JPH0248414B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a quantitative injection device for a melt of a polymeric substance such as an epoxy resin filled into the inside of a semiconductor element to protect the inside of the semiconductor element.

[Conventional technology and its problems]

Generally, semiconductor devices are injected with a melted polymer material such as epoxy resin and solidified to protect the inside, terminals, and other parts. If the melted polymer substance that is filled inside the semiconductor element is not injected into the semiconductor element in a constant amount as accurately as possible, the product will be uneven and structural defects will occur, and the semiconductor element will be damaged. There is also a risk of damage.

By the way, a conventional quantitative injection device for a polymeric substance melt is shown in FIG. 3, for example.

In Fig. 3, reference numeral 1 denotes a container for storing a polymeric substance melt having the required internal volume, and a polymeric substance melt 2 is filled in this container 1, and the polymeric substance melt is introduced into the bottom of the container 1. A pipe 3 is connected to the lower end of the introduction pipe 3, and a melt metering device main body 4 is connected to the lower end of the introduction pipe 3. Due to its manufacture, this main body 4 has several blocks 4a,
Although it is divided into 4b...4n, they are fixed together with bolts or the like (not shown). Further, 5 is an air cylinder, which in this embodiment is a single-rod type double-acting cylinder, 5a is a cylinder rod of the air cylinder 5, 5b is a valve portion thereof, 5c is a stopper, and 5d is a spacer.

Reference numeral 6 indicates a melt inlet provided at the bottom of the main body, 6a indicates a melt outflow portion of the inlet, and 7 indicates an O-ring used at each connection portion to prevent melt leakage.
8a and 8b are electromagnetic valves, which in this embodiment are normally closed three-port valves, and the air cylinder 5 is connected to an air pressure source 1.
Speed control valves 9a and 9b connected to electromagnetic valves 8a and 8b from 0 are provided.

Next, the operation in the conventional example shown in FIG. 3 will be explained.

First, this type of polymeric substance melt is usually made using a device that mixes two different liquids, such as a base material and a hardening agent, while partially applying temperature or maintaining the temperature. The viscosity of the mixed polymeric substance melt changes with changes in ambient temperature and the passage of time, and usually has a high viscosity and eventually hardens.

A conventional quantitative injection device for a polymeric substance melt is shown in FIG. 3, and its operation will be described below.

The polymeric substance melt is put into a polymeric substance melt reservoir 1 at room temperature, and the polymeric substance melt 2 in the polymeric substance melt reservoir 1 is introduced into the polymeric substance melt introduction pipe 3. The melt is then introduced into the main body 4 of the melt metering injection device. Initially, the inlet melt outflow part 6a at the upper part of the inlet 6 provided at the lower part of the melt metering device main body 4
is closed by the lowest valve portion 5b of the cylinder rod 5a of the air cylinder 5 operated by the electromagnetic valves 8a and 8b, and the polymeric substance melt 2 is stopped here.

Next, the air cylinder 5 is activated by the solenoid valve 8a or 8.
b, the cylinder rod 5a is raised, and the rate of rise is adjusted by the speed control valve 9a or 9b. Then, the polymeric substance melt 2 flows out from the injection port melt outflow part 6a,
Although not shown in the drawings, from the injection port 6, the inside of the semiconductor element located directly below the injection port 6 is injected and filled. When a certain amount of the polymer substance melt 2 has been injected into the inside of the semiconductor element, the solenoid valve 8a or 8b is operated and the cylinder rod 5a is lowered again to close the inlet melt outflow part 6a. The injection and filling of the inside of the semiconductor element with the polymeric substance melt 2 is completed. The descending speed of the cylinder rod 5a is also adjusted by the speed control valve 9a or 9b. Therefore, the amount of the polymer substance melt 2 injected and filled into the inside of the semiconductor element is determined by the air pressure of the air pressure source 10 and the electromagnetic valves 8a and 8b.
It is changed by the difference in opening/closing time and the adjustment of the speed control valves 9a and 9b. Note that 5c and 5d are stoppers and spacers for adjusting the stroke of the cylinder rod 5a.

However, although the polymeric substance melt 2 generally has a high viscosity, in the conventional quantitative injection device for polymeric substance melt, the melt is poured from the polymeric substance melt storage container 1 through the polymeric substance melt introduction pipe 3. Since the outflow of the polymeric material melt 2 from the injection port 6 relies solely on gravity, the outflow may be poor or unstable, and the polymeric material melt 2 may be Because the viscosity of the polymer substance melt changes due to changes in temperature and ambient temperature, the initially set amount of polymer material melt that is filled inside the semiconductor element must be maintained at a relatively accurate constant amount at the beginning. The disadvantage was that the resulting product changed over time and with changes in ambient temperature.
According to experiments conducted by the present inventors, when an epoxy resin is used as a polymeric substance melt, at an epoxy resin temperature of 45°C, the difference between when a certain amount of polymeric substance melt is set and after approximately 60 minutes has passed is as follows: The result was that the amount of epoxy resin injected into semiconductor devices was reduced by approximately 20%.

