JP2016025226A - Wiring board for mounting light-emitting element, and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reflection efficiency in a board for mounting a light-emitting element.SOLUTION: A board for mounting a light-emitting element, includes: an insulation layer; a plurality of connection terminals; and a reflection film. Each connection terminal is formed in the mounting region of a light-emitting element on the insulation layer. The reflection film is laminated on the insulation layer, and the outer peripheral surface of the connection terminal, including a part constituted as a peripheral surface forming a cavity surrounding the mounting region, is in contact with the reflection film. At least a part of the peripheral surface is formed as a curved surface. In the curved surface, the angle formed by a tangent line from an arbitrary point of the peripheral surface toward the side separating from the insulation layer, and a parallel line from an arbitrary point toward the side separating from the connection terminal in parallel with the surface of the insulation layer is larger than 0 degree and smaller than 90 degree, in a cut surface set in the direction perpendicular to the surface of the insulation layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light emitting element mounting wiring board.

  A light emitting element such as an LED may be mounted in a cavity provided on a wiring board. By providing a reflective film on the peripheral surface (wall surface) surrounding such a cavity, in addition to the light emitted directly from the light emitting element, the reflected light from the reflective film can also be emitted to the outside. As the shape of the peripheral surface provided with such a reflective film, a curved shape is known (for example, Patent Document 1). In the disclosure of Patent Document 1, the curved peripheral surface is arranged so as not to contact the connection terminal of the light emitting element.

JP 2006-270046 A

  Based on the above prior art, the invention of the present application aims to improve reflection efficiency. In the case of the above prior art, since the curved peripheral surface is arranged so as not to contact the connection terminal, the area of the reflective film surrounding the mounting region is smaller than the area of the cavity. Therefore, the amount of light irradiated to the part other than the reflective film is increased, and as a result, the reflection efficiency is poor.

  SUMMARY An advantage of some aspects of the invention is to solve the above-described problems, and the invention can be implemented as the following forms.

(1) According to one embodiment of the present invention, an insulating layer; a plurality of connection terminals formed in a mounting region of a light emitting element on the insulating layer; and stacked on the insulating layer and surrounding the mounting region And a reflective film including a portion configured as a peripheral surface forming a cavity. The wiring board for mounting a light emitting element includes: an outer peripheral surface of the connection terminal is in contact with the reflective film; at least a part of the peripheral surface is formed as a curved surface; In a cut surface along the vertical direction, a tangent line extending from an arbitrary point on the curved surface toward the side away from the insulating layer, and a line extending from the arbitrary point parallel to the surface of the insulating layer toward the side away from the connection terminal. The angle with the parallel line is greater than 0 degrees and smaller than 90 degrees. According to this embodiment, the reflection efficiency can be improved. In the case of this form, since the outer peripheral surface of the connection terminal is in contact with the reflection film, the area of the reflection film with respect to the area of the cavity is increased. As a result, the above effect can be obtained.

(2) The reflective film may include a portion disposed in the mounting region. According to this embodiment, the reflection efficiency can be further improved. This is because, in the case of this form, the reflective film is also disposed in the mounting region in addition to the peripheral surface.

(3) The height of the reflective film in a direction perpendicular to the surface of the insulating layer may be the same as the height of the connection terminal at a portion in contact with the outer peripheral surface of the connection terminal. According to this aspect, the reflective film can be brought close to the light emitting element while exposing the connection terminals, so that the reflection efficiency can be improved.

(4) As another form, a method for manufacturing the light emitting element mounting wiring board of the above form is provided. The manufacturing method includes a step of preparing a base material, a base material with a metal sheet, and a first metal sheet laminated on the base material, and a second metal sheet laminated on the first metal sheet. Forming a plating resist layer having an opening on the second metal sheet; and forming a convex metal conductor on the second metal sheet by performing plating in the opening. And a step of etching the metal conductor portion to process the metal conductor portion into a shape corresponding to the peripheral surface; and covering the metal conductor portion with an insulating resin layer serving as the reflective film. And a step of peeling the first metal sheet from the second metal sheet; and a step of removing the second metal sheet and the metal conductor portion from the insulating resin layer. The wiring board for mounting a light emitting element in the above form can be manufactured, for example, by the above method.

