JP2003008191A - Wiring board device - Google Patents

Abstract

(57) Abstract: The present invention provides an extremely effective wiring board device having a structure in which circuit board electrodes can sufficiently withstand mechanical shock and suppressing the generation of solder balls as much as possible. An electronic component (1) is mounted on an electrode (5) of a circuit board (4) and mounted via solder (6), and a specific area on the circuit board is covered with a solder resist (3) made of a heat-resistant coating material. The outer portion 5a of the circuit board electrode facing outward from the edge g of the electronic component has an over-resist structure in which a solder resist is overlapped on at least a part of the electrode. At the inner portion 5b facing inward from the edge, a clearance structure is provided in which a solder resist is applied at a predetermined interval to at least a part of the electrode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board device in which electronic parts are mounted on electrodes of a circuit board via solder and a specific region of the circuit board is covered with a solder resist, and more particularly,
The present invention relates to a solder resist construction condition for an electrode of a circuit board and a portable information terminal device using the condition.

[0002]

2. Description of the Related Art A portable information terminal device for handling electronic information, such as a notebook type personal computer or a mobile phone, is provided for carrying, and therefore, miniaturization is a top priority. Therefore, regarding the electrical components used in this portable information terminal device,
There is a demand for downsizing and thinning, and leadless leadless electrical components are often used to increase the packaging density as much as possible.

In the leadless type component, an external connection electrode provided on the surface of the component is connected to an electrode provided on a wiring board by a joining member such as solder or anisotropic conductive resin. By doing so, they are directly connected electrically and mechanically.

For example, LCC (Leadless Ch
Fig. 10 (A) shows an electronic component that is an "IP Carrier".
Are shown as a bottom view and a side view. A conventional wiring board device mounted with this electronic component is shown in FIG. 10B as a schematic plan view (a perspective view is shown for convenience of explanation), and FIG.
Is an enlarged view of a part of the wiring board device, and FIG. 10D is a sectional view thereof.

In the figure, reference numeral 100 denotes a rectangular electronic component in a plan view, and electrodes 101 are provided on the periphery of the electronic component at predetermined intervals. The electrode 101 of the electronic component 100 is formed by recessing the side end portion of the electronic component 100 into a substantially semicircular shape, and is disposed in a substantially U-shaped cross section on the surface extending over the side surface and both sides of the electronic component.

Reference numeral 102 is a circuit board, and electrodes 103A are provided on the circuit board. The electrode 103A on the circuit board 102 and the electrode 101 of the electronic component 100 are at positions facing each other, and the circuit board electrode 103A
Has a dimension and shape that face the inner portion of the electronic component edge 100a and project outward from the electronic component edge when the electronic component 100 is mounted.

The electrode 103A of such a circuit board 102
The electrode 101 of the electronic component 100 is accurately positioned and mounted on the upper part, and the electrodes 103A, 103A,
101 is soldered.

A specific area on the circuit board 102 is a solder resist (also called a solder resist) 104.
Covered by A. This solder resist 104
A is made of a heat-resistant coating material and prevents solder from adhering to a specific area during the soldering work.

There are two types of conditions for applying the solder resist 104A to the electrodes 103A on the circuit board 102. Here, one of them is called a clearance structure and the other is called an over-resist structure.

The wiring board device described above has the clearance structure specifications. That is, the rectangular electrode 1
The solder resist 10 for each side d, e of 03A.
The peripheral edge of the rectangular opening 104a of 4A is provided with a predetermined clearance (clearance) s.

11 (A), (B) and (C) show a schematic structure of still another conventional wiring board device.
11A is a plan view, FIG. 11B is a partially enlarged view, and FIG. 11C is a sectional view thereof.

The electronic component 100 is mounted on the electrode 103B of the circuit board 102, and the electrodes 103B and 101 of each other are mounted.
Is soldered. A specific area on the circuit board 102 is covered with the solder resist 104B.

