JPH01273398A - Bonder for electronic part - Google Patents

Abstract

PURPOSE:To shorten operating speed, and to conduct bonding stably and positively by performing access operation to a substrate of a vacuum suction collet at high speed under the action of a spring having a large spring constant in a first section and at low speed under the action of a spring having a smaller spring constant in subsequent sections. CONSTITUTION:A support spindle 22 for a vacuum suction collet 21 is provided shapedly with a flange 40, the flange 40 is held between an access inhibiting lever 41 and a pressure lever 42, both the access inhibiting lever 41 and the pressure lever 42 are moved at high speed under the state in which the lever 41 and the lever 42 are drawn nearer mutually by a spring 50 having a large spring constant in the first section of bonding operation, and pressure is continued at low speed by a spring 84 having a small spring constant under the state in which the movement of the access inhibiting lever 41 is stopped and pressure by the spring 50 having the large spring constant is also cancelled in subsequent sections. Accordingly, the vacuum suction collet 21 is shifted at high speed while overcoming the force of the spring for maintaining the collect at a position separate from a substrate 92 and the inertia of the vacuum suction collet, and lastly the substrate is pressed softly.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Applicability The present invention relates to a bonding device for pressing and bonding electronic components (including semiconductor pellets) to a substrate.

(B) Prior Art Various types of devices for bonding electronic components to substrates have been proposed and are widely put into practical use. −
As an example, the apparatus described in Japanese Patent Publication No. 51-9141 is cited. In this example, the solder cutting part on the board surface and the solder bump on the pellet are heated and melted on the spot using hot gas, but the two are temporarily bonded with solder cream, silver paste, etc., and then used in the subsequent process. There is also a method of reflow soldering.

(c) Problems to be Solved by the Invention Regardless of the bonding mode, all bonding devices have a common operation in that they vacuum-adsorb electronic components with a collet and press them against a substrate with a predetermined pressure. Now, regarding the point of pressing onto the board with a predetermined pressure, many of the electronic components to be bonded are fragile, so be careful in how you apply the force so as not to apply too much pressure and damage the components. is necessary. However, simply reducing the pressure and slowing down the operation will not improve work efficiency. The present invention seeks to resolve this contradiction.

(d) Means for Solving the Problems In the present invention, the vacuum suction collet approaches the substrate in the first section under the action of a spring with a large spring constant.
The test was performed at high speed, and the subsequent sections were performed at low speed under the action of a spring with a small spring constant. In the second invention, a flange is formed on the support spindle of the vacuum suction fret, and this flange is sandwiched between the access suppression lever and the pressure lever, and in the first section of the bonding operation, the approach suppression lever and the pressure lever are held in place by the spring. Both are pulled together at high speed by a spring with a large constant, and in the subsequent section, the movement of the approach suppression lever is stopped and the pressure applied by the spring with a large spring constant is canceled.
Pressurization was continued at low speed using a spring with a small spring constant.

(E) Effect In the first invention, since the vacuum suction collet is initially brought close to the substrate under the action of a spring with a large spring constant, the inertia of the vacuum suction collet and the separation of the vacuum suction collet from the substrate are reduced. The collet can be moved at high speed by overcoming the force of the spring that keeps it in position. After shortening the operating time in this way, the pressure is applied softly under the action of the spring with a small spring constant. The second invention is similar to the first invention in that the action of the spring with a large spring constant and the action of a spring with a small spring constant are switched midway through, but by stopping the movement of the approach suppression lever, the vacuum suction The collet should not approach the substrate by more than a certain distance of 1ul1. In this way, even if the collet approaches the board without picking up the electronic component due to a suction error, the collet can be stopped before the tip of the collet touches the solder cream, etc. on the board, and the collet can be stopped due to the suction of foreign matter. This can be prevented.

(f) An example will be explained based on the example drawings. Bonding device (1)
has an XY child table 10) and a base (20) supported by the XY child table 10). X-axis part (1) of XY child table 10)
1) moves in the direction perpendicular to the plane of the paper in Figure 1, and Y
The shaft portion (12) moves in the left-right direction on the paper.

- The space (20) is an elongated member extending in the Y-axis direction and has a vacuum suction fret <21 at the tip.

As seen in FIG. 6, two identical vacuum suction freds (21) are arranged symmetrically. For convenience, the symbol (21') on the right side of the figure is placed one inch apart.The elevating mechanism is the same for both the vacuum suction collet (21) and the vacuum suction collet (21'), so the vacuum suction collet (21') is the same as the vacuum suction collet (21').
The explanation of the elevating mechanism will be continued using only 21) as an example.

A collet (21) is mounted on the lower end of a vertical support spindle (22). The support spindle (22) has a spline shaft (23) that vertically passes through a bearing (24) at the tip of the base (20) and a gear (25). The spline shaft (23) has a bearing part (
24), but not relative to the gear (25).

