JP2003163449A - Mounting method of chip component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting method of a chip component in which cream solder can be printed with high precision on a land of a substrate and which is suitable for high density mounting. <P>SOLUTION: Before a substrate 1 of a lot is supplied to a printing machine 5, degree of dimensional deviation between a plurality of recognition marks which are formed on the substrate 1 in the lot to a reference value is recognized, and an optimum mask is selected from among a plurality of kinds of masks 10A-10C on the basis of the recognized result and set on the printing machine 5. Substrates 1 of the same lot are supplied in sequence to the printing machine 5. After the cream solder 4 is printed on the respective lands 3a of these substrates 1, chip components 2 are mounted on the lands 3a by mounter equipment 7, the cream solder 4 is fused by a reflow furnace 9, and the chip components 2 are subjected to reflow soldering on the lands 3a. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip component mounting method in which cream solder is printed on a land of a substrate by using a printing machine, and then the chip component is mounted on the substrate and then reflow soldered. , A chip component mounting method suitable for high-density mounting.

[0002]

2. Description of the Related Art FIG. 3 is a plan view of an electronic circuit unit used as, for example, a high frequency device, and FIG. 4 is a sectional view of the electronic circuit unit. The electronic circuit unit is made of an insulating material such as glass epoxy resin. A substrate 1 and a large number of chip components 2 including chip capacitors, chip resistors and the like mounted on the substrate 1 are provided. A wiring pattern 3 made of copper foil or the like is provided on the substrate 1, and a large number of pairs of lands 3a are formed on the wiring pattern 3. Cream solder 4 is placed on these lands 3a.
After the electrode portions 2a provided on both ends of the chip component 2 are mounted on the paired lands 3a, the cream solder 4 is melted in a reflow furnace, so that each chip component 2 is placed on the substrate 1. It is designed to be mounted at a predetermined position.

FIG. 5 is a conventional example showing a manufacturing process of such an electronic circuit unit. As shown in the figure, first, the board 1 is supplied to the printing machine 5, and then the cream solder 4 is printed on each land 3 a of the board 1 using the printing machine 5. In this printing process, after the metal mask is placed on the substrate 1 positioned at a predetermined position, the cream solder 4 is squeezed on the metal mask to screen-print the cream solder 4 on each land 3a through the metal mask. To do. As shown in FIG. 6, the metal mask 10 is composed of a rectangular metal plate 10a and a printing mask 10b provided in the center thereof, and the printing mask 10b corresponds to each land 3a of the substrate 1. A transparent portion is formed.

Next, the substrate 1 after the printing process is discharged from the printing machine 5, and the substrate 1 is carried into the mounter device 7 from the conveyor 6. In this mounter device 7, a component mounting step of mounting various chip components 2 on the lands 3a of the substrate 1 is performed, and by this component mounting step, both electrode portions 2a of each chip component 2 via the cream solder 4. It is mounted on the corresponding land 3a. After that, the substrate 1 discharged from the mounter device 7 is transferred to the reflow furnace 9 by the conveyor 8.
Then, a reflow process of melting and solidifying the cream solder 4 on each land 3a is carried out in the reflow furnace 9. Then, when the substrate 1 on which the reflow process is completed is discharged from the reflow furnace 9, as shown in FIGS. 3 and 4, an electronic circuit unit in which the corresponding chip component 2 is soldered on each land 3a of the substrate 1 is obtained. .

[0005]

By the way, in recent years, the technology for miniaturizing the chip component 2 such as the chip capacitor and the chip resistor has been remarkably advanced, and accordingly, a large number of chips are provided in a limited space on the substrate 1. It has become possible to mount the components 2 at a high density. However, when the high-density mounting is promoted in this way, the area of each land 3a itself and the distance between the lands 3a forming a pair become smaller, so that the printing process Therefore, unless the cream solder 4 is printed with high accuracy on each land 3a, a mounting defect of the chip component 2 is likely to occur in the subsequent component mounting process and reflow process.

However, in the above-mentioned conventional example, the substrate 1 and the metal mask 10 are manufactured on the basis of the pattern data of the required circuit structure, and the substrate 1 is formed by using one kind of the metal mask 10. Since the cream solder 4 is printed, the land 3a of the substrate 1 supplied to the printing machine 5
However, if there is a slight deviation from the reference position, the cream solder 4 cannot be printed on the land 3a with high accuracy. In particular, the substrate 1 tends to cause a deviation in the land interval for each manufacturing lot due to a change in environmental conditions (temperature and humidity) during manufacturing, a mask deviation for patterning the wiring pattern 3, and the like. Although the mounting failure does not occur with respect to the substrate 1, the mounting failure may occur when the substrate 1 of another lot is supplied to the printing machine 5.

