JP3005552B1 - Resin sealing method for work - Google Patents

Abstract

An object of the present invention is to provide a resin sealing method and a resin sealing mold for a work that can be released without damaging the work. SOLUTION: After using a pair of molds 1 and 2 surrounding a work to form a cavity C, the cavity is filled with a sealing resin 7 to seal the work, and then an ejector pin 3 is inserted into the cavity. Protruding to release a part of the sealing resin from the inner surface of the cavity, and then supplying compressed air 20 to the interface between the sealing resin and the cavity,
The sealing resin is released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of sealing a resin for a work and a mold for resin sealing, and more particularly to a method of sealing a resin for a work and a resin suitable for sealing a semiconductor chip with a resin. The present invention relates to a sealing mold.

[0002]

2. Description of the Related Art Conventionally, a technique as shown in FIG. 4 has been known as this kind of resin sealing method. This technique uses a semiconductor device 6 on one side of a lead frame 5 as a work W.
The lead frame 5 is set between a pair of molds 1 and 2 using a work W having a structure on which the semiconductor device 6 is mounted.
A cavity C is formed around the cavity C, and the cavity C is filled with the sealing resin 7 and solidified.
In addition to sealing the semiconductor device 6, the sealing resin 7 is adhered to the lead frame 5 to seal the semiconductor device 6 with resin. After the resin sealing is completed, the molds 1 and 2 are greatly opened, and then the ejector pins are inserted into the cavity C from one mold 1 (the mold on the side where the cavity C is formed). The work W is released from the mold by projecting the sealing resin 7 to isolate the sealing resin 7 from the cavity C. Here, as the sealing resin 7, a high-adhesion encapsulating resin having high adhesion to the lead frame 5 is often used in order to enhance the sealing property of the semiconductor device 6.

On the other hand, as another example of a technique for removing a resin-sealed work W, Japanese Patent Application Laid-Open Nos. 9-262876 and 3-193427 have been proposed. As shown in FIG. 5, these techniques are to open the two dies 1 and 2 after resin encapsulation to a large extent, and then, at the interface between the encapsulation resin 7 and the cavity C, the projecting opening of the ejector pin 3 The work W is released from the mold 1 by supplying the compressed air 20 via the compressed air supply path 4 and communicating the sealing resin 7 with the cavity C. .

[0004]

By the way, in the above-mentioned prior art, the work W (thin product) having a small rigidity, that is, a so-called bending force, and furthermore, the resin sealing portion is large and the installation interval of the ejector pins 3 is large. In the work W which must be set large, the tensile force is generated between the part released first and the part released last, the bending amount of the work W becomes large, and the work W is sealed. There is a disadvantage that the semiconductor device 6 also bends and cracks occur when it reaches the limit. In order to reduce the occurrence of this phenomenon, it is necessary to keep the mold release as good as possible, and it is necessary to frequently clean the mold as a countermeasure. Therefore, there is a disadvantage that the efficiency of the actual enclosing operation is significantly reduced, and furthermore, in order to reduce the occurrence of cracks, the operation of the ejector pin 3 is operated at an extremely low speed in order to reduce the impact at the time of peeling. A method or a method of providing a large number of ejector pins 3 to reduce the interval as much as possible can be considered as a countermeasure. However, in the former method, the mold release time is significantly increased, which causes a reduction in manufacturing efficiency, and In the latter method, the mold structure is complicated, and when a process such as engraving is performed on the product surface, it is practically impossible to install the ejector pin 3 on the product surface. Is difficult.

[0005] In the conventional technique of releasing the mold using compressed air, in the state where the molds 1 and 2 are completely opened, in the process of releasing the mold, a part which has been released first,
The bending of the work W occurs between the last part to be released and the same trouble as described above. In this technology as well, it is thought that the above-mentioned problems can be solved by providing a large number of compressed air supply paths, but from the viewpoint of the size of the work W and securing of the stamping surface, it is practically implemented. Is impossible.

[0006] These problems become remarkable when the above-mentioned high adhesion resin is used as the sealing resin 7.

