JP2021019153A - Wiring board, module and method of manufacturing the same - Google Patents

Abstract

To cut the manufacturing cost of a module including a wiring board, and shorten a delivery term.SOLUTION: A method of manufacturing a module comprises the steps of: preparing a wiring board 12 having two lands 1a and 1b apart from each other and disposed to be mirror symmetrical to each other, and including slit parts 6a and 6b arranged in the lands 1a and 1b respectively by notching the corresponding land along part of a periphery of a given region; making a print of solder pastes 21, 22 in the given region of each of the two lands 1a and 1b so as to run along the corresponding slit parts 6a, 6b; putting electrodes 26 and 27 of an electronic component 24 on the solder pastes 21 and 22; and reflowing the solder pastes 21 and 22, thereby forming solder fillets 21a and 22b on sides of the electrodes 26 and 27 of the electronic component 24, and bonding the electronic component 24 to two lands 1a and 1b by soldering.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wiring board, a module and a method for manufacturing the same, and more particularly to a wiring board on which electronic components are surface-mounted, a module including the wiring board, and a method for manufacturing the module.

With the progress of miniaturization and weight reduction of electronic device modules, miniaturization of individual electronic components such as semiconductor elements and electronic components to be mounted is being promoted. In this type of module, a technique of surface mounting electronic components on a printed wiring board is adopted in order to realize high-density mounting commensurate with the miniaturization of mounted components.

Electronic components mounted on such electronic device modules, such as capacitive elements, resistance elements, light emitting elements, and various filters, have various sizes depending on their electrical characteristics, and the length and width of the components It is standardized by size. On the printed wiring board on which the components are mounted, lands that match the electrode positions of the components to be mounted and wiring that connects the lands are formed in advance.

Japanese Patent No. 6376386

However, in recent years, with the diversification and subdivision of specifications of electronic device modules, there has been a situation in which components of different standards must be mounted at the same position on a printed wiring board. The shape and size of lands corresponding to the electrode positions of each standard are defined for these electronic components, and when trying to mount electronic components of different standards on a common land, solder is not attached, the mounting floats, or the component tilts. There is a risk that problems such as these will occur frequently.

The present invention has been made in view of such a situation, and an object of the present invention is to ensure desired electrical characteristics and reliability, and to provide electronic components having different standards without modifying the wiring board. It is an object of the present invention to provide a wiring board capable of mounting the above on a common land, a module including the wiring board, and a method for manufacturing the module.

The method for manufacturing a module according to the first aspect of the present invention is a wiring board including a first land and a second land in which the first land is separated from each other and arranged mirror-symmetrically. A first step and a first step of preparing a wiring board including a slit portion in which a land is cut out along a predetermined area and a part of a peripheral edge of the predetermined area inside each of the land and the second land. The second step is to print the solder paste along the slits in the respective predetermined areas of the land and the second land, and the electronic component having two electrodes is printed on each of the solder paste and the two electrodes. A third step of placing them in contact with each other and by reflowing the solder paste extend from the respective surfaces of the first and second lands to the respective sides of the two electrodes. It comprises a fourth step of forming the two solder fillets to be used and soldering each of the two electrodes of the electronic component to the first land and the second land.

According to the second aspect of the present invention, in the first aspect, in the wiring board prepared in the first step, the first land and the second land are the first region and the second region, respectively. The first region and the second region include overlapping regions in which a part of each region overlaps with each other, and the first region projects from the second region toward the axis of mirror symmetry. The slit portion is provided inside the second region on the peripheral edge of the first region of the overlapping region.

According to the third aspect of the present invention, in the second aspect, the predetermined region is the first region including the overlapping region.

According to the fourth aspect of the present invention, in the third aspect, each of the two solder fillets extends along the slit portion of each of the first land and the second land.

According to the fifth aspect of the present invention, in the second aspect, the predetermined region is a region excluding the overlapping region and the slit portion from the second region.

According to the sixth aspect of the present invention, in the fifth aspect, each of the two electrodes of the electronic component is placed so as to cover the second region on which the solder paste is printed, the slit portion, and the overlapping region. Will be done.

