embodiment of the present disclosure.
• Figure 2 is an explanatory diagram showing a wiring board 1 according to an embodiment of the present disclosure.
• the wiring board 1 according to the embodiment includes an insulating substrate 2 and a solder resist 3.
• the insulating substrate 2 has a first surface f1 and a second surface f2 located on the opposite side of the first surface f1.
• the insulating layers constituting the insulating substrate 2 include a core insulating layer and a build-up insulating layer.
• the build-up insulating layer is not particularly limited as long as it is made of an insulating material.
• insulating materials include resins such as epoxy resins, bismaleimide-triazine resins, polyimide resins, and polyphenylene ether resins. Two or more of these resins may be mixed together.
• the build-up insulating layer may contain a reinforcing material.
• reinforcing materials include insulating cloth materials such as glass fiber, glass nonwoven fabric, aramid nonwoven fabric, aramid fiber, and polyester fiber. Two or more types of reinforcing materials may be used in combination.
• the build-up insulating layer may have inorganic insulating fillers such as silica, barium sulfate, talc, clay, glass, calcium carbonate, and titanium oxide dispersed therein. Two or more types of inorganic insulating fillers may be used in combination.
• the build-up insulation layer is located on the upper and lower sides of the core insulation layer.
• the thickness of the build-up insulation layer is not particularly limited, and is, for example, 10 ⁇ m or more and 50 ⁇ m or less.
• a via hole conductor is located in the build-up insulating layer to electrically connect the upper and lower surfaces of the build-up insulating layer.
• the via hole conductor is located in a via hole that penetrates the upper and lower surfaces of the build-up insulating layer.
• the via hole conductor is formed of a metal such as copper, specifically a metal plating such as copper plating.
• the via hole conductor may be filled in the via hole, or may be formed only on the inner wall surface of the via hole.
• the via hole conductor is connected to conductor layers located on the upper and lower surfaces of the build-up insulating layer.
• the core insulating layer is also not particularly limited as long as it is made of an insulating material.
• examples of insulating materials include resins such as epoxy resin, bismaleimide-triazine resin, polyimide resin, and polyphenylene ether resin.
• it may contain a reinforcing material and may have inorganic insulating fillers dispersed therein.
• the core insulation layer is located approximately at the center in the thickness direction of the wiring board 1, and is usually thicker than the build-up insulation layer. There are no particular limitations on the thickness of the core insulation layer, and it is, for example, 100 ⁇ m or more and 1500 ⁇ m or less.
• a through-hole conductor is located to electrically connect the upper and lower surfaces of the core insulating layer.
• the through-hole conductor is located in a through-hole that penetrates the upper and lower surfaces of the core insulating layer.
• the through-hole conductor is formed of a metal such as copper, specifically, a metal plating such as copper plating.
• the through-hole conductor may be formed only on the inner wall surface of the through-hole, or may be filled in the through-hole.
• the through-hole conductor is connected to a conductor layer located on the upper and lower surfaces of the core insulating layer.
• the shape of the insulating substrate 2 is not limited.
• the insulating substrate 2 may have a rectangular shape as shown in FIG. 2, or may have a polygonal shape other than a rectangular shape, a circular shape, an elliptical shape, or the like.
• the insulating substrate 2 has a recess 21 recessed from the periphery of the insulating substrate 2 toward the center. At least one recess 21 is included in the insulating substrate 2.
• the recess 21 is positioned so as to recess toward the center from one side (first side) of the sides constituting the rectangular shape.
• the size of the recess 21 is set appropriately according to the size of the adapter 4 located in the recess 21. At least one recess 21 needs to be included in the insulating substrate 2, and if the insulating substrate 2 is polygonal, such as rectangular, multiple recesses 21 may be included on one side.
• a number of electrodes 8 are located along the recess 21 on the first surface f1 of the insulating substrate 2.
• the first surface f1 of the insulating substrate 2 is the upper surface on the surface side in the thickness direction of the wiring substrate 1, and the second surface f2 is the lower surface located on the opposite side to the first surface f1 in the thickness direction of the wiring substrate 1.
• the electrodes 8 are made of a metal such as copper, and are part of the conductor layer located on the first surface f1 of the insulating substrate 2.
• the electrodes 8 are located not only along the recess 21, but also, for example, in approximately the center of the insulating substrate 2, as shown in FIG. 2.
• a terminal of the processor die is connected to this central electrode 8 via solder 7, which will be described later.
• the solder resist 3 is located on the first surface f1 of the insulating substrate 2.
• the solder resist 3 is made of a resin, such as an acrylic-modified epoxy resin.
• the solder resist 3 has a thickness of, for example, 10 ⁇ m or more and 50 ⁇ m or less.
• the solder resist 3 has openings that expose each electrode 8 individually.
• solder 7 is attached to the electrodes 8 exposed in the openings.
• the solder resist 3 When viewed in a plan view, the solder resist 3 is formed according to the shape of the insulating substrate 2.
