JPH10209685A - Manufacture of circuit module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a circuit module in which the parts can be connected accurately by setting the laser irradiating position accurately. SOLUTION: A decision is made whether the optical axis of laser light is actually aligned with a target electrode 11a on a substrate or not by detecting the level of reflected light through a photosensor 5 when a laser light LB1 for inspecting position is projected toward the substrate. When the optical axis of laser light is not aligned with the target electrode 11a on the substrate, the substrate 11 is subjected to microdisplacement through a table 9 and the position thereof is corrected. According to the arrangement, the target electrode 11a on the substrate is irradiated accurately with a laser light for connecting a part even when a predetermined reference position of the optical axis of laser light is shifted or an error is present in the movement of the table.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a circuit module for connecting an electronic component and a substrate by using irradiation energy of a laser beam.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional method of connecting components of this type. In the drawing, reference numeral 21 denotes a substrate which transmits laser light, and 21a denotes an electrode ( Land), 22 is an electronic component such as an IC or LSI, 22a
Is an electrode provided on the lower surface of the electronic component 22, 22b is a bump (projection electrode) provided on the component electrode 22a, 23 is a condenser lens, and LB is a laser beam. The bump 22b is
It is made of a metal material having a lower melting point than each of the electrodes 21a and 22a, for example, a Sn-Pb-based alloy (solder), and itself serves as a bonding material.

In order to electrically connect the electronic component 22 to the board 21, first, the board 2 is placed on an XY table (not shown).
1 is held, and the position of the substrate electrode 21a is recognized by numerical input or image processing.

[0004] Next, the electronic component 22 at the component supply position is sucked by a collet (not shown), and the board electrode 21a previously recognized and the electrode 22a of the electronic component 22 are aligned so that they match. Then, the electronic component 21 is placed on the substrate 22.

[0005] Next, the laser beam axis is adjusted to the substrate electrode 2 corresponding to the component.
1a, the substrate 21 is moved by the XY table while the components are placed, and a laser beam LB for component connection is irradiated from the lower surface side of the substrate 21 to the substrate electrode 21a via the substrate 21. Similarly, while moving the substrate 21, the remaining substrate electrodes 21a are also sequentially irradiated with the laser beam LB.

Thus, the substrate electrode 21a is heated by the irradiation energy of the component-connecting laser beam LB, and the bump 22b is heated and melted by the heat conduction from the substrate electrode 21a. 22
And the electrode 21a of the substrate 21 are electrically connected.

[0007]

In the above-described conventional component connection method, the substrate 21 is moved by the XY table so that the substrate electrode 21a recognized by numerical input or image processing and the laser optical axis coincide with each other. Only
If the predetermined reference position of the laser optical axis is displaced, the actually irradiated laser light LB deviates from the target substrate electrode 21a due to the error of the table movement, and energy shortage occurs. As a cause, there is a problem that expected parts cannot be connected.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method of manufacturing a circuit module capable of optimizing a laser beam irradiation position and connecting components with high accuracy.

[0009]

In order to achieve the above object, the present invention relates to a method for manufacturing a circuit module for connecting an electronic component and a substrate by irradiating a laser beam to a portion to be connected. Irradiation is performed by irradiating the target connection target with the position inspection laser light using laser light irradiation means capable of selectively irradiating light and laser light for position inspection having smaller energy than the laser light for connecting the parts. Its main purpose is to perform a position quality inspection and correct the irradiation position when the irradiation position does not match the target connected portion, and then irradiate the target connected portion with the component connection laser beam. Features.

[0010] According to the present invention, the quality of the irradiation position is inspected by irradiating the target connection portion with the laser beam for position inspection. When the irradiation position does not match the target connection portion, the irradiation is performed. Since the component connection laser beam is irradiated to the target connected part after the position is corrected, even if the reference position of the predetermined laser optical axis is shifted, the component connection laser Light can be accurately applied to a target connected portion.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] FIGS. 1 and 2 relate to a first embodiment of the present invention. In the drawings, reference numeral 1 denotes a laser oscillator, 2 denotes a deflection beam splitter, 3 denotes a quarter-wave plate, and 4 denotes condensing light. Lens, 5
Is an optical sensor, 6 is a control unit of a computer configuration, 7 is a table drive unit, 8 is a collet drive unit, 9 is a table, 10
Denotes a collet, 11 denotes a substrate, 12 denotes an electronic component, LB1 denotes a laser beam for position inspection, and LB2 denotes a laser beam for component connection.