(5) As another form, a method for producing a light emitting element mounting wiring board of the above form is provided. The manufacturing method includes: a step of forming the plurality of connection terminals on the insulating layer; a step of covering the insulating layer and the plurality of connection terminals with a photosensitive insulating resin layer serving as the reflective film; Exposing and developing the photosensitive insulating resin layer to form a recess in the insulating resin layer; applying heat curing to the insulating resin layer in which the recess is formed; and And a step of deforming the wall surface of the dent into the curved surface by performing photocuring. The wiring board for mounting a light emitting element in the above form can be manufactured by the above method, for example.

  The present invention can be realized in forms other than those described above. For example, it can be realized as a light emitting device equipped with a light emitting element.

Sectional drawing of a wiring board for light emitting element mounting (henceforth Embodiment 1). Sectional drawing of the wiring board for light emitting element mounting which mounted the light emitting element. The manufacturing process figure of a board | substrate. The figure which shows a mode that the multilayer metal sheet was laminated | stacked on the support substrate (P205). The figure which shows a mode that the plating resist layer was formed (P210). The figure which shows a mode that the metal conductor part was formed on the multilayer metal sheet (P215). The figure which shows a mode that the curved conductor part was formed from the metal conductor part (P220) The figure which shows a mode that the reflecting film was formed on the multilayer metal sheet (P230). The figure which shows a mode that the 1st via hole was formed in the reflecting film (P235). The figure which shows a mode that the conductor part was formed (P245). The figure which shows a mode that the insulating layer was formed (P250). The figure which shows a mode that the 2nd via hole was formed in the insulating layer (P255). The figure which shows a mode that the connection terminal was formed (P265). The figure which shows a mode that the reflective film was formed (P270). The figure which shows a mode that the opening part was formed in the reflecting film (P275). The figure which shows a mode that the both ends of the whole laminated body were cut off (P280). The figure which shows a mode that copper foil and copper foil were peeled (P285). The top view of the wiring board for light emitting element mounting (henceforth Embodiment 2). Sectional drawing of the wiring board for light emitting element mounting. The top view of the wiring board for light emitting element mounting which mounted the light emitting element. Sectional drawing of the wiring board for light emitting element mounting which mounted the light emitting element. The manufacturing process figure of a board | substrate. The figure which shows a mode that the core board | substrate with copper foil was prepared (P405). The figure which shows a mode that the via hole was formed in the core board | substrate (P410). The figure which shows a mode that the via conductor and the plating layer were formed (P420). The figure which shows a mode that the dry film was pattern-formed (P425). The figure which shows a mode that the plating layer was etched (P430). The figure which shows a mode that the dry film was peeled (P435). The figure which shows a mode that the reflective film was coated on the core board | substrate (P440). The figure which shows a mode that the reflecting film used as an outer side area | region was photocured (P445). The figure which shows a mode that it was immersed in the sodium carbonate aqueous solution (P450). The figure which shows a mode that the reflective film was emulsified (P455). The figure which shows a mode that the reflective film which swelled and emulsified was removed (P460). Sectional drawing of the wiring board for light emitting element mounting (Embodiment 3).

  Embodiment 1 will be described. FIG. 1 is a cross-sectional view of a light emitting element mounting wiring substrate 10 (hereinafter referred to as “substrate 10”). FIG. 2 is a cross-sectional view of the substrate 10 on which the light emitting element (LED) 500 is mounted. The substrate 10 has a structure in which the reflective film 21, the insulating layer 50, and the reflective film 23 are stacked. The cross section thereof is along a direction perpendicular to the surface of the insulating layer 50 shown in FIGS. The surface of the insulating layer 50 is a surface that becomes a boundary with the reflective film 21 or the reflective film 23. As shown in FIG. 2, the light emitting element 500 is sealed with a colorless and transparent sealing resin M.