In other words, when the gear (25) rotates, the spline shaft (23
) also rotates. The spline shaft (23) is hollow,
The center hole serves as a vacuum suction path leading to the collet (21). The upper end of the spline shaft (23) has a connecting pipe (2
6) is fixed, and a vacuum hose (27) leading to a vacuum source (not shown) is connected to this connecting pipe (26) via a rotary joint (28). A compression coil spring (29) is inserted between the gear (25) and the connecting tube (26) to maintain the support spindle (22) in the raised position at all times.

Gear (25) meshes with gear (30), gear <30
) has an electric motor installed near the center of the base (20).
from the pulse motor) (31) to the timing pulley (32).
), Timing Held (33), Timing Bulliff 3
4) Transmit rotation via. As the gear (30) rotates, the spline shaft (22>) also rotates, and the vacuum suction collet (2)
1) The electronic components adsorbed are directed in a predetermined direction.

The connecting pipe (26) has a flange (40), and this flange (40) is connected to the access prevention lever (41) and the pressure lever (
42) are clamped from above and below via rollers (43) and (44) at their tips, respectively. The access suppression lever (41) has a bell crank shape and is attached to a bracket (45) fixed to the base 20) so as to be rotatable in a vertical plane with a shaft (46). The roller (43) of the approach suppression lever (41) supports the flange (40) from below. The pressurizing bar (42) is connected to the access suppression lever (
41), which is pivotally supported by a shaft (47) on the arm portion extending upward. The roller (44) of the pressure lever (42) presses the flange (40) from above. Note that the pressure lever (42) also has a bell flank shape. (48) is a pulling lever that brings the rollers (43) and 44) closer together. The pull lever (48) has a seesaw shape, and the pressure lever (4
2) It is located above and is pivotally supported by a shaft (49). A tension coil spring (50) is stretched between the forward protruding arm of the approach suppression lever (41) and the pull lever <48), and the front end of the pull lever (48) is applied by the force of the tension coil spring (50). A force is generated that pushes the roller (51) on the side of the pressure lever (42), thereby pinching the flange (40) between the pressure lever (42) and the access prevention lever (41). A bracket (52) is fixed in line with the bracket (45), and a stopper bolt (53) is screwed into the upper end of the bracket (52) so as to face the rear end of the pull lever (48).

The access control lever (41) obtains its movement from the cam drive (60). The structure of the cam drive device (60) is as follows. First, a pair of vertical support plates (62) (62) are fixed to both sides of the base (20), and the camshaft (63) is placed between them.
) is supported horizontally. One end of the camshaft (63) is connected to an electric motor (64) mounted on the vertical support plate (61).

A plate-shaped cam (65) is fixed to the camshaft (63).
(66) is a cam follower lever mounted on the base (20) with a shaft (67) so that it can swing in a vertical plane.The cam follower lever (66) is a roller ( The cam follower lever (68) is located in the middle part, and its swinging end is connected to the end of the upward arm of the access suppression lever (41) by a connecting rod (69).
66) (7) Also connect the rod <71) of the air cylinder <70) to the swinging end. The base end of the air cylinder (70>) is pivotally supported by the base (20).

The vertical support plates (61) and (62) support the bobbin shaft (80) in line with the camshaft (63). Boori axis (80)
One end of the electric motor (8) attached to the vertical support plate (61)
Connect to 1). The electric motor (81) is a pulse motor and can be stopped at a desired rotation angle. A pulley (83) for winding a steel cord (82) is attached to the bobbin shaft (80).
) is fixed. The tip of the cord (82) is connected to the rear end of the pressure lever (42) via a tension coil spring (84). Comparing the spring constants here, the tension coil spring (50) easily moves the compression coil spring (29) when the access prevention lever (41) is rotated counterclockwise in Figure 1. Compress and support spindle (22)
The spring constant is large enough to lower the

On the other hand, the spring constant of the tension coil spring (84) is smaller than that of the tension coil spring (50). However, even with this, it is possible to compress the compression fill spring (29).

(90) is a substrate transport section arranged in front of the XY child table 10). The board transport section (90) carries electronic components (9
The substrate (92) to which 1) is to be bonded is guided in a direction perpendicular to the paper plane in FIG. substrate(
92) can be held in a predetermined position by a positioning means (not shown) in front of the bonding device (1). It is the rotary index table (93) shown in FIG. 7 that delivers the electronic component (91) to the collet 21).
The rotary index table (93) is located in front of the bonding apparatus (1) with the substrate transport section (90) interposed therebetween. Rotary index table (93)
On the top surface of the
Four adsorption pressures (94) are arranged. Each adsorbent dust (
A vacuum suction hole (95) is opened in the center of 94).
The rotary index table (93) attracts the electronic component (91) and transports it to the component delivery station set at the position closest to the board transport section (90).The collet (21) attracts the electronic component (91). At this point, the suction of the vacuum suction hole (95) is cut off.0 A component receiving station is set at an index position other than the component delivery station, and here, a hand (not shown); (
91) and place it in the center of the suction R seat (94).

The bonding device (1) operates as follows.

