KR20200140195A - High density mounting module - Google Patents

Abstract

An electronic component is fixed to a printed circuit board with sufficient mechanical strength, and positional deviation during solder reflow is suppressed, thereby improving mounting positional accuracy. A high-density mounting module includes: a printed circuit board having a plurality of lands; and an electronic component mounted on the printed circuit board and including a plurality of connection terminals connected to a plurality of lands, wherein the plurality of lands includes a first cutout and a second cutout stretched in an orientation facing each other in a first direction, and a third cutout and a fourth cutout stretched in a second direction orthogonal to the first direction in an orientation opposite to each other, and a solder fillet extending over the surface of each land to which the connection terminal is connected is formed from each side surface of the plurality of connection terminals of the electronic component.

Description

High density mounting module {HIGH DENSITY MOUNTING MODULE}

The present invention relates to a high-density mounting module, and more particularly, to a module for surface mounting electronic components on a printed circuit board with high density.

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, in order to realize high-density mounting suitable for miniaturization of mounted components, a technique of surface mounting electronic components on a printed circuit board is employed.

As described above, in a module employing a high-density surface mounting technology, individual electronic components are mounted on a printed board by a solder reflow technology, securing the mechanical strength of fixing the electronic parts to the printed board, and It is compatible to reduce the electrical resistance between each connection terminal and the conductive layer of the printed circuit board.

Japanese Patent Laid-Open No. Hei 10-335795

In the solder reflow technology, an appropriate amount of cream solder is attached to the mounting land of the printed circuit board by a printing method, and the electronic components are aligned and mounted on the mounting land, and then, once heated to melt the solder, and then cooled. By doing so, the solder is solidified and electrical connection is obtained while fixing the electronic component on the printed circuit board.

In such a surface mount technology, when the solder is melted, the electronic component is in a state of floating on the molten solder, so the electronic component moves on the solder until it is cooled and solidified, and the electronic component is placed in alignment It may deviate from the position of. As a technique for suppressing such positional shift, for example, a technique described in Cited Document 1 is proposed.

On the other hand, in order to secure the mechanical strength for fixing the electronic component to the printed circuit board, it is necessary to sufficiently form a solder fillet surrounding the connection terminals of the electronic component on the mounting land. For this, it is necessary to supply a sufficient volume of solder to surround the connection terminal of the electronic component on the mounting land, which causes a situation where the electronic component is more likely to move when the solder is melted.

The present invention has been made in view of such a situation, and its object is to provide sufficient mechanical strength for the electronic component and the printed circuit board by sufficiently forming a solder fillet surrounding the connection terminal of the electronic component on the mounting land. It is to provide a high-density mounting module having satisfactory mounting position accuracy while being held and fixed, and prevents the electronic components from moving on the solder during solder reflow and shifting from the original position on which the electronic components are aligned and mounted.

The high-density mounting module of the first aspect of the present invention is a high-density mounting module comprising a printed circuit board having a plurality of lands, and an electronic component including a plurality of connection terminals mounted on the printed board and connected to the plurality of lands, The plurality of lands includes a first cutout and a second cutout stretched in an orientation facing each other in a first direction, and a third cutout and a fourth cutout stretched in a second direction orthogonal to the first direction in an orientation opposite to each other. A solder fillet is formed that includes notches and extends over the surface of each land to which the connection terminal is connected from each side surface of the plurality of connection terminals of the electronic component.

According to a second aspect of the present invention, in the first aspect, the plurality of lands have lands in which notches are arranged.

According to a third aspect of the present invention, in the first aspect, the plurality of lands have lands in which only one notch is disposed.

According to the fourth aspect of the present invention, in the first aspect, the plurality of lands has at least four lands, and has four lands in which only one notch is disposed.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, each of the first notch and the second notch is disposed on a separate land, and the separate land is a second Spaced apart from each other in the direction.

According to a sixth aspect of the present invention, in the fifth aspect, each of the third and fourth notches is disposed on a separate land, and the separate lands are spaced apart from each other in the first direction.

According to a seventh aspect of the present invention, in the sixth aspect, the plurality of lands further include a fifth notch extending in the first direction and a sixth notch extending in the second direction.

The high-density mounting module of the eighth aspect of the present invention includes a printed circuit board having a plurality of lands, a solder resist covering each periphery of the plurality of lands, and having a plurality of openings included in each region of the plurality of lands, It is a high-density mounting module mounted on a printed circuit board and including an electronic component including a plurality of connection terminals connected to a plurality of lands, and a plurality of openings included in the plurality of lands face each other in a first direction, each A plurality of connection of electronic components including a first protrusion and a second protrusion protruding inward, and a third protrusion and a fourth protrusion facing each other in a second direction orthogonal to the first direction, and each protruding inwardly From each side surface of the terminal, a solder fillet extending over the surface of each land to which the connection terminal is connected is formed.

