JPS5993337A - Transfer molding machine - Google Patents

Abstract

PURPOSE:To detect the failure of molding by providing a device by which the time taken to feed a plunger is measured, and when the time exceeds a set value, a warning is sent out. CONSTITUTION:The first limit switch 11 as the first detector is provided at a given position on the outside of the rod of a plunger 6, and the startup point of the feeding of the plunger is detected. The second limit switch 12 as the second detector is provided at a given position below the first detector 11, and the ending point of the feeding of the plunger is detected. The timing of the signals sent out from these detectors 11 and 12 is measured by a timer 13, and when the time exceeds a set time, an alarm is sent out by a buzzer 14.

Description

[Detailed description of the invention] The present invention relates to a transfer molding machine.

Generally, in the manufacturing process of semiconductor devices, a transfer molding machine is used to mold a non-hermetically sealed package because it is suitable for mass production.

As a conventional transfer molding machine of this type, there is one shown in FIG. 1, for example. This Tora 777 molding machine is equipped with a combination mold 1 consisting of an upper mold 2 and a lower mold 3).
Approximately in the center of the upper mold 2 is a tablet 4' preformed with a molding material whose main component is resin! -Housing Bot 5
is provided.

A plunger 6 is fitted into the bot 5 so as to be able to move up and down, and a runner 7 communicates with the mating surface of the lower mold 3 directly below the bot 5, and from that position in both directions (front and back directions with respect to the page).
It is laid out so that it extends to. On the mating surfaces of the upper and lower molds 2 and 3, a large number of cavities 8 are formed in alignment on both sides of the lunch 70, and each cavity 8 has a respective gate 9.
It is communicated with the runner 7 via. Further, a detected portion 10 is provided protruding from the middle portion of the rod of the plunger 6, and a limit switch 11 is provided at a predetermined height position on the outside of the plunger rod. This switch 11 is connected to a cylinder (not shown) so as to detect the detected part Lot-, switch the descending speed of the plunger 6 from high speed to low speed, and substantially start the transfer of the molding material.

In such a transfer molding machine, the bottle
□ Place the tablet in the tablet 5 and heat it to 4? ! ! The melted resin is extruded with a plunger 6 and forced into each cavity B through a runner 7 and a gate 9, and a semiconductor integrated circuit or large-scale integrated circuit set in advance in the cavity is molded with this resin. Make a non-airtight seal.

In such a conventional transfer molding machine, the resin transfer time by the plunger is set at the lower limit 1 of the plunger from the time when the IJ Mitswitch detects the detected part of the plunger lot when there is no resin in the pot. The time is set to adjust the speed of the plunger.

However, in such conventional transfer molding machines, the transfer time of the resin by the plunger is set when the resin is not used, so there is a delay in the transfer during actual molding using the resin. There is a drawback that molding defects may occur.

During actual molding, this is due to fluctuations in various molding conditions such as contamination by resin residue on the plunger and pot, melting state of the resin, temperature of the mold, etc. (3) Sliding resistance between the plunger and pot, This is thought to be due to the fact that the transfer resistance etc. may become abnormally large.

The present invention has been devised in view of the drawbacks of the prior art, and it is an object of the present invention to provide a transfer molding machine that can issue an alarm when a delay in transfer occurs.

Hereinafter, the present invention will be explained according to embodiments shown in the drawings.

FIGS. 2 and 3 are longitudinal sectional views showing an embodiment of a transfer molding machine according to the present invention, and the same reference numerals as in FIG. 1 have the same structure as in FIG. 1! ! It shows the basics.

In this embodiment, a first limit switch 11 (shared with the high-low speed switching 8w) as a first detector is provided at a predetermined height position outside the lot of the plunger 6. A second detector and a second limit switch 12 are provided at a predetermined height below. A timer 13 is connected to both switches 11 and 12, and (4) a buzzer 14, which is an example of an alarm device, is connected to this tie ff13.
is connected. Both switches 12 and 13, timer 13
The buzzer 14 is configured, for example, in the electric circuit shown in FIG.

