JP2008041811A - Wiring circuit board, multiple-chip wiring circuit board, and method for manufacturing the wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring circuit board including a conductor for surely and rigidly mounting electronic components and an element such as a light emitting element, and also to provide a multiple-chip wiring circuit board and a method for manufacturing the wiring circuit board. <P>SOLUTION: The wiring circuit board 1a is provided with a substrate body 2 having a front surface 3 and a rear surface 4 formed of ceramic (insulating material) layers s1 to s3, and a conductor 10 formed at the bottom surface 6 of a cavity 5 opening to the front surface 3 of the substrate body 2, including an Au-Sn alloy layer 14 in a thickness of 2 μm or larger at the front surface thereof. This conductor 10 partly includes an element mounting part a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wiring board having a conductor portion for mounting an element such as an electronic component or a light emitting element on the surface of a substrate body or the bottom surface of a cavity, a multi-piece wiring board, and a method for manufacturing the wiring board.

A mounting portion for mounting a light emitting element is formed at the center of the upper surface of the base made of ceramic via solder, and is inclined so that the outer peripheral portion of the upper surface of the base surrounds the mounting portion and the inner peripheral surface extends upward. There has been proposed a light emitting element storage package in which the frame is provided, and the solder is made of an Au-Sn alloy, and the outer peripheral end of the solder extends outside the lower end of the side surface of the light emitting element. (For example, refer to Patent Document 1).
According to the light emitting element storage package, since the reflectance of the light emitting element by the solder is 40% or more, a light emitting device with high brightness does not generate a shadow (dark part) at the lower end of the side surface of the light emitting element. Can be created.

JP 2004-319598 A (pages 1 to 6, FIG. 1)

By the way, the solder made of an Au—Sn alloy for mounting a light emitting element is made of a pre-formed sheet so as to be placed on the surface of a metallized layer made of W or the like. In addition, there is a problem that it becomes complicated.
On the other hand, the solder thickness of the preform sheet previously mounted on the bottom surface of the light emitting element has been 2 μm or less. Thus, when the thickness of the solder is 2 μm or less, it becomes difficult to absorb the warp of the substrate made of ceramic, or the uneven shape resulting from the rough surface of the metallized layer or the surface of the Ag plating layer. For this reason, when a light emitting element is mounted with such solder and heated (reflowed), between the solder made of the Au—Sn alloy attached to the bottom surface of the light emitting element and the surface of the Ag plating layer, or Bubbles and pores are generated inside the solder. As a result, there is a problem in that the adhesion strength between the light emitting element and the mounting portion is lowered, the heat transfer property between the light emitting element and the mounting portion is lowered, and conduction is likely to be unstable.

  The present invention solves the problems described in the background art, and provides a wiring board having a conductor portion that can securely and securely mount elements such as electronic components and light emitting elements, a multi-piece wiring board, and a method of manufacturing the wiring board. The issue is to provide.

Means for Solving the Problems and Effects of the Invention

The present invention has been obtained by optimizing the thickness of an Ag-Sn alloy layer for bringing an element into close contact with a mounting portion in order to solve the above-described problems.
That is, the wiring board of the present invention (Claim 1) is made of an insulating material, and has a substrate body having a front surface and a back surface, and an Au—Sn alloy layer having a thickness of more than 2 μm formed on the surface of the substrate body. A conductor portion, and the conductor portion is an element mounting portion or includes the element mounting portion in part.
The upper limit of the thickness of the Au—Sn alloy layer is 15 μm.

  According to this, since a conductor portion having an Au—Sn alloy layer (solder) having a thickness of more than 2 μm is formed on the surface of the substrate body, a light emitting element is formed on the element mounting portion on the Au—Sn layer. Even when an element such as an electronic component is mounted and heated (reflowed), bubbles or pores are less likely to be generated between the bottom surface of the element and the Au-Sn alloy layer or in the Au-Sn alloy layer. . Therefore, the element can be mounted on the mounting portion of the conductor portion without preparing separately preformed solder, the adhesion strength between the element and the mounting portion is improved, and heat transfer from the element to the conductor portion is improved. In addition, the conduction between the element and the conduction portion can be stabilized.

