KR19980075720A - Semiconductor chip package and manufacturing method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor chip package and a method of manufacturing the same, and according to a rate at which a liquid molding compound is injected into a cavity of a molding die in a molding process of encapsulating a lead frame in which an electrical connection process between a semiconductor chip and a lead is completed. In order to solve the problems caused by the flow of the semiconductor chip, the die pad of the lead frame and the internal lead existing in the cavity of the mold, the semiconductor chip is attached to the upper surface of the lower package body manufactured by the molding process in advance, The lead is attached to the outside of the semiconductor chip and the lead is electrically connected to the semiconductor chip formed on the upper surface of the lower package body using a liquid molding compound, and a portion of the lead electrically connected to the semiconductor chip is encapsulated. Semiconductor chip package with a package body and a method of manufacturing the same It is.

Description

Semiconductor chip package and method for manufacturing thereof

The present invention relates to a semiconductor chip package and a method of manufacturing the same, and more particularly, transfer parts of a semiconductor chip and a lead part electrically connected to the semiconductor chip in a state in which a semiconductor chip and a lead are attached to an upper part of a prefabricated lower package body. The present invention relates to a semiconductor chip package encapsulated by a process and having an upper package body formed therein and a method of manufacturing the same.

The purpose of packaging a semiconductor chip is to provide a means for electrically connecting the semiconductor chip and an external system while forming a protective body to ensure the normal operation and reliability of the semiconductor chip. When the protective package body is formed by a plastic molding method using a thermosetting resin or a thermoplastic resin, it is less reliable than a ceramic package but has an advantage of low manufacturing cost and mass production.

The transfer molding process is the most widely used process to form plastic package bodies. This consists of mounting a lead frame strip on which a semiconductor chip is attached to a mold, and then injecting a liquid molding compound in a predetermined container into the mold cavity and then releasing the mold. The mold can be divided into upper mold and lower mold.

1 is a cross-sectional view showing a state in which a molding resin is injected while a lead frame in which a semiconductor chip is mounted on a die pad is inserted into a molding die.

Referring to FIG. 1, the molding die 100 includes an upper mold 10 and a lower mold 20, and the upper and lower molds 10 and 20 respectively form a high temperature liquid molding compound 30. Is connected to the molding furnace 29, the runner and the molding furnace 29 through which the molding compound flows, and is connected to the gate 27 and the gate 27 into which the liquid molding compound 30 is injected. It has a structure in which the cavity (15, 25; Cavity) for determining the shape of the package body to be formed is formed.

Referring to the molding process using the molding die 100 having the above structure, first, the lead frame 50 in which the semiconductor chip 40 is mounted on the die pad 52 is the cavity 25 of the lower mold 20. Are mounted aligned. The semiconductor chip 40 is attached to the die pad 52 of the lead frame by an adhesive 60, and is electrically connected by the lead 51 and the bonding wire 70. In the state where the lead frame 50 is inserted into the lower mold 20 as described above, the upper mold 10 descends to press the lower mold 20 to fix the outside of the lead frame 50 by pressing the gate ( 27) and the molding compound 30 through the molding furnace 29 is injected into the cavity (15, 25) is formed into a package body through a curing process.

Therefore, a problem arises in that the lead frame and the chip attached to the die pad are moved by the liquid molding compound enclosed around the top and bottom in one direction.

In addition, since the semiconductor chip is attached to the die pad of the lead frame by an adhesive and the outside is encapsulated by the liquid molding compound, four interfaces exist between the semiconductor chip, the adhesive, the die pad, and the molding compound to be cured. Therefore, the peeling phenomenon due to the difference in the coefficient of thermal expansion between each material is a problem.

2 is a cross-sectional view showing a state in which a molding resin is injected while a lead frame having a lead end attached to an upper surface of a semiconductor chip is inserted into a molding die.

Referring to FIG. 2, the lead frame 150 in which the semiconductor chip 140 inserted into the molding die 200 is mounted has a lead on chip structure. That is, the leads 151 of the lead frame are attached to one surface on which the bonding pads 142 of the semiconductor chip are formed by polyimide tape 160, and the bonding pads 142 and the leads 151 of the semiconductor chip. ) Is electrically connected by the bonding wire 170, and the lead portion 151b positioned outside the semiconductor chip 140 is stepped downward with respect to the lead portion 151a positioned on the semiconductor chip 140. Formed. The bonding pad 142 is a center pad formed at the center of the semiconductor chip 140.

Referring to the molding process of the lead frame 150 having the lead-on chip structure, the lead mold 150 having the lead-on chip structure is mounted in a state in which the lead frame 150 is mounted to correspond to the cavity 125 of the lower mold 120. 110 is lowered to press the lower mold 120 to fix the outside of the lead frame 150 by pressing the liquid molding compound 130 through the gate 127 and the forming furnace 129, the cavity 115 , 125, and a portion of the semiconductor chip 140, the lead 151, and the bonding wire 170 are encapsulated to form a package body.