  A cavity 15 is provided in the substrate 10. The cavity 15 forms a mounting area for the light emitting element 500. In the cavity 15, the connection terminals 34a and 34b are exposed. This exposed portion is called an exposed portion S3. A surface parallel to the surface of the insulating layer 50 outside the cavity 15 is referred to as an upper surface S1. The surface of the reflective film 21 between the exposed portion S3 and the upper surface S1 is referred to as a peripheral surface S2. In the cross-sectional view, a region sandwiched between two exposed portions S3 is referred to as a bottom surface S4. The peripheral surface S2 in the present embodiment is formed as a curved surface that is entirely curved. The outer peripheral surfaces of the connection terminals 34 a and 34 b are in contact with the peripheral surface S 2, that is, the reflective film 21.

  The curved shape of the peripheral surface S2 can be expressed as follows. An angle θ between a tangent line from the arbitrary point T1 on the peripheral surface S2 toward the side away from the insulating layer 50 and a parallel line from the point T1 parallel to the surface of the insulating layer 50 and away from the connection terminal 34a. Satisfies 0 ° <θ <90 °.

  As shown in FIG. 1, the height of the reflective film 21 in the direction perpendicular to the surface of the insulating layer 50 is defined as a height H1 at a portion T2 in contact with the outer peripheral surface of the connection terminal 34b. On the other hand, as shown in FIG. 1, the height of the connection terminal 34b in the direction perpendicular to the surface of the insulating layer 50 at the portion T2 is defined as a height H2. The height H1 is equal to the height H2, as shown in FIG. Accordingly, the peripheral surface S2 is arranged as high as possible while exposing the connection terminal 34b. As a result, the peripheral surface S2 becomes closer to the light emitting element 500, and the reflection efficiency is improved. Such a height relationship also applies to the connection terminal 34a.

  Further, effects of the substrate 10 will be described. The following effects are common to Embodiment 2 described later. In the following description, the case of Embodiment 2 is described in parentheses.

Since the outer peripheral surfaces of the connection terminals 34a and 34b (103a and 103b) are in contact with the reflective film 21 (105), the area of the reflective film in the cavity 15 (115) is increased, thereby improving the reflection efficiency.
Since the peripheral surface S2 (S12) is curved as described above, the reflection efficiency of parallel light is particularly improved as shown in FIG. 2 (FIG. 21).
Reflection efficiency is improved by reflection at the bottom surface S4 (S14) disposed in the mounting region.
Since the light from the light emitting element 500 is not irradiated onto the insulating layer 50 (core substrate 101), deterioration of the insulating layer 50 (core substrate 101) is suppressed.

  Hereinafter, a method for manufacturing the substrate 10 will be described. FIG. 3 is a manufacturing process diagram of the substrate 10. Hereinafter, FIGS. 4 to 17 will be referred to as explanatory diagrams of the manufacturing process.

  First, a support substrate 51 is prepared, and as shown in FIG. 4, a multilayer metal sheet 54 is laminated on the support substrate 51 to form a base 59 with a metal sheet (process P205). The support substrate 51 is formed of glass epoxy resin or the like. The multilayer metal sheet 54 is composed of two copper foils 55 and 56 (first metal sheet and second metal sheet) bonded to each other. The copper foils 55 and 56 are bonded to each other with an adhesive force that can be separated from each other in a later step. Specifically, it is bonded by metal plating. More specifically, bonding is performed by any one of chromium plating, nickel plating, titanium plating, and composite plating thereof.

  Next, as shown in FIG. 5, the plating resist layer 52 is formed on the multilayer metal sheet 54 (process P210). Specifically, an entire plating layer covering the support substrate 51 and the multilayer metal sheet 54 is formed by electroless copper plating. Then, when a dry film is laminated on the multilayer metal sheet 54 and the dry film is exposed and developed (hereinafter referred to as “exposure development”), the plating resist layer 52 is formed. The plating resist layer 52 is provided with openings having a desired pattern.