The conditions for applying the solder resist 104B to the circuit board electrode 103B are the specifications for the overresist structure. That is, the circuit board electrode 10
The solder resist 104B is applied so as to overlap each side portion e, f of 3B, and the solder resist 104B and the circuit board 1 are provided.
02 sandwiches each side of the electrode 103B.

The electronic components include not only the above-mentioned LCC but also chip-shaped electronic components (hereinafter referred to as chip components). Also in this chip component, the state of being mounted on the electrodes of the circuit board via the solder is almost the same.

That is, FIGS. 12A and 12B and FIG.
As shown in FIGS. 3A and 3B, the chip component 112 is mounted on the electrodes 111A and 111B on the circuit board 110.
Electrode portions 11 formed on both sides of the chip component 112
2a is soldered to the electrodes 111A and 111B of the circuit board 110.

In particular, in the wiring board device of FIGS. 12A and 12B, the opening edges of the solder resist 113A are provided at predetermined intervals on the sides d and e of the circuit board electrode 111A. The clearance structure described above is adopted.

Further, in the wiring board device of FIGS. 13A and 13B, the solder resist 113B is applied on the respective sides e and f of the circuit board electrode 111B so as to overlap each other, and the solder resist 113B and the circuit board 110 are provided. An overresist structure in which the electrode 111B is sandwiched by is adopted.

Incidentally, in the past, most of them have adopted a clearance structure which can be accurately processed by setting the size of the mask opening, and the over-resist structure has been very recently seen.

For example, in the case of a portable information terminal device such as a notebook type personal computer or a mobile phone, the circuit board electrode may be separated from the circuit board due to the impact when it is carried or dropped. Further, when a malfunction occurs in the operation of the electronic component, the electronic component is removed using a soldering iron and replaced with a new one, but the electrode sometimes peels during the removal.

It is the over-resist structure specification that is effective in preventing the occurrence of such a problem, that is, the solder resists 104B and 113B and the circuit boards 102 and 11.
Since the side portions e and f of the electrodes 103B and 111B are sandwiched between the electrodes 0 and 0, the solder resists 104B and 113B press the electrodes 103B and 111B and prevent peeling even if a shock is applied.

[0021]

However, although the wiring board device having the over-resist structure has improved impact resistance, there is a problem in that solder balls are generated in the mounting process.

That is, at the time of main heating in the mounting process, the flux between the circuit board and the electronic component violently flows due to the capillary phenomenon. At that time, the solder protruding from the electrode moves by being pushed by the flux, and becomes a solder ball when it protrudes at a certain timing. The solder collected on the electrodes is not moved by the flux.

When arranged in chronological order, the solder melts--
Most of the solder is attracted to the electrodes, but there is solder that cannot be collected at the electrodes-flux flows violently-
The solder that cannot be collected on the electrode moves according to the flow of the flux-The moved solder is flowed by the flux and pushed out of the electronic component to form a solder ball.

That is, the flux flows violently during the main heating, but if there is a step of the solder resist as in the clearance structure specification or if there is a step of silk printing or the like, it will not get over the step.

As described above, in the wiring board device having the clearance structure specification, there is a problem that the electrode is separated from the circuit board by the mechanical shock applied to the solder connection portion of the electronic component. On the other hand, the wiring board device having the over-resist structure specification has a problem that the solder balls increase although the impact resistance is improved.

A large number of electrodes are arranged in an orderly manner, and B is placed here.
There is also a wiring board device on which an AG type semiconductor package is mounted. In the semiconductor package and the circuit board, thermal distortion occurs due to the ambient temperature and heat generation of the semiconductor element, and the circuit board electrode is affected by the thermal distortion.

As a result of various tests, it was found that the effect of thermal strain appears in the electrode portion farthest from the center of the semiconductor package and the portion closest to the center of the semiconductor package, and is likely to be deformed by strain. Further, the portion of the electrode in the direction orthogonal to the line connecting the farthest portion and the most proximal portion is not easily affected by thermal strain, and strain deformation is small.

If the deformation of the electrode is large, the electrode is liable to peel off from the circuit board. When a temperature cycle test or the like is performed, peeling is seen from the boundary between the solder and the circuit board. There is.