The present invention has been made in view of such conventional problems, and provides a resin sealing method and a resin sealing mold for a work that can be released without damaging the work. The purpose is to:

[0008]

According to a first aspect of the present invention, there is provided a resin sealing method for a work , wherein a semiconductor device is mounted on one surface of a lead frame to achieve the above-mentioned object .
A work is mounted, and the semiconductor device surrounds the semiconductor device.
Using a pair of molds to form the
After filling the semiconductor device with a sealing resin,
Then, from the mold located on the lead frame side,
Open both molds by a specified amount while ejecting the ejector pins.
The lead frame from one of the molds.
Mold and then into the cavity from the other mold.
With the ejector pins projected, a part of the sealing resin is
The mold is released from the inner surface of the cavity, and then the sealing resin and
Supply compressed air to the interface with Viti to release the sealing resin
It is characterized by making it. Also, as described in claim 2 of the present invention.
The method of sealing a mounted work with a resin according to claim 1, wherein
Supply compressed air to the interface between the sealing resin and the cavity inner surface.
After releasing these molds, open both molds greatly,
Then, by ejecting the ejector pin,
To discharge the resin-sealed work from the mold.
Sign. Furthermore, the work according to claim 3 of the present invention
The resin sealing method according to claim 1 or 2,
The sealing resin is a highly adhesive resin.

According to the method for sealing a resin of a work according to the first aspect of the present invention, after the sealing resin is filled, a part of the sealing resin is released by an ejector pin. By supplying the compressed air to the interface with the compressed air, during the supply of the compressed air, the part released by the ejector pin triggers, and the release of the sealing resin by the compressed air is performed smoothly, The bending moment generated in the sealing resin at the time of release from the mold can be suppressed as small as possible, whereby damage to the resin-sealed work can be suppressed. Also, at the time of releasing the sealing resin, by performing the releasing operation in a state where the mold is opened by a predetermined amount, the deformation amount of the sealing resin at the time of releasing can be regulated by the pair of dies. Thus, it is possible to reliably prevent the sealing resin from being excessively deformed, and to more reliably prevent damage to the work. Also,
Since the operating range of the ejector pin is forcibly regulated, it is not necessary to reduce the operating speed, and the management of the supply pressure of the compressed air and the like can be managed in a rough manner, thereby shortening the manufacturing cycle. be able to. In addition, the frequency of cleaning the mold can be reduced with the reliable release operation. On the other hand, at the time of release, the lead frame side can be reliably released from the mold,
As a result, the workpiece can be released smoothly. According to the second aspect of the present invention, after the work release operation is completed, the work is further pushed out by the ejector pins, so that the work after the release can be easily handled. According to the third aspect of the present invention, by using a high-adhesion resin as the sealing resin, the mold releasing operation can be performed smoothly and reliably while the hermeticity of the work is sufficiently ensured.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
None This will be described in detail with reference to FIG. In the following description, the same parts as those of the related art will be denoted by the same reference numerals, and the description will be simplified. As shown in FIG. 1, a sealing die used in the present embodiment fills a lower die 1 with a sealing resin 7 and seals a lower portion of a cavity C that seals a semiconductor device 6 constituting a work W. In order to push up the work W (sealing resin 7) after sealing, an ejector pin 3 which can be raised and lowered at an arbitrary position is slidably installed. When the ejector pin 3 is lowered to a predetermined size, the mold is provided with a structure in which the compressed air supply path 4 is secured. The opening of the mold and the operation of the ejector pin 3 are controlled at an arbitrary speed and position accuracy by the driving power from the sealing press, and the upper mold 2 is opened at the position of the fixed mold opening amount 8 as shown in FIG. A small amount of the sealing resin 7 is pushed up by the rise of the ejector pin 3, and FIG.
As shown in (1), an operation for creating a trigger for release (release trigger portion 9) is performed. After the release trigger 9 of the ejector pin 3 is formed at the time of release, the ejector pin 3 is lowered to supply the compressed air 20 to the lower mold 1 with the projecting opening of the ejector pin 3 as a tip. 4 are formed.

Next, a work W using the molds 1 and 2
An example of encapsulating and molding a single-side encapsulated work W such as a BGA package will be described with reference to the operation flow shown in FIG. First, when the encapsulation molding operation is completed, the upper mold 2 is opened by a predetermined amount. The mold opening 8
The lead frame 5 is separated from the upper die 2 by the return of the upper ejector pin 3 and then released from the lower die 1 so that the semiconductor device 6 does not crack even if the sealing resin 7 is bent. The size is set up to the size, and is set according to the size of the sealing resin 7 and the size of the built-in semiconductor device 6.

