JPH10172995A - Transfer resin molding method and its device for electronic part matrix lead frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set the utility efficiency of thermosetting molding resin to be satisfactory, by arranging a resin filling/pressurizing device in the arbitrary part of an electronic parts matrix lead frame, and filling/pressurizing thermoset ting molding resin melted in more than two cavities from the resin filling/ pressurizing device. SOLUTION: The pots P of the resin filling/pressurizing device are arranged on arbitrary places on the electronic parts matrix lead frame L having the products of more than two strings, which are loaded on an electronic parts molding die heated at a prescribed temperature, or below the electronic parts matrix lead frame L. Thermosetting resin melted in more than two cavities 2 is charged from the pots P. The multiple products can simultaneously be transfer resin-molded setting resin utility efficiency in the products against supplied resin is not more than 90%, and product cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic part transfer resin mold for filling a cavity with a melted thermosetting resin to obtain a desired shape.

[0002]

2. Description of the Related Art A transfer resin mold of a thermosetting molding resin is a thermosetting molding resin preliminarily formed in a cylindrical shape in a pot portion on a mold which has been heated in advance to a temperature at which the thermosetting molding resin melts. After the mold is closed and the mold is closed, the plunger of the resin filling and pressurizing device slidably fitted in the pot is operated, and the melted thermosetting resin is filled into the cavity through the runner and the gate and pressurized to a predetermined pressure. After the heat curing time has elapsed, the mold is opened and the product is taken out.

As a well-known electronic component transfer resin molding method, there are known two methods, a single pot molding method and a multi-pot molding method. In the multi-pot molding method, products are arranged in series in a single row. Two methods are known: one using a lead frame and one using a matrix lead frame arranged in a matrix in a plurality of rows on one lead frame. The advantages and disadvantages will be described below with reference to the drawings. First, the single pot molding method
As shown in the mold plan view of FIG. 1, the molten thermosetting molding resin is filled from one pot 1 into all cavities 2 on all lead frames placed on the mold by a plunger. To press. The single-pot molding method has the advantage of simple structure, but the resin used in the product for the resin to be put in because the resin of the long runner 3, the part and the large diameter pot 1, the part is wasted. The efficiency is extremely low, less than 20%, and has a disadvantage that it greatly affects the product cost. Currently, it is hardly used. The thermosetting resin used in the molding of electronic components is a mixture of epoxy resin as a base material, fine silica spheres, and other mold release agents mixed with a filler. Once reused, it is impossible to recycle and is usually landfilled as industrial waste, which has been criticized by public opinion as a social issue.

The mainstream method at present is a multi-pot molding method, in which a plurality of pots 4 are arranged on one mold as shown in FIG. , And one or more cavities 2 are filled with molten thermosetting resin and pressurized. Therefore, when compared with the conventional single pot molding method, runner 5 ...
The resin of the part and the pot 4..., The part can be reduced in the same number of products to be obtained, and less resin is wasted. The resin use efficiency in the multi-pot molding method is about 50%. However, this multi-pot molding method has a disadvantage that a plurality of (many) plungers are required, so that the structure of a mold is complicated. When molding many products at the same time, many plungers and the plungers are required. A drive mechanism was required.

Accordingly, a multi-pot molding method using a matrix lead frame in which products are arranged in rows and columns on a lead frame has recently appeared. As shown in FIG. 3, the matrix lead frame has two or more rows of semiconductor chips which have been conventionally arranged in one row on one lead frame, and the number of products per lead frame increases. However, the filling and pressurization of the resin from the pot and the plunger are performed in units of rows, and the columns are communicated by the communication runners 6.
With the number of plungers, twice the number of products can be obtained. Also, compared with the conventional single-row lead frame, the resin use efficiency is 50% to 6 for the same number of products.
Although it is slightly higher at 0%, about half of it is still thrown away as waste, and further improvement has been required.

In a molding apparatus using each of the above-described molding methods, the molding is completed after a predetermined heat curing time, and after the mold is opened, a matrix lead frame is formed.
There is a gate break step in which the cull portion and the runner portion are taken out in an integrally molded state and the unnecessary portion, the cull portion and the runner portion, are separated from the package portion formed on the lead frame. However, when performing the peeling operation for removing the molded product from the inside of the mold, or during the transportation, unnecessary portions, such as intermediate portions of the runner, are broken at undesired positions. There is a problem that the disconnection operation cannot be performed. In addition, in order to prevent breakage in the middle of such a runner, it is necessary to make the runner section, which should be unnecessary resin, thicker than the runner cross-sectional area required for resin filling in order to have strength enough to withstand transportation. This is the cause of the deterioration of the resin use efficiency.