  Subsequently, as shown in FIG. 6, a metal conductor portion 57 is formed on the multilayer metal sheet 54 (process P215). Specifically, electrolytic copper plating is performed using the opening of the plating resist layer 52. Thereafter, when the plating resist layer 52 is peeled off, the state shown in FIG. 6 is obtained. The metal conductor portion 57 is convex as shown in FIG.

  Next, as shown in FIG. 7, the curved conductor part 58 is formed from the metal conductor part 57 by etching (process P220). As shown in FIG. 7, the curved conductor 58 has a curved cross-sectional shape. The shape of the curved conductor portion 58 is for transferring the shape of the cavity 15. For example, an aqueous ferric chloride solution is used for the etching. The cross-sectional shape after etching varies depending on the etching conditions. The etching conditions are an etching speed that changes with a change in the concentration of the aqueous solution and the like. In this embodiment, the etching conditions are appropriately determined by experiments so that the target shape can be obtained.

  Subsequently, the surface of the curved conductor portion 58 is roughened (process P225). When roughening is performed, the adhesion between the curved conductor portion 58 and the photosensitive insulating resin layer (described later) increases.

  Thereafter, as shown in FIG. 8, the reflective film 21 is formed so as to cover the multilayer metal sheet 54 and the curved conductor portion 58 (process P230). The material of the reflective film 21 is a photosensitive insulating resin layer, specifically, a white solder resist layer. The reflective film 21 is formed by laminating the prepared solder resist film.

  Next, as shown in FIG. 9, first via holes 33a and 33b are formed in the reflective film 21 (process P235). This formation is carried out using exposure and development in the same manner as the plating resist layer 52. Thereafter, desmear processing in the first via holes 33a and 33b is performed (step P240). A desmear process is a process which removes a smear (resin deposit | attachment). An etching solution such as a potassium permanganate solution is used for the desmear treatment. The same method is also used in desmear processing described later.

  Subsequently, as shown in FIG. 10, connection terminals 34a and 34b are formed (process P245). This formation is performed by electroless copper plating and electrolytic copper plating. The connection terminals 34 a and 34 b include a via conductor provided in the first via holes 33 a and 33 b and a conductor layer provided on the reflective film 21. Each of the connection terminals 34 a and 34 b is electrically connected to the curved conductor portion 58.

  Next, as shown in FIG. 11, the insulating layer 50 is formed so as to cover the conductor layers of the connection terminals 34a and 34b (process P250). The insulating layer 50 is made of resin and is made of a material different from that of the reflective film 21.

  Subsequently, as shown in FIG. 12, second via holes 35a and 35b are formed in the insulating layer 50 (process P255). Laser processing is used for this formation. The second via holes 35a and 35b expose part of the conductor layers of the connection terminals 34a and 34b. Next, desmear processing is performed on the second via holes 35a and 35b (process P260).

  Subsequently, as shown in FIG. 13, conductor portions 36a and 36b are formed (process P265). This formation is performed by electroless copper plating and electrolytic copper plating. The conductor portions 36 a and 36 b are formed of via conductors provided in the second via holes 35 a and 35 b and a conductor layer provided on the insulating layer 50. The conductor portion 36a is electrically connected to the connection terminal 34a. The conductor portion 36b is electrically connected to the connection terminal 34b.

  Next, as shown in FIG. 14, the reflective film 23 is formed so as to cover the conductor layers of the conductor portions 36a and 36b (process P270). The material of the reflective film 23 is the same as that of the reflective film 21.

  Subsequently, as shown in FIG. 15, openings 37a and 37b are formed in the reflective film 23 (process P275). This formation is performed using exposure and development in the same manner as the connection terminals 34a and 34b formed on the reflective film 21. The opening portion 37a exposes the conductor layer of the conductor portion 36a. The opening 37b exposes the conductor layer of the conductor part 36a.

  Next, as shown in FIG. 16, the edge of the whole laminated body formed by the steps so far is cut off (step P280). By cutting off in this way, as shown in FIG. 16, the end of the multilayer metal sheet 54 is exposed.