• the periphery of the solder resist 3 includes a first periphery 31 that follows the recess 21 of the insulating substrate 2, and a second periphery 32 that follows the periphery of the insulating substrate 2 other than the recess 21.
• the first periphery 31 of the solder resist 3 overlaps with the periphery of the recess 21 of the insulating substrate 2. In other words, the side of the first periphery 31 and the side of the recess 21 are positioned so as to be approximately flush with each other.
• the first periphery 31 of the solder resist 3 overlaps with the periphery of the recess 21 of the insulating substrate 2, so that the width of the solder resist 3 can be sufficiently secured.
• the thermal effect on the wiring board 1 when mounting the electronic component 5 described below is reduced.
• the gap between the underside of the electronic component 5 and the mounting area of the wiring board 1 (solder resist 3) becomes constant, and the filling of the sealing resin 6 becomes uniform.
• the second periphery 32 of the solder resist 3 includes a first region 321 connected to the first periphery 31, as shown in FIG. 3.
• the first region 321 is located toward the center from the periphery other than the recess 21 of the insulating substrate 2.
• FIG. 3 is a plan view of region X shown in FIG. 2.
• the first region 321 of the second periphery 32 is located toward the center from the first side of the insulating substrate 2.
• the first region 321 is located toward the center from the periphery of the insulating substrate 2, for example, when the sealing resin 6 is filled between the wiring substrate 1 and the electronic component 5, the overflowing sealing resin 6 is retained on the first surface f1 of the insulating substrate 2 exposed from the solder resist 3.
• a step is formed between the periphery (second periphery 32) of the solder resist 3 and the periphery of the insulating substrate 2.
• the sealing resin 6 is less likely to overflow onto the outer periphery side of the wiring substrate 1.
• the sealing resin 6 flows up to the step, as shown in FIG. 5, the sealing resin 6 flows along the step and is less likely to overflow onto the outer periphery side of the wiring substrate 1.
• the optical connector 41 is well connected to the wiring substrate 1 via the adapter 4.
• FIGS. 4 and 5 are enlarged explanatory views showing the connection between the adapter 4 and the optical connector 41 in the mounting structure 10 shown in FIG. 1.
• the solder resist 3 is relatively fragile, chips or scratches are likely to occur on the periphery.
• the second periphery 32 is less likely to be subjected to impacts that occur during transportation, etc.
• chips and scratches are less likely to occur on the second periphery 32 of the solder resist 3.
• Chips that occur on the periphery of the solder resist 3 become starting points for the sealing resin 6 to flow out onto the outer peripheral side surface of the wiring board 1. Therefore, reducing the occurrence of chips is also advantageous in terms of preventing the sealing resin 6 from flowing out.
• the distance between the first region 321 and the periphery of the insulating substrate 2 that is located closest to the first region 321 is not limited.
• the third distance L3 may be, for example, 50 ⁇ m or more and 500 ⁇ m or less.
• the electrodes 8 located on the first surface f1 of the insulating substrate 2 include a first electrode 81 located closest to the first periphery 31 and a second electrode 82 located closest to the first region 321 of the second periphery 32.
• first distance L1 may be shorter than the distance between the first region 321 of the second periphery 32 and the second electrode 82 (second distance L2).
• first distance L1 may be 100 ⁇ m or more and 400 ⁇ m or less
• the second distance L2 may be 200 ⁇ m or more and 600 ⁇ m or less.
• the width of the recess 21 is sufficiently secured while maintaining sufficient electrical insulation reliability between the multiple electrodes 8 located along the recess 21. Furthermore, a region in which the sealing resin 6 can be retained in the direction of the outer peripheral side surface of the wiring substrate 1 can be secured, thereby further reducing the risk of the sealing resin 6 flowing out to the outer peripheral side surface.
• the difference between the first distance L1 and the second distance L2 may be, for example, 100 ⁇ m or more. If the difference between the first distance L1 and the second distance L2 is 100 ⁇ m or more, the sealing resin 6 is more likely to be filled between the electronic component 5 and the wiring board 1 (solder resist 3). As a result, it is expected that the electrical insulation reliability between the multiple electrodes 8 will be improved. Furthermore, the risk of the sealing resin 6 flowing out onto the outer peripheral side surface of the wiring board 1 can be further reduced.
• the difference between the first distance L1 and the second distance L2 may be, for example, 200 ⁇ m or less.
• the above-mentioned third distance L3 may be shorter than the first distance L1.
• the third distance L3 By making the third distance L3 shorter than the first distance L1, it becomes easier to sufficiently fill the spaces between the multiple electrodes 8 located along the recess 21 with the sealing resin 6, improving the electrical insulation reliability.
• the third distance L3 shorter than the first distance L1 the exposed portion of the first surface f1 of the insulating substrate 2 is reduced, and the wiring substrate 1 can be made smaller.
• the arithmetic mean roughness of the first surface f1 of the insulating substrate 2 and the surface of the solder resist 3 is not limited.
• the arithmetic mean roughness of the first surface f1 of the insulating substrate 2 exposed along the second periphery 32 may be greater than the arithmetic mean roughness of the surface of the solder resist 3.
• the arithmetic mean roughness of the surface of the solder resist 3 may be 200 nm or more and 400 nm or less.