Although the circuit board electrode is affected by such thermal strain and the details of the result have been clarified, in the past, effective means could not be taken and the electrode was allowed to deform.

The present invention has been made in view of the above circumstances. A first object of the present invention is to construct a solder resist on a circuit board electrode with a structure that can sufficiently withstand mechanical impact, and It is an object of the present invention to provide an extremely effective wiring board device that suppresses the generation of solder balls as much as possible.

A second object of the present invention is to apply the solder resist to the circuit board electrodes as follows.
An extremely effective wiring board device that can cope with the thermal distortion caused by heat generation of the circuit board or the like and prevent peeling of electrodes from the circuit board or peeling from the boundary between the solder and the circuit board to improve reliability. It is the one we are trying to provide.

[0032]

In order to satisfy the first object, the present invention provides, as claim 1, an electronic component mounted on an electrode of a circuit board via solder, and In a wiring board device in which a specific region of the circuit board electrode is covered with a solder resist made of a heat resistant coating material, the solder resist is formed on at least a part of the electrode at an outer portion of the circuit board electrode facing outward from an edge of the electronic component. No over-resist structure with overlapping
At the inner portion of the circuit board electrode facing inward from the edge of the electronic component, at least a part of the electrode has a clearance structure in which the solder resist is applied at a predetermined interval.

According to a second aspect of the present invention, in the wiring board device according to the first aspect, an outer side portion of the circuit board electrode formed in a rectangular shape in a plane is parallel to an area corresponding to an edge when an electronic component is arranged. The side part that is perpendicular to the edge of the electronic component is an over-resist structure, and the side part that is orthogonal to the edge is a clearance structure.
It is characterized in that all the side portions have a clearance structure inside the circuit board electrode.

According to a third aspect of the present invention, in the wiring board device according to the first aspect, the outer side portion and the inner side portion of the circuit board electrode formed in a planar rectangular shape correspond to edges when electronic components are arranged. The side portion parallel to the region has an over-resist structure, and the side portion orthogonal to the region corresponding to the edge when the electronic component is arranged is a clearance structure in the outer portion and the inner portion of the circuit board electrode. It is characterized by

According to a fourth aspect of the present invention, in the wiring board device according to the first aspect, the electronic parts are arranged at all of the outer side portions and inner side portions of the circuit board electrode formed in a planar rectangular shape. The side parallel to the area corresponding to the edge is formed as an over-resist structure, and the side inside the circuit board electrode, which is orthogonal to the area corresponding to the edge when electronic components are arranged, has a clearance structure. It is characterized by

According to a fifth aspect of the present invention, in the wiring board device according to the first aspect, all the side portions are formed in an over-resist structure at the outer side portion of the circuit board electrode formed in a rectangular plane shape, and the inside of the circuit board electrode is formed. It is characterized in that all sides of the part have a clearance structure.

In order to satisfy the above second object, the present invention provides
A wiring board device in which a semiconductor package is mounted on a plurality of electrodes formed on a circuit board via solder, and a specific region on the circuit board is covered with a solder resist made of a heat resistant coating material. Of the above electrode,
The portion farthest from the center of the semiconductor package and the portion closest to the center of the semiconductor package have a clearance structure in which the solder resist is provided at a predetermined distance from the electrode. It is characterized in that the portion in the direction orthogonal to the line connecting the lines has an over-resist structure in which the solder resist is overlapped.

A seventh aspect of the present invention is a portable information terminal device comprising the wiring board device according to any one of the first to sixth aspects.

By adopting the means for solving the above-mentioned problems, according to the inventions of claims 1 to 5, it is possible to sufficiently withstand mechanical impact and to suppress the generation of solder balls as much as possible. can do.

Further, according to the invention of claim 6, it is possible to reliably prevent the peeling of the electrode from the circuit board and the peeling from the boundary between the solder and the circuit board by coping with the heat distortion of the circuit board or the like due to the heat generation. The reliability can be improved.