  Then, as shown in FIG. 17, the copper foil 55 and the copper foil 56 are peeled off (process P285). Finally, the copper foil 55 and the curved conductor portion 58 are removed (process P290). For this removal, an etching solution is used. By this removal, the substrate 10 shown in FIG. 1 is completed.

  The effect by said manufacturing method is described. The following effects are common to Embodiment 2 described later. In the following description, the case of Embodiment 2 is described in parentheses.

  The peripheral surface S2 (S12) has a small surface roughness and is smooth as compared with the case where polishing (for example, buffing) is used to form the cavity 15 (115). For this reason, the reflection efficiency is improved.

  Since polishing is not used to form the cavity 15 (115), there is almost no risk of damaging the miniaturized wiring pattern.

  Since the substrate 10 (100) is made of resin, it has excellent processability and can be easily downsized. For this reason, the board | substrate 10 (100) is suitable for the small wiring board for light emitting element mounting whose one side is 1 mm or less, for example.

  A second embodiment will be described. 18 and 19 are configuration diagrams of the light emitting element mounting wiring substrate 100 (hereinafter referred to as “substrate 100”). 18 is a plan view of the substrate 100, and FIG. 19 is a cross-sectional view of the substrate 100 taken along line XX in FIG.

  20 and 21 are configuration diagrams of the substrate 100 on which the light emitting element 500 is mounted. 20 is a plan view of the light-emitting element 500 and the substrate 100, and FIG. 21 is a cross-sectional view of the light-emitting element 500 and the substrate 100 taken along line YY in FIG. The light emitting element 500 is sealed with a colorless and transparent sealing resin M as shown in FIGS.

  As shown in FIG. 19, the substrate 100 includes a core substrate 101, a conductor layer 102, a conductor layer 103, a plurality of via conductors 104 b, and a reflective film 105. The conductor layer 102 is formed on the back side of the core substrate 101. The conductor layer 103 is formed on the surface side of the core substrate 101. The front surface side is a surface on which the light emitting element is mounted. Each of the plurality of via conductors 104 b connects the conductor layer 102 and the conductor layer 103. The reflective film 105 is provided on the surface side of the core substrate 101.

  The core substrate 101 is a plate-shaped resin substrate made of an insulating heat-resistant resin plate (for example, bismaleimide-triazine resin plate) or a fiber reinforced resin plate (for example, glass fiber reinforced epoxy resin). Acts as a layer.

  The core substrate 101 includes a reinforcing material. In this embodiment, the reinforcing material is an invar. Since invar has a small coefficient of thermal expansion, it is possible to suppress thermal expansion and thermal contraction of the core substrate 101 due to temperature change by including invar in the core substrate 101. As a result, the reliability of the substrate 100 is improved.

  The conductor layer 102 has a plurality of connection terminals 102a and 102b and wiring (not shown). The wiring is connected to the connection terminals 102a and 102b. The conductor layer 103 has a plurality of connection terminals 103a and 103b and wiring (not shown). The light emitting element 500 is mounted on the connection terminals 103a and 103b. The wiring is connected to the connection terminals 103a and 103b.

  The light emitting element 500 is mounted on the substrate 100 by connecting the connection terminal 500a of the light emitting element 500 to the connection terminals 130a and 103b via the solder P. The conductor layer 102 and the conductor layer 103 are electrically connected by a via conductor 104 b that penetrates the core substrate 101. The conductor layer 102, the conductor layer 103, and the via conductor 104b are formed of a material having high electrical conductivity, for example, copper.

  A cavity 115 is formed in the substrate 100. The reflective film 105 forms a peripheral surface S12 and a bottom surface S14 in the cavity 115. The reflective film 105 forms an upper surface S11 that is parallel to the surface of the core substrate 101 outside the cavity 115. The peripheral surface S12 is a surface surrounding the mounting area of the light emitting element 500. The entire peripheral surface S12 in the present embodiment is formed as a curved surface. The bottom surface S14 is a plane located lower than the upper ends S13 of the plurality of connection terminals 102a and 102b in the mounting region. The outer peripheral surfaces of the connection terminals 103a and 103b are in contact with the peripheral surface S12, that is, the reflective film 105.