[Means for solving problems]

The present invention has been made in view of this, and includes a main body in which two valve opening/closing means are arranged side by side, and a valve provided inside the main body and provided in one of the valve opening/closing means. a melt measuring section that moves, closes, and opens, and an inlet that is opened and closed by a valve provided in the other valve opening/closing means, is located below the melt measuring section, and communicates with the melt measuring section. A quantitative injection device for a polymeric substance melt is provided, which has an inlet and a heater at the bottom of the main body.

〔Example〕

The present invention will be explained below based on the embodiment shown in FIGS. 1 and 2.

In the figure, reference numeral 1 denotes a polymer melt storage container having the required internal volume and shape, and an inlet pipe 3 for the polymer melt is connected to the bottom of this container 1. The molecular substance melt 2 is filled and supplied. Further, a main body 11 of a melt metering device is connected to the lower end of the introduction pipe 3, and this main body 11 is divided into several blocks 11a, 11b, 11c...11n in order to facilitate manufacturing. They are manufactured and then fixed together with bolts etc. to form the desired body shape. An O-ring 7 is applied to the connecting portion of each block and the connecting portion with the introduction pipe to prevent liquid leakage.

In addition, a space 19 which is connected to the introduction pipe and into which the melt is introduced and a space 20 into which the melt is not introduced are formed independently in the main body 11.
and 20 are connected at their bottoms, and an inlet 6 is formed in one of the spaces 20, and this inlet is also connected to the space, and the upper parts of both spaces 19 and 20 are connected to each other at the bottom. Air cylinders 13 and 12 are arranged in the main body 11 of the main body 11, respectively. Both of these air cylinders 12 and 13 are single-rod type multiple cylinders, and stoppers 12c and 13c are provided at the top, and rods 12a and 13a of the cylinders are provided with stoppers 12c and 13c.
are inserted into the spaces 20 and 19, respectively. Valve parts 13b and 12b are fixed to the lower ends of the cylinder rods 13a and 12a, and these valve parts are connected to the stepped part (upper end part) 18a of the melt measuring part 18 connected to the space part 19 and the inlet 6. It faces the stepped portion 6a, and is capable of closing the stepped portion.

Further, a Teflon packing 14 is applied to the outer periphery of the piston rods 13a and 12a to allow the piston rods to slide so as not to leak upward from the space 19 or the upper part of the injection port. 15 is a pressing bolt for this Teflon packing. In addition, the block 11b of the main body 11 includes a heater 16 and a thermocouple 1.
7 are provided at different positions.

[Effect]

The operation of the apparatus for quantitatively injecting a polymeric substance melt according to the present invention constructed as described above will be explained with reference to FIG.

Initially, in the state shown in FIG. 1, the cylinder rods 12a and 13a of both the air cylinders 12 and 13 are raised by the operation of solenoid valves (not shown), and the melt outlet part 6a of the inlet and the upper end part 13a of the melt measuring part are The polymer substance melt 2 in the polymer substance melt inlet pipe 3 flows out from the melt measuring part 18 to the injection port 6, and a small amount of the polymer substance melt 2 is discharged to the outside. As a result, the entire device main body space 19 is filled with the polymer substance melt 2. In addition, by doing this, when the injection work of the polymeric substance melt into the inside of the semiconductor element (not shown) located directly below the injection port 6 is started, the space in the main body of the apparatus is heated by the heater 16. If there is a polymeric material melt that has started to harden relatively at the heater 19 (the heater 16 will be explained later), it can be discharged and thrown away. next,
From the state shown in FIG. 1, only the air cylinder 12 is operated, and only the cylinder rod 12a is lowered to close the inlet melt outlet 6a as shown in FIG. 2a.
Next, from the state shown in Fig. 2a, only the air cylinder 13 is operated, and only the cylinder rod 13a is lowered, and when the valve part 13b of the cylinder rod 13a reaches the upper end 18a of the melt measuring part, as shown in Fig. 2b,
Operate the air cylinder 12 to release the cylinder rod 1.
Raise 2a. When the cylinder rod 12a has reached the upper limit and the cylinder rod 13a has reached the lower position in the melt measuring section 18, as shown in FIG. 2c,
As shown in the figure, the polymeric substance melt 2 having a volume corresponding to the length 1 is forced to flow downward from the upper end 18a of the melt measuring part 18 through the injection port 6. The inside of the semiconductor device located directly below the inlet 6 is injected and filled. The volume corresponding to the length 1 from the upper end 18a of the melt measuring section 18 (hereinafter referred to as "quantified amount") is the volume that the viscosity of the polymeric substance melt 2 changes over time or as the ambient temperature changes. Even if it changes with change, it doesn't change at all because there is no relationship. In other words, even if the viscosity of the polymeric substance melt 2 changes, it is possible to inject and fill an accurate amount of the polymeric substance melt 2 into the semiconductor element located below the injection port 6. Even if the polymer substance melt has a large amount, it is forced to flow out from the injection port 6. After a fixed amount of the polymeric substance melt 2 flows out from the injection port 6 and is injected into the inside of the semiconductor element, as shown in FIG.
From the state shown in FIG. 2, the air cylinder 12 is operated to lower the cylinder rod 12a as shown in FIG.
2a is closed by the valve portion 12b at the bottom, and the injection and filling operation of the polymeric substance melt 2 into the semiconductor element is completed. Note that the operation of discharging and discarding a small amount of the first polymeric substance melt 2 to the outside may be performed in this one step. Further, when performing the operation of forcing the polymer substance melt 2 to flow out from the injection port 6 and injecting it into the inside of the semiconductor element as shown in FIG. By descending step by step without descending to
The operation of filling the interior of the semiconductor element with the polymer substance melt 2 from the injection port 6 can be made more reliable. Next, in order to continuously inject and fill the semiconductor element with the polymeric substance melt 2 again, the cylinder rod 13 is operated from the state shown in FIG. 2d, and the cylinder rod 13a is raised. As shown in FIG.
The melt is introduced into the melt measuring section 18, as shown in Fig. 2 a to d below.
Repeat the process.

