CN218366106U

CN218366106U - Mold flow balancing structure of semiconductor plastic package mold

Info

Publication number: CN218366106U
Application number: CN202222479551.3U
Authority: CN
Inventors: 傅东家
Original assignee: Jiangsu Silicon Integrity Semiconductor Technology Co Ltd
Current assignee: Jiangsu Silicon Integrity Semiconductor Technology Co Ltd
Priority date: 2022-09-19
Filing date: 2022-09-19
Publication date: 2023-01-24
Anticipated expiration: 2032-09-19

Abstract

The utility model discloses a mould flow balance structure of semiconductor plastic envelope mould, including runner plate and buffering portion. The runner plate is communicated with two upper die cavities of the plastic package die, the two upper die cavities are symmetrically arranged on two sides of the runner plate, and the runner plate guides the plastic package material flowing from the injection part of the plastic package die to the two upper die cavities; the buffer part is arranged in the runner plate, and the plastic package material is buffered by the buffer part and then uniformly flows to the two upper die cavities. The utility model discloses a set up buffering portion, twice balanced mould flow through buffering portion for the mould flow velocity that the plastic envelope material flowed into two last mould cavities is the same, has improved the plastic envelope yield of product.

Description

Mold flow balancing structure of semiconductor plastic package mold

Technical Field

The utility model belongs to the technical field of the semiconductor plastic envelope technique and specifically relates to a mould flow balance structure of semiconductor plastic envelope mould is related to.

Background

The semiconductor plastic package mold is a mold which extrudes and fills a hot-melted plastic package material into a cavity and then wraps a product to be plastic packaged.

The injection molding part of the existing semiconductor plastic package mold is generally in a bilateral symmetry structure, and plastic package of two products to be plastic packaged can be completed by one-time injection molding. The injection molding part structure specifically comprises: the device comprises an upper die frame and a lower die frame, wherein the upper die frame comprises a runner plate and upper die cavities symmetrically arranged on two sides of the runner plate; the lower die frame comprises a charging barrel, an injection molding part and lower die cavities symmetrically arranged at two sides of the charging barrel; the lower die cavity is arranged corresponding to the upper die cavity, the charging barrel is arranged corresponding to the runner plate, and the runner plate is in a trapezoidal groove shape; the injection molding part comprises an injection molding rod and an injection molding head which are connected up and down and arranged in the charging barrel, and the inner wall of the charging barrel can be melted with plastic package materials through hot melting; and a product to be plastically packaged is placed in the lower die cavity.

The injection molding process of the plastic package mold comprises the following steps:

1. the manipulator firstly places a product to be plastically packaged into a lower mold cavity, and places a plastic package material into a charging barrel;

2. the lower die frame is driven by the press to vertically ascend and is tightly sealed with the upper die frame in a fit manner, and the top of the charging barrel and the runner plate form a sealed cavity;

3. the plastic package material is melted by the high-temperature hot melting of the charging barrel, the melted plastic package material is vertically and upwards extruded into the runner plate by the injection molding rod and the injection molding head, after the runner plate is filled with the molten plastic package material, the plastic package material flows into the upper mold cavities on two sides of the runner plate through the pouring gates, and then the plastic package product is subjected to plastic package.

The above injection molding process has the following problems:

in order to allow the manipulator to smoothly transfer the molding compound into the cylinder (the cylinder and the molding compound are cylindrical), the inner diameter of the cylinder is set to be larger than the diameter of the molding compound, for example, the inner diameter of the cylinder is set to be 16.6mm, and the diameter of the molding compound is set to be 16mm. Thus, it is not guaranteed that the molding compound is centered in the cartridge, for example: the plastic package material close to the right side of the inner wall of the charging barrel can be extruded into the runner plate by the injection molding head after being melted, and is guided into the upper die cavity on the right side preferentially, so that the die flow velocities of the upper die cavity on the left side and the upper die cavity on the right side are different. And the mold flow velocity exceeding the normal mold flow velocity can cause impact bending on the line arc of the product to be subjected to plastic packaging, thereby affecting the plastic packaging quality of the product.

Therefore, a new mold flow balancing structure for a semiconductor plastic mold is needed to overcome the above-mentioned deficiencies in the prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome the defect that exists among the prior art, provide a novel semiconductor plastic envelope mould's mould flow balance structure, do not exist the cavity between other function chips and base plate, the barrier film.

In order to solve the technical problem, the utility model provides a mould flow balance structure of semiconductor plastic envelope mould, including runner plate and buffering portion. The runner plate is communicated with two upper die cavities of the plastic package mold, the two upper die cavities are symmetrically arranged on two sides of the runner plate, and the runner plate guides the plastic package material flowing from the injection part of the plastic package mold to the two upper die cavities; the buffer part is arranged in the runner plate, and the plastic package material uniformly flows to the two upper die cavities after being buffered by the buffer part.

In some embodiments, the buffer part comprises a first weight and a second weight which are identical in structure, the first weight and the second weight are arranged on the top in the flow channel plate, a buffer groove is formed between the first weight and the second weight, the injection part enables the plastic package to flow to the buffer groove, and the plastic package in the buffer groove is guided to the two upper mold cavities through the first weight and the second weight.