  The curvature of the peripheral surface S12 can be expressed as follows. A tangent line extending from an arbitrary point T11 on the peripheral surface S12 toward the side away from the core substrate 101, which is an insulating layer, and a parallel line extending from the point T11 in parallel to the surface of the core substrate 101 and away from the connection terminal 103a The angle [theta] satisfies 0 [deg.] <[Theta] <90 [deg.].

  In the cavity 115, the upper ends S13 of the connection terminals 103a and 103b are positioned higher than the bottom surface S14 as a part of the reflective film 105 and the connection portion between the peripheral surface S12 and the connection terminals 103a and 103b. A part of the outer peripheral surface of 103 b is exposed from the reflective film 105. Due to this exposure, heat generated by the light emitting element 500 is easily radiated.

  FIG. 22 is a manufacturing process diagram of the substrate 100. Hereinafter, FIGS. 23 to 33 will be referred to as explanatory diagrams of the manufacturing process.

  First, as shown in FIG. 23, a core substrate 101 in which copper foils L1 and L2 are attached to the front and back surfaces of a plate-shaped resin substrate is prepared (process P405).

  Next, as shown in FIG. 24, via holes 104a are formed in the core substrate 101 (process P410). The via hole 104a is a through hole and is formed by a drill. Subsequently, a desmear process is performed on the via hole 104a (process P415).

  Subsequently, as shown in FIG. 25, the via conductor 104b is formed in the via hole 104a, and the plating layers M1 and M2 are formed on the front surface and the back surface of the core substrate 101 (process P420). Electroless copper plating and electrolytic copper plating are used to form the via conductor 104b and the plating layers M1 and M2. The plating layers M1 and M2 are the basis of the conductor layers 102 and 103 described above. Since the copper foils L1 and L2 are integrated with the plating layers M1 and M2 by the process P420, they are illustrated as a part of the plating layers M1 and M2.

  Next, as shown in FIG. 26, photosensitive dry films DF1 and DF2 are formed into a desired pattern on the surfaces of the plating layers M1 and M2 (step P425). Specifically, after the dry films DF1 and DF2 are laminated on the surfaces of the plating layers M1 and M2, exposure and development are performed.

  Subsequently, as shown in FIG. 27, the plating layers M1 and M2 are etched using the patterned dry films DF1 and DF2 as a mask (process P430). In this embodiment, dry etching is used to cope with miniaturization.

  Next, as shown in FIG. 28, the dry films DF1 and DF2 are peeled off (process P435). As a result, the conductor layers 102 and 103 formed in a desired pattern can be obtained.

  Subsequently, as shown in FIG. 29, a photosensitive insulating resin layer to be the reflective film 105 is coated on the surface side of the core substrate 101 (process P440). The reflective film 105 having a thickness D1 greater than the thickness D3 of the conductor layer 103 is laminated. In this embodiment, the photosensitive insulating resin layer is a solder resist layer.

  Next, as shown in FIG. 30, the insulating resin layer located outside the predetermined region of the cavity 125 is photocured using a mask MS (process P445). The cavity 125 is a cavity having a shape that is the basis of the cavity 115.

  Subsequently, the substrate 100 being manufactured is immersed in an aqueous sodium carbonate solution (process P450). FIG. 31 schematically shows the swollen portion by hatching. The time for dipping is a short time. Specifically, the time is such that the surface of the insulating resin layer of the unexposed portion is slightly swollen. The concentration of the aqueous solution was set to 1% by mass in this embodiment.

  Thereafter, as shown in FIG. 32, the swollen insulating resin layer is emulsified by washing with water (process P455). When the above immersion (process P450) and water washing (process P455) are performed once, the connection terminals 103a and 103b of the conductor layer 103 may not be exposed. In such a case, the above immersion and washing are repeated until the connection terminals 103a and 103b are exposed.