According to the invention of claim 7, it is possible to provide a portable information terminal device excellent in impact resistance and highly reliable.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. Before describing the wiring board device of the present invention, a schematic configuration of an LCC which is an electronic component mounted on the wiring board device will be described. FIG. 14 shows the back surface of the LCC. The substrate a is formed in a two-step shape in a rectangular shape. This substrate a is composed of a first stage substrate (not shown because it is on the front side) and a second stage substrate a2,
On the first-stage substrate and the second-stage substrate a2, terminal electrodes c having constant intervals are formed on end faces b composed of four sides. The terminal electrode c is formed by forming a plurality of plated through holes on the outer end surface of the substrate a and cutting the plated through holes in half. Less than,
The LCC is called an electronic component, and the terminal electrode c is called an electronic component electrode.

A first embodiment of the present invention is shown in FIG. 1, and FIG. 1A is a plan view of a wiring board device (a part of which is transparent for convenience of explanation) and FIG. 1B is an enlarged plan view of a part of the apparatus, and FIG. 1C is a cross-sectional view taken along the line C-C of FIG. 1B.

In the figure, 1 is the electronic component described above,
Electrodes 2 are formed around the electronic component 1. In addition,
All of these electrodes 2 are shown schematically. Reference numeral 3 is a solder resist made of a heat resistant coating material applied to a specific region on the circuit board 4 as described later. Reference numeral 5 denotes a rectangular electrode formed on the circuit board 4, and the electronic component 1
The electrode 2 is provided so as to face it, as will be described later. 6
Is solder that connects the electrode 2 of the electronic component 1 and the electrode 5 of the circuit board 4.

The electrode 5 on the circuit board 4 will be further described. The electrode 5 is provided so as to extend from the edge g of the electronic component 1 to the inside and the outside from the edge g. .

The portion of the electrode 5 facing outward from the edge g of the electronic component is called an outer portion 5a, and the portion facing the inner side of the edge g of the electrode 5 (that is, the lower surface of the electronic component 1) is an inner portion 5b. , The electrode 5 has the outer portion 5a.
And the inner portion 5b.

On the outer side portion 5a of the circuit board electrode 5 and on the side portion parallel to the edge g of the electronic component, a part of the solder resist 3 is overlapped and applied. It is called an over-resist structure.

Further, the solder resist 3 is a side portion which is orthogonal to the electronic component end edge g of the outer portion 5a and all the side portions which are the inner portion 5b, which are all side portions other than the overresist structure, of the electrodes 5. The peripheral edge is provided with a predetermined clearance (clearance), and such a form is hereinafter referred to as a clearance structure.

In the wiring board device described above, a part of the outer side portion 5a of the circuit board electrode 5 has an over-resist structure, and the remaining side portions of the outer side portion 5a and the inner side portion 5b.
All of the sides will have a clearance structure.

When soldering the electrode 2 of the electronic component 1 to the electrode 6 of the circuit board 4, there is a step of printing (applying) a solder paste on the electrode 6 of the circuit board 4 in advance using a mask.

Here, as shown in FIG. 2A, when the circuit board electrode 5 has a rectangular shape extending over the outer portion 5a and the inner portion 5b, the outer portion 7a and the inner portion 7 of the mask opening 7 are formed.
The portions facing b are of different shapes.

That is, the outer portion 5a of the circuit board electrode 5
The outer portion 7a of the mask opening 7 facing to each other has the same shape area. Also, the inner portion 5b of the circuit board electrode 5
The inner portion 7b of the mask opening 7 opposed to is set to an approximately half area.

As shown in FIG. 2B, the circuit board electrode 5
With the mask opening 7 superposed on the upper portion, the outer portion 5a
The mask opening 7a facing to the inner side 5b has a corresponding 100% area, and the mask opening 7b facing the inner portion 5b has a 50% area.

The circuit board electrode 5 is printed with the solder paste by using the mask opening 7 described above, the electrode 2 of the electronic component 1 is mounted on the electrode 5, and then the well-known reflow process is performed to obtain the electronic component. The electrode 2 of 1 and the circuit board electrode 5 are soldered.