The substrate 11 is made of ceramics or glass such as sapphire, zirconia, calcium fluoride, aluminum nitride, alumina, quartz, or polyimide, acrylic, PET,
It is made of a resin such as silicon, epoxy, or glass epoxy, and has transparency to the laser beam LB. Gold, silver, aluminum, copper, nickel,
A substrate electrode (land) 11a made of platinum, palladium or an alloy thereof is provided corresponding to the connection component.

The electronic component 12 is an IC, an LSI, etc.
A component electrode 12a made of silver, aluminum, copper, nickel, platinum, palladium or an alloy thereof is provided on the lower surface. Also, each component electrode 12a is provided with each electrode 11a, 1
Bump (protruding electrode) made of a metal material having a lower melting point than 2a, for example, an Sn—Pb alloy (solder) or the like, which also serves as a bonding material.
12b is provided.

The laser oscillator 1 is composed of a CW oscillation Q-switched YAG laser using an Nd: YAG single crystal, and emits a continuous pulse train of infrared light (fundamental wave light) at a wavelength of 1064 nm. The outgoing laser light is supplied to the deflection beam splitter 2,
The light is radiated toward the lower surface of the substrate 11 through the 波長 wavelength plate 3 and the condenser lens 4. The laser oscillation of the laser oscillator 1 is controlled by the control unit 6, and a laser beam LB1 having lower energy than the laser beam LB2 when the components are connected is emitted at the time of a position inspection described later. Incidentally, the outputs and irradiation times of the laser beams LB1 and LB2 during the position inspection and the component connection are set in advance by a preliminary experiment or the like.

The optical sensor 5 comprises a photodetector such as a photodiode or a phototransistor. The optical sensor 5 receives the reflected light of the laser beam LB1 emitted at the time of position detection, and outputs the reflected light to the ４ wavelength plate 3 and the deflecting beam splitter 2
Incident through.

The table 9 comprises a well-known XY table, which can be moved in a two-dimensional direction (XY directions) by a drive mechanism (not shown).
Is held horizontally. Further, a hole 9a for exposing the lower surface of the substrate is formed on the lower surface of the table 9 so that the lower surface of the substrate 11 can be irradiated with laser light. The movement of the table 9 in the X and Y directions is controlled by the control unit 6 through the table driving unit 7.

The collet 10 can be moved in a three-dimensional direction by a drive mechanism (not shown), and the electronic component 12 is attracted to the collet 10 in a horizontal state. In the illustrated example, a concave portion conforming to the external shape of the component is formed on the lower surface of the collet, but the concave portion is not always required. The three-dimensional movement of the collet 10 is controlled by the control unit 6 through the collet driving unit 8.

In order to electrically connect the electronic component 12 to the substrate 11, first, the substrate 11 is held on the table 9, and the position of the substrate electrode 11a is recognized by numerical input or image processing. In the case of numerical input, the position of the substrate electrode 11a is recognized based on the input numerical information. In the case of image processing, the position of the substrate electrode 11a is determined based on an electrode image in a substrate image captured by a CCD camera or the like. Recognize.

Next, the electronic component 12 at the component supply position is sucked by the collet 10, and the previously recognized board electrode 11a is detected.
The electronic component 12 is placed on the substrate 11 after the electronic components 12 are aligned so as to match the electrodes 12a of the electronic component 12.

Next, the laser beam axis is set to the substrate electrode 1 corresponding to the component.
The board 9 is moved by the table 9 while keeping the components mounted thereon so as to match one of the parts 1a. Then, in the same state, the laser beam LB1 for position inspection is passed from the lower surface side of the substrate 11 through the deflection beam splitter 2, the quarter-wave plate 3 and the condenser lens 4 to the substrate electrode 11a via the substrate 11.
(See FIG. 1).