The method for manufacturing a module according to a seventh aspect of the present invention has at least one electronic component having two electrodes and capable of soldering a first electronic component or a second electronic component having different sizes to a wiring board. In a method of manufacturing a module including a first electronic component or a second electronic component by soldering a first electronic component or a second electronic component to a pair of lands, the pair of lands is a first. It consists of a land and a second land, and the first land and the second land are arranged in a mirror-symmetrical manner apart from each other, and the first land and the second land respectively solder the first electronic component. A first region for soldering and a second region for soldering a second electronic component larger than the first electronic component are provided, and the first region and the second region are respectively provided. A part of the regions have overlapping regions that overlap each other, and the first region is arranged so as to project from the second region toward the axis of symmetry of mirror plane symmetry, and a land is cut inside the second region. The notched slit portion is provided along the periphery of the first region of the overlapping region, and the first step of preparing a wiring board including the first land and the second land, and the first step. A step of printing the solder paste on each of the first land and the second land, the second step of printing the solder paste on a predetermined area along the slit portion of the second region, and the first electron. The third step of placing the component or the second electronic component so that each of the solder paste and each of the electrodes is in contact with each other, and the solder paste is reflowed so that a solder fillet is formed on the side surface of the electrode. It comprises a fourth step of soldering the first electronic component or the second electronic component to the first land and the second land, and in the fourth step, the first electronic component is soldered. If so, solder fillets are formed along the slits.

The wiring board of the eighth aspect of the present invention includes a first land and a second land which is arranged symmetrically with respect to the first land so as to be separated from each other, and the first land and the second land are provided. Lands include a first region and a second region, respectively, and the first region and the second region have overlapping regions in which a part of each region overlaps with each other, and the first region is a second region. A slit portion is provided inside the second region along the peripheral edge of the first region of the overlapping region so as to project from the region of the above region toward the axis of symmetry of mirror plane symmetry.

The module of the ninth aspect of the present invention further includes a first electronic component having two electrodes in the wiring board of the eighth aspect, and each of the two electrodes of the first electronic component is a first. It is fixed with solder to the first region of each of the land and the second land.

According to the tenth aspect of the present invention, in the ninth aspect, it extends from the surface of each first region of the first land and the second land to each side surface of the two electrodes. The solder fillet further comprises a solder fillet to be formed, and the solder fillet extends along the slit portion of each of the first land and the second land.

According to the eleventh aspect of the present invention, the wiring board of the eighth aspect further includes a second electronic component having two electrodes, and each of the two electrodes of the second electronic component is a first. It is fixed with solder to the second region of each of the land and the second land.

According to the wiring board of the present invention, the module including the wiring board, and the manufacturing method of the module, electronic components having different standards can be shared without modifying the wiring board while ensuring desired electrical characteristics and reliability. By making it mountable on the land, the degree of freedom in component selection is expanded, design changes of the wiring board are avoided, the manufacturing cost of the module including the wiring board is reduced, and the delivery period is shortened.

It is a top view of the wiring board of the 1st Embodiment of this invention. It is sectional drawing of the line segment AA'in FIG. It is a top view in one step of the manufacturing method of the module of 1st Embodiment of this invention. It is sectional drawing of the line segment AA'in FIG. It is a top view in one step of the manufacturing method of the module of 1st Embodiment of this invention. It is sectional drawing of the line segment AA'in FIG. It is a top view of the module of the 1st Embodiment of this invention. It is sectional drawing of the line segment AA'in FIG. It is a top view in one step of the manufacturing method of the module of 1st Embodiment of this invention. It is sectional drawing of the line segment AA'in FIG. It is a top view in one step of the manufacturing method of the module of 1st Embodiment of this invention. It is sectional drawing of the line segment AA'in FIG. It is a top view of the module of the 1st Embodiment of this invention. It is sectional drawing of the line segment AA'in FIG. It is a top view of the wiring board of the 2nd Embodiment of this invention. It is a top view of the module of the 2nd Embodiment of this invention. It is a top view of the modification of the module of the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a plan view showing a configuration of a wiring board 12 prepared in the first step in the method of manufacturing a module according to the first embodiment of the present invention. On the surface of the wiring board 12, a first land 1a and a second land 1b having the same shape are arranged so as to be separated from each other and mirror-symmetrical with respect to the axis of symmetry 9. These lands are made of, for example, a conductive layer containing copper as a main component.

