JPH029555Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The invention provides
The present invention relates to a device for pressing and fixing a frame such as a lead frame onto a mounting surface of a bonding station.

(Prior Art) FIG. 3 shows a part of a bonding apparatus including a conventional frame holding device. In the figure, a heater block 2 is fixed to a fixed wall 1, and the upper surface of this heater block 2 functions as a bonding station. Guide rails 4 are provided on both sides of the heater block 2 along the longitudinal direction of a frame such as a lead frame 3.
The lead frame 3 is guided by a predetermined frame feeding device (not shown) and is intermittently transferred one pitch at a time, that is, one pitch at a time, to the bonding station of the semiconductor 5 disposed on the upper surface of the lead frame 3.

On the other hand, a frame holding device that presses and fixes the lead frame 3 against the mounting surface of the bonding station during bonding is configured as follows. That is, the fixed wall 1 is provided with a slide shaft 7 that can freely slide vertically via a slide receiver 6, and the base end of a frame presser 8 is fixed to the upper end of this slide shaft 7. The tip of the frame presser 8 serves as a presser for the lead frame 3, and the center of this presser, that is,
An opening 9 is formed in a portion facing the bonding region including the semiconductor 5. On the other hand, a spring mounting member 10 is attached to the base end of the frame retainer 8 and the fixed wall 1.
and 11 are fixed, and both members 10
A pressing spring 12 is stretched between and 11.
Therefore, the lead frame 3 is fixed on the mounting surface of the bonding station by the frame presser 8 due to the downward biasing force of the presser spring 12.

A bearing 13 is provided at the lower end of the slide shaft 7.
is provided, and this bearing 13 is connected to the shaft 14
It is opposed to a lever 15 which can swing freely using the lever 15 as a fulcrum. Note that the lever 15 swings because one end thereof follows the presser cam 16.

In the conventional frame holding device described above, bonding is performed in the state shown in the figure, that is, with the lead frame 3 fixed to the mounting surface of the bonding station by the frame holding device 8. In addition, in this state, the slide shaft 7 and lever 15
The cam action with is in a released state. Therefore, the lead frame 3 is fixed by a constant force exerted by the pressing spring 12.

Next, after the bonding is completed, intermittent transfer of the lead frame 3 is performed, but during this transfer,
It is necessary to retract the frame presser 8 upward so that it does not come into contact with the semiconductor 5, and this frame presser 8
The retraction is performed by pushing the slide shaft 7 upward via the lever 15 by the cam operation of the presser cam 16.

As described above, in the conventional apparatus, the lead frame 3 is fixed during bonding, and the frame presser 8 is moved away when the lead frame 3 is transferred.
When adjusting the fixing force of the frame presser 8, the presser spring 12 must be replaced, and when adjusting the retraction amount and movement timing of the frame presser 8,
There is a structural restriction that the presser cam 16 must be replaced.

(Problems to be Solved by the Invention) In recent years, various types of semiconductors have been used in various sectors, and this has created a need to bond different types of semiconductors using a common bonding device. By the way, as is well known, the thicknesses of the lead frame 3 and the semiconductor 5 vary depending on the type of the semiconductor 5, and the substrate of the lead frame 3 also varies depending on the purpose, such as metal or plastic. Therefore, in bonding, it is necessary to set the fixing force of the lead frame 3, the retraction amount of the frame presser 8, and the movement timing of the frame presser 8 to optimal values every time the type of the lead frame 3 is changed. be. This is because if the fixing force of the lead frame 3 is weak, there is an inconvenience that the lead frame 3 may move during bonding, and if it is too strong, the plastic substrate etc. may crack or the gold or silver on the lead frame surface may be damaged. This is because problems such as presser scratches may occur on the plating portion. Furthermore, if the retraction amount of the frame presser 8 is too small, the lead frame 3 will not be able to be transferred, and if it is too large, it will be retracted more than necessary, resulting in time loss.
This is because it becomes a hindrance to speeding up the bonding work. Furthermore, if the thickness of the lead frame 3 differs, it is necessary to adjust the movement timing of the frame presser 8 accordingly.

However, with conventional equipment, when bonding lead frames 3 of different types,
Each time the thickness of the lead frame 3 differs, the pressing spring 12 expands and contracts by the difference in thickness, resulting in an inconvenience that the pressing and fixing force of the frame presser 8 is not constant. Therefore, in order to ensure the optimum fixing force for the type of lead frame 3,
Select a suitable presser spring from among multiple presser springs,
There is the trouble of having to replace the presser spring, and similarly, the presser cam 16 must also be replaced in order to ensure the optimal retraction amount of the frame presser 8 each time the thickness of the semiconductor 5 differs. figure,
Furthermore, when replacing the cam, the cam must be selected in consideration of the movement timing of the frame presser 8, which is a hassle.