In the embodiment, an air cylinder is used to open and close the valve portions 12b and 13b, but instead of an air cylinder, it is also possible to use an opening and closing means that performs reciprocating motion using an electric motor, rack, pinion, etc. .

According to experiments conducted by the present inventors, in the case of epoxy resin, at 45°C, the amount of epoxy resin injected into the inside of a semiconductor element decreases by less than 5% between the initial setting of the fixed amount of polymeric substance melt and 60 minutes after it has passed. I stayed there.

Note that the valve portion 13 at the bottom of the cylinder rod 13a
The shape of b is, for example, one having a structure as shown in FIG. If a valve head 134 is inserted into the valve head 134, if the cylinder rod 13a rises from the state shown in Fig. 2d to the state shown in Fig. 2a, the polymeric substance melt 2 will be Since the cylinder rod 13a can move toward the valve head 134 through the melt escape hole 132, the cylinder rod 13a can rise smoothly. However, in experiments conducted by the present inventors, the air cylinder 1 can
The air pressure injected into 2 and 13 is approximately 6Kgf/
cm ² (gauge pressure), the shape shown in FIG. 4B was sufficiently usable.

Note that the heater 16 is connected to the melt metering device main body 11.
The purpose is to heat and maintain the polymer substance melt 2 at a constant temperature to make it easier to flow, and to maintain the temperature at a temperature at which the polymer material melt 2 is injected into the semiconductor element through the injection port 6 and hardened as soon as possible after being filled. The output of the heater 16 is controlled based on the temperature measurement, and the melt metering device body 11 is maintained at a constant temperature. In this embodiment, the epoxy resin present in the device main body space 19 is kept at about 80°C. In this case, the epoxy resin is injected into the semiconductor element and then placed in an electric furnace for 80
It hardens in 3 hours if held at 150°C, and in 1 hour if held at 150°C.

Furthermore, the polymer material may be not only epoxy resin but also liquid silicone rubber or the like having relatively low viscosity.

〔Effect of the invention〕

As described above, according to the present invention, even if the viscosity changes due to the passage of time or changes in ambient temperature, and even if the melt is a high-viscosity polymeric substance that is difficult to flow out, it is possible to maintain an accurate and constant volume. There is an advantage that it becomes possible to inject and fill a semiconductor element with a polymeric substance melt of

[Brief explanation of the drawing]

FIG. 1 is a sectional view, FIG. 2 is an explanatory diagram showing the operating sequence of FIG. 1, FIG. 3 is a sectional view of a conventional example, and FIG. 4 is an explanatory diagram of the valve portion. 11 is the main body, 12 and 13 are air cylinders, 1
2b, 13b are valve parts, 18 is a melt light weight part, 19,
20 is a space, and 6 is an injection port.

Claims (1)

[Claims] 1. A main body provided with two valve opening/closing means arranged side by side,
A melt measuring section that is provided inside the main body and is slid, closed, and opened by a valve provided in the one valve opening/closing means, and a valve provided in the other valve opening/closing means. A quantitative injection device for a polymeric substance melt, which has an injection port that is opened and closed and is located below the melt measuring section and communicates with the melt measuring section, and a heater at the bottom of the main body.