The present invention has been made in view of the circumstances of the prior art as described above, and an object thereof is to make it possible to print cream solder on the land of the substrate with high precision and to be suitable for high-density mounting. It is to provide a mounting method of components.

[0008]

In order to achieve the above object, in the chip component mounting method according to the present invention, a board recognizing step of recognizing a plurality of land intervals of a board supplied to a printing machine and the board recognizing step. A mask selection step of selecting an optimum mask from a plurality of masks based on the recognition result of the step, and a printing step of printing cream solder on the land of the substrate using the mask selected in the mask selection step, A component mounting step of mounting a chip component on the substrate after the printing step and a reflow step of heating the substrate after the component mounting step to melt the cream solder are provided.

A plurality of kinds of masks including a standard mask are prepared in advance, and before feeding a lot of substrates to the printing machine, it is recognized how much the land of the substrate is displaced from the reference position. , If you select the most suitable mask from each mask based on the result, the deviation of the land is corrected for the boards of the same lot printed by using this mask. It can be printed with high precision. In addition, when supplying a substrate of another lot to the printing machine, the same procedure as above may be performed, and an optimal mask may be selected and printed on the substrate of the lot.
Therefore, by adopting such a method, it is possible to reduce the mounting failure of the chip component due to the deviation of the land and to mount the chip component on the substrate with high density.

In the above arrangement, as a means for recognizing the land interval in the board recognizing step, the lands on the board may be image-recognized to directly measure the deviation amount between the plurality of lands relative to the reference value. It is preferable to form a plurality of recognition marks on the substrate in the same step as the land and measure the dimension between the recognition marks. For example, as a result of image recognition of the dimension between the recognition marks formed on the substrate of a certain lot, if the dimension is larger than the reference value, the land will also deviate from the reference position according to the dimension deviation of the substrate. You can easily recognize the deviation.

In the above structure, as the mask used in the mask selecting step, at least a standard mask corresponding to a substrate having a land interval within a reference value and a first mask corresponding to a substrate having a land interval larger than the reference value. It is preferable to prepare the above mask and the second mask corresponding to the substrate whose land interval is smaller than the reference value.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a mounting method of a chip component according to an embodiment, and FIG. 2 is a flowchart of the mounting method. is there.

As shown in FIG. 1, in the manufacturing line to which this embodiment is applied, a printing machine 5 and a mounter device 7 are provided.
Further, the reflow furnace 9 is arranged in series, and these are used to manufacture the electronic circuit unit as shown in FIGS. However, the difference between the present embodiment example and the conventional example shown in FIG. 5 is that the substrate recognition step 1 is performed for each lot with respect to the substrate 1 before being supplied to the printing machine 5.
1 and the mask selecting step 12 are performed, and the optimum masks 10A to 10C selected in the mask selecting step 12 are used to apply the cream solder 4 on each land 3a of the substrate 1 supplied to the printing machine 5. To print.

In the board recognizing step 11, the board 1 in a certain lot is picked up as a sample, and the board 1 is photographed by, for example, an image pickup camera, whereby a plurality of recognition marks (not shown) formed on the board 1 are formed. Measure how much the gap is displaced from the standard value. Here, generally, the wiring pattern 3 including the land 3a on the substrate 1 is formed by etching a copper foil provided on the entire surface of the substrate 1 into a desired pattern shape, and a mask used at the time of etching is CAD ( Computer Aided Design) is created based on the data. Therefore, if a plurality of recognition marks are formed on the substrate 1 in the same process as the land 3a, when the substrate 1 expands and contracts and the dimension deviates from the reference value, the land 3a also has the original CAD data position. The deviation of the land 3a can be recognized by measuring the dimensional deviation between the recognition marks and the reference value. Since all the substrates 1 of the same lot are manufactured under the same manufacturing conditions, one or a plurality of substrates 1 may be sampled from the same lot in the substrate recognition step 11.