When the electronic component 1 is mounted on the circuit board 4,
Among the solder pastes printed at the time of preheating, a part of the solder paste under the electronic component 1 (inner portion) is pressed by the electronic component 1 and spreads around.

As described above, the inner portion 7b of the mask opening 7 facing the inner portion 5b of the circuit board electrode 5 is formed to be 5
Since the area is set to 0%, even if it spreads on the electrode 5 while being pressed by the electronic component 1, it hardly flows out from the peripheral edge of the electrode 5.

However, a very small part of the solder paste spreads in the clearance between the electrode 5 and the solder resist 3. Most of the solder paste is attracted to the electrode 2 of the electronic component 1 during the main heating, and the remaining solder paste vigorously flows with the flux.

On the other hand, in the above-described structure, since a part of the outer side portion 5a of the circuit board electrode 5 and the entire inner side portion 5b have the clearance structure, the outflow of the flux is surely prevented. As a result, solder balls are not generated in the inner portion 5b of the electrode 5. On the other hand, with the flow of flux, the solder paste may be absorbed by the electrodes 5 on the circuit board 4.
Often attracted to and trapped.

FIG. 3 shows the number of solder balls generated after reflow and the result of observing the fillet shape. As for the solder balls, the balls in the vicinity of the outer portion 5a of the circuit board electrode 5 were counted.

The shape of the fillet means a state in which the solder 6 has risen to the side surface of the electrode 2 of the electronic component 1 as shown in FIG. 1 (C). The case where the solder 6 goes up to the upper end of the side surface of the component electrode 2 is 5, and the solder 6 is the component electrode 2.
3 when it reaches only half of the side of the, 1 when rising to the bottom, and 0 when it does not reach the side.
Was evaluated in 6 levels.

Further, in the figure, in the embodiment of the present invention having both the over-resist structure and the clearance structure, the inner and outer parts are all over-resist structure and the inner and outer parts are all clearance. The structure was used for comparison.

As a result, in the embodiment of the present invention and the total clearance structure specification, almost no solder balls are generated, whereas in the all over resist structure specification, solder balls are often generated.

Regarding the fillet shape, it has been found that there is almost no difference between the embodiment of the present invention and the specifications of the total clearance structure and the total over-resist structure.

Next, for each of the wiring board devices having the above-mentioned three types of specifications, various mechanical strength tests and parts replacement were performed. This replacement of parts is necessary when there is a defect in the parts.

As a result, the strength of the circuit board of the embodiment of the present invention and the specifications of all over-resist structure was sufficiently maintained, but in the circuit board of specification of all clearance structure,
A large amount of peeling was observed on the copper foil (circuit board electrode) on the wiring board located outside the electronic component, and it was found that the strength was insufficient.

This is because the largest load is applied to the outside of the component in the replacement of the electronic component or the bending test.
This is because the adhesion strength of the electrodes on the circuit board in this portion is different between the total clearance structure specification and the all over resist structure specification.

By using the wiring board device of the first embodiment of the present invention described above, there is no insufficient fillet formation, the generation of solder balls is suppressed, and the mounting effect of electronic parts is improved. It is possible to improve mechanical reliability with respect to impact.

The conditions for applying the solder resist 3 to the electrodes 5 on the circuit board 4 are not limited to the above-described embodiment, but various modifications as described below are conceivable.

In FIG. 4A, the side portions (two sides) parallel to the edge g of the electronic component in the outer side portion 5a and the inner side portion 5b of the circuit board electrode 5A are formed as an over-resist structure, and are orthogonal to these side portions. Both sides that have a clearance structure. In this case, the shape of the electrode 5A and the opening shape of the solder resist 3A are rectangular.

In FIG. 4B, the opening shape of the solder resist 3B is rectangular, whereas the circuit board electrode 5B is formed in a substantially convex shape in plan view, and wide from a narrow portion. The position of changing to the part matches the position of the edge g of the electronic component.

Then, the side portions (two sides) of the outer side portion 5a and the inner side portion 5b of the circuit board electrode 5 which are parallel to the electronic component edge g and the side portion of the outer portion 5a which is orthogonal to the electronic component edge g are overlaid. The resist structure is formed, and the side portion of the inner portion 5b orthogonal to the electronic component edge g is formed as a clearance structure.