According to the present invention, by sufficiently forming a solder fillet surrounding the periphery of the connection terminal of the electronic component on the mounting land, the electronic component is fixed to the printed board with sufficient mechanical strength, and the position where the electronic component is fixed is soldered. It is possible to provide a high-density mounting module having good mounting position accuracy by moving on the molten solder during reflow, aligning the position, and preventing shifting from the mounted original position.

1 is a plan view of a first embodiment of a high-density mounting module of the present invention.
2 is a plan view of a modified example of the first embodiment of the high-density mounting module of the present invention.
3 is a plan view of a further modified example of the first embodiment of the high-density mounting module of the present invention.
4 is a cross-sectional view of a line segment A-A' of FIG. 3.
5 is a cross-sectional view of a line segment B-B' of FIG. 3.
6 is a cross-sectional view of a line segment C-C' of FIG. 3.
7 is a plan view of another modified example of the first embodiment of the high-density mounting module of the present invention.
8 is a plan view of a second embodiment of the high-density mounting module of the present invention.

Hereinafter, various embodiments of the present invention will be described based on the drawings.

<First embodiment>

Fig. 1 shows a module 101 as a first embodiment of the high-density mounting module of the present invention. The module 101 includes a printed circuit board 105 having a first land 111, a second land 112 and a third land 113. The printed circuit board 105 includes a first connection terminal 151 and a second connection terminal 152 connected to the corresponding respective of the first land 111, the second land 112, and the third land 113. And an electronic component 150 including a third connection terminal 153 is mounted.

A first notch 121 extending in a first direction (X direction) is disposed on the first land 111, and a second direction perpendicular to the first direction (X direction) is disposed on the second land 112. The third notch 123 extending in (Y direction) is disposed. In addition, in the third land 113, a second cutout 122 extending in an orientation opposite to the first cutout 121 in the first direction (X direction) and a third cutout in the second direction (Y direction) A fourth cutout 124 extending in an orientation opposite to 123 is disposed.

In this first embodiment, during solder reflow, when a force to move the electronic component floating in the molten solder in the negative direction in the first direction (X direction) is generated, the first notch 121 is made of the electronic component. 1 The movement of the connection terminal 151 is suppressed. And when a force to move in the positive direction is generated, the second notch 122 suppresses the movement of the third connection terminal 153 of the electronic component.

Similarly, when a force to move in the negative direction in the second direction (Y direction) is generated, when the third cut-out 123 suppresses the movement of the connection terminal 151 of the electronic component and a force to move in the positive direction occurs , The second notch 122 suppresses movement of the third connection terminal 153 of the electronic component.

In order to prevent the electronic components floating in the molten solder from moving in parallel in the first direction (X direction) and in the second direction (Y direction), at least in any position among the plurality of lands. In the first direction (X direction), two cutouts that are stretched in an orientation opposite to each other, in a direction in a second direction (Y direction) orthogonal to the first direction (X direction), are stretched in an orientation opposite to each other It is necessary to place two cutouts.

However, the movement of the electronic component floating in the molten solder is not limited to parallel movement, for example, when a force to move in the negative direction in the first direction (X direction) is generated, the first notch 121, Although it suppresses movement of the first connection terminal 151 of the electronic component in the negative direction in the first direction (X direction), it suppresses the movement of the entire electronic component to rotate around the first cutout 121 I can't.

Similarly, for the second cutout 122, the third cutout 123, and the fourth cutout 124, as in the first cutout 121, the parallelism of the connection terminals of the electronic components in the direction in which each cutout corresponds The movement can be suppressed, but the movement of the entire electronic component rotating around each notch cannot be suppressed.

With respect to this rotational movement, a positional shift can be suppressed by combining a plurality of notches. For example, the movement of the third connection terminal 153 is suppressed by the second cut-out 122 and the fourth cut-out 124 with respect to the movement that tries to rotate clockwise around the first cut-out 121 Is prevented. Regarding the movement that tries to rotate in the counterclockwise direction, the movement of each of the first connection terminal 151 and the third connection terminal 153 is suppressed and prevented by the third cut-out 123 and the fourth cut-out 124 do.

