WO2018164038A1

WO2018164038A1 - Soldering device

Info

Publication number: WO2018164038A1
Application number: PCT/JP2018/008269
Authority: WO
Inventors: 田嶋　久容; 杉山　和弘
Original assignee: 東レエンジニアリング株式会社; 株式会社ワンダーフューチャーコーポレーション
Priority date: 2017-03-08
Filing date: 2018-03-05
Publication date: 2018-09-13
Also published as: JP6773331B2; TW201838750A; JP2018144093A; TWI759440B

Abstract

Provided is a soldering device comprising: a conveyance means 12 that conveys a substrate 11 on which an electronic part C is mounted; and a heating means that melts solder interposed between an electrode 13 and the electronic part to solder the electronic part to the electrode. The heating means comprises: a coil 20 having a space on the inside thereof; a plurality of ferrites 30 that are arranged in the space of the coil along the conveyance direction of the substrate; an adjustment mechanism 40 that independently adjusts the interval between each ferrite and the electrode formed on the substrate; and a power source 50 that applies an alternating current voltage to the coil to inductively heat the electrode formed on the substrate.

Description

Solder bonding equipment

The present invention relates to a solder bonding apparatus that solders an electronic component to an electrode formed on a substrate using induction heating.

In a conventional soldering apparatus using a reflow method, a board on which electronic components are mounted is heated to a temperature at which the solder melts. For this reason, excessive heat is applied to a region other than the region to be soldered, and the thermal load on the electronic component, the substrate, etc. is increased.

In recent years, as electronic devices have become smaller and lighter, flexible substrates have been used as substrates for mounting minute electronic components. However, in order to reduce the cost of flexible substrates, polyester or Resins such as polyethylene are being used.

However, inexpensive resins such as polyester have a lower melting point than polyimide resins. Therefore, there is a problem that the substrate is deformed when the flexible substrate is heated to a temperature higher than the heat-resistant temperature at the time of soldering.

For such a problem, Patent Document 1 discloses a method of locally heating a portion to be soldered using induction heating. In this method, with the heating element in contact with the substrate, the heat of the heating element heated by induction heating is transmitted to the solder via the electrode of the substrate that is in contact with the solder. It is to be melted.

JP 2009-95873 A

However, in the method disclosed in Patent Document 1, the heat of the heating element heated by induction heating is transmitted to the electrode of the substrate in contact with the solder by heat conduction, so that the heating efficiency is poor. Further, since the heating element heated by induction heating unnecessarily heats the substrate in the vicinity of the electrode of the substrate in contact with the solder, the substrate may be deformed. In addition, when a small electronic component is mounted on a substrate, since the part to be soldered is small, it is difficult to accurately contact the part to be soldered when the heating element is brought into contact with the board. Become.

The present invention has been made in view of the above problems, and its main purpose is to suppress heating of a substrate in a solder bonding apparatus that solders an electronic component to an electrode formed on the substrate by using induction heating. In addition, an object of the present invention is to provide a soldering apparatus with high heating efficiency, which can easily solder even a small electronic component. Furthermore, in a solder bonding apparatus for soldering an electronic component to an electrode formed on the substrate while conveying the board on which the electronic component is mounted, a solder bonding apparatus capable of soldering the electronic component with high productivity is provided. There is to do.

A solder bonding apparatus according to the present invention is a solder bonding apparatus that solders an electronic component to an electrode formed on the substrate while transporting the substrate on which the electronic component is mounted, and transports the substrate on which the electronic component is mounted. And a heating means for melting the solder interposed between the electrode and the electronic component and soldering the electronic component to the electrode, and the heating means has a space portion on the inside in a plan view. A coil, a plurality of ferrites arranged in the space of the coil along the substrate conveyance direction, an adjustment mechanism for independently adjusting the distance between each ferrite and the electrode formed on the substrate, and an alternating current to the coil A power source that applies a voltage and induction-heats an electrode formed on the substrate.