When the position inspection laser beam LB1 hits the target substrate electrode 11a, the substrate electrode 11a
Is incident on the optical sensor 5 through the condenser lens 4, the quarter-wave plate 3, and the deflecting beam splitter 2, but the laser light LB1 for position inspection is off the target substrate electrode 11a. At times, the laser beam LB1 escapes above the substrate, so that no reflection effect is obtained, and almost no light enters the optical sensor 5.

In other words, whether or not the target substrate electrode 11a and the laser optical axis actually match can be determined based on the light incident level on the optical sensor 5 when the position inspection laser light LB1 is irradiated. .

When the light incident level on the optical sensor 5 has reached a predetermined level and it is determined that the target substrate electrode 11a is coincident with the laser optical axis, the substrate position is not corrected. When it is determined that the light incident level on the optical sensor 5 is low and the target substrate electrode 11a does not match the laser optical axis, the table 9
Is repeatedly irradiated with the laser beam LB1 for position inspection while slightly displacing the laser beam, the reflected light is detected by the optical sensor 5, and when the light incident level on the optical sensor 5 reaches a predetermined level, the correction of the substrate position is completed. I do.

Next, in the same state, laser light L for component connection is used.
B2 is passed from the lower surface of the substrate 11 to the substrate 1 through the deflecting beam splitter 2, the quarter-wave plate 3, and the condenser lens 4.
The substrate electrode 11a whose position has been inspected is irradiated through 1 (see FIG. 2).

Subsequently, the remaining substrate electrode 11a corresponding to the component
For the position inspection laser beam LB1 in the same manner as described above.
Is used to inspect the irradiation position, and the laser light LB2 for component connection is sequentially irradiated while correcting the substrate position as necessary.

Thus, the laser light LB2 for connecting components
The substrate electrode 11a is heated by the irradiation energy of
The bump 12b is heated and melted by heat conduction from the substrate electrode 11a, and the electronic component 1 is solidified by solidification of the melted portion.
The second electrode 12a and the electrode 11a of the substrate 11 are electrically connected.

According to the present embodiment, the level of the reflected light when the substrate inspection laser beam LB1 is irradiated toward the substrate is detected by the optical sensor 5, whereby the laser optical axis and the target substrate electrode 11a are detected. Is determined whether the substrate electrode 11a and the laser optical axis do not coincide with each other. If the target substrate electrode 11a does not coincide with the laser optical axis, the substrate 9 is slightly displaced by the table 9 to correct its position. Therefore, even when the reference position of the predetermined laser optical axis is deviated or there is an error in the table movement, the target substrate electrode 11a is accurately irradiated with the laser light LB2 for component connection. Desired component connection can be performed with high accuracy.

Also, since the laser beam LB1 for position inspection and the laser beam LB2 for component connection are emitted from the same laser oscillator 1, only one laser oscillator is required and the optical system is not complicated, and the cost is reduced. It is also advantageous.

In the above embodiment, the bumps themselves are used as a bonding material. However, a bonding material layer having a lower melting point than the bumps, for example, a solder layer, is provided on the bump surface, and only the bonding material layer is heated. The same component connection may be performed by melting. Of course, the same action and effect can be obtained even when the bump is eliminated and a bonding material such as solder is provided on one of the component electrode and the substrate electrode, and the component electrode and the substrate electrode are connected using the bonding material. Can be expected.

In the above embodiment, the electronic component is
C, LSI, and the like are illustrated, but the connection method described in the embodiment can be widely applied to chip-shaped electronic components such as a chip capacitor, a chip inductor, and a chip resistor, and other electronic components.

Further, when it is not convenient if the reflected light upon irradiation of the component connecting laser beam is incident on the optical sensor, when irradiating the component connecting laser beam, the deflection beam splitter and the 1/4 wavelength are used. The plate may be removed from the optical path, or a shutter may be provided on the incident side of the optical sensor to close the shutter.