The insulating material includes a high-temperature fired ceramic such as alumina, a low-temperature fired ceramic such as glass-ceramic, or an epoxy resin.
The surface of the substrate body also includes a bottom surface of a cavity that opens to the surface.
Furthermore, the desirable thickness of the Au—Sn alloy layer is in the range of 5 to 10 μm.
The Au—Sn alloy layer is made of a plated layer of such an alloy.
Further, the conductor portion is made of, for example, a metallized layer made of W, Mo, Cu, a Ni plated layer formed on the surface, an Au plated layer formed on the surface, and the Au—Sn alloy layer formed on the surface. It will be.
The form in which the conductor part includes the element mounting part is, for example, an element mounting part in which the light emitting element is partially mounted in plan view, and the surface of the conductor part excluding the mounting part is the light emitting element. And a reflecting surface that reflects light from the surface.

According to the present invention, the surface of the substrate body is a bottom surface of a cavity that opens to the surface, and the conductor portion is formed on the bottom surface of the cavity, and partly includes an element mounting portion. (Claim 2) is also included.
According to this, since the conductor portion having the Au—Sn alloy layer having a thickness of more than 2 μm is formed on the bottom surface of the cavity, the light emitting element and the electronic component are formed on the element mounting portion on the Au—Sn alloy layer. Even if it is mounted and heated (reflowed), bubbles and pores are hardly generated between the bottom surface of the element and the Au—Sn alloy layer or inside the Au—Sn alloy layer. Accordingly, it is not necessary to prepare a separate solder, the adhesion strength between the mounted element and the mounting portion is improved, the heat transfer from the element to the conductor portion is improved, and the conduction between the element and the conductor portion is also improved. It becomes possible to stabilize.
The cavity has a circular bottom surface and a substantially conical side surface in plan view, an elliptical bottom surface and a substantially conical side surface in plan view, or an elliptical bottom surface in plan view. The form which consists of a side surface of a substantially elliptical cone shape is included.

Furthermore, in the present invention, a multi-piece wiring board comprising a product region in which a plurality of wiring boards are arranged vertically and horizontally, and an ear portion made of the insulating material located around the product region ( Claim 3) is also included.
According to this, since it is a multi-piece wiring substrate having a plurality of wiring substrates provided with the conductor portion including the element mounting portion on the surface or the bottom surface of the cavity along the vertical and horizontal plane directions, adjacent wiring A large number of wiring boards can be efficiently provided by performing a cutting process along the planned cutting surfaces that divide between the boards and between the wiring boards and the ears. In addition, the form which the said ear | edge part adjoins only to the one side or two sides around a product area | region is also contained.

On the other hand, a method for manufacturing a wiring board according to the present invention (Claim 4) includes a step of forming a substrate body made of an insulating material and having a front surface and a back surface, a step of forming a metallized layer on the surface of the substrate body, And applying a metal plating layer to the metallized layer to form an Au—Sn alloy layer having a thickness of more than 2 μm.
According to this, it is possible to reliably manufacture the wiring board in which the conductor part including the element mounting part having high adhesion with the element to be mounted is provided on the surface or the bottom surface of the cavity. In addition, it is good also as a manufacturing method which divides | segments into each wiring board, after producing the said multi-piece substrate by said each process.

In the following, the best mode for carrying out the present invention will be described.
FIG. 1 is a plan view showing a wiring board 1a for mounting a light emitting device according to the present invention, FIG. 2 is a vertical sectional view taken along line XX in FIG. 1, and FIG. It is the elements on larger scale of the dashed-dotted line part Y in the inside.
As shown in FIGS. 1 and 2, the wiring board 1a has a substrate body 2 having a substantially square shape in plan view and having a front surface 3 and a back surface 4, and an opening in the front surface 3 of the substrate body 2. The bottom surface has a circular shape in plan view. 6 and a cavity 5 having a side surface 7 extending in a substantially conical shape from the bottom surface 6 toward the surface 3, a pad 15 formed on the bottom surface 6 of the cavity 5, and a bottom surface 6 of the cavity 5 excluding the vicinity of the pad 15. The formed plan view includes a substantially semicircular conductor portion 10a. The elevation angle of the side surface 7 of the cavity 5 is, for example, in the range of about 30 degrees to 70 degrees.