In addition, in the movement centering on the second cutout 122, the rotation in the clockwise direction is the movement of the first connection terminal 151 by the first cutout 121, and the rotation in the counterclockwise direction is the third cutout ( 123) and the fourth notch 124, each movement of the first connection terminal 151 and the third connection terminal 153 is suppressed.

In FIG. 1, in the first land 111 in which the first cutout 121 extending in the first direction (X direction) is disposed, the second cutout 122 in an orientation facing the first cutout 121 is disposed. The third land 113 is separated from each other in a second direction (Y direction) orthogonal to the first direction (X direction) in which the first cutout 121 and the second cutout 122 are stretched.

In addition, the second land 112 in which the third cutout 123 extending in the second direction (Y direction) is disposed is a third cutout 123 in which the fourth cutout 124 in an orientation facing the third cutout 123 is disposed. The three lands 113 and the third cutout 123 and the fourth cutout 124 are spaced apart from each other in a first direction (Y direction) orthogonal to the second direction (X direction) in which the third and fourth cutouts 124 are stretched.

In consideration of not only the direction in which the electronic component moves in parallel, but also the suppression of the positional shift in the rotational direction, it is more preferable that the two cutouts extending in at least mutually opposite orientations are respectively dispersed and disposed in lands spaced apart from each other.

2 shows a modified example of the module 101 according to the first embodiment of the present invention. In this modified example, in the module 101 illustrated in FIG. 1, the third cutout 123 disposed in the second land 112 is disposed in the first land 111. The direction and orientation in which the third cutout 123 is stretched are the same as the direction and orientation in which the third cutout 123 described in FIG. 1 is stretched. In this modification, the notch is not arranged in the second land 112.

Also in this modified example, the first land 111 on which the third cutout 123 extending in the second direction (X direction) is disposed is the fourth cutout 124 in an orientation facing the third cutout 123 The arranged third lands 113 are spaced apart from each other in a first direction (Y direction) orthogonal to the second direction (X direction) in which the third cutout 123 and the fourth cutout 124 are stretched.

Fig. 3 shows another modified example of the module 101 of the first embodiment of the present invention. In this still another modified example, in addition to the module 101 shown in FIG. 1, the fifth notch 125 and the third land 113 extending in the first direction (X direction) of the second land 112 A sixth notch 126 extending in the first direction (X direction) and a seventh notch 127 extending in the second direction (Y direction) of the first land 111 are added.

The fifth notch 125 and the sixth notch 126 are stretched in orientations facing each other in the first direction (X direction), and the seventh notch 127 is the fourth notch 124 and the second direction ( In the Y direction) in an orientation opposite to each other.

In this still another modified example, the negative direction in the first direction (X direction) is suppressed by the movement of the first connection terminal 151 by the first notch 121, and by the sixth notch 126. Movement of the third connection terminal 153 is also suppressed. And, with respect to the positive direction of the first direction (X direction), the second cutout 122 and the fifth cutout 125 suppress the movement of each of the third connection terminal 153 and the second connection terminal 152 do.

With respect to the negative direction in the second direction (Y direction), the third cut-out 123 and the seventh cut-out 127 suppress movement of the second connection terminal 152 and the first connection terminal 151, respectively. With respect to the positive direction in the second direction (Y direction), the movement of the electronic component is suppressed by the fourth notch 124, which is the same as the module 101 illustrated in FIG. 1 here.

Further, in this still another modified example, it is configured to similarly suppress the movement of the entire electronic component to move in the inclined direction. For example, the movement in the oblique direction (positive/definite direction) in which the first direction (X direction) is positive and the second direction (Y direction) is also positive, the second notch 122 and the fourth notch 124 3 It is prevented by suppressing the movement of the connection terminal 153.

Similarly, as for the movement in the positive/negative direction, the third cut-out 123 and the fifth cut-out 125 suppress the movement of the second connection terminal 152, and the movement in the negative/positive direction is the fourth cut-out 124 And the sixth notch 126 suppresses the movement of the third connection terminal 153, and the movement in the negative/negative direction is the first cutout 121 and the seventh cutout 127 of the first connection terminal 151. Movement can be suppressed and movement of electronic components can be prevented.

In this way, if parallel movement in the first direction (X direction) and the second direction (Y direction) can be suppressed and positional displacement in the four oblique directions can be suppressed, the electronic component is All rotating movements can be suppressed. In this still another modified example, there is an effect of equally suppressing positional shift in all directions.

4, 5, and 6 are a cross-sectional view of a line segment A-A', a line segment B-B' of the third land 113 shown in FIG. 3, and a line segment C-C' of the second land 112, respectively. It is a cross-sectional view of a part. In FIGS. 4 and 5, the third land 113 is disposed on the printed circuit board 105, and the third connection terminal 153 of the electronic component 150 is soldered on the third land 113.