FIG. 4C shows the opening of the solder resist 3C and the circuit board electrode 5C having the same shape as that of FIG. 4B, and all side portions of the outer part 5a with the electronic component end edge g as a boundary. Has an over-resist structure, and all sides of the inner portion 5b have a clearance structure.

Even with these wiring board devices, there is no insufficient fillet formation, the generation of solder balls is suppressed, the electronic component mounting effect is improved, and the mechanical reliability against impacts is improved. Can be achieved.

Under the conditions for applying the solder resist 3 to the circuit board electrode 5 described above, the opening shape of the solder resist 3 is all rectangular, but it is a circular solder resist opening as described below. May be.

For example, FIG. 5A shows a case where the circuit board electrode 5 has a rectangular shape and the opening of the solder resist 3D has a circular shape. The side portions (two sides) parallel to the edge g of the electronic component have an over-resist structure, and both side portions orthogonal to these side portions have a clearance structure.

In FIG. 5B, the circuit board electrode 5 has a rectangular shape, and the opening of the solder resist 3E has a circular shape.
An example in which a portion of the outer portion of the electronic component facing the component end edge g has a circular over-resist structure and the others have a clearance structure will be shown.

In the case where the solder resist opening has a circular shape, the portion of the outer portion of the electronic component facing the component edge has a rectangular over-resist structure, and the other has a clearance structure. From the above to a rectangular shape, the outside part of the electronic component has an over-resist structure, and the others have a clearance structure.

The width of the clearance and the width of the over-resist may be arbitrary, and may be determined in consideration of the strength of the electrode and the number of solder balls generated. Further, the clearance width and the over-resist width may be set for each side or for each part.

FIG. 6 shows a second embodiment of the present invention, in which a chip component 10 is a circuit board 11 as an electronic component.
2 is an example of a wiring board device mounted on a substrate and mounted via solder 14.

Also in this wiring board device, as the conditions for applying the solder resist 13 to the circuit board electrode 12, both an over resist structure and a clearance structure are provided.

Specific examples are shown in FIGS. 7A, 7B and 7C. Again, the circuit board electrodes 12A, 12B,
A portion of 12C that faces the outside of the chip component 10 on both side edges g is referred to as an outer portion 12a, and a portion that faces the inside is referred to as an inner portion 12b.

In the wiring board device shown in FIG. 7A, all of the outer portion 12a of the circuit board electrode 12A has an over-resist structure and all of the inner portion 12b has a clearance structure.

In the wiring board device shown in FIG. 7B, all of the outer portion 12a of the circuit board electrode 12B and
The side portion of the inner portion 12b which is orthogonal to both side edges g of the chip component has an over-resist structure, and the side portion of the inner portion 12b which is parallel to both side edges g of the chip component has a clearance structure.

In the wiring board device shown in FIG. 7C, the side portion of the outer portion 12a of the circuit board electrode 12C which is parallel to both side edges g of the chip component has an over resist structure.
All of the side portions of the outer portion 12a orthogonal to both side edges g of the chip component and the inner portion 12b have a clearance structure.

As described above, also in the wiring board device shown in FIGS. 7A, 7B and 7C, the fillet formation is not insufficient and the solder balls are not generated, so that the mechanical reliability can be improved. It will be.

When the wiring board device described in the first embodiment and the second embodiment described above is incorporated into a portable information terminal device and a drop test is conducted, all electrode structures of the circuit board are clearance structures. The rate at which the device is damaged or destroyed when dropped is lower than that when the wiring board device, which has been used in the above, is incorporated into a portable information terminal device.

Besides the above-mentioned embodiments, various structures can be adopted without departing from the scope of the claims of the present invention, the clearance width and the over-resist width may be arbitrary, and the strength of the electrode and the solder ball It may be determined in consideration of the number of occurrences of.