The lead frame having the lead-on chip structure as described above may also cause defects such as chip cracks due to the blocked portion of the lead and the edge portion of the semiconductor chip adjacent thereto due to the flow rate of the molding compound injected into the cavity.

In addition, there is a problem that the manufacturing cost of the polyimide tape used as a means for attaching the lead on the semiconductor chip is expensive.

Accordingly, an object of the present invention is to provide a semiconductor chip package and a method for manufacturing the same, which can prevent chip cracks caused by injection of a liquid molding compound in a molding process.

Another object of the present invention is to provide a semiconductor chip package and a manufacturing method thereof without the need for a die pad.

It is still another object of the present invention to provide a semiconductor chip package in which a lead is mounted on a chip in a lead-on chip structure and a manufacturing method thereof.

1 is a cross-sectional view showing a state in which a molding resin is injected in a state in which a lead frame on which a semiconductor chip is mounted is inserted into a die pad.

2 is a cross-sectional view showing a state in which a molding resin is injected in a state in which a lead frame having an end of a lead attached to an upper surface of a semiconductor chip is inserted;

3 is a cross-sectional view illustrating a semiconductor chip mounted on an upper portion of a lower package body according to an exemplary embodiment of the present invention.

4 is a cross-sectional view illustrating a state in which a molding resin is injected while a lower package body in which the semiconductor chip of FIG. 3 is mounted is inserted into a molding die.

5 is a cross-sectional view illustrating a semiconductor chip package according to an embodiment of the present invention.

6 is a cross-sectional view illustrating a semiconductor chip having a lead-on chip structure mounted on an upper portion of a lower package body according to another embodiment of the present invention.

7 is a cross-sectional view illustrating a state in which a molding resin is injected while a lower package body having a lead-on chip structure of FIG. 6 is put into a molding die.

8 is a sectional view showing a semiconductor chip package according to another embodiment of the present invention.

※ Explanation of code about main part of drawing ※

210, 310: upper mold 220, 320: lower mold

215, 225, 315, 325: Cavity 330, 430: Molding Compound

232, 332: chip attachment surface 234, 334: lead attachment surface

235, 335: lower package body 237, 337: upper package body

240, 340: semiconductor chips 242, 342: bonding pads

251, 351: lead 260, 360: adhesive

270, 370: bonding wire

In order to achieve the above object, a lower package body having a chip attaching surface to which the semiconductor chip is attached, and a lead attaching surface to which the lead of the lead frame is attached, the chip attaching surface formed to be stepped upward with respect to the chip attaching surface; A semiconductor chip attached to the chip attaching surface and having a plurality of bonding pads formed on one surface thereof; A plurality of leads formed at predetermined intervals and attached to said lead attachment surface; A bonding wire electrically connecting the leads and the bonding pads to each other; and an upper package body in which a portion of the semiconductor chip, the bonding wires and the leads are sealed by a liquid molding compound, and providing a semiconductor chip package. do.

In order to achieve the another object of the present invention, the semiconductor chip is attached to one surface, the lead electrically connected to the semiconductor chip having a lower package body attached to the outside of the semiconductor chip; Mounting to a lower mold having a space suitable for forming a lower portion of the lower package body; A lower mold positioned on an upper portion of the lower mold and having a cavity formed therein, the cavity being a space for encapsulating a portion of the lead electrically connected to the semiconductor chip to be engaged with the lower mold; And injecting a liquid molding compound into the cavity of the upper mold to form an upper package body.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

3 is a cross-sectional view illustrating a semiconductor chip mounted on an upper portion of a lower package body according to an exemplary embodiment of the present invention.

Referring to FIG. 3, a structure of a semiconductor chip package according to an exemplary embodiment of the present inventive concept is formed to be stepped upward with respect to the chip attaching surface 232 to which the semiconductor chip 240 is to be attached and the chip attaching surface 232. The lower package body 235 having a lead attachment surface 234 to which the lead 251 of the lead frame is attached is provided. The lower package body 235 is manufactured in advance before a molding process of encapsulating an electrical connection portion including the semiconductor chip 240 using a plastic molding compound, and the pre-fabricated lower package body 235 is formed in a conventional package body. A portion corresponding to the package body positioned under the semiconductor chip and the inner lead.

The semiconductor package 240 is attached to the chip attaching surface 232 using the adhesive 260a while the lower package body 235 is manufactured by the molding process, and the plurality of leads 251 formed at predetermined intervals. ) Is attached to the lead attaching surface 234 with the adhesive 260b interposed therebetween.