As shown in FIG. 2, the substrate body 2 is made of an insulating material in which ceramic layers s1 to s3 made of glass-ceramic, which is a kind of alumina (ceramic: insulating material) or a low-temperature fired ceramic, are integrally laminated. The size is about 5 × 5 × 1 mm.
Further, as shown in FIG. 3, the conductor portion 10a is formed on the surface of the metallized layer 11 with a Ni plating layer 12 and an Au plating layer 13 having the same thickness as described above, and an Au- A Sn alloy layer (solder) 14 is formed by electrolytic plating. The metallized layer 11 is made of W, Mo or Cu having a thickness of several tens of μm, the Ni plating layer 12 has a thickness of about 2 to 15 μm, and the Au plating layer 13 has a thickness of about 0.5 to 4 μm. The Au—Sn alloy has a composition of, for example, 80 wt% Au-20 wt% Sn.

In the vicinity of the center of the bottom surface 6 of the cavity 5 in the conductor portion 10a, a light emitting diode (light emitting element: hereinafter simply referred to as LED) 9 indicated by a one-dot chain line in FIGS. The mounting part a is located. Of the conductor portion 10a excluding the element mounting portion a of the LED 9, the portion where the Au—Sn alloy layer 14 is exposed forms a light reflecting surface that reflects the light emitted by the LED 9 and emits it to the outside. ing.
On the other hand, as shown in FIG. 3, the pad 15 is formed on the surface of the metallized layer 16 having the same thickness formed on the bottom surface 6 of the cavity 5 as described above on the surface layer through the Ni plating layer 17 having the same thickness. The Au plating layer 18 is formed.
Further, on the side surface 7 of the cavity 5, a light reflecting layer 8 made of a metallized layer, a Ni plated layer, an Au plated layer, and an Ag plated layer having the same thickness as described above is formed.

As shown in FIG. 2, a plurality of wiring layers 20 made of W or the like and having a predetermined pattern are formed between the ceramic layers s2 and s3, and a plurality of connection terminals made of W or the like are formed on the back surface 4 of the substrate body 2. 19 is formed. The conductor portion 10a and the pad 15 can be electrically connected to any one of the wiring layers 20 and the connection terminals 19 through via conductors v penetrating the ceramic layers s2 and s3. The connection terminal 19 is used for conduction with a mother board (not shown) on which the wiring board 1a is mounted.
The LED 9 mounted on the conductor portion 10a through the Au-Sn alloy layer 14 so as to be conductive is bonded to the pad 15 through a wire w indicated by a broken line in FIG. That is, the conductor part 10a and the pad 15 are also electrodes for the LED 9 to be electrically connected to the wiring board 1a.
The LED 9 may be connected to the surface of the conductor portion 10a via the bonding wire w. After the LED 9 is mounted and the wire w is bonded (connected), the cavity 5 is filled with a sealing resin (not shown) before solidification, and the level is almost the same as the surface 3 of the substrate body 2. Solidified.

FIG. 4 is a plan view similar to FIG. 1, showing a different form of the wiring board 1b.
As shown in FIG. 4, the wiring board 1b includes a substrate body 2, a cavity 5, and a light reflecting layer 8 similar to the wiring board 1a.
The wiring board 1b is different from the wiring board 1a in that a pair of left and right pads 15a and 15b are formed on the bottom surface of the cavity 5, and a conductor portion 10b having a substantially oval shape in plan view is formed between them. It is formed so as to pass through the center. The conductor portion 10b also has the same metallized layer 11, Ni plating layer 12, Au plating layer 13, and Au—Sn alloy layer 14 having a thickness of more than 2 μm to 15 μm as the conductor portion 10a.
The LED 9 mounted on the element mounting portion a near the center of the conductor portion 10b and the pads 15a and 15b are individually bonded by the wire w. For this reason, the conductor portion 10b is not directly conducted to the LED 9.