FIG. 8 shows a wiring board device according to a third embodiment of the present invention. 9 (A) and 9 (B),
It is the partial enlarged view. FIG. 9C shows FIG. 9A.
It is sectional drawing which follows the AA line or CC line in (B). FIG. 9D is a- in FIG. 9A and FIG.
It is sectional drawing which follows the a line or the cc line.

A semiconductor package 22, which is a BGA type electronic component, is mounted on a circuit board 21 on which a large number of circular electrodes 20 arranged in plan view are arranged, and is mounted via solder 23. Moreover, with respect to the electrode 20,
A solder resist 24 having a rectangular opening is applied.

Thermal distortion occurs in the semiconductor package 22 and the circuit board 21 due to the ambient temperature and the heat generated by the semiconductor element. At this time, the large thermal strain appears in the circuit board electrode 20 in the portion farthest from the center O of the semiconductor package 22 and the portion closest thereto.

To explain further, for example, the AA line passing through the center O of the semiconductor package 22, the BB line and the C line.
In the electrode 20 which is crossed by the -C line, thermal strain is largely generated at both end portions of each line, and the AA line, the BB line, the C line, and the
The occurrence of thermal strain is small at both end portions of the aa line, the bb line, and the cc line orthogonal to the -C line.

With respect to the circuit board electrode 20, an auxiliary line m-m is formed at an angle of 45 ° with respect to the AA line, the aa line, the CC line, and the cc line. , Nn were described. Of the four parts divided by these auxiliary lines m-n and n-n, the part that the A-A line and the C-C line cross is defined as the clearance structure (shown in FIG. 9C), and the a-a line Then, a portion which the cc line crosses was formed into an overresist structure (shown in FIG. 9D).

The semiconductor package 2 of the above-described embodiment
In No. 2, if the entire peripheral portion of the electrode 20 has a clearance structure specification, a defect that the electrode 20 is separated from the circuit board 21 is likely to occur. On the other hand, if the entire peripheral portion of the electrode 20 has an over-resist structure, it peels from the boundary surface between the solder 23 and the electrode 20 on the circuit board 21 in a temperature cycle test or the like.

Therefore, in order to prevent the peeling of the electrode 20 and improve the impact resistance, it is desirable to provide both the clearance structure and the over-resist structure, and further, the thermal strain appears largely as in the above-mentioned embodiment. It is optimal to form the portion as a clearance structure and the portion with a small thermal strain as an over-resist structure.

The relationship between the clearance structure and the over-resist structure in the third embodiment is the same as that described in the first embodiment (FIG. 1) so long as the shape structure does not depart from the scope of the claims. For example, various modifications are possible.

By providing a circuit using the wiring board device thus constructed and applying the circuit to a portable information terminal device which is an electric product having portability, a highly reliable product is provided. Will be able to.

[0097]

As described above, according to the present invention, it is possible to provide an extremely effective wiring board device having a structure capable of sufficiently withstanding mechanical shock and suppressing the generation of solder balls as much as possible.

Then, it is possible to prevent the peeling of the electrode from the circuit board and the peeling from the boundary between the solder and the circuit board by making it possible to cope with the heat distortion caused by the heat generation of the circuit board or the like, and to improve the reliability. A very effective wiring board device can be provided.

By using this wiring board device, it is possible to provide a portable information terminal device having excellent impact resistance.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a wiring board device showing a first embodiment of the present invention, a partially enlarged view, and a sectional view thereof.

FIG. 2 is a diagram showing a mask opening shape for a circuit board electrode and a diagram in which a mask opening is overlapped with an electrode according to the same embodiment;

FIG. 3 is a diagram showing a comparison of the characteristics of the number of solder balls and the fillet shape between the configuration of the same embodiment and another configuration.

FIG. 4 is a plan view of a part of a wiring board device according to different modifications of the embodiment.

FIG. 5 is a plan view of a part of a wiring board device of a modification of the embodiment, which is different from that of FIG. 4;

FIG. 6 is a schematic sectional view of a circuit board electrode showing a second embodiment of the present invention.

FIG. 7 is a view for explaining conditions for applying solder resist to different circuit board electrodes of the same embodiment.