Here, the line segment A-A' is a portion in which the second cutout 122 and the sixth cutout 126 are disposed, so that the third land 113 protrudes from the end of the third connection terminal 153 in the transverse direction. The amount is small. In addition, since it is limited on the third land 113 that is a conductive layer that can hold the solder during melting, the molten solder in the transverse direction of the end of the third connection terminal 153 is returned. The amount is a trace amount, and no solder fillet is formed, and a thin solder layer 160 is formed on the surface of the third land 113.

On the other hand, the phenomenon in which the electronic component 150 is displaced in the solder reflow process is caused by floating on the molten solder and moving. Therefore, if there is no rotation of the molten solder in the transverse direction of the end of the third connecting terminal 153, the third connecting terminal 153 cannot move in the transverse direction, that is, in the direction A and A'in FIG. 4. . Therefore, in the portion where the notch is arranged, movement of the electronic component in the direction closer to the notch during solder reflow is suppressed.

5 is a cross-sectional view of the third land 113 at a portion where a notch is not formed, and both ends of the third land 113 largely protrude from the third connection terminal 153 in the transverse direction. Therefore, the rotation of the molten solder in the transverse direction of the end of the third connection terminal 153 is sufficient, and from the both ends of the third connection terminal 153 to the surface of the third land 113, solder Fillet 165 is formed.

In this way, by sufficiently securing the amount of protrusion in the lateral direction of the third land 113 from both ends of the third connection terminal 153, the solder fillet 165 is formed, and the third connection terminal 153 and the third The mechanical strength of fixing the land 113, that is, the mechanical strength of fixing the electronic component 150 to the printed circuit board 105 can be secured.

6 is a cross-sectional view of a line segment C-C' in which the second connection terminal 152 is disposed on the second land 112 in which the fifth notch 125 is disposed on one side. Like the third land 113, a solder fillet is not formed in the vicinity of the fifth notch 125, and extends from the side surface of the second connection terminal 152 to the second land 112 in a portion where there is no notch. A sufficient solder fillet 165 is formed.

As described above, the movement of the electronic component 150 during solder reflow can be suppressed in the portion where the notch is arranged in the land. Further, even in the land on which the notches are arranged, a solder fillet for holding the electronic component with sufficient strength can be formed outside the vicinity of the notches.

As described above, according to the first embodiment of the present invention, by sufficiently forming the solder fillet surrounding the connection terminal of the electronic component on the mounting land, the electronic component is fixed to the printed board with sufficient mechanical strength, The position at which the electronic component is fixed moves on the molten solder during solder reflow, and it is prevented from shifting from the original position on which the electronic component is mounted and aligned, thereby providing a high-density mounting module having good mounting position accuracy.

7 is a plan view showing another modified example of the first embodiment. In this other variant, it includes at least four lands 211, 212, 213, 214, and the minimum necessary four cutouts 221, 222, 223, 224, lands 211, 212, 213, 214 Each of them is distributed and arranged one by one. In the case of an electronic component having four or more connection terminals, it is more preferable that the cutouts are distributed and disposed at positions spaced apart from each other.

<2nd embodiment>

8 is a plan view showing a second embodiment of the high-density mounting module of the present invention. This still another modification is to realize the solder structure of the first embodiment shown in Fig. 1 by the over-resist structure.

The module 101 includes a printed circuit board 105 having a first land 341, a second land 342 and a third land 343. The printed circuit board 105 includes a first connection terminal 151 and a second connection terminal 152 connected to the corresponding respective of the first land 341, the second land 342, and the third land 343. And an electronic component 150 including a third connection terminal 153 is mounted.

The surface of the printed circuit board 105 is covered with a solder resist. In this solder resist, a first opening 311 is disposed that covers the periphery of the first land 341 and is included in a region in which the first land 341 is disposed. In the first opening 311, the first A first protrusion 321 protruding inward in the direction (X direction) is disposed. In addition, a second opening 312 that covers the periphery of the second land 342 and is included in the area in which the second land 342 is disposed is also disposed, and the second opening 312 has a first direction (X direction). A third protrusion 323 protruding inward in a second direction (Y direction) orthogonal to) is disposed.