FIG. 5 is a plan view showing a wiring board 1c which is an applied form of the wiring board 1a. As shown in FIG. 5, the wiring board 1c also includes a board body 2, a cavity 5, a conductor portion 10a, and the like. The wiring board 1c is different from the wiring board 1a in that the light reflecting layer 8 is not provided on the side surface 7 of the cavity 5, and the alumina-based white side surface 7 itself is exposed as a light reflecting surface.
FIG. 6 is a plan view showing a wiring board 1d which is an applied form of the wiring board 1b. As shown in FIG. 6, the wiring board 1d also includes a board body 2, a cavity 5, a conductor portion 10b, and the like. The wiring board 1d is different from the wiring board 1b in that the light reflecting layer 8 is not provided on the side surface 7 of the cavity 5, and the alumina-based white side surface 7 itself is exposed as a light reflecting surface.
According to the wiring boards 1b, 1c, and 1d as described above, since the conductor portions 10a and 10b having the Au—Sn alloy layer 14 with a thickness of more than 2 μm to 15 μm are formed, the element mounting on the solder layer 14 is performed. Even if the LED 9 is mounted on the part a and heated, bubbles or pores are hardly generated between the bottom surface of the LED 9 and the solder 14 or in the solder 14. Accordingly, it is not necessary to prepare a separate solder, the adhesion strength between the LED 9 and the element mounting portion a can be improved, and heat removal to the conductor portions 10a and 10b can be facilitated.

The wiring boards 1a and 1b were manufactured as follows.
In advance, a three-layer green plate for large plates having alumina as a main component and having a substantially rectangular plan view was prepared. The thickness of the front surface and the back surface of the green sheet is obtained by punching a plurality of portions of the green sheet for a large plate with a punch having a predetermined clearance and a receiving hole of the die. A plurality of substantially conical through-holes were formed along the vertical and horizontal directions along the direction.
In addition, the remaining two layers of large green sheets are punched into a plurality of locations by punching with the smallest clearance punch and die receiving holes to form a plurality of via holes, and each via ball Each was filled with a conductive paste containing W or Mo powder particles, and a via conductor v was formed at each location.

Furthermore, a predetermined pattern is formed on a plurality of through-holes having a substantially conical shape formed in the one-layer large plate green sheet and a plurality of locations on at least one of the front and back surfaces of the two-layer large plate green sheet. Following this, a conductive paste containing W or Mo powder particles was screen-printed to form a plurality of sets of the metallized layers 11, 16, wiring layers 20, and connection terminals 19. At this time, the metallized layers 11, 16, the wiring layer 20, and the connection terminal 19 were connected via the via conductors v, respectively.
Next, a large plate green sheet in which a plurality of substantially conical through holes are formed, and a two-layer large plate green sheet in which a plurality of sets of the metallized layers 11, 16, wiring layers 20, and the like are formed, Lamination and pressure bonding were performed to form a large green sheet laminate, and this laminate was heated to a predetermined temperature zone and fired.
As a result, a plurality of substrate bodies 2 formed of the ceramic layers s1 to s3 and having the cavity 5 opened on the surface 3 and the metallized layers 11 and 16 formed on the bottom surface 6 are arranged in the vertical and horizontal directions. It was. The side surface 7 of each cavity 5 was covered with the metallization.

Further, electrolytic Ni plating and electrolytic Au plating were respectively applied to the metallized layers 11 and 16 of each group, and further, the metallized layer 11 was subjected to electrolytic plating of an Au—Sn alloy. In addition, the metallization on the side surface 7 of the cavity 5 was subjected to electrolytic Ni plating, electrolytic Au plating, and electrolytic Ag plating.
As a result, as shown in the plan view of FIG. 7, a product region A in which a plurality of wiring boards 1 a are arranged vertically and horizontally, and an ear m formed of the ceramic layers s <b> 1 to s <b> 3 are provided around the product region A. A multi-cavity wiring board K1 was obtained.
Further, through the same steps as described above, as shown in the plan view of FIG. 8, the ceramic regions s1 to s3 are located around the product region A in which a plurality of wiring boards 1b are arranged vertically and horizontally and the periphery thereof. Thus, a multi-cavity wiring board K2 provided with the ear part m is obtained.
The broken lines in FIGS. 7 and 8 indicate virtual cutting planes c that divide the wiring boards 1a and 1a, the wiring boards 1b and 1b, and the wiring boards 1a and 1b and the ear m.