Each of the first land 1a and the second land 1b includes a first region 3a and 3b, a second region 5a and 5b, overlapping regions 8a and 8b, and slit portions 6a and 6b, respectively. The first regions 3a and 3b and the second regions 5a and 5b each have a substantially rectangular shape, and the first regions 3a and 3b are directed from the second regions 5a and 5b toward the mirror-symmetric axis of symmetry 9. Is protruding.

Further, the overlapping regions 8a and 8b are regions in which a part of the first regions 3a and 3b and a part of the second regions 5a and 5b overlap each other. The overlapping regions 8a and 8b are shown in FIG. 1 from a geometrical point of view, but in an actual land, the first regions 3a and 3b, the second regions 5a and 5b, and the overlapping regions 8a and 8b And, there is no mark that can clearly distinguish the boundaries between each other.

The slit portions 6a and 6b are formed by cutting out lands, and are installed inside the second regions 5a and 5b along at least a part of the peripheral edges of the first regions 3a and 3b of the overlapping regions 8a and 8b. ing. For example, the length of the slit portion 6a in the first direction Y is substantially the same as the length of the first region 3a in the first direction Y, and the width in the second direction X is very small. The slit portions 6a and 6b are regions in which the conductive layer constituting the land is not formed, and may be included in the land.

FIG. 2 is a cross-sectional view of the line segment AA'shown in FIG. The first regions 3a and 3b are arranged so as to be close to each other and directly face each other. On the other hand, the second regions 5a and 5b are arranged so as to sandwich the first regions 3a and 3b, respectively. Further, a slit portion 6a is installed between the first region 3a and the second region 5a, and similarly, a slit portion 6b is installed between the first region 3b and the second region 5b. There is. The conductive layer forming the land is cut out in the slit portions 6a and 6b, and the first regions 3a and 3b and the second regions 5a and 5b are separated from each other.

First, a method of manufacturing a module when mounting a small electronic component will be described. 3 to 6 show the second step of the method of manufacturing the module of the first embodiment. As shown in FIGS. 3 and 4, the metal mask 15 provided with the openings 16 and 17 is placed on the surface of the wiring board 12. At this time, the openings 16 and 17 are aligned in advance so as to coincide with the first regions 3a and 3b, respectively. Here, the first regions 3a and 3b include overlapping regions 8a and 8b.

In FIGS. 5 and 6, the solder paste is supplied to the surface of the metal mask 15 and the squeegee is slid on the surface of the metal mask 15 to selectively select the solder pastes 21 and 22 in the openings 16 and 17. Print. Since the openings 16 and 17 are aligned with the first regions 3a and 3b, respectively, the solder pastes 21 and 22 are selectively printed in the regions of the first regions 3a and 3b. The thickness of the solder pastes 21 and 22 at this time can be controlled by the thickness of the metal mask 15.

Next, in the third step of the module manufacturing method of the first embodiment, a first electronic component 24 having two electrodes 26 and 27, for example, a capacitance element, a resistance element, etc., is placed on the surface of the wiring board 12. Place it. At this time, each of the electrodes 26 and 27 is aligned and placed on the printed solder pastes 21 and 22, and the viscosity of the solder pastes 21 and 22 holds the first electronic component 24.

Subsequently, in the fourth step of the module manufacturing method of the first embodiment, the module 10 holding the first electronic component 24 is subjected to a heat treatment for reflowing the solder pastes 21 and 22, and FIG. 7 And as shown in FIG. 8, each of the two electrodes 26, 27 of the first electronic component 24 is soldered to the first regions 3a, 3b of the first land 1a and the second land 1b. Here, the first regions 3a and 3b include the overlapping region 8.

