WO2014029176A1

WO2014029176A1 - Clamp for reducing bending in package and method therefor

Info

Publication number: WO2014029176A1
Application number: PCT/CN2012/085608
Authority: WO
Inventors: 杨文波; 刘晓明; 阙燕洁; 魏元华; 卫安琪
Original assignee: 无锡华润安盛科技有限公司
Priority date: 2012-08-24
Filing date: 2012-11-30
Publication date: 2014-02-27
Also published as: CN103624909B; CN103624909A

Abstract

The present invention provides a clamp for reducing bending in a package and a method therefor, belonging to the technical field of integrated circuit chip packaging. The clamp comprises an upper pressing plate and a lower pressing plate, wherein in the cooling process of the packaging, the package is placed between the upper pressing plate and the lower pressing plate and is clamped down by the upper pressing plate and the lower pressing plate to reduce bending of the package. The clamp significantly improves the package bending, the method is simple, and efficiency is high.

Description

Fixture for reducing bending of plastic body and method thereof

The invention belongs to the technical field of integrated circuit chip packaging, and relates to a plastic sealing process of a package, and particularly relates to clamping a plastic body after molding by using a jig to prevent bending of the plastic sealing body during cooling. Background technique

The packaged integrated circuit chip is substantially wrapped by the molding material from the outside, and the outer lead of the conductor portion of the lead frame protrudes from the molding compound. The encapsulated molding compound is often referred to as a "molding body", which has the function of protecting the inner chip and the soft metal wire, and further, the packaged integrated circuit chip can be conveniently used.

Therefore, in the packaging process of an integrated circuit chip, a process for forming a molded body is generally referred to as a plastic sealing process. The molding process is also a thermal process (i.e., undergoes a significant change in temperature). Therefore, after the molding is formed into a plastic body, thermal stress usually causes the molding body to bend in the molding body, thereby causing deformation of the packaged integrated circuit chip. The deformation caused by such bending may cause serious problems during use, and the reduction of the bending of the plastic body is also a problem that has been solved in the art.

In today's semiconductor packaging industry, there are usually two options to reduce the bending of the molded body:

The first is to reduce the bending of the molded body from the source by precise design during the design of the integrated circuit chip product; for example, the Chinese patent application number is

CN1122637, the Chinese patent entitled "Flat Plastic Packaging Module for Integrated Circuits", provides an additional layer of material in the plastic at the layer different from the leadframe connection leads in order to balance the forces and thereby reduce the plastic body Bending

The second is a method of adjusting the parameters or by changing the shape and material of the molding resin during the molding process.

Among them, the first solution has high requirements on design technology, and it is difficult to completely avoid the bending phenomenon. Once the design is not perfect, the bending of the plastic body will exceed the standard requirements; The problem of bending can be alleviated by improving the process conditions and materials. However, it is difficult to meet the standard requirements for the integrated circuit chip products of the bulky plastic package. Summary of the invention

It is an object of the invention to reduce the degree of bending of the molded body.

To achieve the above object or other objects, the present invention provides the following technical solutions. According to an aspect of the invention, there is provided a jig for reducing bending of a molding body, comprising an upper pressing plate, and a lower pressing plate, the molding body of the plastic cooling process being placed between the upper pressing plate and the lower pressing plate And being pinched by the upper platen and the lower platen.

According to an embodiment of the present invention, the upper surface of the lower pressing plate is provided with a cavity for positioning the plastic sealing body.

A jig according to still another embodiment of the present invention, wherein the jig further includes means for carrying and transferring the laminator carrier, the molding body being placed between the upper plate and the lower plate simultaneously with the carrier.

In the jig of any of the preceding embodiments, preferably, the upper surface of the lower pressing plate is provided with a groove, and a laminating carrier placed between the upper pressing plate and the lower pressing plate is placed in the groove in.

In the jig of any of the preceding embodiments, preferably, the carrier includes a carrier frame and a handle, the carrier frame being embedded in the recess.

According to still another embodiment of the present invention, the upper pressing plate or the lower pressing plate is provided with a cooling member for accelerating cooling of the molding body.

According to still another embodiment of the present invention, the surface of the upper platen that acts on the surface of the molded body has a roughness greater than or equal to Ral and less than or equal to Ra2, and the upper platen acts on the molded body. The flatness of the surface is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

In the clamp of any of the preceding embodiments, preferably, the roughness of the bottom surface of the cavity is greater than or equal to RaO.l and less than or equal to Ra0.35, and the flatness of the bottom surface of the cavity is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

According to still another aspect of the present invention, a method for reducing bending of a molding body is provided, characterized in that the molding body is taken out from a molding die and placed in any of the jigs described above to complete the cooling process. Being pinched. Preferably, the molded body is placed in the jig at least until its temperature drops to 150 degrees Celsius.