In some embodiments, the first weight and the second weight have a semicircular cross section, and a gap is provided between the first weight and the second weight, and the gap is a buffer groove.

In some embodiments, the vertical section of the buffer slot is trapezoidal, and the notch of the buffer slot faces to the lower bottom of the trapezoid.

In some embodiments, the vertical cross-section of the first weight and the second weight is in a trapezoidal shape.

In some embodiments, the edges of the first weight and the second weight are set to be circular-arc-shaped.

In some embodiments, the runner plate and the upper mold cavities on two sides are arranged on the upper mold frame, the lower mold frame is arranged below the upper mold frame, the lower mold frame is provided with a material cylinder, lower mold cavities symmetrically arranged on two sides of the material cylinder and an injection molding part, the runner plate is arranged above the material cylinder, a product to be injected is placed in the lower mold cavity, and the upper part of the product to be injected faces the upper mold cavity; the injection molding part extrudes the plastic package material melted in the charging barrel into a buffer groove in the runner plate, and the plastic package material in the buffer groove is guided to the two upper die cavities by the first balance block and the second balance block.

The utility model provides a mould flow balance structure of semiconductor plastic envelope mould compares with prior art, has following beneficial effect:

1. the structure effectively solves the problem of different mold flow velocities at two sides in the prior art by arranging the buffer part in the runner plate, namely when the injection part extrudes the plastic package material melted in the charging barrel into the runner plate, the plastic package material firstly flows into the buffer groove because of the arrangement of the first balance block and the second balance block, and then the plastic package material in the buffer groove is guided to the two upper mold cavities through the first balance block and the second balance block;

2. the buffer part is provided with a buffer groove formed by the first balance block and the second balance block, so that the whole structure is simple, practical and extremely ingenious;

3. the vertical sections of the first balance block and the second balance block are in a trapezoid shape, and the mold flow speed is balanced for the first time when the molten plastic package material is filled in the buffer groove; after the molten plastic package material is filled in the buffer groove and before flowing to the sprue positions on two sides, the molten plastic package material firstly passes through the side surfaces, far away from the buffer groove, of the first balance block and the second balance block, and the speed of the mold flow is balanced for the second time; through twice die flow speed balance, the die flow speeds on two sides can be ensured to be the same;

4. the edges of the first balance weight and the second balance weight are arc-shaped, so that the melted plastic package can flow to the buffer groove conveniently and can flow out of the buffer groove conveniently.

Drawings

Fig. 1 is a schematic view of an injection molding structure of a semiconductor plastic package mold according to the present invention;

fig. 2 is a schematic structural view of a mold flow balancing structure of the semiconductor plastic package mold of the present invention;

fig. 3 is a schematic structural view of a cross section of the buffering part in fig. 2.

Detailed Description

The following description will further describe embodiments of the present invention with reference to the accompanying drawings and examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

As shown in fig. 1, the present embodiment provides an injection structure of a semiconductor plastic package mold, which is a bilaterally symmetric structure, and can complete plastic package of two products 7 to be plastic packaged by one-time injection. The die comprises an upper die frame 1 and a lower die frame 2. The upper die frame 1 is provided with a runner plate 3, and a left upper die cavity 101 and a right upper die cavity 102 which are arranged at two sides of the runner plate 3. And the runner plate 3 is communicated with the left upper die cavity 101 and the right upper die cavity 102 through the gate 4. The lower die frame 2 is arranged below the upper die frame 1, and the lower die frame 2 is provided with a material cylinder 5, lower die cavities symmetrically arranged at two sides of the material cylinder 5 and an injection molding part 6. The lower mold cavity is divided into a left lower mold cavity 201 and a right lower mold cavity 202. The runner plate 3 is arranged above the charging barrel 5, the left lower mold cavity 201 corresponds to the position of the left upper mold cavity 101, and the right lower mold cavity 202 corresponds to the position of the right upper mold cavity 102. The products 7 to be plastic-packaged are respectively placed in the lower left mold cavity 201 and the lower right mold cavity 202.

The embodiment also discloses a mold flow balancing structure used for the injection structure of the semiconductor plastic package mold, which comprises the runner plate 3 and the buffer part 8. The buffer part 8 is arranged in the runner plate 3, and the plastic package material 9 is buffered by the buffer part 8 and then uniformly flows to the left upper die cavity 101 and the right upper die cavity 102.

In concrete implementation, as shown in fig. 2, the buffer portion 8 is formed by a first weight 801 and a second weight 802 having the same structure, the first weight 801 and the second weight 802 are both disposed on the top portion inside the flow path plate 3, and a buffer groove 803 is formed between the first weight 801 and the second weight 802. Specifically, as shown in fig. 3, the cross sections of the first weight 801 and the second weight 802 are semicircular, and a gap is provided between the first weight 801 and the second weight 802, which is the buffer groove 803. The vertical section of the buffer groove 803 is trapezoidal, the notch of the buffer groove 803 faces the lower bottom of the trapezoid, i.e. the distance between the notches is larger than that between the groove bottoms, so that the plastic package material 9 can flow into the buffer groove 803 first. Because of the arrangement of the first weight 801 and the second weight 802, the plastic package material 9 will flow into the buffer groove 803 first, and the plastic package material 9 in the buffer groove 803 is guided to the upper left mold cavity 101 and the upper right mold cavity 102 through the first weight 801 and the second weight 802.