• the arithmetic mean roughness of the first surface f1 of the insulating substrate 2 exposed along the second periphery 32 may be 500 nm or more and 800 nm or less.
• the above arithmetic mean roughness can be measured, for example, by a laser microscope.
• the sealing resin 6 is more easily filled. Furthermore, the wettability of the first surface f1 of the insulating substrate 2 exposed along the second periphery 32 is improved. Therefore, for example, as shown in FIG. 5, even if the sealing resin 6 flows onto the exposed first surface f1 of the insulating substrate 2, the sealing resin 6 is more likely to spread onto the exposed first surface f1 along the corner between the end face of the solder resist 3 and the exposed first surface f1. As a result, the sealing resin 6 is less likely to overflow onto the outer peripheral side surface of the wiring substrate 1.
• a mounting structure 10 includes a wiring board 1 according to the above-described embodiment, an adapter 4, an electronic component 5, an optical connector 41, and a sealing resin 6.
• the adapter 4 is a member for connecting the optical connector 41 to the wiring board 1, and is located in the recess 21 of the insulating board 2.
• the width L4 of the first region 321 may be longer than the width L5 of the optical connector 41 in the direction along the first region 321.
• the portion of the optical connector 41 that faces the outer periphery of the wiring board 1 is contained within the first region 321. Since the first region 321 is located closer to the center of the wiring board 1 than the periphery of the insulating board 2, it is possible to reduce the flow of the sealing resin 6 onto the outer periphery of the wiring board 1, and the connectivity between the optical connector 41 and the wiring board 1 can be improved.
• the electronic components 5 are connected to the adapter 4 and a plurality of electrodes 8 located on the first surface f1 of the insulating substrate 2.
• Examples of the electronic components 5 include optoelectronic elements and interface elements.
• the sealing resin 6 is located between the bottom surface of the electronic components 5 and the solder resist 3.
• the sealing resin 6 is used to fix the electronic components 5 to the wiring substrate 1.
• Examples of the sealing resin 6 include epoxy resin, polyimide resin, and urethane resin.
• the wiring board according to the present disclosure includes an insulating substrate having a first surface and a second surface located opposite to the first surface, and a solder resist located on the first surface.
• the insulating substrate includes at least one recess recessed from the periphery of the insulating substrate toward the center in a plan view, and a plurality of electrodes located on the first surface along the recess.
• the solder resist has openings that expose the electrodes.
• the periphery of the solder resist includes a first periphery along the recess, and a second periphery along the periphery of the insulating substrate other than the recess.
• the first periphery overlaps with the periphery of the recess, and the second periphery includes a first region that is connected to the first periphery. In a plan view, the first region is located toward the center from the periphery of the insulating substrate.
• the insulating substrate in a planar view, has a rectangular shape including a first side, the recess is recessed toward the center from the first side, and in a planar view, the first region of the second peripheral edge is located toward the center from the first side of the insulating substrate.
• the arithmetic mean roughness of the first surface of the insulating substrate exposed along the second peripheral edge is greater than the arithmetic mean roughness of the surface of the solder resist.
• the multiple electrodes include a first electrode located closest to the first periphery and a second electrode located closest to a first region of the second periphery, and a first distance between the first periphery and the first electrode is shorter than a second distance between the first region of the second periphery and the second electrode.
• the difference between the first distance and the second distance is 100 ⁇ m or more.
• a third distance between the first region and a periphery of the insulating substrate that is located closest to the first region is shorter than the first distance.
• a mounting structure includes a wiring board as described above in any one of (1) to (6), an adapter located in the recess, and an electronic component connected to the adapter and to a plurality of electrodes located on a first surface of the insulating substrate, and a sealing resin is located between the underside of the electronic component and the solder resist.
• the adapter is connected to the optical connector on the side opposite the recess, and the width of the first region in the direction along the periphery of the insulating substrate is longer than the width of the portion facing the first region of the optical connector.

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• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Manufacturing & Machinery (AREA)
• Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• General Physics & Mathematics (AREA)
• Computer Hardware Design (AREA)
• Power Engineering (AREA)
• Non-Metallic Protective Coatings For Printed Circuits (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Cited By (1)

Citations (6)

• 2023
  • 2023-09-26 CN CN202380068057.2A patent/CN119856576A/zh active Pending
  • 2023-09-26 EP EP23872292.0A patent/EP4598286A1/en active Pending
  • 2023-09-26 WO PCT/JP2023/034821 patent/WO2024071069A1/ja not_active Ceased
  • 2023-09-26 JP JP2024549390A patent/JPWO2024071069A1/ja active Pending

Patent Citations (6)

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