As shown in FIGS. 7 and 8, on the bottom surface 6 of the cavity 5 in each wiring substrate 1a, 1b, a Ni plating layer 12, an Au plating layer 13, and Au having a thickness of 5 to 15 μm are formed on the surface of the metallization layer 11. -The conductor portions 10a and 10b coated with the Sn alloy layer 14 and the pads 15, 15a and 15b coated with the Ni plating layer 17 and the Au plating layer 18 on the surface of the metallized layer 16 are formed. A light reflecting layer 8 was formed on the side surface 7.
Then, by cutting the multi-piece wiring boards K1 and K2 in the thickness direction with a cutter (not shown) along the planned cutting surface c, as shown in FIGS. A plurality of wiring boards 1a and 1b could be obtained.
The LED 9 is mounted on the element mounting portion a of the conductor portions 10a and 10b on the wiring boards 1a and 1b, and after the LED 9 and the pads 15, 15a and 15b are connected by the bonding wires w, The sealing resin before solidification is filled and solidified to almost the same level as the surface 3 of the substrate body 2.

According to the wiring boards 1a and 1b as described above, the conductor portion 10a having the Au—Sn alloy layer 14 having a thickness of more than 2 μm to 15 μm on the bottom surface 6 of the cavity 5 opened on the surface 3 of the substrate body 2; 10b is formed. For this reason, even if the LED 9 is mounted on the element mounting portion a on the Au—Sn alloy layer 14 and heated (reflowed), there are bubbles or bubbles between the bottom surface of the LED 9 and the solder layer 14 or in the solder layer 14. It becomes difficult to produce pores. Accordingly, the adhesion strength between the LED 9 to be mounted and the element mounting portion a is improved without separately preparing solder, the heat transfer from the LED 9 to the conductor portions 10a and 10b is improved, and the LED 9 and the conductor portion 10 are also improved. It is also possible to stabilize the conduction between the two.
In the multi-piece wiring boards K1 and K2, the light reflecting layer 8 is not formed on the side face 7 of the cavity 5 for each of the wiring boards 1a and 1b, but the side face 7 is exposed, so that the wiring boards 1c and 1d are exposed. A plurality of wiring boards in which a plurality of wiring boards are arranged vertically and horizontally can be formed, and a plurality of wiring boards 1c and 1d can be obtained by dividing them.

Here, specific examples of the present invention will be described together with comparative examples.
A plurality of green sheets made of alumina and having the same thickness were prepared, and a conductive paste containing W powder particles on the surface thereof was screen-printed to form a metallized layer having the same pattern. The plurality of green sheets were heated and fired at a predetermined temperature range to form a ceramic layer.
The surface of the metallized layer 11 after firing was subjected to electrolytic Ni plating and electrolytic Au plating under the same conditions to form a Ni plating layer 12 and an Au plating layer 13 having the same thickness. The surface roughness (Ra) of the Au plating layer 13 was unified as 0.4 μm.

Next, on the surface of the Au plating layer 13 for each ceramic layer, 10 Au—Sn alloy layers 14 having a thickness of 2.0 to 20.0 μm shown in Table 1 are provided for each thickness by electrolytic plating. Formed one by one.
Further, in the plurality of ceramic layers on which the Au—Sn alloy layer 14 is formed, the same LED 9 is placed on the Au—Sn alloy layer 14 and the same time is kept in the temperature zone immediately above the melting point of the Au—Sn alloy. (Reflow).
Each of the ceramic layers after heating was cut directly under the LED 9, and the inside of the Au—Sn alloy layer 14 or between the Au—Sn alloy layer 14 and the LED 9 was visually checked to see if there was even one. It was shown in Table 1 as “Yes” for the group and “None” for the group that was not found in all 10 groups.

