JPS5932059B2 - bonding head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bonding head of a bonding apparatus used for bonding semiconductor elements and the like.

To bond semiconductor elements to metal frames,
In the conventional method, as shown in FIG. 1, first, a heating block 1 is heated to a predetermined temperature.
The metal frames 2 are arranged in parallel on top, and the solder 3 attached to the bonding pads 2a on each frame in the previous process is
Then, the semiconductor elements 5 pasted on the vinyl sheet 4 are sucked one by one with a needle of a bonding device (not shown) and transported onto the bonding pad 2a, and the solder 3 is applied. After that, the metal frame 2 was cooled and fixed.

The bonding head of the bonding apparatus used for the bonding operation is generally constructed as shown in FIGS. 2 and 3.

That is, in each of these figures, a bearing cylinder T is attached to the distal end of the bonding arm 6 facing toward the soil, and a needle 9 is provided at the lower part of the bearing cylinder T, and a needle 9 is provided at the upper part of the bearing cylinder T. , a spindle 8 with a diameter difference at the lower part is inserted vertically and slidably, and is prevented from rotating by a rotation prevention member 10, and air pressure is introduced into the bearing cylinder T from a pipe 11 to prevent the spindle 8 from rotating.
A predetermined downward pressure is applied to the spindle 8, and the spindle 8 is connected to a vacuum pump through a pipe 12, and the needle 9 is
A negative pressure, that is, a suction force for the semiconductor element 5 is generated at the tip of the semiconductor element 5. Therefore, with the bonding head having such a configuration, the semiconductor element 5 can be attracted by the needle 9, and the buffering during this attraction and pressurized attachment to the metal frame 2 can be achieved by introducing air pressure into the bearing cylinder T. In addition to being able to perform the bonding operation by moving the spindle 8, the position of the spindle 8 is regulated by the rotation preventing member 10 during the operation, so that accurate bonding work can be performed. In order to automate and commercialize the equipment itself with the aim of performing the bonding work with high efficiency, it is necessary to detect and correct the position and orientation of semiconductor elements using pattern recognition technology. However, in addition to the inconvenience that the operation control devices are multiple and expensive, there is a natural limit to its working capacity because the semiconductor elements are bonded one by one.

Further, as shown in FIG. 4, a series of metal frames 13 are disposed on the heating block 1 at a predetermined pitch interval P1, and the metal frames 13 are connected in series at a predetermined pitch interval P1 on the tray 14.
In the square hole 14a formed with a pitch interval P2 equal to 1,
A conceivable method is to store each semiconductor element 5, simultaneously attract and transport a plurality of semiconductor elements 5 through each square hole 14a, and simultaneously pressurize and attach a plurality of semiconductor elements 5 to each bonding pad 13a fixed to the metal frame 13. Note that the bonding conditions at this time are →1, pitch interval Pl,
It is sufficient if P2 is 12 degrees, the temperature of the needle is about 300° C., and the pressing force of the needle is about 1 Kf. The bonding head used in this method has a structure with multiple spindles and is constantly exposed to a heated zero atmosphere, so the distance between the spindles does not change due to heat, and it is difficult to operate at high temperatures. It is necessary to satisfy conditions such as smoothness. This invention satisfies these conditions,
To provide a bonding head that can simultaneously bond a plurality of semiconductor devices to each bonding pad of a corresponding metal frame.

Hereinafter, embodiments of the bonding head according to the present invention will be described in detail with reference to FIGS. 5 to 7.

In FIGS. 5 to 7, an integrated support block 17 is attached to the tip of the bonding arm 15 via a spacer 16 to avoid thermal effects.

This support block 1r has a plurality of receiving holes 17 opened downward at pitch intervals equal to the pitch intervals Pl and P2.
A, and in order to uniformly control the heating of the entire heater, a predetermined number of heaters 18 and thermocouples 19 are distributed and arranged, and these are connected to a control device (not shown) by respective lead wires 18a and 19a. There is. Further, pressure adjustment screws 20 from Hijikata are screwed into each of the receiving holes 17a,
The receiving holes 17a are communicated with each other by a communication path 21, and the receiving holes 17a are connected to each other through a pipe 21a.
is connected to a vacuum pump (not shown). Further, a bearing block 22 is fixed to the lower part of the support block 17, and the bearing block 22 has the same number of bearing holes 22a vertically formed in accordance with the positions of the respective receiving holes 17a.
A hollow tubular suction spindle 2 with a head with a large diameter
3 from the receiving hole side so as to be slidable up and down, and
A spring 24 is interposed between the upper end opened toward the receiving hole 17a and the pressure adjustment screw 20, so that each spindle 23 is elastically held at a predetermined pressure.