  Next, the swollen and emulsified insulating resin layer is removed from the substrate 100 being manufactured (process P460). As a result, as shown in FIG. 33, a cavity 125 is formed.

  Thereafter, the non-photosensitive insulating resin layer is thermally cured (process P465). Specifically, it is initially heated at a low temperature and then heated at 100 to 200 ° C. for 30 to 60 minutes. In this embodiment, the conditions of 150 ° C. and 60 minutes are adopted.

Subsequently, the thermally cured insulating resin layer is photocured (process P470). Ultraviolet rays are used for photocuring. Integrated irradiation amount, 0.5 J / cm ² or more, preferably 2.5 J / cm ² or less, 1 J / cm ² or more, 2J / cm ² or less is more preferable.

  Thus, when it is made to act on an insulating resin layer in order of thermosetting and photocuring, it will harden in the state where wall surface S12a changed to peripheral surface S12 (Drawing 19). That is, the reflective film 105 is cured with the cavity 125 deformed into the cavity 115 (FIG. 19). As a result, the substrate 100 is completed.

  A third embodiment will be described. FIG. 34 shows a light emitting element mounting wiring substrate 200 (hereinafter referred to as “substrate 200”). The board 200 is different from the board 100 in that a mounting surface includes a peripheral surface S22 instead of the peripheral surface S12.

  The peripheral surface S22 includes a curved surface S221 and a flat surface S222. The curved surface S221 is smoothly connected to the plane S222. The plane S222 is a plane parallel to the surface of the core substrate 101, and connects the curved surface S221 and the connection terminals 102a and 103a. Such a connection can also be expressed as “the edge is not standing at the connection portion between the curved surface S221 and the plane S222”. Alternatively, it can also be expressed as “the cross-sectional shape of the peripheral surface S22 is differentiable at an arbitrary point”. Θ defined in the second embodiment is θ = 0 degrees at the connection portion with the plane S222.

  The formation of the peripheral surface S22 is realized by changing the shape of the mask used for photocuring (process P445) and the post-curing conditions (process P465, P470) from the second embodiment.

  According to the substrate 200, the area of the reflective film in the cavity can be increased by the plane S222. Furthermore, since the curved surface S221 and the flat surface S222 are smoothly connected, the reflection angle of light can be changed smoothly, and it becomes easy to improve the reflection efficiency of parallel light.

  The present invention is not limited to the embodiments, examples, and modifications of the present specification, and can be implemented with various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in the embodiments described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the effects described above, replacement or combination can be performed as appropriate. If the technical feature is not described as essential in this specification, it can be deleted as appropriate. For example, the following are exemplified.

Examples of the modification of the first embodiment are as follows.
Laser processing may be used for forming the via hole. As the laser, an excimer laser, a UV laser, a CO ₂ laser, or the like may be used.
For the desmear process, a plasma ashing process using O ₂ plasma may be used.
The step (P205) of laminating the multilayer metal sheet on the support substrate may not be performed. When this step is not performed, a support substrate on which a multilayer metal sheet is laminated may be prepared. As this preparation, you may purchase, for example.

In the first embodiment, the first metal sheet itself exemplified as the copper foil may have a multilayer structure. In this case, the surface peeled in the peeling step (P285) becomes the boundary between the first metal sheet and the second metal sheet. Similarly, the second metal sheet itself may have a multilayer structure.
The height H1 of the reflective film 21 may be lower than the height H2 of the conductor portions 36a and 36b.
The peripheral surface may include a flat surface as in the third embodiment, or may include a portion where the tangent line is orthogonal to the surface of the insulating layer. That is, it may include a portion where θ = 0 degrees or θ = 90 degrees.

Examples of the modification of the second embodiment are as follows.
The via hole may be formed by a processing method other than drilling, for example, laser processing.
The etching of the plating layer may be wet etching.
The peripheral surface S12 may have the same height as the exposed portion S3 in the portion that contacts the connection terminals 103a and 103b.
The peripheral surface may include a portion orthogonal to the surface of the core substrate. That is, it may include a portion of θ = 90 degrees.
A part of the multilayer substrate may be configured as described in the second embodiment.