According to Table 1, no bubbles or pores were generated in the examples in which the thickness of the Au—Sn alloy layer 14 was 3.0 to 15.0 μm and the comparative example in which the thickness was 20.0 μm. On the other hand, in the comparative example in which the thickness of the Au—Sn alloy layer 14 was 2.0 μm, bubbles and pores were generated. This is because the surface of the Au—Sn alloy layer 14 becomes smooth as the thickness of the Au—Sn alloy layer 14 increases, and it becomes easy to absorb the influence of warpage of the ceramic layer. Therefore, the inside of the Au—Sn alloy layer 14 and the LED 9 and the Au It is presumed that no bubbles or pores were generated between the alloy layer 14 and the Sn alloy layer 14.
Furthermore, as shown in the lower part of Table 1, when the thickness of the Au—Sn alloy layer 14 was 20.0 μm, the plating cost was high (marked with ×), whereas if it was 15.0 μm or less, It was also found that there was no significant difference from the normal plating cost (○ mark). Furthermore, it has been found that when the thickness of the Au—Sn alloy layer 14 is 15.0 μm or less, it is easy to prevent a short circuit with the adjacent pad 15 and to cope with fine pitch properties.

From these results, the thickness of the Au—Sn alloy layer 14 formed on the surface layer of the conductor portions 10a and 10b is set to 3.0 (over 2 μm) to 15.0 μm to prevent generation of bubbles and the like. It has been found that a short circuit with the pad 15 to be performed can be easily prevented, and that there are few problems in terms of cost.
From the results of the above examples, the effect of the present invention was confirmed.

FIG. 9 is a plan view showing a wiring board 21 of a different form, and FIG. 10 is a vertical cross-sectional view taken along the line ZZ in FIG.
As shown in FIGS. 9 and 10, the wiring substrate 21 includes a substrate body 22 composed of a plurality of ceramic layers s <b> 4 to s <b> 6 similar to the above and having a front surface 23 and a back surface 24 in a plan view and a surface of the substrate body 22. And a cavity 25 having a bottom surface 26 that is substantially oval in plan view and a side surface 27 that extends in a substantially conical shape toward the surface 23. Three conductor portions 30a, 30b, 30c are formed in a strip shape along the short axis direction of the bottom surface 26 of the cavity 25.
Among these, the central conductor portion 30b is separated from one long side of the bottom surface 26 and is slightly shorter than the other conductor portions 30a and 30c. The conductor portions 30a, 30b, and 30c are also formed of the same metallized layer, Ni plated layer, Au plated layer, and Au—Sn alloy, and an Au—Sn alloy layer having a thickness of more than 2 μm to 15 μm.

Also, as shown in FIGS. 9 and 10, three pads 31 to 33 are formed near both ends and the center of the bottom surface 26 of the cavity 25 in the same manner as described above. The same Ni plating layer and Au plating layer as described above are formed on the surface, and are individually connected to the via conductors v in the ceramic layer s5.
The conductor portions 30a, 30b, and 30c partially include an element mounting portion a for mounting the LED (element) 29, and the LED 29 can be mounted by heating (reflowing) the solder layer on the surface layer. The LED 29 mounted on each of the conductor portions 30a, 30b, and 30c and the pads 31 to 33 are individually bonded by wires w indicated by two-dot chain lines in FIG. In addition, the surface which consists of Au-Sn alloy layer of the conductor parts 30a-30c except the element mounting part a forms the light reflection surface which reflects the light of LED29.

Furthermore, as shown in FIG. 10, a plurality of wiring layers 34 made of W or the like and having a predetermined pattern are formed between the ceramic layers s5 and s6, and a plurality of wiring layers 34 made of W or the like are formed on the back surface 24 of the substrate body 22. Connection terminals 36 and 38 are formed.
The conductor portions 30a to 30c and the pads 31 to 33 can be electrically connected to any one of the wiring layers 34 and the connection terminals 36 and 38 through via conductors v penetrating the ceramic layers s5 and s6. The connection terminals 36 and 38 are used for electrical connection with a mother board (not shown) on which the wiring board 21 is mounted.