Setting the optimum conditions by replacing parts such as the presser spring 12 and the presser cam 16 requires skill, and it is also necessary to spend a lot of time selecting these parts and making adjustments when replacing them. Furthermore, there was an economic disadvantage in that a large number of parts had to be prepared in order to cope with various conditions.

The present invention was developed in consideration of the above-mentioned conventional problems, and even when the type of frame such as a lead frame is changed, the frame fixing force and retraction of the frame presser are optimal for the changed frame. It is an object of the present invention to provide a frame presser device that allows the amount and movement timing of the frame presser to be set extremely easily, accurately, and quickly.

(Means for solving the problems) In order to solve the above problems, the present invention is configured as follows. That is, the present invention includes a frame presser that presses and fixes the frame against the mounting surface of the bonding station, and a frame presser driving means that moves the frame presser in the presser direction and the retracting direction to fix and release the frame. In the frame presser, the frame presser driving means includes a moving body that moves the frame presser in conjunction with the frame presser, and a moving body feeding mechanism that can control the amount and speed of movement of the moving body. , the movable body is a frame presser device having a spring body that cooperates with the frame presser when moving in the presser direction, and an actuation piece that cooperates with the frame presser when moving in the retracting direction.

(Function) In the present invention having the above configuration, fixing the frame during bonding is carried out as follows. That is, first, the moving body is moved in the holding direction of the frame by driving the feeding mechanism of the moving body. At this time, since the frame presser is linked to the spring body of the movable body, the frame presser receives force from the spring body and moves in conjunction with the movement of the movable body. Due to this interlocking movement of the frame presser, the frame presser moves from the retracted position to the frame surface, engages with the frame surface, and stops. However, since the control motor continues to rotate by a predetermined number of rotations, the movable body also moves further than the presser frame.
However, since the frame presser cannot be linked to this extra movement of the movable body, the amount of movement is absorbed and alleviated by the elastic deformation of the spring body. Therefore,
The spring pressure caused by the elastic deformation of the spring body acts as a fixing force for the frame holder, and the frame is fixed on the mounting surface of the bonding station by the frame holder. Therefore, the fixing force of the frame holder can be arbitrarily set by controlling the amount of elastic deformation of the spring body, that is, the amount of extra movement of the movable body that continues after the frame holder contacts the frame surface. is possible.

On the other hand, after completion of bonding, the retracting movement of the frame presser during frame transfer is performed by moving the movable body in the retracting direction by driving the feeding mechanism. At this time, the retracting movement of the frame presser is performed in conjunction with the operating piece of the movable body. This amount of retraction movement can be arbitrarily set by controlling the feed amount of the feed mechanism.

Further, the timing of the operation of the frame presser is arbitrarily set by controlling the timing of the feeding operation of the feeding mechanism.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. Note that the same members as those in the conventional device are given the same reference numerals and their explanations will be omitted.

FIG. 1 shows an embodiment of the present invention, in which a moving body 17 is engaged with a bearing 13 provided at the lower end of a slide shaft 7. As shown in FIG. That is, the movable body 17 has a block member 19 on which the actuating piece 18 is formed.
and a spring plate 20 as a spring body fixed to this block member 19, the tip of the spring plate 20 is opposed to the upper end surface of the bearing 13, and the operating piece 18 is opposed to the lower end surface of the bearing 13,
The bearing 13 is sandwiched between an operating piece 18 and a spring plate 20. Note that the bearing 13 is provided with a negative electrode 40, and the actuating piece 18 is provided with a positive electrode 41. By this engagement between the bearing 13 and the movable body 17, the frame presser 8 is linked with the movable body 17 via the slide shaft 7 that is integral with itself.

A screw hole is formed at the base of the movable body 17, and a feed screw 21 is screwed into this screw hole. This feed screw 21 is rotatably fixed to the fixed wall 1 via a bearing 22. The feed screw 21 is connected via a coupling 23 to an output shaft of a control motor 24 such as a pulse motor.
This control motor 24 is driven by a drive circuit 25, and the number of rotations, the direction of rotation, and the rotation speed are controlled by a control circuit 26. These feed screws 2
1 and the control motor 24 constitute a feed mechanism 27 that controls the movement of the moving body 17.