FIG. 1 shows that a bonding device (1) takes an electronic component (91) from a rotary device (93), and
The vacuum suction collet (21) is shown stationary on the substrate (92).The cam (65) is at the angle shown, so that the support spindle (22) maintains the raised position. . Electronic components (9) on the surface of the board (92)
1) Apply a thick ream in advance to the area where bonding is to be performed. Naori Mufuorowareha (66)
) is maintained in contact with the cam (65) by the force of the air cylinder (70). When the cam (65> changes its angle as shown in Figure 2), the cam follower lever (66) tilts forward, and the access prevention lever (41)
) rotates by a certain angle. At this time, the movement is fast. Pulled by the approach suppression lever (41), the pressure lever (42) also moves at the same time, and the support spindle (22) descends at high speed. When the support spindle (22) has descended to a certain height, the rear end of the pull lever (48) touches the stopper port (53), and at that point the support spindle (22) is no longer pressurized by the tension coil spring (50). This occurs when the electronic component (91) contacts or does not contact the solder cream on the board (92).The roller <43) of the access suppression lever (41) 〉 cam curve, it is lowered to a position slightly lower than the current height, and maintains that height for a while. At this point, as shown in Figure 3, the pulley shaft (80) begins to rotate and the cord (
82)'E The cord winds up relatively slowly (
82) is connected to the pressure lever (82) via the tension coil spring (84).
42), which causes the support spindle (22) to
In comparison with the previous example, by adjusting the winding amount of the cord (82), which presses the W near part (91) against the board (92) under low speed and light load pressure, the electronic component (91) ) can be adjusted. The stress generated in the tension coil spring (84) or the hood (82) or the value of the current flowing through the electric motor (81) may be monitored and the electric motor (81) may be stopped at an appropriate value. After continuing to apply light pressure for a while, the suction of the vacuum suction collector (21) is shut off. Following this, the cam (65) also enters the phase of raising the support spindle (22). The bobbin shaft (80) also rotates in the opposite direction and returns to its old position.

If the vacuum suction collet (91) had not been adsorbed, the vacuum suction collet (21> would have moved closer to the board (92) than the distance that would have been obtained by the electronic component (91>), but this approach would have caused On the way, it was stopped by the approach suppression lever (41),
The vacuum suction collet (21) does not come into contact with the solder cream.

As mentioned above, the bonding apparatus (1) has two vacuum suction columns 1- (21) (21'), but these are rarely lowered toward the substrate (92) at the same time. However, since the cam shaft (63) is common, when it is desired to lower only one collet, the other must be kept from being affected by the cam.

Here the air cylinder (70) plays a role, namely the fourth
As shown, if the rod (71) of the air cylinder (70) is kept retracted, the cam follower lever (66) will remain at a constant angle no matter what angle the cam (65) rotates, thus The support spindle (22) will remain in the raised position.

(g) Effects of the invention In the present invention, by properly using springs with large spring constants and springs with small spring constants, the vacuum suction collet is moved at high speed until full-scale pressurization is applied, and during the pressurization stage, the vacuum suction collet is moved to the electronic component. Since the process is carried out slowly with a light load commensurate with the strength of the bonding material, it is possible to satisfy both the requirements of shortening the operating speed and ensuring safe and secure bonding. In addition, in the second invention, since the movement of the vacuum suction collet is stopped at a certain position even in the pressurizing stage by the approach suppression lever, even if the electronic component is not suctioned due to a suction error, the vacuum suction collet This prevents the tip of the mouthpiece from touching the board and inhaling foreign matter.

4. Drawing III! The explanatory drawings show one embodiment of the present invention, and FIGS. 1 to 4 are cross-sectional views in different operating states, FIG. 5 is a top view, FIG. 6 is a front view, and FIG. 7 is an electronic component supply. FIG.

(91)...Electronic component, (92)...Substrate, (2t
)(2t')...Vacuum suction collet, (50)...
Tension coil spring (spring with large spring constant), (84)・
・Tension coil spring (spring with small spring constant), (22
)...Support spindle, (40>...7 lunge, (
41)... Approach suppression lever, (42)... Pressure lever.

Claims (2)

[Claims] (1) In devices where electronic components are sucked up by a vacuum suction collet and pressed onto the substrate surface for bonding, the vacuum suction collet approaches the substrate at high speed in the first section under the action of a spring with a large spring constant. The electronic component bonding apparatus is characterized in that the subsequent section is performed at low speed under the action of a spring with a small spring constant. (2) In devices where electronic components are sucked up by a vacuum suction collet and pressed onto the substrate surface for bonding, a flange is formed on the support spindle of the vacuum suction collet, and this flange is sandwiched between an access control lever and a pressure lever to perform bonding. In the first section of the operation, the approach suppression lever and the pressure lever are pulled together by a spring with a large spring constant and are moved together at high speed, and in the subsequent section, the movement of the approach suppression lever is stopped and the spring constant is reduced. An electronic component bonding device characterized by continuing pressurization of a pressurizing lever at low speed by a spring with a small spring constant while canceling pressurization by a large spring.