The vertical cross sections of the first balance block 801 and the second balance block 802 are also in a trapezoid shape, and when the melted plastic package material 9 fills the buffer groove 803, the mold flow velocity is balanced for the first time; after the molten plastic package material 9 fills the buffer groove 803 and before flowing to the two side gates 4, the molten plastic package material firstly passes through the side surfaces of the first balance block 801 and the second balance block 802 away from the buffer groove 803, which is the second balance mold flow speed; through twice mold flow speed balance, the mold flow speeds on two sides can be ensured to be the same. The edges of the first weight 801 and the second weight 802 are formed in circular arc shapes. This facilitates the flow of the molten molding compound 9 to the buffer tank 803 and also facilitates the flow out of the buffer tank 803 thereafter.

The above-described structure of the buffer portion 8 is only an embodiment, and other structures that are simply deformed and improved based on the structure of the buffer portion 8 of the present embodiment should be regarded as the protection scope of the present invention.

The injection molding process of the semiconductor plastic package mold comprises the following steps: the product 7 to be plastic-packaged is firstly placed in the lower left mold cavity 201 and the lower right mold cavity 202 by a manipulator, and the plastic package material 9 is placed in the charging barrel 5. The lower die carrier 2 is driven by a press to vertically ascend and is tightly attached to the upper die carrier 1 for sealing, and the top of the charging barrel 5 and the runner plate 3 form a closed cavity. The plastic package material 9 is melted by the high-temperature hot melt of the charging barrel 5, the melted plastic package material 9 is vertically and upwardly extruded into the flow channel plate 3 by the injection molding rod and the injection molding head, because of the arrangement of the first balance block 801 and the second balance block 802, the plastic package material 9 firstly flows into the buffer groove 803, after the buffer groove 803 is filled with the plastic package material 9, the plastic package material 9 in the buffer groove 803 is guided to the pouring gate 4 through the first balance block 801 and the second balance block 802, then flows to the upper left mold cavity 101 and the upper right mold cavity 102, and then the product 7 to be plastic packaged is subjected to plastic package.

The utility model discloses a set up buffering portion 8, twice balanced mould through buffering portion 8 flows for the mould flow velocity that mould cavity was gone up in two to the plastic envelope material 9 inflow is the same, has improved the plastic envelope yield of product.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the technical principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The mold flow balancing structure of the semiconductor plastic package mold is characterized by comprising a runner plate and a buffer part, wherein the runner plate is communicated with two upper mold cavities of the plastic package mold, the two upper mold cavities are symmetrically arranged on two sides of the runner plate, and the runner plate guides a plastic package material flowing from an injection part of the plastic package mold to the two upper mold cavities; the buffer part is arranged in the runner plate, and the plastic package material uniformly flows to the two upper die cavities after being buffered by the buffer part.

2. The mold flow balancing structure of a semiconductor plastic package mold according to claim 1, wherein the buffering portion comprises a first weight and a second weight having the same structure, the first weight and the second weight are both disposed at the top of the flow channel plate, a buffering groove is formed between the first weight and the second weight, the injection molding portion enables plastic package material to flow to the buffering groove, and the plastic package material in the buffering groove is guided to the two upper mold cavities through the first weight and the second weight.

3. The mold flow balancing structure of the semiconductor plastic package mold according to claim 2, wherein the cross sections of the first weight and the second weight are semicircular, a gap is provided between the first weight and the second weight, and the gap is a buffer groove.

4. The mold flow balancing structure of the semiconductor plastic package mold according to claim 3, wherein the vertical cross section of the buffer slot is trapezoidal, and the notch of the buffer slot faces the bottom of the trapezoid.

5. The mold flow balancing structure of the semiconductor plastic package mold according to claim 4, wherein the vertical cross-sections of the first weight and the second weight are trapezoidal.

6. The mold flow balancing structure of a semiconductor plastic package mold according to claim 5, wherein edges of the first weight and the second weight are set to be arc-shaped.

7. The mold flow balancing structure of the semiconductor plastic package mold according to claim 6, wherein the runner plate and the upper mold cavities at two sides are disposed on an upper mold frame, a lower mold frame is disposed below the upper mold frame, the lower mold frame is provided with a material cylinder, lower mold cavities symmetrically disposed at two sides of the material cylinder, and an injection molding part, the runner plate is disposed above the material cylinder, a product to be injected is placed in the lower mold cavity, and the upper side of the product to be injected faces the upper mold cavity; the injection molding part extrudes the plastic package material melted in the charging barrel into a buffer groove in the runner plate, and the plastic package material in the buffer groove is guided to the two upper mold cavities by the first balance block and the second balance block.