Generally, when the solder is reflowed, a phenomenon occurs in which the softened solder spreads along the surface of the conductive layer having good wettability. Therefore, if the land is enlarged in order to share the land between electronic components having different size standards, the volume of the solder is insufficient and the solder fillet is not sufficiently formed, and if the solder is sufficiently supplied, the reflow occurs. Due to the surface tension of the softened solder in the meantime, electronic components are pulled and their positions are displaced.

In the first embodiment of the present invention, slit portions 6a and 6b are provided between the overlapping regions 8a and 8b and the second regions 5a and 5b, respectively. As a result, the portion where the conductive layer continuously extends from the overlapping regions 8a and 8b to the second regions 5a and 5b is limited to the vicinity of both ends of the slit portions 6a and 6b, and the total extension thereof is the overlapping region. It is sufficiently shorter than the peripheral length of the first regions 3a and 3b including 8a and 8b. Therefore, the phenomenon that the solder spreads from the overlapping regions 8a and 8b to the second regions 5a and 5b through the portion where the conductive layer extends continuously is suppressed, and the solder softened during the reflow is generally overlapped. It is held in the first regions 3a and 3b including the regions 8a and 8b.

Since the solder pastes 21 and 22 are generally held in the first regions 3a and 3b during the reflow, the misalignment of the first electronic component 24 is suppressed, and the two electrodes 26 of the first electronic component 24 are suppressed. Two solder fillets 21a and 22a extending along the slits 6a and 6b are formed on the side surfaces of the respective ends of the 27 and 27 in a sufficient size. Therefore, the first electronic component 24 is fixed to the wiring board 12 with sufficient mechanical strength and sufficiently low electrical resistance.

Further, since the softened solder is held in the first regions 3a and 3b and hardly moves in the direction of the second regions 5a and 5b, the solder in which the first electronic component 24 is softened during the reflow. The phenomenon that the placement position shifts due to being pulled by the surface tension of the surface is also suppressed.

Next, a method of manufacturing a module when an electronic component larger than the above-mentioned electronic component is mounted will be described. As shown in FIGS. 9 and 10, a metal mask 35 provided with openings 36 and 37 is placed on the surface of the wiring board 12. The openings 36 and 37 have a shape obtained by removing the overlapping regions 8 and the slit portions 6a and 6b from the second regions 5a and 5b, but are arranged in advance so as to match the corresponding portions of the second regions 5a and 5b, respectively. Perform alignment.

In FIGS. 11 and 12, the solder paste is supplied to the surface of the metal mask 35, and the squeegee is slid on the surface of the metal mask 35 to selectively select the solder pastes 41 and 42 in the openings 36 and 37. Print. Since the openings 36 and 37 are aligned with the predetermined portions of the second regions 5a and 5b, the solder pastes 41 and 42 are selectively printed in the predetermined regions of the second regions 5a and 5b. To. The thickness of the solder pastes 41 and 42 at this time can be controlled by the thickness of the metal mask 35.

Subsequently, as shown in FIGS. 13 and 14, a second electronic component 44 having two electrodes 46 and 47, such as a capacitance element and a resistance element, is placed on the surface of the wiring board 12. At this time, each of the electrodes 46 and 47 covers the entire second region 5a and 5b including the overlapping region 8 and the slit portions 6a and 6b, but the solder paste 41 and 42 are printed on the soldered region. It is only a region (that is, a predetermined region) excluding the overlapping region 8 and the slit portions 6a and 6b from the second regions 5a and 5b.

Then, the module 10 holding the second electronic component 44 is subjected to a heat treatment for reflowing the solder pastes 41 and 42. Then, each of the two electrodes 46 and 47 of the second electronic component 44 is soldered to predetermined positions in the second regions 5a and 5b of the first land 1a and the second land 1b, respectively.

Here, since the second regions 5a and 5b extend sufficiently protruding from the respective ends of the electrodes 46 and 47 in the second direction X, the electrodes 46 of the second electronic component 44, Solder fillets 41a and 42a are formed on the side surfaces of the respective ends of 47 in a sufficient size. Therefore, the second electronic component 44 is fixed to the wiring board 12 with sufficient mechanical strength and sufficiently low electrical resistance.