According to the wiring board 22 as described above, the LED 29 can be mounted with high mounting strength on the element mounting portion a for each of the conductor portions 30a to 30c without separately preparing solder, and heat conductivity is also improved. In addition, by using those three LEDs 29 that emit red (R), green (G), and blue (B) light, full-color light is emitted and the light is transmitted through the conductor bodies 30a to 30c. It is also possible to reflect the light on the light reflecting surface and the side surface 27 of the cavity 25 and efficiently radiate to the outside.
By forming a light reflecting layer similar to the above on the entire side surface 27 of the cavity 25 in the wiring substrate 22, it is possible to reflect full-color light and radiate the outside more efficiently with a wider area. . In addition, the wiring board 22 can be efficiently and reliably manufactured by cutting and dividing a multi-piece wiring board obtained through the same manufacturing process as described above.

The present invention is not limited to the above embodiments.
For example, the substrate body may have a form made of a low-temperature fired ceramic such as glass-ceramic or a form in which a plurality of epoxy-based resin layers are laminated and bonded.
The substrate body may have a flat surface without a cavity, and the conductor and the pad may be formed on the surface.
Further, the conductor portion may be configured to include only (overlapping) the element mounting portion in a plan view, or may have a substantially similar shape that slightly extends around the element mounting portion in a plan view.
Further, the side surface of the cavity may be a vertical surface along the thickness direction of the substrate body. In the form in which a white ceramic such as alumina is exposed, light is reflected as it is or the light reflecting layer is formed. It is good also as the form which did.
Furthermore, one or a plurality of protrusions or ridges for preventing the sealing resin from floating may be provided on the surface side of the substrate body on the side surface of the cavity toward the center of the cavity.
The elements mounted on the element mounting portion of the conductor portion include electronic components such as an IC chip.
In addition, the multi-cavity wiring board is in a form as it is or divided into several parts, and an LED is mounted on the element mounting part of each conductor part in each of the plurality of wiring boards, so that a relatively large light emitting device It is also possible to utilize it.

The top view which shows the wiring board of this invention. FIG. 2 is a vertical sectional view taken along line XX in FIG. 1. The elements on larger scale of the dashed-dotted line part Y in FIG. The top view which shows the wiring board of a different form. FIG. 4 is a vertical sectional view showing an application form of the wiring board of FIGS. Vertical sectional view showing an application form of the wiring board of FIG. The top view which shows the multi-piece wiring board for obtaining the wiring board of FIGS. FIG. 5 is a plan view showing a multi-cavity wiring board for obtaining the wiring board of FIG. 4. Furthermore, the top view which shows the wiring board of a different form. FIG. 10 is a vertical sectional view taken along the line ZZ in FIG. 9;

Explanation of symbols

1a to 1d, 21 ………………………………… Wiring board 2,22 …………………………………………… Board body 3,23 …………… ……………………………… Front 4,24 …………………………………………… Back 5,25 ………………………………… ………… Cavity 6,26 …………………………………………… Bottom 7,27 …………………………………………… Side 9,29 …………………………………………… Light-emitting diode (element)
10a, 10b, 30a-30c ……………… Conductor 11 ………………………………………………… Metalized layer 14 ……………………………… ………………… Au—Sn alloy layer s1 to s6 ………………………………………… Ceramic layer (insulating material)
a …………………………………………………… Element mounting part K1, K2 ………………………………………… Multiple wiring board A… ………………………………………………… Product area m …………………………………………………… Ear

Claims (4)

A substrate body made of an insulating material and having a front surface and a back surface;
A conductor part formed on the surface of the substrate body and having an Au-Sn alloy layer with a thickness of more than 2 μm on the surface layer;
The conductor part is an element mounting part or includes the element mounting part in part.
A wiring board characterized by that. The surface of the substrate body is a bottom surface of a cavity that opens to the surface,
The conductor portion is formed on the bottom surface of the cavity and includes an element mounting portion in part.
The wiring board according to claim 1. A product region in which a plurality of the wiring boards according to claim 1 or 2 are arranged vertically and horizontally;
Located around the product area, and comprising ears made of the insulating material,
A multi-piece wiring board characterized by that. A step of forming a substrate body made of an insulating material and having a front surface and a back surface;
Forming a metallized layer on the surface of the substrate body;
Applying electroplating to the metallized layer to form an Au—Sn alloy layer having a thickness of more than 2 μm.
A method for manufacturing a wiring board.

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