The lead 251 is formed as an inner lead 251a attached to the lead attachment surface 234 and an outer lead 251c which is integrally formed with the inner lead 251a and protrudes to the outside of the lower package body 235. consist of.

As described above, in the state where the semiconductor chip 240 and the inner lead 251a of the lead frame are attached to the upper surface of the lower package body 235, the bonding pads 242 corresponding to the inner lead 251a are bonded to the bonding wire ( 270 is electrically connected to each other. The reason why the chip attaching surface 232 is formed stepped downward with respect to the lead attaching surface 234 is to improve wire bonding property.

4 is a cross-sectional view illustrating a state in which a molding resin is injected while a lower package body in which the semiconductor chip of FIG. 3 is mounted is inserted into a molding die.

5 is a cross-sectional view illustrating a semiconductor chip package according to an embodiment of the present invention.

Referring to FIG. 4, a process of encapsulating a semiconductor chip, an inner lead, and a bonding wire manufactured on an upper surface of a lower package body is described. An electrical connection process between the semiconductor chip 240 and the inner lead 251a of FIG. 3 is completed. The lower package body 235 is inserted into and mounted in the cavity 225 of the lower mold. In addition, the upper mold 210 positioned above the lower mold 220 is lowered and pressed while being in contact with the lower mold 220 to fix the lead frames 250 outside the cavities 215 and 225 by pressing. In the state, the liquid molding compound 230 is injected into the upper cavity 215 through the gate 227 and the forming furnace 229, so that the semiconductor chip 240, the internal lead 251a, and the bonding are shown in FIG. 5. The wire 270 is sealed to form the upper package body 237. The external lead 251c protruding to the outside of the upper and lower package bodies 235 and 237 may be bent in accordance with the mounting structure of the external electronic device.

FIG. 5 illustrates a semiconductor chip in which a semiconductor chip 240, an inner lead 251a, and a bonding wire 270 formed on an upper surface of a lower package body 235 are sealed by a liquid molding compound to form an upper package body 237. The package 500 is shown. The external lead 251 c is bent to fit the mounting structure of the external electronic device.

6 is a cross-sectional view illustrating a semiconductor chip having a lead-on chip structure mounted on an upper portion of a lower package body according to another embodiment of the present invention.

Referring to FIG. 6, a structure of a semiconductor chip package according to another exemplary embodiment of the present disclosure will be formed to be stepped upward with respect to the chip attaching surface 332 to which the semiconductor chip 340 is attached and the chip attaching surface 332. And a lower package body 335 having a lead attachment surface 334 to which the lead 351 of the lead frame is attached. The semiconductor chip 340 on which the center pad 342 is formed is attached to the chip attaching surface 332 by the adhesive 360a, and the lead 351 is attached to the adhesive attaching portion 334 to the adhesive 360b.

The lead 351 is formed integrally with the attachment portion 351b attached to the lead attachment surface 334 and the attachment portion 351b and includes a mounting portion 351a positioned on the upper surface of the semiconductor chip 340. It is formed integrally with the inner lead 351d and the attachment portion 351b and has an outer lead 351c protruding to the outside of the lower package body 335. In addition, the mounting portion 351a of the lead and the center pad 342 have a structure electrically connected by the bonding wire 370.

When comparing the lead-on-chip structure according to the present invention and the lead-on-chip structure according to the prior art, the conventional lead-on-chip structure uses a double-sided adhesive tape such as polyimide tape on one surface where a bonding pad of a semiconductor chip is formed. Although the internal lead is attached to the surface where the bonding pad of the chip is formed close to the bonding pad, in the present invention, since the attachment portion 351a of the internal lead is attached to and fixed to the lead attachment portion 334, The mounting part 351a of the internal lead positioned on the upper surface is not attached to the upper surface of the semiconductor chip 340 and is located close to the upper surface of the semiconductor chip. In addition, the mounting portion 351a of the internal lead should not fall more than a predetermined level with respect to the upper surface of the semiconductor chip 340. In the wire bonding process of performing stick bonding to the mounting portion 351a after ball bonding is performed on the bonding pad 342 of the semiconductor chip when the gap is out of a predetermined level, This is because a spring phenomenon may occur in the sticky bonding portion of the inner lead 351d to cause wire bonding defects. Therefore, it is preferable to mount the mounting portion 351a of the lead on the upper surface of the semiconductor chip 340.

And, although not shown in the drawings, conventionally in the release process for releasing the package body after the molding process is completed, the release pin protruding on the cavity of the upper and lower molds, the package body in which the molding process is completed, the cavity of the upper and lower molds Push out of However, since the liquid molding compound has an adhesive property, it adheres to the surface of the upper and lower molds forming the cavity, thereby causing a problem in releasing the package body after the molding process. However, in the present invention, the lower package body 235 is preformed. ) Is not used, so problems caused by the release do not occur.