According to the present invention, in a solder bonding apparatus that solders an electronic component to an electrode formed on a substrate by using induction heating, heating of the substrate is suppressed, and even a small electronic component can be easily soldered. Therefore, it is possible to provide a solder bonding apparatus with high heating efficiency. Furthermore, in a solder bonding apparatus for soldering an electronic component to an electrode formed on the substrate while conveying the board on which the electronic component is mounted, a solder bonding apparatus capable of soldering the electronic component with high productivity is provided. can do.

It is the figure which showed typically the structure of the solder joint apparatus in one Embodiment of this invention. It is the figure explaining the method of solder-joining an electronic component to the electrode formed on the board | substrate using induction heating. (A), (b) is the figure which showed the relationship between the space | interval of a ferrite and the electrode on a board | substrate, and the temperature of the electrode heated by induction heating. (A)-(e) is the figure which showed the state in the middle of conveying the board | substrate which mounted several electronic components under the several ferrite arranged along the conveyance direction of a board | substrate in time series. It is the graph which showed typically the time change of the temperature of the electrode which solder-joins the electronic component in the head of a conveyance direction. (A), (b) is the figure which showed the arrangement | sequence of the electronic component and arrangement | positioning of a coil in the modification of this invention. It is the figure which showed the arrangement | sequence of the electronic component and arrangement | positioning of a coil in the modification of this invention.

The applicant of the present application arranges the coil above the solder bonding target portion (electrode) of the substrate, arranges the ferrite adjacent to the solder bonding target portion inside the coil, supplies current to the coil, and performs solder bonding. A solder joining apparatus for solder joining by induction heating of a target portion is disclosed in the application specification of PCT / JP2016 / 076332.

According to the solder bonding apparatus disclosed in the above application specification, the magnetic flux generated inside the coil can be transmitted through the ferrite so as to be focused on the solder bonding target site without being attenuated. Therefore, it is possible to perform soldering efficiently. Further, the range of induction heating can be limited to the solder bonding target site by matching the tip of the ferrite with the size of the solder bonding target site. Thereby, even a small electronic component can be easily soldered. Moreover, since the solder bonding target site (electrode) is directly heated by induction heating rather than heat conduction from the heating element, heating of the substrate can be suppressed. Thereby, even if it uses a flexible substrate with low heat resistance, the thermal deformation of a board | substrate can be suppressed.

As a result of further examination of the above-described solder bonding apparatus, the inventors of the present application soldered the electronic component to the electrode formed on the substrate while transporting the substrate on which the electronic component is mounted. The present inventors have found an excellent solder bonding apparatus and have come up with the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment. Moreover, it can change suitably in the range which does not deviate from the range which has the effect of this invention.

FIG. 1 is a diagram schematically showing a configuration of a solder bonding apparatus according to an embodiment of the present invention. The solder bonding apparatus according to the present embodiment is a solder bonding apparatus that solders an electronic component to an electrode formed on the substrate while conveying the substrate on which the electronic component is mounted.

As shown in FIG. 1, the solder bonding apparatus 10 according to the present embodiment includes a conveying means 12 that conveys a substrate 11 on which an electronic component C is mounted, and a solder interposed between an electrode (not shown) and the electronic component C. And a heating means for melting (not shown) and soldering the electronic component C to the electrode.

The heating means includes a coil 20 having a space portion 21 on the inner side in a plan view (z direction), and a plurality of ferrites 30 arranged in the space portion 21 of the coil 20 along the transport direction A of the substrate 11. is doing. Here, the distance between each ferrite 30 and the electrode formed on the substrate 11 is independently adjusted by the adjusting mechanism 40. The adjustment of the interval can be performed using, for example, an actuator (for example, a robot cylinder, a linear slider, etc.) 41 provided for each ferrite 30. The substrate 11 is transported in the direction of arrow A (x direction) by the transport means 12 and passes under the coil 20 and the ferrite 30. Both ends of the coil 20 are connected to the power source 50 via the wiring 51, and by applying an AC voltage to the coil 20, the electrode formed on the substrate 11 located below the ferrite 30 is induction-heated. The

FIG. 2 is a diagram illustrating a method of soldering an electronic component to an electrode formed on the substrate 11 using induction heating in the present embodiment. Here, an example is shown in which solder 14 is supplied to the electrode 13 formed on the substrate 11, and an electronic component (for example, a chip capacitor, chip resistor, etc.) C having terminals (not shown) is soldered thereon. ing.

As shown in FIG. 2, the end 30 a of each ferrite 30 has a tapered shape in accordance with the size of the electrode 13 that is a solder bonding target site. When an AC voltage is applied to the coil 20, a magnetic flux Φ is generated around the coil 20. The magnetic flux Φ generated inside the coil 20 travels through the ferrite 30 disposed inside the coil 20 and is perpendicular (z) to the electrode 13 formed on the substrate 11 from the end 30a of the ferrite 30. Direction). Thereby, the electrode 13 is induction-heated. The heat heated by induction heating is transmitted from the electrode 13 to the solder 14, so that the solder 14 is melted, whereby the terminal 15 of the electronic component C is soldered to the electrode 13.

According to the solder bonding apparatus in the present embodiment, the magnetic flux Φ generated inside the coil 20 can be transmitted to the electrode (solder bonding target site) 13 via the ferrite 30 without being attenuated. Therefore, soldering can be performed efficiently. Further, the range of induction heating can be limited to the electrode 13 by matching the end 30 a of the ferrite 30 with the size of the electrode 13. Thereby, even a small electronic component C can be easily soldered. Moreover, since the electrode 13 is directly heated by induction heating, the heating of the substrate 11 can be suppressed. Thereby, even if it uses a flexible substrate with low heat resistance, the thermal deformation of the board | substrate 11 can be suppressed.

Furthermore, in this embodiment, since the plurality of ferrites 30 are arranged in the space portion 21 of the coil 20 along the conveyance direction A of the substrate 11, the substrate 11 on which the plurality of electronic components C are mounted is replaced with the plurality of ferrites. By transporting it below 30, a plurality of electronic components C can be continuously soldered to the electrodes formed on the substrate 11. Thereby, the electronic component C can be soldered to the electrode formed on the substrate 11 with high productivity.

In the solder bonding apparatus according to the present embodiment, the electronic component C is locally solder-bonded while the substrate 11 is continuously conveyed, so that the solder heating time is set to the conventional reflow method (usually time in minutes). Can be very short (usually time in seconds).

In the solder bonding apparatus according to the present embodiment, the interval between each ferrite 30 and the electrode formed on the substrate 11 is set such that the plurality of electrodes arranged inside the coil 20 are heated by induction heating. An adjustment mechanism 40 that adjusts in advance so that the temperature has a predetermined temperature profile along the conveyance direction A is provided.

FIGS. 3A and 3B are diagrams showing the temperature change of the electrode 13 heated by induction heating when the distance D between the end 30a of the ferrite 30 and the electrode 13 on the substrate 11 is changed. It is. As shown in FIG. 2, the magnetic flux Φ irradiated to the electrode 13 from the end 30 a of the ferrite 30 is proportional to the square of the distance D between the end 30 a of the ferrite 30 and the electrode 13 on the substrate 11. It attenuates. Therefore, since the heating amount of the electrode 13 heated by induction heating is proportional to the magnetic flux Φ, the temperature of the electrode 13 is set on the end 30a of the ferrite 30 and the substrate 11 as shown in FIG. It changes in inverse proportion to the square of the distance D from the electrode 13. Therefore, by adjusting the distance D between each ferrite 30 and the electrode 13 formed on the substrate 11, the temperature of each electrode 13 heated by induction heating can be accurately set along the conveyance direction A. Can do.

4 (a) to 4 (e) show a time t = during transfer of the substrate 11 on which the plurality of electronic components C are mounted below the plurality of ferrites 30 arranged along the transfer direction A of the substrate 11. FIG. FIG. ₄ is a diagram showing a state from t ₀ to t ₄ in time series. Here, it is assumed that the electronic component C has two terminals, and the two terminals are arranged in the transport direction A of the substrate 11.

FIG. 5 is a graph schematically showing a temporal change in the temperature of the electrode on the transport direction A side in the electronic component C _{1 at} the head in the transport direction A. In the graph illustrated in FIG. 5, the temperature change of the electrode starts to increase from time t = t ₀ , and the constant temperature T ₁ is maintained for the period indicated by P ₁ , and then the temperature increases again. , P ₂ , a constant temperature T ₂ is maintained, and then the temperature drops. That is, the interval between each ferrite 30 and the electrode formed on the substrate 11 is adjusted in advance so that the temperature change of the electrode becomes a temperature change as shown in FIG.

For example, in order to prevent “chip standing”, the temperature of the electrode on the transport direction A side and the temperature of the other electrode have a temperature change as shown in FIG. It is preferable to adjust in advance the distance between the electrode and the electrode formed on the substrate 11. In this case, temperatures T ₁ is set to the activation temperature of the flux, temperature T ₂ is set to a heating temperature for melting the solder. Further, when the temperature of the conveying direction A of the side electrodes is increased to T _2, the temperature of one electrode is preferably increased to T _1.

Incidentally, the graph shown in FIG. 5 shows the time variation of the temperature of the electronic components C ₁ electrodes at the beginning of the conveying direction A, the temperature of each electrode on the substrate 11 at a certain time, the transport direction A A temperature profile similar to the temperature change shown in FIG.

As described above, the solder bonding apparatus according to the present invention can transmit the magnetic flux generated inside the coil 20 to the electrode 13 on the substrate 11 through the ferrite 30 without being attenuated. Solder bonding can be performed well. In addition, by adjusting the tip of the ferrite 30 to the size of the electrode 13, the induction heating range can be limited to the electrode 13. Thereby, even a small electronic component can be easily soldered. Moreover, since the electrode 13 is directly heated not by heat conduction from the heating element but by induction heating, heating of the substrate 11 can be suppressed. Thereby, even if it uses a flexible substrate with low heat resistance, the thermal deformation of the board | substrate 11 can be suppressed.

Furthermore, the substrate 11 on which the plurality of electronic components C are mounted is conveyed below the plurality of ferrites 30 arranged along the conveyance direction A of the substrate 11, so that a plurality of electrodes 13 are formed on the substrate 11. The electronic component C can be continuously soldered. Thus, the electronic component C can be soldered to the electrode 13 formed on the substrate 11 with high productivity. In addition, by independently adjusting the distance between each ferrite 30 and the electrode 13 formed on the substrate 11, the plurality of electrodes 13 arranged inside the coil 20 are heated by induction heating. The temperature of each electrode 13 can be adjusted along the conveyance direction A so as to have a predetermined temperature profile. Thereby, for example, it is possible to prevent “chip standing” that occurs due to a time difference in which the solder of the two terminals of the electronic component melts.

In the present embodiment, the ferrite 30 only needs to have a high magnetic permeability that can transmit the magnetic flux generated inside the coil 20 so as to be focused on the solder joint target portion (electrode) without being attenuated. For example, soft ferrite can be used as the ferrite 30. Soft ferrite is a soft magnetic material mainly composed of iron oxide, has a large electric resistance, and hardly conducts current. For this reason, eddy currents are unlikely to occur in soft ferrite during induction heating. As a result, since the soft ferrite itself can be prevented from generating heat when performing induction heating, the influence of the heat received by the substrate 11 can be reduced even if the soft ferrite is close to the solder joint target portion (electrode).

In the present embodiment, the adjusting mechanism 40 that independently adjusts the distance between each ferrite 30 and the electrode formed on the substrate 11 is formed on each ferrite 30 and the substrate 11 as shown in FIG. Based on the data stored in the storage unit 43 and the data stored in the storage unit 43, the electrodes 13 formed on the ferrite 11 and the substrate 11 You may further have the control part 42 which adjusts these space | intervals automatically.

In the storage unit 43, the distance between each ferrite 30 and the electrode 13 formed on the substrate 11 is such that the temperature of each electrode 13 heated by induction heating has a predetermined temperature profile along the transport direction A. The data set in is stored. The control unit 42 automatically adjusts the distance between each ferrite 30 and the electrode 13 formed on the substrate 11 based on the data stored in the storage unit 43.

The optimal temperature profile varies depending on conditions such as the type of solder used, the type of electronic component C, and the arrangement. Therefore, an optimal temperature profile suitable for each condition is acquired in advance, and data on the interval between each ferrite 30 set to have the optimal temperature profile and the electrode 13 formed on the substrate 11 is stored. By storing it in the unit 43, automated solder bonding can be realized.

Further, in the present embodiment, as shown in FIG. 1, the substrate 11 is opposite to the side where the coil 20 is disposed and is parallel to the substrate 11 at a position facing the plurality of ferrites 30. A ferrite plate 31 may be provided. Thereby, since the magnetic flux transmitted through the ferrite 30 on the coil 20 side passes through the substrate 11 and is transmitted to the ferrite plate 31, the magnetic flux generated in the coil 20 is more reliably applied to the solder bonding target site (electrode). Can do. As a result, the electronic component C can be soldered more reliably. In place of the ferrite plate 31, rod-shaped ferrite may be disposed at a position facing the ferrite 30.

In the present embodiment, the substrate 11 may be made of an insulating material, and the type thereof is not particularly limited. For example, as the substrate 11, a circuit substrate having circuit wiring formed on the surface, an interposer having electrode pads formed on both surfaces, or the like can be used. Moreover, the electronic component C should just be a component which has a terminal, and the kind is not specifically limited. For example, as an electronic component, a chip capacitor, a chip resistor, an LED element, a semiconductor element, an LSI, or the like can be used.

In the present embodiment, it is preferable that the electrode 13 that is a solder bonding target site has an area that can be locally heated by induction heating. The area of the electrode 13 is preferably 0.25 mm × 0.25 mm or more. When the area of the electrode 13 is small, an auxiliary heating metal pad may be provided adjacent to the electrode 13.

Further, in the present embodiment, the coil 20 is not particularly limited as long as the coil 20 is parallel to the substrate 11 and has a space portion on the inner side in plan view. Further, the coil 20 may be formed in a pipe shape and circulated inside with a refrigerant.

(Modification)
In the present invention, the plurality of ferrites 30 are arranged along the conveyance direction A of the substrate 11, and the arrangement is aligned with the arrangement of the electronic components C mounted on the substrate 11. For example, FIG. 1 illustrates the ferrites 30 arranged in a line on the substrate 11 so as to be aligned with the electronic components C arranged in a line. In this case, the size of the end portion of the ferrite 30 is adjusted to the size including the solder bonding target portion (electrode) of the electronic component C.

However, as shown in FIGS. 6A and 6B, when the electronic components C are arranged close to each other (for example, the interval is within 2 to 3 mm) and arranged in two rows, the size of the ferrite 30 is reduced. Alternatively, the size may be adjusted so as to include the solder bonding target portion (electrode) of two electronic components arranged in parallel. At this time, as shown in FIG. 6A, the ferrite 30 has a belt-like shape extending in the direction (y direction) perpendicular to the transport direction A of the substrate 11. In this case, solder joining by induction heating is simultaneously performed on the two electronic components C arranged in parallel. In FIG. 6B, the ferrite 30 is omitted.

7 shows an example in which the electronic components C are arranged on the substrate 11 in a plurality of rows (four rows in FIG. 7) along the transport direction of the substrate 11. In this case, the coils 20 </ b> A and 20 </ b> B may be arranged for the column including the parallel electronic component Ca and the column including the parallel electronic component Cb, respectively. In FIG. 7, ferrite is omitted, but the shape may be as shown in FIG.

Of course, in the present embodiment, the shape and arrangement of the ferrites 30 are not limited to those shown in FIGS. 1, 6A, 6B, and 7, and the electrons mounted on the substrate 11 are not limited to those shown in FIGS. It can be changed as appropriate according to the type and size of the component C, the way of arrangement, and the like.

The length of the ferrite 30 is preferably in the range of 30 to 40 mm. The ferrite 30 preferably has a shape as close as possible to the inner dimension of the coil 20.

As mentioned above, although this invention has been demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible. For example, in the above embodiment, the ferrite 30 is tapered at the end portion 30a on the substrate 11 side, but the shape is not particularly limited. For example, the end 30a of the ferrite 30 can be two-sided or four-sided. Further, the end portion 30a on the substrate 11 side is not necessarily tapered.

In the above embodiment, the interval between each ferrite 30 and the electrode formed on the substrate 11 is automatically adjusted based on the data stored in the storage unit 43. A unit in which the distance from the electrode formed on the substrate 11 is adjusted may be prepared, and the unit may be replaced according to the size and arrangement of the electronic components C mounted on the substrate 11. .

In the above embodiment, the interval between each ferrite 30 and the electrode formed on the substrate 11 is set in order to prevent “chip standing” that occurs due to a time difference in which the solder of the two terminals of the electronic component melts. Although the temperature of each electrode heated by induction heating is adjusted to have a predetermined temperature profile, the present invention is not limited to such an object. For example, you may adjust so that it may have a temperature profile similar to the temperature profile in the conventional reflow system.

10 Solder bonding equipment
11 Substrate
12 Transport means
13 electrodes
14 Solder
15 terminals
20 coils
21 Space
30 Ferrite
31 Ferrite plate
40 Adjustment mechanism
42 Control unit
43 Memory 50 Power supply
51 Wiring

Claims

A solder bonding apparatus for solder-bonding the electronic component to an electrode formed on the substrate while conveying the substrate on which the electronic component is mounted,
Transport means for transporting the substrate on which the electronic component is mounted;
Heating means for melting the solder interposed between the electrode and the electronic component, and soldering the electronic component to the electrode;
The heating means includes
In a plan view, a coil having a space inside,
In the space portion of the coil, a plurality of ferrites arranged along the transport direction of the substrate,
An adjustment mechanism for independently adjusting the interval between each ferrite and the electrode formed on the substrate;
A solder bonding apparatus, comprising: a power source that applies an AC voltage to the coil to inductively heat the electrode formed on the substrate.
The solder joint device according to claim 1, wherein the ferrite is composed of soft ferrite.
The intervals between the ferrites and the electrodes formed on the substrate are such that, when an AC voltage is applied to the coil, the plurality of electrodes disposed inside the coil are heated by induction heating. The solder bonding apparatus according to claim 1, wherein the temperature of the electrode is adjusted in advance by the adjusting mechanism so as to have a predetermined temperature profile along the conveyance direction.
The distance between each ferrite and the electrode formed on the substrate is adjusted in advance so that the temperature of the electrode positioned on the substrate transport direction side is higher than the temperature of the electrode positioned on the opposite side of the transport direction. The solder bonding apparatus according to any one of claims 1 to 3, wherein:
The adjustment mechanism is
A storage unit storing data in which the interval between each ferrite and the electrode formed on the substrate is set to a predetermined value;
The control unit according to any one of claims 1 to 4, further comprising a control unit that automatically adjusts an interval between each ferrite and an electrode formed on the substrate based on data stored in the storage unit. A solder bonding apparatus according to claim 1.
The storage unit is set such that the distance between each ferrite and the electrode formed on the substrate is such that the temperature of each electrode heated by induction heating has a predetermined temperature profile along the transport direction. Remembered data,
The solder bonding apparatus according to claim 5, wherein the control unit automatically adjusts an interval between each ferrite and an electrode formed on the substrate based on the data stored in the storage unit.
The substrate is made of an insulating material,
7. The solder bonding apparatus according to claim 1, wherein the electrode has an area that can be locally heated by induction heating.
The solder bonding apparatus according to claim 1, wherein the ferrite has a tapered shape at an end portion on the substrate side.
The heating means further includes a ferrite plate disposed on a side opposite to the side on which the coil is disposed with respect to the substrate and disposed in a position facing the plurality of ferrites and parallel to the substrate. Item 2. A solder bonding apparatus according to Item 1.