As described above, the first land 1a and the second land 1b can be mounted by soldering the first electronic component 24 including the two electrodes 26 and 27 to the first regions 3a and 3b. .. On the other hand, instead of the first electronic component 24, the second electronic component 44 including the two electrodes 46 and 47 can be mounted by soldering to a predetermined region of the second regions 5a and 5b. Is.

Here, the first electronic component 24 may be, for example, a two-terminal component such as a capacitance element or a resistance element having a chip size of 10 mm × 5 mm, and the first electronic component 24 may be, for example, a chip size of 16 mm × 8 mm. It may be a two-terminal component such as a capacitance element or a resistance element. It is self-evident that the present invention can be applied to other chip size combinations.

This means that either the first electronic component 24 or the second electronic component 44 having different specifications (sizes) can be mounted on the pair of lands composed of the first land 1a and the second land 1b. It means that there is. That is, it means that any one of a plurality of electronic components having different specifications (sizes) can be selected and mounted on a specific location on the surface of the wiring board 12.

As described above, according to the wiring board of the present invention, the module including the wiring board, and the manufacturing method of the module, electronic components having different standards can be obtained without modifying the wiring board while ensuring desired electrical characteristics and reliability. By making it possible to mount components on a common land, the degree of freedom in component selection is expanded, design changes to the wiring board are avoided, the manufacturing cost of modules including the wiring board is reduced, and the delivery period is shortened. Ru.

<Second embodiment>
Next, a second embodiment of the present invention will be described. FIG. 15 is a plan view of the wiring board 101 of the second embodiment. General lands 102a, 102b, 103a, 103b, 104 and the like are formed on the surface of the wiring board 101.

In addition, three land pairs on which two-terminal electronic components corresponding to the first land 1a and the second land 1b described in the first embodiment of the present invention are mounted are arranged. These are illustrated as lands vs. C1 (including lands 105a, 105b), lands vs. C2 (including lands 106a, 106b), and lands vs. C3 (including lands 107a, 107b).

These lands are connected to each other by wiring as illustrated by wirings 110, 111, 112, 113, 114 and the like. The surface of the wiring board 101 may be covered with a solder resist 120 having only a land portion opened.

FIG. 16 illustrates a module 100 in which various electronic components are mounted on a wiring board 101. The lands 102a and 102b are equipped with, for example, a two-terminal electronic component 121 which is a resistance element. Lands 103a and 103b are equipped with electronic components 122 having two terminals, which are smaller than the electronic components 121, for example, resistance elements. An integrated circuit 123 having multiple terminals is mounted on the land 104.

A first capacitive element 125, a second capacitive element 126, and a third capacitive element 127 are mounted on the land-to-C1, land-to-C2, and land-to-C3, respectively. As shown, the first capacitive element 125 and the third capacitive element 127 have a large chip size, and the second capacitive element 126 has a smaller chip size.

Thus, land-to-C1, land-to-C2, and land-to-C3 each have exactly the same shape, but electronic components of different chip sizes, such as the first capacitive element 125 and the second capacitive element 126. Can be installed.

FIG. 17 is a plan view of a modified example of the module of the second embodiment of the present invention. In this modification, in the second embodiment shown in FIG. 16, the large chip size third capacitance element 127 mounted on the land vs. C3 is replaced with the small chip size fourth capacitance element 128. Is.

As described above, the module of the second embodiment of the present invention has a chip size (size standard) at the same location on the wiring board having the same land arrangement and wiring layout without changing the design of the wiring board. It is possible to select and mount one of a plurality of electronic components having different characteristics.