Next, the ejector pins 3 of the lower mold 1 are raised to a position where the mold release is performed only in the vicinity of the ejector pins 3 of the lower mold 1 at a position below the mold opening range. Thereafter, the ejector pin 3 is lowered to bring the compressed air supply path 4 provided around the guide of the ejector pin 3 into communication with the opening for projecting the ejector pin 3 into the cavity C. As a result, the compressed air 20 is supplied to the interface between the cavity C and the sealing resin 7, and the pressure generated by the ejector pins 3 by the pressure of the compressed air 20 exerts a force to spread the separation. Release from 7 is performed.
The supply of the compressed air 20 is stopped after a lapse of a predetermined time for the release operation or after confirming the pressure drop due to the leak of the compressed air 20 indicating the completion of the release. Further, thereafter, in parallel with the complete opening of the mold, the ejector pins 3 of the lower mold 1 are raised, and the sealing resin 7 is completely lifted on the surface of the lower mold 1. At this time, the substrate positioning gauge pin 10 of the lower die 1 slightly looks into the lead frame 5 and is positioned at a position where the workpiece W can be discharged. After discharging the molded workpiece W by another mechanism, the ejector pin 3 of the lower mold 1 is lowered again, the compressed air supply path 4 is secured, and after the inside of the cavity C is blown, the ejector pin 3 is removed. After returning to the molding position, a series of operations is completed. However, air blowing at this time is performed as necessary and can be omitted.

As described above, according to the present embodiment, the trigger for releasing is formed by the ejector pin 3 and the releasing operation is performed by the compressed air using the trigger, so that the releasing operation can be performed smoothly. Can be done,
Excessive deformation of the workpiece W can be prevented and its damage can be suppressed. Also, frequent cleaning work of the cavity C is not required, and there is no need to lower the operation speed of the ejector pin 3, and it is not necessary to set the supply pressure of the compressed air low.
The resin sealing cycle can be shortened. Furthermore, by adjusting the mold opening amount in the initial stage of the mold release, the deformation amount of the work W at the time of the mold release is forcibly limited, whereby the deformation amount of the work W is forcibly put into an allowable range. The damage prevention can be further enhanced.

In the above-described embodiment, an example of a single-sided mold such as a BGA has been described. However, the present invention is not limited to a single-sided mold, but can be implemented with a general double-sided mold, and can provide similar effects. Things.

[0015]

As described above, according to the first aspect of the present invention,
According to the resin sealing method for a work described in above, after filling the sealing resin, a part of the sealing resin is released by an ejector pin, and then compressed air is supplied to an interface between the sealing resin and the cavity. By this, when supplying this compressed air,
The part released by the ejector pin triggers the smooth release of the sealing resin by compressed air, and minimizes the bending moment generated in the sealing resin during release. Thus, damage to the resin-sealed work can be suppressed. Also, at the time of releasing the sealing resin, by performing the releasing operation in a state where the mold is opened by a predetermined amount, the deformation amount of the sealing resin at the time of releasing can be regulated by the pair of dies. Thus, it is possible to reliably prevent the sealing resin from being excessively deformed, and to more reliably prevent damage to the work. In addition, since the operating range of the ejector pin is forcibly regulated, there is no need to reduce the operating speed, and the management of the supply pressure of the compressed air and the like can be managed in a rough manner. Can be shortened. In addition, the frequency of cleaning the mold can be reduced with the reliable release operation. On the other hand, at the time of release, the lead frame side can be reliably released from the mold, and thereby the workpiece can be released smoothly. According to the second aspect of the present invention, after the work release operation is completed, the work is further pushed out by the ejector pins, so that the work after the release can be easily handled. According to the third aspect of the present invention, by using a high-adhesion resin as the sealing resin, the mold releasing operation can be performed smoothly and reliably while the hermeticity of the work is sufficiently ensured.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part showing an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a main part showing one embodiment of the present invention.

FIG. 3 is a flowchart for explaining the operation of one embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a main part showing one conventional example.

FIG. 5 is a longitudinal sectional view of a main part showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Die 2 Die 3 Ejector pin 4 Compressed air supply path 5 Lead frame 6 Semiconductor device 7 Sealing resin 8 Fixed amount of opening 9 Trigger part 10 Gauge pin 20 Compressed air C Cavity W Work

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 45/26-45/44 B29C 45 / 02,45 / 14

Claims (3)

(57) [Claims] A semiconductor device is mounted on one side of a lead frame.
The mounted work is mounted and surrounds the semiconductor device.
Using a pair of molds to form a cavity
Filling the sealing resin into the cavity and sealing the semiconductor device with resin
After stopping, the gold positioned on the lead frame side
Predetermine amount of both molds while ejector pin protrudes from mold
By opening the mold, the lead frame is
The mold is released from the mold, and the cavity is removed from the other mold.
The ejector pin protrudes into the
Part is released from the inner surface of the cavity.
Compressed air is supplied to the interface between
Resin sealing of work characterized by releasing grease
Law. 2. An interface between the sealing resin and the inner surface of the cavity.
After supplying compressed air to these molds and releasing them,
Open the mold, and then push the ejector pin
The resin-sealed work from the mold
2. The work tree according to claim 1, wherein the work is discharged.
Fat sealing method. 3. The sealing resin is a high-adhesion resin.
The method according to claim 1 or 2, wherein
A method of sealing the work with resin.