In the mask selection process 12, the substrate recognition process 1
Based on the deviation amount of the land interval measured by 1,
The optimum mask is selected from a plurality of types of metal masks prepared in advance. In the present embodiment example, the standard mask 10A, the first mask 10B, and the second mask 10 are used.
Three types of masks 10A to 10C called C are prepared. Here, the standard mask 10A is manufactured based on the CAD data, and the standard mask 10A corresponds to the substrate 1 in which the measured land interval is within the range of the reference value. The first and second masks 10B and 10C are C
The first mask 10B corresponds to the substrate 1 in which the measured land interval is larger than the reference value, and the second mask 10C is manufactured by adding a slight correction value to the AD data.
Corresponds to the substrate 1 whose measured land spacing is smaller than the reference value. Therefore, in the board recognition step 11, the board 1
If it is recognized that the land interval of is within the range of the reference value, the standard mask 10A is selected in the mask selection step 12,
The standard mask 10A may be set on the printing machine 5.
Further, when it is recognized that the land interval of the substrate 1 is larger than the reference value in the substrate recognition step 11, the mask selection step 12
To select the first mask 10B and select the first mask 10B.
B may be set on the printing machine 5. Alternatively, when it is recognized in the board recognition step 11 that the land interval of the board 1 is smaller than the reference value, the second mask 10C is selected in the mask selection step 12, and the second mask 10C is set in the printing machine 5. Just set it.

Next, using the above manufacturing line, the substrate 1
A method of mounting the chip component 2 on the above will be described with reference to the flowchart of FIG.

First, as a preparatory step before operating the production line, one or a plurality of substrates 1 of the same lot to be supplied to the printing machine 5 are sampled, and as shown in step S-1, To what extent the dimensions between the plurality of recognition marks formed on the substrate 1 using an image pickup camera or the like deviate from the reference value, in other words, how many land intervals on the substrate 1 differ from the reference value. It is measured whether or not there is a deviation (board recognition step 11). After measuring the land spacing of the substrate 1 in step S-1, the process proceeds to step S-2, and in this step S-2, three types of masks 10 are used.
An optimum mask capable of correcting the deviation amount of the measured land interval is selected from A to 10C (mask selection step 1
2). That is, the standard mask 10A is selected when the land interval of the substrate 1 is within the range of the reference value, and the first mask 10B is selected when the land interval of the substrate 1 is larger than the reference value.
If the land spacing of the substrate 1 is smaller than the reference value, the second mask 10C is selected. After that, the process proceeds to step S-3, and in this step S-3, the optimum masks 10A to 10C selected in step S-2 are set in the printing machine 5. The steps S-1 to S-3 described above are executed off-line outside the manufacturing line, and thereafter, the operations from step S-4 to step S-7 are executed online inside the manufacturing line.

That is, after the optimum masks 10A to 10C are set on the printing machine 5 in step S-3, step S3 is performed.
-4, the substrates 1 of the same lot as the sampling target are sequentially supplied to the printing machine 5 by using a loader or the like (not shown), and as shown in step S-5, the substrates 1 are printed by the printing machine 5 as shown in step S-5. The cream solder 4 is printed on each land 3a (printing step). In this printing process, the optimum masks 10A to 10A are placed on the substrate 1 positioned at a predetermined position of the printing machine 5.
After C is placed, the cream solder 4 is squeezed on this mask to screen print the solder paste 4 on each land 3a through the mask. In this case, even if there is some dimensional variation in the substrate 1 supplied to the printing machine 5, the optimum masks 10A to 10C corresponding to the dimensional deviation of the substrate 1 are used for printing, so that the same lot is printed. The deviation of the land interval of the board 1 is corrected, and the cream solder 4 can be printed on each land 3a with high accuracy.

Next, the substrate 1 after the printing process is discharged from the printing machine 5, and the substrate 1 is carried into the mounter device 7 from the conveyor 6, so that the mounter device 7 is operated as shown in step S-6. Various chip components 2 are mounted on the lands 3a of the substrate 1 (component mounting step). By this component mounting step, both electrode portions 2a of each chip component 2 are mounted on the corresponding lands 3a via the cream solder 4. After that, the substrate 1 ejected from the mounter device 7
Is carried into the reflow furnace 9 by the conveyor 8 and step S-7
As shown in, the reflow furnace 9 melts and solidifies the cream solder 4 on each land 3a (reflow process). And
When the board 1 on which the reflow process is completed is discharged from the reflow furnace 9, an electronic circuit unit in which the corresponding chip component 2 is soldered on each land 3a of the board 1 is obtained as shown in FIGS.