The control circuit 26 includes an arithmetic circuit (computer) and a memory circuit, and controls the relationship between the thickness of the lead frame 3, the material of the substrate, bonding work conditions, the thickness of the semiconductor 5, the amount of deflection of the spring plate 20, and the spring pressure. The optimal fixing force, retraction amount, and operation timing of the frame presser are calculated based on this information, and a control command is output to the drive circuit 25 based on the calculated values. Based on this control command, the drive circuit 25 controls the control motor 24.
to drive.

This embodiment has the above configuration, and its operation will be explained below.

First, before bonding is started, the frame presser 8 is in a position retracted from the lead frame 3, as shown in FIG. In this state, the control circuit 2
By outputting an operation command from 6 to the drive circuit 25, the control motor 24 is rotated and the feed screw 21 is rotated in conjunction with this rotation. As the feed screw 21 rotates, the movable body 17 moves in the pressing direction, that is, downward in FIG. The downward movement of the frame presser 8 is stopped by contacting the lead frame 3. However, after the frame presser stops lowering, the control motor 24 continues to rotate by a predetermined amount, and the movable body 17 moves downward by the amount of rotation, and as shown in FIG. 20 bends upward in response to the difference in the amount of movement between the frame presser 8 and the movable body 17. The spring pressure caused by this elastic deformation acts as a fixing pressure for the frame presser 8, and the lead frame 3 is fixed to the mounting surface of the bonding station. The amount of deflection is detected by the off signal generated when the frame presser 8 contacts the lead frame 3 and the electrodes 40 and 41 are separated. The amount of excessive movement of the body, that is, the amount of excessive rotation of the control motor 24 is
This is calculated and set by the control circuit 26 based on information such as the thickness of the lead frame 3 and the relationship between the amount of deflection of the spring plate 20 and the spring pressure, so the lead frame is fixed with the optimum fixing force that suits the lead frame, and the desired bonding is achieved. Work is done.

Next, after the bonding is completed, a command for retracting the frame presser 8 is issued from the control circuit 26 to the drive circuit 25, and the control motor 24 is rotated in the opposite direction. As a result, the feed screw 21 also rotates in the opposite direction, and the movable body 17 moves upward. Therefore, the frame presser 8 also receives force from the actuating piece 18 and moves upward,
Evacuate from lead frame 3. This retraction amount is calculated by the control circuit 26 based on the information on the thickness of the semiconductor 5, and as a result of driving the motor based on this calculated value, the optimum retraction amount is determined for each lead frame 3 that is the target of bonding work. Set.

As described above, in this embodiment, the fixing force of the lead frame, the amount of retraction, and the operation timing of the frame presser are calculated and set by the control circuit 26 according to the conditions of the lead frame 3, and as a result, the type of lead frame 3 is changed. Even if this occurs, by inputting information about the lead frame 3 to be changed into the control circuit 26, it is possible to immediately calculate and set the optimum value of the fixing force, etc.

(Effects of the invention) Since the invention is configured as described above,
Even when the type of frame is changed, the fixing force of the frame holder, the amount of retraction of the frame holder, and the timing of the movement of the frame holder can be easily adjusted to the optimum frame holder for the new frame without the troublesome work that was previously required. Settings can be made quickly and accurately, which not only improves bonding work efficiency but also sufficiently improves bonding quality.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, FIG. 1 is a front view showing the frame holder in a retracted state, FIG. 2 is a front view showing the frame holder in a fixed state, and FIG. 3 is a front view showing the frame holder in a fixed state. It is a front view showing a conventional frame holding device. 8... Frame presser, 17... Moving object, 18...
... Actuation piece, 20 ... Spring plate, 21 ... Feed screw,
24...control motor, 27...feeding mechanism.

Claims (1)

[Claims for Utility Model Registration] (1) A frame holder that presses and fixes the frame against the mounting surface of the bonding station, and a frame holder that moves the frame holder in the holding direction and the retracting direction to fix and release the frame. In the frame presser device, the frame presser drive means includes a movable body that moves the frame press in conjunction with the frame presser, and a movable body that can control the amount and speed of movement of the movable body. a feeding mechanism, wherein the movable body has a spring body that cooperates with the frame presser when moving in the presser direction, and an actuation piece that cooperates with the frame presser when moving in the retracting direction. (2) The feed mechanism includes a feed screw that screws into the moving body,
The frame holding device according to claim 1, which is a registered utility model, and further comprising a control motor that controls the rotation of the feed screw.