[Second Embodiment] FIG. 3 relates to a second embodiment of the present invention. The difference of the present invention from the first embodiment is that a の 間 に wavelength plate 3 and a condenser lens 4 are provided. The difference lies in that the galvanomirror 13 is interposed and the mirror driving unit 14 that drives and controls a driving mechanism (not shown) of the galvanomirror 13 is provided. The other configuration is the same as that of the first embodiment, and the description thereof will be omitted using the same reference numerals.

In order to electrically connect the electronic component 12 to the substrate 11, first, the substrate 11 is held on the table 9, and the position of the substrate electrode 11a is recognized by numerical input or image processing. In the case of numerical input, the position of the substrate electrode 11a is recognized based on the input numerical information. In the case of image processing, the position of the substrate electrode 11a is determined based on an electrode image in a substrate image captured by a CCD camera or the like. Recognize.

Next, the electronic component 12 at the component supply position is sucked by the collet 10 and the previously recognized board electrode 11a is detected.
The electronic component 12 is placed on the substrate 11 after the position of the electronic component 12 is aligned with the electrode 12 a of the electronic component 12.

Next, the laser beam axis is set to the substrate electrode 1 corresponding to the component.
The board 9 is moved by the table 9 while keeping the components mounted thereon so as to match one of the parts 1a. Then, in the same state, the laser beam LB1 for position inspection is passed through the deflecting beam splitter 2, the quarter-wave plate 3, the galvanometer mirror 13 and the condenser lens 4 from the lower surface side of the substrate 11 via the substrate 11 Irradiate the electrode 11a.

When the position inspection laser beam LB1 hits the target substrate electrode 11a, the substrate electrode 11a
Reflected light from the condenser lens 4, the galvanometer mirror 13,
Although it is incident on the optical sensor 5 through the quarter-wave plate 3 and the deflection beam splitter 2, the laser light LB1 for position inspection is used.
Is off the target substrate electrode 11a,
Since the laser light LB1 escapes above the substrate, no reflection effect is obtained, and almost no light enters the optical sensor 5.

That is, whether or not the target substrate electrode 11a and the laser optical axis actually match can be determined based on the light incident level on the optical sensor 5 when the laser light LB1 for position inspection is irradiated. .

When the light incident level on the optical sensor 5 has reached a predetermined level and it is determined that the target substrate electrode 11a and the laser optical axis match, the laser optical axis is not corrected. However, the light incident level on the optical sensor 5 is low,
When it is determined that the target substrate electrode 11a does not coincide with the laser optical axis, the optical sensor 5 repeatedly emits the position inspection laser light LB1 while slightly displacing the laser optical axis by the galvanomirror 13. The reflected light is detected, and when the light incident level on the optical sensor 5 reaches a predetermined level, the correction of the laser optical axis ends.

Next, in the same state, the laser light L for component connection is used.
B2 passes through a deflection beam splitter 2, a quarter-wave plate 3, a galvanometer mirror 13 and a condenser lens 4 to a substrate 11
Irradiation is performed from the lower surface of the substrate electrode 11 a through the substrate 11 to the substrate electrode 11 a whose position has been inspected.

Subsequently, the remaining substrate electrode 11a corresponding to the component
For the position inspection laser beam LB1 in the same manner as described above.
Is used to inspect the irradiation position, and the laser light LB2 for component connection is sequentially irradiated while correcting the optical axis position as necessary.

Thus, the laser light LB2 for connecting components
The substrate electrode 11a is heated by the irradiation energy of
The bump 12b is heated and melted by heat conduction from the substrate electrode 11a, and the electronic component 1 is solidified by solidification of the melted portion.
The second electrode 12a and the electrode 11a of the substrate 11 are electrically connected.

According to this embodiment, the level of the reflected light when the substrate inspection laser beam LB1 is irradiated toward the substrate is detected by the optical sensor 5, so that the laser optical axis and the target substrate electrode 11a are detected. It is determined whether or not the laser beam actually coincides with the target. If the target substrate electrode 11a does not coincide with the laser optical axis, the laser optical axis is slightly displaced by the galvanomirror 13 to correct the optical axis. Therefore, even when the reference position of the predetermined laser optical axis is deviated, the target substrate electrode 11a is irradiated with the laser light LB2 for component connection accurately, and the intended component connection is performed. It can be performed with high accuracy. Other operations and effects are the same as those of the first embodiment.