Furthermore, a heating block 25 is individually fixed to the downwardly projecting portion of each spindle 23, and this is connected to the bearing block 22 to obtain a rotation prevention effect, and the heating block 25 is also , similarly to the support block 17, a heater 26 and a thermocouple 27 from which lead wires 26a and 27a are taken out are arranged.
Therefore, in the configuration of this embodiment, since negative pressure from the vacuum pump is applied to each suction spindle 23 arranged at a predetermined pitch interval, the semiconductor elements in each square hole 14a shown in FIG. 5 at the same time and attach them to each bonding pad 13 on the corresponding metal frame 13.
It can be attached to a by pressure via molten solder,
In addition, the buffering and bonding pressure during adsorption can be set to arbitrary values by adjusting the pressure adjusting screw 20. Furthermore, the support block 17 and the heating block 22 are each equipped with internal heating means, that is, heaters 18, 26 and their The thermocouples 19 and 27 for heat generation control can always maintain a predetermined temperature.

Further, during the bonding work, the bearing block 22 that pivotally supports each spindle 23 is attached to the metal frame 1 described above.
Radiant heat from heating block 1 of 3 and each spindle 2
Thermal expansion occurs due to the conduction heat from the heating block 25 of No. 3,
The pitch between the spindles 23 will vary, making accurate bonding impossible.

As a countermeasure against this, in this embodiment, this bearing block 2
The support block 17 that fixedly supports the spindles 2 is heated to bring the bearing block 22 into a thermally expanded state before starting work, and at the same time, the pitch between each spindle 23 is also adjusted to the normal pitch at this thermal expansion point. Interval Pl, P
It is processed in advance so that it becomes 2. According to the experimental results, the temperature of the bearing block 17 rises to approximately 100°C in response to the temperature of each heating block 1, 25. Therefore, the temperature of the supporting block 17 is set to the optimal temperature to obtain this temperature, which is approximately 300°C in this case. When the temperature was set, the pitch accuracy between each spindle 23 was ±0.04m.
I was able to get it down to about 1. Further, by subjecting the sliding surfaces of the bearing hole 22a and the spindle 23 to, for example, nitriding treatment, smooth sliding can be achieved at all times at this temperature. Note that although the above embodiments have been described with respect to bonding of semiconductor elements, it goes without saying that the present invention can be similarly applied to other types of bonding. As detailed above, according to the bonding head of the present invention, it is possible to bond multiple objects such as semiconductor devices simultaneously, and the bonding work can be made highly efficient. It has the advantage of being simple.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the operation of conventional bonding work,
Figure 2 is a perspective view of a conventional bonding head; Figure 3 is a perspective view of a conventional bonding head;
The figure is a sectional view of the same as above, FIG. 4 is an explanatory diagram conceptually showing the operation of bonding work in this invention, FIG. 5 is a perspective view showing one embodiment of the bonding head according to this invention, and FIG. The cross-sectional view of the soil, Figure 7, is a cutaway front view of the main part of the soil. 15...Bonding arm, 16...
・Spacer, 17... Support block, 17a.
...-Receiving hole, 18, 26... Heater, 1
9, 27...Thermocouple, 20...Pressure adjustment screw, 22...Bearing block, 22a...
... Bearing hole, 23 ... Adsorption spindle, 2
4... Spring, 25... Heating block.

Claims (1)

[Claims] 1. A support block that is attached to the tip of the bonding arm via a spacer and has a plurality of receiving holes opened downward at predetermined pitch intervals, and a support block that has bearing holes that correspond to the positions of each of the receiving holes. A bearing block fixed to the lower part, a plurality of suction spindles that are vertically slidably fitted into each of the bearing holes and are elastically pressed in an adjustable manner from the receiving hole side, and each suction spindle also serves as a rotation stopper. 1. A bonding head comprising fixedly attached individual heating blocks, and heating means for heating the support block and each heating block to a set temperature.