FIG. 8 is a schematic plan view of a wiring board device according to a third embodiment of the present invention.

FIG. 9 is an enlarged view of a different portion of the wiring board device according to the same embodiment, and a cross-sectional view thereof.

FIG. 10 is a plan view of a conventional wiring board device, a partially enlarged view, and a sectional view thereof.

11A and 11B are a plan view of a further different conventional wiring board device, a partially enlarged view, and a sectional view thereof.

12A and 12B are a sectional view and a plan view of still another conventional wiring board device.

13A and 13B are a sectional view and a plan view of still another conventional wiring board device.

FIG. 14 is a rear side perspective view of an LCC which is an electronic component described in the present invention.

[Explanation of symbols]

4 ... circuit board, 5 ... electrode (on circuit board), 1 ... Electronic parts, 6 ... Solder, 3 ... Solder resist, 5a ... outer part, 5b ... inner part, g ... Edge of electronic component.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tadao Otani             33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa             Inside the Toshiba Production Technology Center (72) Inventor Takeshi Ito             33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa             Inside the Toshiba Production Technology Center (72) Inventor Yoichiro Maehara             33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa             Inside the Toshiba Production Technology Center (72) Inventor Eiichi Harada             One share at 3-1, Asahigaoka, Hino City, Tokyo             Ceremony Company Toshiba Hino Factory F-term (reference) 5E319 AA03 AB05 AC01 AC12 AC15                       BB05 CC33 CD04 GG03 GG09                       GG11 GG15

Claims (7)

[Claims] 1. A wiring board device in which an electronic component is mounted on electrodes of a circuit board via solder, and a specific region on the circuit board is covered with a solder resist made of a heat-resistant coating material. An outer portion of the board electrode facing outward from the edge of the electronic component has an over-resist structure in which the solder resist is overlapped on at least a part of the electrode, and the circuit board electrode is provided with the electronic component of the electronic component. A wiring board device having a clearance structure in which the solder resist is applied to at least a part of an electrode at a predetermined interval at an inner portion facing inward from an edge. 2. An outer resisting portion of the circuit board electrode, which is formed in a rectangular shape in a plane, and has a side portion parallel to a region corresponding to an edge when an electronic component is arranged, has an over-resist structure and an electronic component 2. The wiring board device according to claim 1, wherein the side portion orthogonal to the edge when arranged is a clearance structure, and all the side portions are a clearance structure inside the circuit board electrode. . 3. A side portion parallel to an area corresponding to an edge when an electronic component is arranged is formed as an over-resist structure in an outer side portion and an inner side portion of the circuit board electrode formed in a planar rectangular shape. The side portions of the outer side portion and the inner side portion of the circuit board electrode, which are orthogonal to a region corresponding to an edge when an electronic component is disposed, have a clearance structure.
The wiring board device described. 4. A side portion parallel to an area corresponding to an edge when an electronic component is arranged, at all side portions and inside portions of the outside portion of the circuit board electrode formed in a planar rectangular shape. 2. An over-resist structure, wherein a side portion of the inside of the circuit board electrode, which is orthogonal to a region corresponding to an edge when an electronic component is arranged, has a clearance structure. Wiring board device. 5. The outside portion of the circuit board electrode formed in a planar rectangular shape has an over-resist structure on all sides, and the inside portion of the circuit board electrode has all sides on a clearance structure. The wiring board device according to claim 1, wherein: 6. A wiring board device in which a semiconductor package is mounted on a plurality of electrodes formed on a circuit board via solder, and a specific region on the circuit board is covered with a solder resist made of a heat resistant coating material. The portion of the electrode farthest from the center of the semiconductor package and the portion closest to the center of the semiconductor package has a clearance structure in which the solder resist is provided at a predetermined distance from the electrode, and the portion of the electrode farthest from the center of the semiconductor package is The part in the direction orthogonal to the line connecting the closest part is
A wiring board device having an over-resist structure in which solder resists are overlapped. 7. A portable information terminal device comprising the wiring board device according to any one of claims 1 to 6.