According to the above embodiment, before the substrates 1 in a lot are supplied to the printing machine 5, the substrates 1 in the lot are
Of the masks 10A to 10C prepared in advance based on the result of recognizing the deviation of the land interval of the substrate 1 from the reference value.
After the optimum mask is selected from among the above, the mask 5 is used to print the cream solder 4 on each land 3a of the board 1 by using this mask. The amount of misalignment is corrected and the cream solder 4 can be printed on each land 3a with high accuracy. Moreover, when supplying the substrate 1 of another lot to the printing machine 5, the same procedure as the above is performed, and each mask 10A-1.
If the optimum mask is selected and printed on the board 1 of the lot from 0C, the cream solder 4 can be printed on the lands 3a of the board 1 of this lot with high accuracy. Therefore, by adopting such a method, it is possible to reduce the mounting failure of the chip component 2 due to the deviation of the land interval, and it is possible to mount the chip component 2 on the substrate 1 at a high density.

In the above embodiment, the standard mask 10A, the first mask 10B, and the second mask 10 are previously prepared.
The case where three types of metal masks C are prepared and one of these three types is selected as the optimum mask in the mask selection step 12 has been described. However, the dimensional deviation of the substrate 1 (land gap deviation) is described. Therefore, in order to respond more finely, an optimum mask may be selected from four or more kinds of metal masks including the standard mask 10A.

Further, in the above embodiment, the case where the chip component mounting method according to the present invention is applied to the production line in which the printing machine 5, the mounter device 7 and the reflow oven 9 are arranged in series has been described. Manufacturing machine in which a plurality of mounter devices 7 are arranged in parallel between the printing machine 5 and one reflow furnace 7, and a plurality of mounter devices between one printing machine 5 and one reflow furnace 7 It is also applicable to a production line in which 7 units are arranged in series.

[0023]

The present invention is carried out in the form as described above, and has the following effects.

A plurality of types of masks including a standard mask are prepared in advance, and before feeding a lot of substrates to the printing machine, it is recognized how much the land of the substrate is displaced from the reference position. , If you select the most suitable mask from each mask based on the result, the deviation of the land is corrected for the boards of the same lot printed by using this mask. It can be printed with high precision. In addition, when supplying a substrate of another lot to the printing machine, the same procedure as above may be performed, and an optimal mask may be selected and printed on the substrate of the lot.
Therefore, by adopting such a method, it is possible to reduce the mounting failure of the chip component due to the deviation of the land and to mount the chip component on the substrate with high density.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a method of mounting a chip component according to an exemplary embodiment.

FIG. 2 is a flowchart of the mounting method.

FIG. 3 is a plan view of an electronic circuit unit.

FIG. 4 is a sectional view of the electronic circuit unit.

FIG. 5 is a layout diagram showing a manufacturing line of an electronic circuit unit according to a conventional example.

FIG. 6 is an explanatory diagram of a metal mask used in the printing machine of the manufacturing line.

[Explanation of symbols]

1 substrate 2 chip parts 2a Electrode part 3 wiring patterns 3a land 4 cream solder 5 printing machines 7 Mounter device 9 reflow furnace 10A standard mask 10B first mask 10C second mask 11 Board recognition process 12 Mask selection process

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazutoshi Ishibashi             69 Takarada Ishigami, Soma City, Fukushima Prefecture Ali Co., Ltd.             Inside F-term (reference) 5E319 AA03 AB05 AC01 BB05 CC33                       CD29 GG01

Claims (4)

[Claims] 1. A board recognition step of recognizing a plurality of land intervals of a board supplied to a printing machine, and a mask selection step of selecting an optimum mask from a plurality of masks based on a recognition result of the board recognition step. A printing step of printing cream solder on the land of the board using the mask selected in the mask selection step, a component mounting step of mounting a chip component on the board after the printing step, and a component mounting step. And a reflow step of melting the cream solder by heating the substrate after the step. 2. The chip component mounting method according to claim 1, wherein the substrate recognition step recognizes a deviation of a plurality of land sizes from a reference value. 3. The chip component mounting method according to claim 1, wherein the land interval is recognized by a dimension between a plurality of recognition marks formed in the same step as the land. 4. The standard mask according to claim 1, wherein the mask used in the mask selection step is at least a standard mask corresponding to a substrate whose land interval is within a reference value, and the land interval is less than the reference value. A method of mounting a chip component, characterized in that a first mask corresponding to a substrate having a large size and a second mask corresponding to a substrate having a land interval smaller than a reference value are prepared.