Furthermore, when separating unnecessary portions from the package portion, the cured thermosetting molding resin must be sufficiently cooled and then broken, and the cooling time increases the turnaround time of the molding process, Furthermore, it was necessary to have various auxiliary equipment such as a cooling device in the molding process.

[0008]

One of the problems with the above-mentioned molding methods is that, in any case, the use efficiency of the thermosetting molding resin is low, and the molding cost is large. The point is that the increase in industrial waste has become a social problem.

In the molding apparatus according to each of the above-described molding methods, when performing a peeling operation for removing a molded product from the mold after the completion of molding, unnecessary portions such as intermediate portions of the runner may be removed at undesired positions. There is also a quality problem such that the wire is broken and a normal separating operation cannot be performed in a gate break process during the molding process.

Furthermore, when separating the unnecessary portion from the package portion, the cured thermosetting resin must be sufficiently cooled and then broken, and the cooling time increases the turnaround time of the molding process. That there is
There is also a problem that it is necessary to have a number of additional facilities such as a cooling device in the molding process.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems occurring in each of the conventional molding methods, and has an object to improve the use efficiency of thermosetting molding resin and reduce the cost of resin material in product cost. It is a first object of the present invention to provide a molding method that produces a small amount of industrial waste with a small amount.

Further, the present invention eliminates a gate break step in a molding step which requires a large number of auxiliary facilities, eliminates various troubles caused by the presence of the gate break step, and reduces a turnaround time in the molding step. A second object is to achieve simplification and downsizing of the molding apparatus.

[0013]

According to the present invention, as means for achieving the above-mentioned object, two or more product rows placed on an electronic component mold heated to a predetermined temperature are used. An electronic component matrix lead frame is arranged at an arbitrary position on the surface of the electronic component matrix lead frame having a pot and a plunger so that a resin filling press device including a pot and a plunger faces each other. A method for molding an electronic component matrix lead frame, wherein the cavity is filled with a melted thermosetting resin, and a transfer resin molding die for an electronic component matrix lead frame using the method, and the method. And an electronic component matrix lead frame transfer molding apparatus.

[0014]

Embodiment 1 Next, an embodiment of the present invention will be described in detail with reference to the drawings.

As described in the above-mentioned prior art, the transfer resin mold of the thermosetting resin is preliminarily formed into a cylindrical shape in a pot portion on a mold previously heated to a temperature at which the thermosetting resin melts. After the thermosetting resin is injected, the mold is closed, and the plunger of the resin filling and pressurizing device slidably fitted in the pot is operated to fill the molten thermosetting resin into the cavity through the runner and gate. After the pressurization and a predetermined heat curing time have elapsed, the mold is opened to take out the product.

First, each component of an electronic component matrix lead frame transfer resin mold using the electronic component matrix lead frame transfer resin molding method according to the present invention will be described with reference to the drawings. FIG. 3 is an external view of a matrix lead frame of two columns and four rows used in an electronic component matrix lead frame transfer resin mold according to the present invention. The electronic component matrix lead frame L has eight semiconductor chips C,. Is mounted and electrically connected to the lead electrodes by wires. The above matrix lead frame is molded with a mold.
FIG. 4 shows a sectional view of the mold. Plungers 10 are slidably fitted in the plurality of pots P, respectively. Each of the pots P is connected to a corresponding one of the four lower cavities 11 through a runner 12 to supply molten resin. In addition, each pot P ...,
The lower part of each of the plungers 10 slidably inserted is connected to a transfer control mechanism provided outside the mold.
Each of the pots P... Is connected to each of the pot facing portions 13 of the electronic component matrix lead frame and each of the runners 12.
.. Correspond to the respective runner facing portions 14.

Next, the operation will be described with reference to the drawings. 6 to 8 are sectional views in the width direction (narrow direction) of an electronic component matrix lead frame transfer resin mold according to the present invention. The upper and lower molds are previously heated to a temperature higher than the melting point of the thermosetting resin.

First, with the plunger 10 lowered, a tablet T, in which a thermosetting resin is preformed in a cylindrical shape, is put into the pot P ,. Next or simultaneously, the electronic component matrix lead frame L, is placed at a predetermined position on the lower die. Next, the lower mold is raised or the upper mold is lowered, and the upper and lower molds are engaged. next,
The plunger 10 is raised, and the upper and lower cavities 11 and 15 are filled and pressurized with the thermosetting molding resin already melted at the mold temperature via the runner 12. After a predetermined heat curing time, the lower mold is lowered or the upper mold is raised to open the mold.

Each of the upper and lower molds is provided with an eject pin 16... For reliably releasing the electronic component matrix lead frame which has been molded from the mold surface, if necessary. In the embodiment of the invention, the package is provided so as to be pushed into the cavity. However, the same effect can be obtained by protruding the electronic component matrix lead frame into a frame portion other than the electronic component package. . Finally, the electronic component matrix lead frame that has been molded on the lower mold is taken out, and the molding process is completed.