1a 1st land 1b 2nd land 3a, 3b 1st area 5a, 5b 2nd area 6a, 6b Slit part 8a, 8b Overlapping area 10 Module 12 Wiring board 21, 22 Solder paste 21a, 22a Solder fillet 24 First electronic component 44 Second electronic component 26, 27, 46, 47 Electrodes

Claims (11)

A wiring board including a first land and a second land arranged symmetrically with respect to each other at a distance from the first land, and inside each of the first land and the second land. In the first step, a wiring board including a predetermined area and a slit portion in which a land is cut out along a part of the peripheral edge of the predetermined area is prepared.
A second step of printing the solder paste along the slit portion in the predetermined area of each of the first land and the second land.
A third step in which an electronic component having two electrodes is placed so that each of the solder paste and each of the two electrodes is in contact with each other.
By reflowing the solder paste, two solder fillets extending from the respective surfaces of the first land and the second land to the respective side surfaces of the two electrodes are formed, and the electrons are formed. A fourth step of soldering each of the two electrodes of the component to the first land and the second land.
How to manufacture the module. In the wiring board prepared in the first step,
The first land and the second land include a first region and a second region, respectively.
The first region and the second region have overlapping regions in which a part of each region overlaps with each other, and the first region protrudes from the second region toward the axis of symmetry of the mirror plane. Arranged to do
The method for manufacturing a module according to claim 1, wherein the slit portion is provided inside the second region along the peripheral edge of the first region of the overlapping region. The method for manufacturing a module according to claim 2, wherein the predetermined region is a first region including the overlapping region. The method for manufacturing a module according to claim 3, wherein each of the two solder fillets extends along the slit portion of each of the first land and the second land. The method for manufacturing a module according to claim 2, wherein the predetermined region is a region obtained by removing the overlapping region and the slit portion from the second region. The manufacture of the module according to claim 5, wherein each of the two electrodes of the electronic component is placed so as to cover the second region on which the solder paste is printed, the slit portion, and the overlapping region. Method. The first electronic component or the first electronic component is located on at least one pair of lands each having two electrodes and capable of soldering a first electronic component or a second electronic component of different sizes to a wiring board. In the method of manufacturing a module including the first electronic component or the second electronic component by soldering the second electronic component,
The pair of lands consists of a first land and a second land.
The first land and the second land are arranged symmetrically with each other separated from each other.
The first land and the second land respectively solder a first region for soldering the first electronic component and a second electronic component larger than the first electronic component. With a second area for soldering
The first region and the second region have overlapping regions in which some of the regions overlap each other, and the first region is directed from the second region toward the axis of symmetry of the mirror plane. Arranged to protrude,
Inside the second region, a slit portion formed by cutting out a land is provided along the peripheral edge of the first region of the overlapping region.
The first step of preparing a wiring board including the first land and the second land, and
A second step of printing the solder paste on each of the first land and the second land, the second step of printing the solder paste on a predetermined area along the slit portion of the second area. Steps and
A third step of placing the first electronic component or the second electronic component so that each of the solder pastes and the electrodes is in contact with each other.
The solder paste is reflowed so that a solder fillet is formed on the side surface of the electrode, and the first electronic component or the second electronic component is soldered to the first land and the second land. With the fourth step,
In the fourth step, when the first electronic component is soldered, the solder fillet is formed along the slit portion.
How to manufacture the module. The first land and
A second land, which is arranged symmetrically with respect to the first land and separated from the first land, is provided.
The first land and the second land include a first region and a second region, respectively.
The first region and the second region have overlapping regions in which a part of each region overlaps with each other, and the first region protrudes from the second region toward the axis of symmetry of the mirror plane. ,
A wiring board in which a slit portion having a land cutout is provided inside the second region along the peripheral edge of the first region of the overlapping region. A first electronic component having two electrodes is further provided, and each of the two electrodes of the first electronic component is soldered to the first region of each of the first land and the second land. A module including the wiring board according to claim 8, which is fixed. Further including a solder fillet extending from the surface of the first region of each of the first land and the second land to the side surface of each of the two electrodes, the solder fillet is the first. 9. The module according to claim 9, which extends along the slit portion of each of the land and the second land. A second electronic component having two electrodes is further provided, and each of the two electrodes of the second electronic component is soldered to the second region of each of the first land and the second land. A module including the wiring board according to claim 8, which is fixed.

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