Further, in this solder resist, a third opening 313 is disposed covering the periphery of the third land 343 and included in the region in which the third land 343 is disposed, and in the third opening 313, The second protrusion 322 protrudes in an orientation opposite to the first protrusion 321 in the first direction (X direction), and the third protrusion 323 protrudes in an orientation opposite to the third protrusion 323 in the second direction (Y direction). The fourth protrusion 324 is disposed.

In this second embodiment, the first land 341, the second land 342 and the exposed portions of the first opening 311, the second opening 312, and the third opening 313 of the solder resist, Cream solder is selectively printed on the respective surfaces of the third lands 343 to perform solder reflow. At this time, cream solder is not formed in each of the protrusions 321 to 324 protruding inwardly of the respective openings 311 to 313.

In addition, while the solder is melted in the reflow process, the molten solder on each land 341 to 343 flows only into the opening of the solder resist, so that the planar shape of the solder after reflow is the respective openings 311 To 313). Therefore, in the second embodiment, it is possible to design the planar shape of the solder after reflow by making the shape of the opening of the solder resist desired.

In the second embodiment as well, by setting the solder to the same planar shape as in the first embodiment shown in Fig. 1, it is possible to restrict the movement of electronic components suspended in the molten solder during solder reflow. For example, when a force to move in the negative direction in the first direction (X direction) is generated, the first protrusion 321 suppresses movement of the first connection terminal 151 of the electronic component. And when a force to move in the positive direction is generated, the second protrusion 322 suppresses the movement of the third connection terminal 153 of the electronic component.

In addition, when a force to move in the negative direction in the second direction (Y direction) occurs, the third protrusion 323 suppresses the movement of the connection terminal 151 of the electronic component, and when a force to move in the positive direction occurs In the same manner as in the first embodiment illustrated in FIG. 1, the second protrusion 322 can suppress the movement of the third connection terminal 153 of the electronic component.

Therefore, also in the over-resist structure, by providing inward protrusions in the openings of the solder resist, by designing the planar shape of the solder, the same effect as in the case of arranging the lands provided with notches can be exhibited.

As described above, according to the second embodiment, the solder fillet surrounding the connection terminal of the electronic component is sufficiently formed on the mounting land, so that the electronic component is fixed to the printed board with sufficient mechanical strength, and the electronic component is It is possible to provide a high-density mounting module having good mounting position accuracy by preventing the position to be fixed from moving on the molten solder during solder reflow and displaced from the original position mounted by alignment.

101: module
105: printed board
111 to 113: first to third land
121 to 126: first to sixth cutout
150: electronic component
151 to 153: first to third connection terminals
165: solder fillet
301: module
305: printed circuit board
311 to 313: first to third openings
321 to 324: first to fourth protrusions
341 to 343: first to third lands
351 to 353: first to third connection terminals
350: electronic component
X: first direction
Y: second direction

Claims (8)

A printed circuit board having a plurality of lands,
A high-density mounting module mounted on the printed circuit board and having an electronic component including a plurality of connection terminals connected to the plurality of lands,
The plurality of lands may include a first cutout and a second cutout stretched in an orientation opposite to each other in a first direction, a third cutout stretched in a second direction orthogonal to the first direction, and Including the fourth cutout,
A high-density mounting module, wherein a solder fillet extending over a surface of each land to which the connection terminal is connected is formed from each side surface of the plurality of connection terminals of the electronic component. The method of claim 1,
The plurality of lands have lands in which notches are not arranged, a high-density mounting module. The method of claim 1,
The plurality of lands has a land in which only one cutout is disposed. The method of claim 1,
The plurality of lands have at least four lands, and have four lands in which only one cutout is arranged. The method according to any one of claims 1 to 4,
Each of the first notch and the second notch is disposed on a separate land, and the separate lands are spaced apart from each other in the second direction. The method of claim 5,
Each of the third cutout and the fourth cutout is disposed on a separate land, and the separate lands are spaced apart from each other in the first direction. The method of claim 6,
The plurality of lands further include a fifth notch extending in the first direction and a sixth notch extending in the second direction. A printed circuit board having a plurality of lands and a solder resist covering each peripheral portion of the plurality of lands and having a plurality of openings included in each region of the plurality of lands,
A high-density mounting module mounted on the printed circuit board and having an electronic component including a plurality of connection terminals connected to the plurality of lands,
The plurality of openings included in the plurality of lands face each other in a first direction, each of a first protrusion and a second protrusion protruding inward, and a second direction orthogonal to the first direction, and , Each includes a third protrusion and a fourth protrusion protruding inward,
A high-density mounting module, wherein a solder fillet extending over a surface of each land to which the connection terminal is connected is formed from each side surface of the plurality of connection terminals of the electronic component.

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