[Third Embodiment] FIG. 4 shows a third embodiment of the present invention. The present invention is different from the first embodiment in that the deflecting beam splitter 2 and the 波長 wavelength plate 3 And that the detection surface is opposed to the lower surface of the substrate by using the infrared sensor 15 instead of the optical sensor 5. The other configuration is the same as that of the first embodiment, and the description thereof will be omitted using the same reference numerals.

The infrared sensor 15 is composed of a thermoviewer or the like, and has a detection area on the entire lower surface of the substrate, and can output its temperature distribution as an electric signal corresponding to the intensity of the emitted infrared rays.

In order to electrically connect the electronic component 12 to the substrate 11, first, the substrate 11 is held on the table 9, and the position of the substrate electrode 11a is recognized by numerical input or image processing. In the case of numerical input, the position of the substrate electrode 11a is recognized based on the input numerical information. In the case of image processing, the position of the substrate electrode 11a is determined based on an electrode image in a substrate image captured by a CCD camera or the like. Recognize.

Next, the electronic component 12 at the component supply position is sucked by the collet 10, and the previously recognized board electrode 11a is detected.
The electronic component 12 is placed on the substrate 11 after the position of the electronic component 12 is aligned with the electrode 12 a of the electronic component 12.

Next, the laser beam axis is set to the substrate electrode 1 corresponding to the component.
The board 9 is moved by the table 9 while keeping the components mounted thereon so as to match one of the parts 1a. Then, in the same state, the substrate electrode 11a is irradiated with the laser light LB1 for position inspection from the lower surface side of the substrate 11 through the condenser lens 4 through the substrate 11.

Next, the temperature distribution on the lower surface of the substrate is recognized by the infrared sensor 15, and based on the temperature distribution, the highest temperature portion, that is, the position irradiated with the position inspection laser beam LB1, is detected. It is determined whether or not the position of 11a and the irradiation position of the position inspection laser beam LB1 match at the top and bottom of the substrate.

When it is determined that the position of the substrate electrode 11a and the irradiation position of the laser beam LB1 match at the top and bottom of the substrate, the substrate position is not corrected, but the position of the substrate electrode 11a and the position of the laser beam LB1 are not corrected. When it is determined that the irradiation position does not coincide with the upper and lower portions of the substrate, the laser beam LB1 for position inspection is displaced by the table 9 while the substrate 11 is slightly displaced.
Is repeatedly irradiated, the temperature distribution on the lower surface of the substrate is detected by the infrared sensor 15, and the position of the substrate electrode 11a and the laser beam LB1 are detected.
When the irradiation position matches, the correction of the substrate position ends.

Next, in the same state, the laser light L for component connection is used.
B2 is irradiated from the lower surface side of the substrate 11 to the substrate electrode 11a whose position has been inspected through the substrate 11 through the condenser lens 4.

Subsequently, the remaining substrate electrode 11a corresponding to the component
For the position inspection laser beam LB1 in the same manner as described above.
Is used to inspect the irradiation position, and the laser light LB2 for component connection is sequentially irradiated while correcting the substrate position as necessary.

Thus, the laser light LB2 for connecting components
The substrate electrode 11a is heated by the irradiation energy of
The bump 12b is heated and melted by heat conduction from the substrate electrode 11a, and the electronic component 1 is solidified by solidification of the melted portion.
The second electrode 12a and the electrode 11a of the substrate 11 are electrically connected.

According to the present embodiment, by detecting the temperature distribution on the lower surface of the substrate when the substrate is irradiated with the laser beam LB1 for position inspection by the infrared sensor 15, the laser optical axis and the target substrate electrode are detected. It is determined whether or not the substrate electrode 11a actually coincides. If the target substrate electrode 11a does not coincide with the laser optical axis, the substrate 9 is slightly displaced by the table 9 to correct its position. Therefore, even if the predetermined reference position of the laser optical axis is deviated or there is an error in the table movement, the target substrate electrode 11a is accurately irradiated with the laser light LB2 for component connection. As a result, desired parts can be connected with high accuracy.