FIG. 9 is an external view of the electronic component matrix screed frame taken out of the lower mold after completion of molding and viewed from the back side. Cal which is unnecessary resin left in the pot part,
Since the runner and the runner are integrally formed on the lead frame, they are cut and molded as they are, after going through the following steps such as the secondary curing step, deburring step, plating step, and stamping step. It is removed in the process.

[0021]

As described above, the molding method according to the present invention, that is, an electronic component matrix lead frame having two or more product lines placed on an electronic component mold heated to a predetermined temperature, Alternatively, a pot is placed at an arbitrary position under a lead frame of an electronic component matrix, and two or more cavities are filled with a molten thermosetting resin at the same time from the pot, and a transfer resin molding method for an electronic component matrix lead frame is provided. By using the conventional single pot method,
Compared to the multi-pot method and other mold methods that have a pot portion other than on the lead frame or below the lead frame, the resin use efficiency of the product with respect to the injected resin is 90% or more, and a significant reduction in product cost Achieved. Also, the amount of unnecessary resin in the cull and runner portions, which are landfilled as industrial waste, has been reduced to about 1/5 as compared with the conventional case. In addition, transfer resin molding of many products can be performed simultaneously with the minimum number of plungers.

Further, in the transfer resin molding apparatus using the transfer resin molding method of the present invention, a gate break step of separating unnecessary resin from a package portion is not required, so that the structure of the apparatus is simplified and the gate break is performed. The various quality problems involved have been eliminated. Further, since there is no need to cool the product for the gate break, the turnaround time in the molding process is shortened, and various auxiliary equipment such as a cooling device is not required.

[0023]

[Brief description of the drawings]

FIG. 1 is a plan view of a mold according to a conventional single pot molding method.

FIG. 2 is a plan view of a mold according to a conventional multi-pot molding method.

FIG. 3 is a plan view of a mold by a multi-pot molding method using a matrix lead frame of the related art.

FIG. 4 is an external view of a lead frame used in an electronic component matrix lead frame transfer resin molding method of the present invention.

FIG. 5 is a plan view of a lower mold of a molding die of the electronic component matrix lead frame transfer resin molding method of the present invention.

FIG. 6 is a cross-sectional view of a mold used in the resin molding method for electronic component matrix lead frame transfer of the present invention.

FIG. 7 is a cross-sectional view of a mold used in the electronic component matrix lead frame transfer resin molding method of the present invention.

FIG. 8 is a cross-sectional view of a molding die of the electronic component matrix lead frame transfer resin molding method of the present invention.

FIG. 9 is an external view of a lead frame in which the molding method of the present invention has been completed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pot 2 ... Cavity 3 ... Runner 4 ... Pot 5 ... Runner 6 ... Communication runner P ... Pot T ... Tablet C ... Semiconductor chip L ... Electronic component matrix lead frame 10 ... Plunger 11 ... Bottom cavity 12 ... Runner 13 ... Pot facing Part 14 ... Runner facing part 15 ... Upper cavity 16 ... Eject pin

 ──────────────────────────────────────────────────の Continued on front page (54) [Title of Invention] Transfer resin molding method for electronic component matrix sleeving frame, transfer resin mold for electronic component matrix sleeving frame, and electronic component matrix lead frame. Transfer resin mold equipment

Claims (3)

[Claims] 1. An arbitrary part on a surface of an electronic component matrix lead frame having two or more product rows placed on an electronic component mold heated to a predetermined temperature, and filled with a resin comprising a pot and a plunger. An electronic component matrix lead wherein an electronic component matrix lead frame is disposed so as to face a pressing device, and two or more cavities are filled with molten thermosetting resin and pressurized from the resin filling and pressing device. How to mold the frame. 2. An arbitrary part on a surface of an electronic component matrix lead frame having two or more product rows placed on an electronic component mold heated to a predetermined temperature and filled with a resin comprising a pot and a plunger. An electronic component matrix lead wherein an electronic component matrix lead frame is disposed so as to face a pressing device, and two or more cavities are filled with molten thermosetting resin and pressurized from the resin filling and pressing device. Mold for frame. 3. An arbitrary portion on a surface of an electronic component matrix lead frame having two or more product rows placed on an electronic component mold heated to a predetermined temperature and filled with a resin comprising a pot and a plunger. An electronic component matrix screed characterized by arranging an electronic component matrix sleeving frame so as to face a pressing device, and filling and pressing molten thermosetting molding resin into two or more cavities from the resin filling and pressing device. Transfer resin molding equipment for frames.