The technical effect of the invention is that the use of the jig can greatly reduce d, the plastic body is bent during the cooling process, and the jig improves the bending effect of the plastic body, the method is simple and the efficiency is high. DRAWINGS

The above and other objects and advantages of the present invention will be more fully understood from the aspects of the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view showing the structure of a jig in accordance with an embodiment of the present invention.

2 is a schematic view showing the structure of the lower platen structure of FIG. 1, wherein FIG. 2(a) is a plan view and FIG. 2(b) is a cross-sectional view of A-A.

Figure 3 is a schematic view of the embodiment of the carrier structure of Figure 1.

4 is a schematic view of the embodiment of the upper platen structure of FIG. 1, wherein FIG. 4) is a bottom view and FIG. 4(b) is a front view. detailed description

The following is a description of some of the various possible embodiments of the invention, which are intended to provide a basic understanding of the invention and are not intended to identify key or critical elements of the invention. It will be readily understood that those skilled in the art can make other alternatives that can be interchanged without departing from the spirit of the invention. Therefore, the following detailed description of the embodiments of the present invention is intended to be illustrative and not restrictive

In the description, components of various embodiments described using directional terms (such as "upper", "lower" and "bottom", etc., and similar terms, mean the directions shown in the figures or can be used by those skilled in the art. The direction of understanding. These directional terms are used for relative description and clarification, and are not intended to limit the orientation of any embodiment to a particular orientation or orientation.

The inventor of the application found that the bending of the plastic body is largely due to the plastic body Caused by the cooling process. During the molding process, the temperature during injection molding is relatively high (for example, it can reach about 175 degrees Celsius), and the plastic body includes the upper part and the lower part, wherein the upper part is formed by the upper cavity of the plastic mold, and the lower part is formed. The lower cavity of the plastic mold is formed by plastic film molding, and the upper mold cavity and the lower mold cavity are combined by a parting surface to form a plastic sealing cavity. Usually, due to the difference in volume between the upper mold cavity and the lower mold cavity, the shrinkage of the plastic seal body on the upper and lower surfaces of the lead frame will be different, and the inside of the plastic seal body will have stress during the cooling process, and the plastic seal body will be bent. Especially for the relatively large volume of the plastic body, the bending phenomenon is more obvious.

1 is a perspective view showing the structure of a jig according to an embodiment of the present invention. In this embodiment, the jig 10 is used to treat the molding 910 that has just been taken out of the molding die. The jig 10 includes an upper platen 150 and a lower platen 110. The molded body 910 is placed between the upper platen 150 and the lower platen 110 for cooling, and the jig 10 further includes a carrier plate 130 for facilitating the transfer of the molded body 910. One or more molding bodies 910 (for example, in the form of a package array) may be simultaneously placed on the carrier 130, and during the process of clamping the molding body 910 by the clamp 10, the carrier 130 may also be placed on the upper platen 150 and under Between the pressure plates 110, therefore, the design of the carrier plate 130 is designed to have the function of carrying the transfer molding body 910, and it needs to be designed such that it does not affect the upper platen 150 and the lower platen 110 respectively acting on the molding body during the nip process. Upper and lower surfaces of 910.

2 is a schematic view showing the structure of the lower platen structure of FIG. 1, wherein FIG. 2(a) is a plan view and FIG. 2(b) is a cross-sectional view of A-A. Figure 3 is a schematic view showing the embodiment of the carrier structure of Figure 1. 4 is a schematic view showing an embodiment of the upper platen structure of FIG. 1, wherein FIG. 4(a) is a bottom view and FIG. 4(b) is a front view. The components of the jig 10 will be further described in conjunction with Figs. 1 to 4.

The lower pressing plate 110 is provided on the upper surface of the body 111 with a plurality of cavities 113 for positioning the plastic sealing body 910. Therefore, the shape of the cavity 113 can be substantially matched with the lower mold for injection molding to form a plastic body. The shape of the cavity is designed such that the molded body can be substantially embedded in the cavity and positioned. As shown in FIG. 2, the cavities 113 may be arranged on the upper surface of the body 111 in rows and columns. The number and arrangement of the cavities 113 are designed according to the array of the molded bodies 910, which are not illustrated by the present invention. Example limitations. The upper surface of the platen body 111 is further provided with a recess 112 for embedding the carrier 130. Specifically, as shown in FIG. 3, the carrier 130 is substantially formed by the carrier frame 132; During the process, the package or package array is placed on the carrier frame 132; during the nip process, the carrier 130 is embedded in the recess 112, without affecting the molding 910 being pinched by the upper platen 150 and the lower platen 110. The shape of the groove 112 may specifically be designed to correspond to the shape of the carrier frame 132. Specifically, the carrier 130 may also be provided with a handle 131, which facilitates handling and handling of the carrier 130.