In the above-described embodiment, an example has been described in which the substrate 11 is slightly displaced by the table 9 to correct its position. However, if a galvanometer mirror as in the second embodiment is interposed in the middle of the optical path, the galvanometer can be replaced. The laser optical axis is slightly displaced by the mirror to correct the optical axis, so that the target portion can be accurately irradiated with the laser light for component connection.

As described above, in each of the above-described embodiments, an example in which the intended component connection is performed by irradiating a YAG laser beam has been described. However, the same applies when the CO ₂ laser beam or another laser beam is irradiated. Component connections can be made.

In the above-described embodiment, the laser beam is applied to the substrate electrode from the lower surface of the substrate via the substrate. However, the laser beam may be applied to the bumps from the lower surface of the substrate via the substrate, or the laser beam may be applied to the substrate electrode. The same component connection can be performed even when directly irradiating bumps, electrodes, bonding materials, and the like.

Furthermore, the method of connecting the components by heating and melting the bumps or the bonding material has been exemplified. However, the connection method described in the above embodiment is also applicable when the components are connected by thermocompression bonding without using the bonding material. It is effective, and more specifically, the same procedure can be used if the bump or electrode is heated to a temperature lower than the melting point by irradiation energy while applying a constant pressure to the electronic component mounted on the substrate with a collet. The components can be connected by thermocompression bonding.

[0058]

As described in detail above, according to the present invention,
Even when the reference position of the predetermined laser optical axis is deviated, it is possible to accurately irradiate the laser light for component connection to the target connected portion with high accuracy and to perform the intended component connection with high accuracy. . In addition, since laser light for position inspection and laser light for component connection are irradiated from the same laser light irradiation unit,
The configuration of the means is not complicated, and it is advantageous in terms of cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing a component connection method according to a first embodiment of the present invention.

FIG. 2 is a view showing a component connection method according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a component connection method according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a component connection method according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a conventional component connection method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser oscillator, 2 ... Deflection beam splitter, 3 ... 1
/ 4 wavelength plate, 4 condensing lens, 5 optical sensor, 6 control unit, 7 table drive unit, 8 collet drive unit, 9 table, 10 collet, 11 substrate, 11a substrate electrode, Reference numeral 12 denotes an electronic component, 12a denotes a component electrode, 12b denotes a bump, LB1 denotes a laser beam for position inspection, LB2 denotes a laser beam for connecting a component, 13 denotes a galvanometer mirror, 14 denotes a mirror driving unit, and 15 denotes an infrared sensor.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomonori Fujii 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Electric Power Co., Inc. (72) Mitsuo Ueno 6-16-20 Ueno, Taito-ku, Tokyo Taiyo (72) Inventor Iwao Fujikawa 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Induction Co., Ltd. (72) Inventor Kazuyuki Shibuya 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Induction Den Co., Ltd.

Claims (3)

[Claims] 1. A method of manufacturing a circuit module for connecting an electronic component and a substrate by irradiating a laser beam to a connected portion, comprising: a component connection laser beam; and a position inspection with a smaller energy than the component connection laser beam. By using laser beam irradiation means that can selectively irradiate the target laser beam, the position of the target position is inspected by irradiating the target portion with the laser beam for position inspection, and the target position is irradiated. A method for manufacturing a circuit module, comprising: correcting an irradiation position when a part does not match, and irradiating a target connected part with laser light for component connection. 2. The laser beam irradiation position correction is performed by repeatedly irradiating a position inspection laser beam while displacing a substrate to match an irradiation position with a target connected portion. The method for manufacturing a circuit module according to claim 1. 3. The correction of the laser beam irradiation position is performed by repeatedly irradiating a laser beam for position inspection while displacing the laser beam axis so that the irradiation position matches the target connected portion. The method for manufacturing a circuit module according to claim 1, wherein: