JP2004228247A - Method and apparatus for peel back of local flow soldering substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for peel back which reduces bad conditions in soldering of soldering short etc. and to provide a peel back apparatus for realizing this method. <P>SOLUTION: After bringing melted soldering into contact with the soldering position of the local part of a substrate lower surface on which an electronic part is arranged, the substrate is tilted respectively in different directions with time differences. This direction can be two directions crossing orthogonally or with a narrow angle of ≤90°. The apparatus consists of a holding frame body (2) which holds a substrate (B) arranged on the top opening surface of a soldering tub (t) and where a carrying means (35) is arranged, and a tilting means (4) for tilting the holding frame body to tilt the substrate in a different direction. As for the tilting means, rotary shafts (T) are respectively arranged at positions parallel to two directions crossing on the substrate, and the holding frame body is rotated about the rotary shafts by linking of arranged driving means (40) and cam mechanisms (43 and 44) linked with this. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for peeling back a substrate for local flow soldering of electronic components, and in particular, a technique of soldering after a solder jet is brought into contact with a plurality of soldering positions (“local”) on the lower surface of the substrate. About the field.
[0002]
[Prior art]
The mounting of electronic components on a printed wiring board or the like is usually performed by soldering and is mainly connected and fixed. With the recent miniaturization of electrical products, unlike the conventional lead terminal insertion type components, double-sided reflow (solder melting) With the emergence of SMPs (Surface Mount Parts) using substrates, the size and weight of substrates have been reduced by high-density mounting.
[0003]
The soldering of the board on which these electronic components are arranged is performed by performing a flux treatment, by contacting the jet flow communicating with the molten solder liquid in the solder tank to the entire back surface of the board, and by moving the board, the contact solder jet is performed. Separation from the substrate ("solder cutting" or "peel back"). Conventionally, the board has been moved with a certain inclination for the purpose of more accurate solder cutting.
[0004]
However, soldering to the entire back surface of the board may be performed by the above method. However, when the electronic components to be soldered are arranged at a plurality of locations ("local") on the board, or after the board is soldered once, In a case where additional electronic components are to be mounted, local soldering has to be performed.
[0005]
As a jet-type soldering apparatus relating to this, there is one disclosed in Patent Document 1. As shown in FIG. 8, the molten solder h in the solder bath t is jetted from the jet nozzle n, and the crucible F provided with the jet nozzle n is lifted to allow the solder flow spouted from the opening of the nozzle n to flow through the substrate. The electronic component D is soldered so as to be in contact with the lower surface local portion of B. At this time, in order to avoid the so-called “solder short-circuit” in which the lead terminals L adjacent to the electronic component D are connected to each other by extra solder, the board B is turned or tilted up in a specific direction and a so-called peel-back operation is performed. (Soldering).
[0006]
Further, in the device disclosed in Patent Document 2, the substrate B is rotated while taking a rotation angle of 45 degrees with respect to the longitudinal direction in consideration of the arrangement of the electronic components D, and is inclined upward.
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-22322 (Section 3-4, FIG. 4)
[Patent Document 2]
JP-A-8-139445 (Section 2-3, FIG. 1)
[0008]
[Problems to be solved by the invention]
By the way, when peeling back (solder cutting) the lead terminals of an electronic component, it usually depends on various conditions such as the wire diameter of the lead terminal, the protruding length, or the arrangement interval. It is effective to increase the inclination of the lead terminal in the longitudinal direction of the lead terminal, and in the short direction, there is a problem that a short circuit of the solder may occur at worst.
[0009]
For this reason, in the one-way tilting mechanism, it is necessary to align the longitudinal direction of the electronic components when arranging a plurality of electronic components on the substrate. The degree was low.
[0010]
Further, in order to solve the above-mentioned problem, in Japanese Patent Application Laid-Open No. H11-157, the inclination is raised while taking a rotation angle of 45 degrees with respect to the longitudinal direction of the substrate. However, in this method, the direction of the peel back is oblique, and the effect may be reduced in some cases. That is, depending on the electronic component, the adjacent distance of the lead terminal on the short side may be shorter than the adjacent distance on the long side. In this case, the longitudinal side can easily obtain a good effect. In such a case, there is a possibility that excess solder flows on the back surface of the substrate to easily cause a solder short. Further, there is a problem that setting of conditions such as the inclination speed becomes complicated.
[0011]
【Purpose】
Therefore, the present invention has been made in view of the above problems, and provides an effective peel-back method for reducing defects in soldering such as short-circuiting of the solder, and the peel-back method while having a simple structure. Is provided.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a peel-back method for a local flow soldered board according to the present invention is performed as follows.
[0013]
That is, the method is characterized in that after the molten solder is brought into contact with a local soldering position on the lower surface of the board on which the electronic components are arranged, the board is inclined in different directions with a time lag to perform the solder cutting.
[0014]
The different directions may be set in two or more directions, but may be two orthogonal directions. Further, two directions intersecting at an included angle of 90 degrees or less may be used.
[0015]
Next, a peel-back device that realizes the above-described peel-back method is configured as follows.
[0016]
That is, a holding frame (2) arranged on the upper open surface of the solder tank (t) and holding the substrate (B), and the substrate (B) holding the holding frame (2) at an angle. And a tilting means (4) for tilting in different directions.
[0017]
As an example of the configuration of the tilting means (4), a rotation axis (T) is provided on the holding frame (2) at a position parallel to two directions intersecting on the substrate (B), and the holding frame (2) is provided. The holding frame (2) is rotated around a rotation axis (T) by the interlocking of the driving means (40) disposed in (2) and the cam mechanisms (43, 44) associated therewith. It is characterized in that.
[0018]
Further, a transport means (35) for transporting the substrate is arranged on the holding frame (2).
[0019]
Note that the reference numerals in parentheses described in the section of the claims and means for solving the problems are provided with reference numerals for reference in order to facilitate understanding of the structure of the invention. Of course, it is not limited to the form.
[0020]
[Action]
According to the above method and configuration, the present invention operates as follows.
That is, the substrate on which the electronic components are locally arranged according to the configuration of the first aspect is individually inclined in different directions. In addition, the inclination time, the time interval, and the inclination direction are appropriately set.
[0021]
According to claim 2, the two directions are orthogonal (for example, the X direction and the Y direction).
[0022]
According to the third aspect of the present invention, the substrate is held by the holding frame, and the substrate is individually tilted in different directions by the tilting means provided on the holding frame.
[0023]
According to the configuration of the fourth aspect, the cam mechanism acts on the rotating shaft to incline.
[0024]
By adopting the configuration of claim 5, the board to be soldered is transported to the holding frame by the transporting means.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, specific examples of a peel-back method for a local flow soldered board according to the present invention and a peel-back device for realizing the method will be described in detail with reference to the drawings.
[0026]
FIG. 1 is an external perspective view showing the peelback device of the embodiment. Here, the positional relationship between the apparatus and the X direction, Y direction, and Z direction (vertical direction) orthogonal to each other is defined with reference to the display in FIG. 1 for convenience of explanation. FIGS. 2A, 2B, 4A, and 4B are perspective views showing the tilting means of the peel-back device of the present embodiment, and FIG. 3 is an arrow along the Y direction in FIG. FIG. 5 is a plan view showing the inclined body when the peelback device is viewed from B ("viewed from arrow B"), and FIG. 5 is a view illustrating the peelback device from arrow A along the X direction in FIG. 6) is a plan view showing the inclined body, and FIG. 6 is a plan view showing the inclined body when the peelback device is viewed from the center line in the direction of the arrow A along the X direction in FIG. It is.
[0027]
The peel-back device 1 (hereinafter, referred to as “the present device”) of the present embodiment mainly includes a holding frame 2, a tilting unit 4, and a substrate holding unit, and is a general jet-type soldering device (hereinafter, referred to as “soldering device”). It is disposed inside the soldering apparatus so as to surround a solder tank t for storing the molten solder installed in the “soldering apparatus”.
[0028]
Further, the soldering apparatus is usually provided with a solder tank t in which molten solder is stored, and a crucible F which moves up and down inside and outside of the solder storage liquid. On the upper surface side of the crucible F, a solder jet nozzle n (hereinafter, abbreviated as “nozzle”) communicating with the solder storage liquid is arranged. The arrangement and number of the solder jet nozzles n are set so as to correspond to the electronic component D to be soldered.
[0029]
[Configuration of holding frame]
The two bases 20a and 20b serving as the bases of the holding frame 2 are formed in a long plate shape, and are arranged outside the both ends of the solder tank t in the Y direction with the length direction attached in the X direction. I have. In FIG. 1, rectangular parallelepiped bearing blocks 21a and 21b are arranged at both ends of a base 20a on the left side as viewed in the direction of arrow A. Of the two bearing blocks 21a and 21b, the bearing block 21a on the left side as viewed from the arrow B is fixed to the base 20a, and the bearing block 21b on the right side as viewed from the arrow B is brought into contact with the base 20a without being fixed to the base 20a. ing.
[0030]
A bearing block 21c is attached to an end of the base 20b on the right side as viewed in the direction of the arrow A, and a contact block 22 is fixed on a right side as viewed in the direction of the arrow B.
[0031]
An elongated plate-shaped movable frame 23 is arranged so as to bridge between the contact block 22 and the bearing block 21c. The movable frame 23 has an end plate 23a attached to an end surface on the right side as viewed from the direction of the arrow B, and a lower surface of the end portion is brought into contact with the contact block 22 in an initial state. The opposite end of the end is fixed to a shaft support block 24 which is pin-coupled (pivotably coupled) to the bearing block 21c by a pivot pin 25a.
[0032]
Next, the two side frames 26a and 26b, which are constituent members of the holding frame 2, are arranged in parallel in the Y direction (longitudinal direction in FIG. 1) above the two bases 20a and 20b.
[0033]
Of the two side frames 26a and 26b, the left side end of the side frame 26a as viewed in the direction of the arrow B has two rotating pins 25b and 25c arranged orthogonally to the connecting block 27, Via a block 27a, the base 20a is connected to the bearing block 21a on the left side of the arrow B so as to be able to rotate in the X and Y directions. In the operation of the present device 1, only this connecting portion does not move up and down. The right end of the side frame 26a on the left side as viewed from the arrow B is in contact with the pivot block 24 via the leg block 28. Thus, the side frame 26a is maintained horizontally in the Y direction in the initial state.
[0034]
The side frame 26b on the right side as viewed in the direction of the arrow B fixes a bearing member 29 to the left end side as viewed in the direction of the arrow A, and the supporting block 29 is pin-connected to the bearing block 21b via a rotation pin 25d. I have. Further, the bearing block 21b and the connection block 27 are maintained at a predetermined distance in the X direction by the connection and holding of the spacer 30.
[0035]
Further, the right side end of the side frame 26b as viewed in the direction indicated by the arrow B is linked to the tilting means 4 described later.
[0036]
Further, as described above, the bracket 31 is attached to both side ends (total of four places) of the side frames 26a and 26b opposed to each other in the X direction, and the both ends are opposed to each other in the X direction. The bracket 31 is formed in a plate shape extending from the upper end edges of the side frames 26a and 26b, and is connected by a support rod 32 extending between the opposed brackets 31.
[0037]
Due to the connection of the two support rods 32, 32 by the rigid nodes, the two side frames 26b, 26a arranged in parallel form a rectangular rigid frame on the same plane without twisting. .
[0038]
Two support members 33 (33 in total) are movably attached to the two support rods 32 at predetermined intervals in the X direction. These four support members 33, 33,... Suspend two parallel rails 34, 34 between the support members 33, 33 facing each other in the Y direction. The interval between these two rails 34 is appropriately set by moving the support member 33 along the shaft 32.
[0039]
The rail 34 is provided with a means for transporting the board B to be soldered (for example, a belt conveyor). In this embodiment, the transport means is a pin chain 35.
[0040]
The holding frame 2 having the above structure causes the substrate B to tilt in the Y direction with a rotation axis Tx in the X direction formed by the rotation pin 25d and the rotation pin 25c disposed to face, The substrate B is tilted in the X direction with a rotation axis Ty in the Y direction, which is constituted by the rotation pin 25a and the rotation pin 25b disposed to face.
[0041]
[Configuration of tilt means]
Next, the tilting means 4 for causing these tilts will be described.
The inclining means 4 includes two motors 40d (lower) and 40u (upper) and two cam mechanisms disposed in two upper and lower stages on the right end side of the side frame 26b viewed from the arrow B in the arrow A direction. It is composed of
[0042]
The configuration of the tilting means 4 in the X direction is set by the configuration on the lower side of the drawing, and the configuration is such that a substantially L-shaped angle plate is provided on the right end surface of the base 20b on the right side of the arrow A as viewed from the arrow B. The motor bracket 41d is fixed, and the motor 40d is fixed to the motor bracket 41d with the motor output shaft 42d facing the frame. An eccentric cam 43d is attached to the motor output shaft 42d, and a columnar cam follower 44d that contacts the outer periphery of the eccentric cam 43d is rotatably supported on the end face plate 23a of the movable frame 23 to form a cam mechanism.
[0043]
The configuration of the inclination means 4 in the Y direction is set by the configuration on the upper side in the drawing, and the configuration is the same as that described above on the upper surface of the mounting portion of the end plate 23a of the movable frame 23. A cam mechanism comprising a substantially L-shaped angled plate-shaped motor bracket 41u, a motor 40u, and an eccentric cam 43u attached to a motor output shaft 42u, and a cylindrical cam follower 44u contacting the outer periphery thereof is attached. The cam follower 44u is pivotally supported on the side of the side frame 26b. In addition, a substantially L-shaped angled plate-shaped stopper body 45 that contacts the lower end surface of the side frame 26b is attached to the upper surface of the end of the corresponding movable frame 23.
[0044]
[Operation of this device]
Next, the operation of the holding frame 2 and the tilting means 4 configured as described above will be described with reference to the drawings.
First, the tilt setting in the X direction is performed by the following operation (see FIGS. 1 to 3).
[0045]
When the lower motor 40d is driven to rotate the lower eccentric cam 43d, the lower cam follower 44d moves in conjunction with the outer periphery of the lower eccentric cam 43d (upward), whereby the movable frame 23 and the upper motor 40u attached thereto are moved. The cam mechanism and the side frame 26b are pushed up while being horizontal (see FIG. 2). At this time, the bearing block 21b attached to the left end of the side frame 26b as viewed in the direction of arrow A separates from the base 20a (see FIG. 3). In addition, the lower surface of the end of the movable frame 23 viewed from the arrow B is separated from the contact block 22 of the base 20b. The substrate B horizontally held on the rail 34 by the upward movement of the side frame 26b and the like moves in the X direction by a tilt angle (θx) with a rotation axis Ty composed of the rotation pin 25a and the rotation pin 25b. Will be inclined. This inclination angle (θx) is set by the amount of rise (Lx) of the side frame 26b, and this amount of rise can be appropriately set by the rotation angle of the eccentric cam 43d.
[0046]
In other words, in other words, a cam mechanism including the lower eccentric cam 43d and the cam follower 44d is interposed between the output of the lower motor 40d as the driving means and the rotation axis Ty, and the two support rods 32 , 32 and the two side frames 26b, 26a serve as levers and rotate.
[0047]
Next, the inclination setting in the Y direction is performed by the following operation (see FIGS. 1 and 4 to 6).
When the upper motor 40u is driven to rotate the upper eccentric cam 43u, the upper cam follower 44u moves in association with the outer periphery (up), thereby pushing up the right side of the side frame 26b in the direction of arrow A (FIG. 4). reference). At this time, the bearing block 21b attached to the left end of the side frame 26b as viewed in the direction of arrow A remains in contact with the base 20a (see FIG. 5). Further, since the two side frames 26b, 26a arranged in parallel are formed into a rigid frame by connecting the two support rods 32, 32, the side frame 26a also moves similarly to the side frame 26b. At this time, the leg block 28 attached to the lower surface of the right side of the side frame 26a as viewed in the direction indicated by the arrow A is separated from the support block 24 (see FIG. 6). By the upward movement of the two side frames 26b, 26a at the right ends as viewed from the direction indicated by the arrow A, the board B horizontally held on the rail 34 is rotated by the rotation pins 25c and the rotation pins 25d. It is inclined in the Y direction by the inclination angle (θy) with the axis Tx. This inclination angle (θy) is set by the amount of rise (Ly) of the side frame 26b, and this amount of rise can be appropriately set by the rotation angle of the eccentric cam 43u.
[0048]
In other words, in other words, a cam mechanism including the upper eccentric cam 43u and the cam follower 44u is interposed between the output of the upper motor 40u as the driving means and the rotation axis Tx in this way, and the two rigid frame members are provided. The side frames 26b and 26a serve as levers and rotate.
[0049]
In the present apparatus, the motors 40d and 40u are motors whose rotation angles can be controlled, for example, servo motors and stepping motors. In addition, it is preferable that the motor include a built-in speed reduction mechanism or a brake mechanism, or that the speed reduction mechanism or the brake mechanism be built in.
[0050]
[Peel back operation of the present application]
Next, the peel-back operation of the substrate will be described with reference to the drawings.
Reference numeral n shown in FIG. 7 is a nozzle for jetting molten solder from an upper end opening, and a substrate B on which electronic components Da to Dd are arranged is arranged close to each nozzle n. When the molten solder is jetted from the nozzle n in this state, the jet solder comes into contact with the lead terminal groups La to Ld exposed on the back surface of the substrate B (the state of FIG. 7A). The specification of the number, shape, and arrangement position of the nozzles is appropriately set according to the arrangement of the electronic component to be soldered.
[0051]
In this state, when the substrate B is lifted or separated from the solder jet at a predetermined inclination angle (“solder cutting”), depending on the arrangement direction of the lead terminal groups La to Ld of the electronic components Da to Dd. However, it is not possible to obtain an optimum peel pack point, and there is a possibility that excess solder may be left unnecessarily. This may not be able to stay in the lead terminal groups La to Ld and may flow to cause a solder short. .
[0052]
Thus, for example, as shown in FIG. 7B, the board is once tilted to the peel back point that is optimal for the electronic components Da and Db by temporarily turning the left front side Ex in the drawing as the rotation axis side. θy), the lead terminals La and Lb of the electronic components Da and Db are soldered.
[0053]
Next, from this state, the board is rotated from the orthogonal side different from the above, that is, the side Ey on the opposite side in the drawing as the rotation axis side, and the substrate is moved to the peel back point optimal for the remaining electronic components Dc and Dd. The lead terminals Lc and Ld of the electronic components Dc and Dd are subjected to solder cutting with the inclination (θx).
[0054]
By tilting the board in two directions with a certain time difference as in the above example, even when electronic components are arranged in different axial directions on the substrate or even when the electronic components are arranged unevenly, solder cutting by the optimum peel back point can be performed. Can be performed well.
[0055]
In addition to the example shown in the drawings, depending on the arrangement and shape of the electronic components, it is also possible to change the order of inclination on the X-axis and Y-axis sides, select a time difference, or appropriately select the inclination speed. It is possible. When the two directions are simultaneously tilted, one direction obtained by vector-combining the two directions becomes the tilt direction after all. However, the tilt angle, the tilt speed, or the time difference between the two directions is appropriately considered. By setting, different multi-directional inclinations can be realized.
[0056]
[Possibility of other embodiments]
In the present embodiment, the holding frame is tilted by a motor driven through an eccentric cam and via a rotating shaft. For example, the holding frame is supported at three points by a cylinder piston mechanism or the like. May be performed by forming a virtual surface.
[0057]
In this case, there is no need to set the rotation axis in two orthogonal directions as in the above-described embodiment, and an appropriate rotation axis can be freely set on the virtual plane, and different tilts in multiple directions can be made more possible. .
[0058]
In this embodiment, the transport method is a pin chain disposed on a suspension rail. However, the transport method may be changed to another transport means, for example, a rack and pinion, a transport robot, or the like.
[0059]
【effect】
Since the present invention is configured as described above, the substrate can be peeled back in different directions, and it is possible to reduce defects such as solder shorts regardless of the arrangement of the electronic components.
[0060]
Further, the degree of freedom in the layout of electronic components on the board can be greatly improved, and it is possible to quickly respond to the production of many kinds and small quantities of specially ordered products.
[Brief description of the drawings]
FIG. 1 is an external perspective view showing the present apparatus.
FIG. 2 is a perspective view showing an X-direction tilting means of the apparatus.
FIG. 3 is a plan view showing an inclined state in a view taken in the direction of arrow B in FIG. 1;
FIG. 4 is a perspective view showing a Y-direction tilting means of the apparatus.
FIG. 5 is a plan view showing an inclined state in a view taken in the direction of arrow A in FIG. 1;
FIG. 6 is a plan view showing an inclined state from the center line of the apparatus in the direction of arrow A in FIG. 1;
FIG. 7 is a perspective view showing an example of a peel-back operation of the present apparatus.
FIG. 8 is a cross-sectional view showing a peel-back operation of a conventional jet-type soldering apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 This apparatus 2 Holding frame body 20a Base 20b (on the left side as viewed from arrow A) Base 21a (on the right side as viewed from arrow A) Base block 21b (on the left side as viewed from arrow B) Bearing block 21c (on the right side as viewed from arrow B) 21c (for 20b) Bearing block 22 Contact block 23 Movable frame 23a End face plate 24 Support block 25a Rotating pin 25b Rotating pin 25c Rotating pin 25d Rotating pin 26a Side frame 26b (on the left side as seen from arrow B) Side (on the right side as seen from arrow B) Frame 27 Connection block 27a Support block 28 Leg block 29 Support block 30 Spacer 31 Bracket 32 Support rod 33 Support member 34 Rail 35 Pin chain 4 Inclination means 40d Motor (lower stage)
40u motor (upper)
41d Motor bracket 41u Motor bracket 42d Motor output shaft (lower)
42u motor output shaft (upper)
43d Eccentric cam 43u Eccentric cam 44d Cam follower 44u Cam follower 45 Stopper body Tx X-direction rotation axis Ty Y-direction rotation axis θx X-direction tilt angle θy Y-direction tilt angle Ex X-direction rotation side Ey Y-direction Rotating side B Boards Da to Dd Electronic components La to Ld Lead terminal group F Crucible h Melted solder n Nozzle t Solder tank

Claims (5)

After the molten solder is brought into contact with a local soldering position on the lower surface of the substrate on which the electronic components are arranged, the substrate is inclined in different directions with a time lag to perform the solder cutting, wherein local flow soldering is performed. How to peel back the substrate. 2. The method according to claim 1, wherein the different directions are two orthogonal directions. A holding frame (2) disposed on the upper open surface of the solder bath (t) and holding the substrate (B);
Tilting means (4) for tilting the substrate (B) held by tilting the holding frame (2) in different directions;
A peel-back device for a local flow soldered board, comprising: In the configuration of the inclination means (4),
The rotation shafts (T) are disposed on the holding frame (2) at positions parallel to the two directions intersecting on the substrate (B), respectively.
By the interlocking of the driving means (40) disposed on the holding frame (2) and the cam mechanisms (43, 44) associated therewith, the holding body (2) is rotated about the rotation axis (T). 4. The peel-back device for a local flow soldering board according to claim 3, wherein the peel-back device is rotated. 5. The peel-back device for a local flow soldered substrate according to claim 3, wherein a transport means for transporting the substrate is disposed on the holding frame.

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