FIG. 7 is a cross-sectional view illustrating a state in which a molding resin is injected while a lower package body having the lead-on chip structure of FIG. 6 is inserted into a molding die. FIG.

8 is a cross-sectional view illustrating a semiconductor chip package according to another exemplary embodiment of the present inventive concept.

FIG. 7 illustrates the semiconductor chip 340, the inner lead 351d, and the bonding wire 370 as the lower mold 320 and the upper mold 310 are engaged with the lead-on chip structure on the upper surface of the lower package body 335. ) Is encapsulated by the liquid molding compound 330, and the description of the above process is the same as the molding process of FIG.

FIG. 8 illustrates a semiconductor chip package 600 in which an upper surface on which the lead-on chip structure of the lower package body 335 is formed is sealed by a liquid molding compound to form the upper package body 337.

Therefore, according to the structure of the present invention, the semiconductor chip and the inner lead electrically connected to the semiconductor chip attached to the upper surface of the pre-fabricated lower package body encapsulated the electrical connection portion including the semiconductor chip and the inner lead Since the molding process is performed, there is an advantage that the problem caused by the flow of the semiconductor chip and the internal lead may be eliminated by the flow rate of the liquid molding compound.

In addition, since the semiconductor chip is directly attached to the lower package body to reduce the adhesive interface, the bonding force with the molding compound is improved as compared with the conventional die pad structure.

In addition, in the lead-on chip structure according to the present invention, since the inner lead portion outside the semiconductor chip is fixed to the upper surface of the lower package body, the mounting of the portion of the inner lead fixedly attached to the upper surface of the semiconductor chip has been conventionally performed. Since it is possible, there is an advantage that the defects caused by the polyimide tape used to attach the inner lead to the upper surface of the conventional semiconductor chip can be eliminated.

Claims (11)

A lower package body having a chip attaching surface to which a semiconductor chip is attached, and a lead attaching surface formed to be stepped upward with respect to the chip attaching surface, and to which a lead of the lead frame is attached; A semiconductor chip attached to the chip attaching surface and having a plurality of bonding pads formed on one surface thereof; A plurality of leads formed at predetermined intervals and attached to said lead attachment surface; Bonding wires electrically connecting the leads and the bonding pads, respectively; And an upper package body in which a part of the semiconductor chip, the bonding wire, and the lead are sealed by a liquid molding compound. The method of claim 1, wherein the lead is formed of an inner lead attached to the lead attaching surface, and an inner lead integrally formed with the inner lead, the outer lead protruding to the outside of the package body, the inner lead is the bonding And a pad and the bonding wire are electrically connected to each other. 2. The lead of claim 1, wherein the lead is formed integrally with an attachment portion attached to the lead attachment surface and the attachment portion, and has an internal lead having a mounting portion mounted on an upper surface of the semiconductor chip, and integrally with the attachment portion. The semiconductor chip package, characterized in that consisting of an outer lead protruding to the outside of the package body. The semiconductor chip package of claim 3, wherein the mounting unit is electrically connected to the bonding pad by the bonding wire. The semiconductor chip package of claim 4, wherein the bonding pad is a center pad positioned at the center of the semiconductor chip. The semiconductor chip package according to any one of claims 1 to 5, wherein the lower package body is made of plastic resin. A semiconductor chip attached to one surface, and a lead electrically connected to the semiconductor chip having a lower package body attached to an outside of the semiconductor chip; Mounting to a lower mold having a space suitable for forming a lower portion of the lower package body; A lower mold positioned on an upper portion of the lower mold and having a cavity formed therein, the cavity being a space for encapsulating a portion of the lead electrically connected to the semiconductor chip to be engaged with the lower mold; And And forming an upper package body by injecting a liquid molding compound into the cavity of the upper mold. The semiconductor package according to claim 7, wherein the lower package body has a chip attaching surface to which the semiconductor chip is attached, and a step attaching upwardly with respect to the chip attaching surface, and a lead attaching surface to which the lead is attached. Chip package manufacturing method. The method of claim 8, wherein the lead is formed integrally with the attachment portion attached to the lead attachment surface and the attachment portion, and formed integrally with the internal lead and the internal lead having a mounting portion mounted on the upper surface of the semiconductor chip. And an external lead protruding to the outside of the upper and lower package bodies, wherein the mounting portion is electrically connected to the semiconductor chip. 10. The method of claim 9, wherein the mounting portion of the lead is electrically connected to the semiconductor chip by a wire bonding process. The method of claim 7, wherein the lower package body is made of plastic resin.