The first limit switch 11 is a regular switch, and is protruded from the plunger rod, and is closed when it comes into contact with the 7ti detection section 1° and detects the point at which the plunger 6 starts to be transferred. The second limit switch 12Fi is a normally closed switch and opens when it detects the end of transfer of the plunger 6 when it comes into contact with the detected part 10.

The timer 13 starts timing operation when the first limit switch 11 is closed, and when the preset time has been counted, a constant time switch 13a f interposed between the second switch 12 and the buzzer 14 is activated. Close it. The buzzer 14 operates to sound when both the second switch 12 and the time switch 13a are closed to generate an alarm.

Next, the entire operation will be explained.

After inserting the tablet 4 into the pot 5, the plunger 6 is moved down the cylinder at high speed.

When the changeover switch 11 contacts and detects the detected portion 10, the operating speed of the cylinder is switched, and the plunger 6 starts a resin transfer operation at a low speed. At the start of the transfer operation of the plunger 6, the timer 13 starts a timing operation.

If there is no abnormality in the sliding resistance between the plunger and the pot or the transfer resistance of the resin, the plunger 6 descends inside the pot 5 at the speed set in the cylinder, and the tablet 4 melts and melts the resin within a predetermined time. Then, it is transferred to each cavity 8 via the runner 7 and gate 9t. That is, in this case, Poonja 6111 reaches the transfer completion point 1 at a predetermined time. At the same time, the second limit switch 12 comes into contact with the detected part 10 and detects it, and the second limit switch 12 is opened. Therefore, even if the timer 13 is activated and the time switch 13a is closed after the set time has elapsed, the buzzer 14 will not sound.

However, if the sliding resistance or flow resistance increases due to various causes, the descending speed of the plunger 6, which is being pushed down with a constant force by the cylinder, decreases.

The time the plunger 6 reaches the transfer completion point l is delayed compared to the case of normal operation. If this delayed time is later than the time preset in the timer 13, the timer 13 closes the time switch 13a during the period when the second switch 12 is in the closed state. Therefore, the second
Buzzer 1 via switch 12 and time switch 13a'i
A current flows through the terminal 4, and the buzzer 14 sounds to generate an alarm. Incidentally, if the entire holding circuit that maintains the closed state of the time switch 13a is turned on when the buzzer 14 generates an alarm sound, the alarm can be maintained.

According to this embodiment, if the plunger transfer time is delayed, it is possible to warn of the occurrence of the delay.
Early detection of abnormalities in working conditions that cause delays, such as increases in sliding resistance and flow resistance, can save kW, and facilitates the discovery of defective molded products such as insufficient resin injection, etc., which are caused by delays. can do. For example, if resin remains in the gap between the plunger and the pot and the sliding resistance increases, the work to remove the residue can be carried out as soon as possible. If the 1'fc% delay is not reported, it will be possible to call attention to the quality inspection of the molded products that have been cut, and it is possible to prevent the flow of defective products. Due to the implementation and statistical maintenance of such work, defective withdrawals can be reduced and quality can be improved.

In addition, 1. The second detector is limited to the limit switch, but any detector such as a contact type switch can be used.As the alarm device, a lighting device or the like can be used.

Furthermore, the present invention is applicable not only to non-hermetic restraint packages for conductor devices, but also to transfer molding in general.

As described above, according to the present invention, it is possible to warn of a delay in the plunger transfer time.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a conventional example, FIGS. 2 and 3 are longitudinal sectional views showing an embodiment of the present invention in each operating state, and FIG. 4 is a circuit diagram of the main parts. 1... Mold, 4... Tablet, 5... Pot,
6... Plunger, 7... Runner, 8... Kievity, 1°... Detected part, 11... First limit switch, (low speed changeover switch), 12... Second limit switch, 13 ...Timer, 13a...Time switch, 14...Buzzer. Figure 1

Claims (1)

[Claims] l. A timer for setting the molding material transfer time of the plunger and setting an alarm device KWff; a first detector for detecting the time point at which the plunger transfer starts and causing the timer to start timing; and a first detector for detecting the time point at which the plunger transfer is completed. a second detector for detecting the detection and causing the alarm device to perform an alarm operation when the detection point is after a suitable time set by a timer.