In this embodiment, as shown in Fig. 4, the lower surface 151 of the upper platen 150 is substantially a flat surface which directly acts on the upper surface of the molded body 910 and presses the molded body 910 during the nip.

Specifically, after the molding body 910 is taken out from the molding die, it is immediately placed on the carrier plate 130 and positioned on the lower pressing plate 110, and the upper pressing plate 150 is then pressed down to cool the molding body in the jig 10, outside the jig. Under the action of pressure, its forcing correction reduces the thermal stress generated by the cooling process inside the molding body and does not cause the molding body to be completely, thereby greatly reducing the shape bending of the molding body 910.

In a preferred embodiment, a cooling member, such as a circulating water cooling system, is disposed within the body of the upper platen 150 or the lower platen 110, thereby improving the cooling efficiency of the molded body and improving the molding efficiency of the package.

In still another preferred embodiment, in order to minimize the bending of the molded body, the roughness of the lower surface 151 of the upper platen 150 is set in the range of Ral to Ra2 (for example, Ral. 5), and the flatness of the lower surface 151 thereof. It is disposed in the range of 0.1 mm to 0.5 mm (for example, 0.2 mm); likewise, the bottom surface of the cavity 113 of the lower pressing plate 110 also acts on the package during the nip, and therefore, the cavity 113 of the lower pressing plate 110 is disposed. The roughness of the bottom surface is in the range of RaO.l to Ra0.35 (for example, Ra0.2), and the flatness of the bottom surface of the cavity 113 is set in the range of 0.1 mm to 0.5 mm (for example, 0.2 mm).

The invention also provides a method for reducing the bending of the plastic body. After the plastic molding body 910 is injection-molded in the plastic mold, it is taken out from the plastic mold, and immediately placed in the jig 10 of the embodiment shown in Fig. 1 for cooling, and is Pinch to avoid bending of the molded body during cooling. Preferably, the molding body 910 should be placed in the jig 10 at a temperature greater than or equal to 150 degrees Celsius, that is, the molding body 910 is placed in the jig 10 at least before its temperature drops to 150 degrees Celsius, so that the molding is performed. The main cooling shrinkage phase of the body is completed in the fixture, which is beneficial to reduce the bending of the molding body.

The above examples mainly illustrate the jig of the present invention and the use of the jig to reduce the plastic seal The method of body bending. Although only a few of the embodiments of the present invention have been described, it will be understood by those skilled in the art that the invention may be embodied in many other forms without departing from the spirit and scope. Accordingly, the present invention is to be considered as illustrative and not restrictive, and the invention may cover various modifications without departing from the spirit and scope of the invention as defined by the appended claims With replacement.

Claims

Claim

A jig for reducing bending of a molding body, comprising: an upper pressing plate, and a lower pressing plate, wherein the molding body of the cooling process of the plastic sealing is placed between the upper pressing plate and the lower pressing plate and is The upper and lower pressure plates are clamped.

The jig according to claim 1, wherein the upper surface of the lower platen is provided with a cavity for positioning the plastic sealing body.

3. The jig according to claim 1, wherein the jig further comprises: for carrying and transferring the laminator carrier, the laminating body and the carrier are simultaneously placed on the upper plate and the lower plate between.

The jig according to claim 3, wherein a groove is disposed on an upper surface of the lower platen, and a laminator carrier plate disposed between the upper platen and the lower platen is placed in the groove in.

5. The clamp of claim 4, wherein the carrier plate includes a carrier frame and a handle, the carrier frame being embedded in the recess.

The jig according to claim 1, wherein a cooling member for accelerating cooling of the molding body is disposed in the upper pressing plate or the lower pressing plate.

The jig according to claim 1, wherein a roughness of a surface of the upper platen acting on the molding body is greater than or equal to Ral and less than or equal to Ra2, and the upper platen acts on the The flatness of the surface of the molded body is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

The jig according to claim 2, wherein a roughness of a bottom surface of the cavity is greater than or equal to RaO.l and less than or equal to Ra0.35, and a flatness of a bottom surface of the cavity is greater than or equal to 0.1 mm and less than or equal to 0.5 mm.

A method for reducing bending of a molded body, characterized in that the molded body is taken out from a molding die and placed in a jig according to claim 1 to complete a cooling process and being pinched.

10. The method of claim 9, wherein the molded body is placed in the jig at least before its temperature drops to 150 degrees Celsius.