DESCRIPTION OF SYMBOLS 10 ... Board | substrate 15 ... Cavity 21 ... Reflective film 23 ... Reflective film 33a ... 1st via hole 33b ... 1st via hole 34a ... Connection terminal 34b ... Connection terminal 35a ... 2nd via hole 35b ... 2nd via hole 36a ... Conductor part 36b ... Conductor part 37a ... Opening part 37b ... Opening part 50 ... Insulating layer 51 ... Support substrate 52 ... Plating resist layer 54 ... Multi-layer metal sheet 55 ... Copper foil 56 ... Copper foil 57 ... Metal conductor part 58 ... Curved conductor part 59 ... Base material with metal sheet 100 ... Substrate 101 ... Core substrate 102 ... Conductive layer 102a ... Connecting terminal 102b ... Connecting terminal 103 ... Conductive layer 103a ... Connecting terminal 103b ... Connecting terminal 104a ... Via hole 104b ... Via conductor 105 ... Reflective film 115 ... Cavity 125 ... Cavity 130a ... Connection terminal 200 ... Substrate 500 ... Light emitting element 500a ... Connection terminal DF1 ... Do Lay film DF2 ... Dry film L1 ... Copper foil L2 ... Copper foil M ... Sealing resin MS ... Mask P ... Solder S1 ... Upper surface S2 ... Peripheral surface S3 ... Exposed part S4 ... Bottom surface S11 ... Upper surface S12 ... Peripheral surface S12a ... Wall surface S13 ... Upper end S14 ... Bottom S22 ... Peripheral surface S221 ... Curved surface S222 ... Plane

Claims (5)

An insulating layer;
On the insulating layer, a plurality of connection terminals formed in the mounting region of the light emitting element,
A wiring board for mounting a light-emitting element, comprising: a reflective film that is laminated on the insulating layer and includes a portion configured as a peripheral surface surrounding the mounting region and forming a cavity;
The outer peripheral surface of the connection terminal is in contact with the reflective film,
At least a portion of the peripheral surface is formed as a curved surface;
In a cut surface along a direction perpendicular to the surface of the insulating layer, a tangent line extending from an arbitrary point of the curved surface to a side away from the insulating layer, and parallel to the surface of the insulating layer from the arbitrary point The wiring board for mounting a light-emitting element, wherein an angle with a parallel line facing away from the connection terminal is larger than 0 degree and smaller than 90 degrees. The wiring board for mounting a light-emitting element according to claim 1, wherein the reflective film includes a portion disposed in the mounting region. The height of the reflective film in a direction perpendicular to the surface of the insulating layer is the same as the height of the connection terminal at a portion in contact with the outer peripheral surface of the connection terminal. Or the wiring board for light emitting element mounting of Claim 2. A method for manufacturing a wiring board for mounting a light emitting element according to any one of claims 1 to 3,
Preparing a base with metal sheet having a base, a first metal sheet laminated on the base, and a second metal sheet laminated on the first metal sheet;
Forming a plating resist layer having an opening on the second metal sheet;
Forming a convex metal conductor on the second metal sheet by performing plating in the opening; and
Processing the metal conductor portion into a shape corresponding to the peripheral surface by etching the metal conductor portion;
Covering the metal conductor portion with an insulating resin layer to be the reflective film;
Peeling the first metal sheet from the second metal sheet;
Removing the second metal sheet and the metal conductor portion from the insulating resin layer. A method for manufacturing a wiring board for mounting a light emitting element according to any one of claims 1 to 3,
Forming the plurality of connection terminals on the insulating layer;
Coating the insulating layer and the plurality of connection terminals with a photosensitive insulating resin layer serving as the reflective film;
Forming a recess in the insulating resin layer by exposing and developing the photosensitive insulating resin layer; and
And a step of deforming the wall surface of the dent into the curved surface by performing thermosetting on the insulating resin layer in which the dent is formed, and then performing photocuring.

Images