JPH02278753A - Thin package equipment - Google Patents

Abstract

PURPOSE:To improve moisture resistance as an IC and miniaturize the title item by allowing a recessed part to be formed at an element-mounting part and then using a substrate where leads are placed at the periphery of the recessed part as a base. CONSTITUTION:An element 7 is mounted to a recessed part 1a which is formed at the center on the surface of a substrate 1 and leads 2a, 2b, 2c, and 2d for leading to the outside are placed on the substrate 1 around the recessed part 1a. Then, the element 7 and the leads 2a, 2b, 2c, and 2d for leading to the outside are connected by leads 5a and 5b for connection. In this case, the element 7 at the surface side of the substrate 1, the leads for 5a and 5b for connection, and the leads 2a, 2b, 2c, and 2d for leading to the outside are covered with resin and the rear surface of the substrate 1 at a part where the recessed part 1a is formed is sealed without being covered with resin. Thus, the thickness of resin layer can be reduced for miniaturization and thinness by eliminating insulation resin layer at the stage rear surface side for mounting elements.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a thin package device such as an IC, and in particular, a thin package that has been made smaller and three-inch without impairing its characteristics, thereby expanding the field of application. Regarding equipment.

3. Detailed description of the invention [4 Already required] Semiconductor devices such as ICs, especially thin package devices [Prior art] In recent years, as LSIs have become highly integrated, there has been a growing trend towards multi-pin single surface mounting. Recently, flat package ICs have come into use especially in order to reduce the thickness of the ICs.

FIG. 3 is a sectional view showing the structure of a conventional flat package IC.

In the figure, 11 is an IC chip (hereinafter referred to as an element), 12 is a stage for mounting an element on a lead frame, and 13 is a stage radially arranged around the stage 12 so as to correspond to a plurality of electrodes on the element 11. A plurality of leads formed are shown, 14 is a wire connecting each hump electrode on the element 11 and the lead 14 corresponding to each hump electrode, 15 is a wire connecting the element 11 to a stage 12. The epoxy resin is shown encapsulated and integrated with the leads 13 and wires 14.

To briefly explain the construction process, after mounting the element 11 at a predetermined position on the element mounting stage 12 of the lead frame and fixing the element 11 to the stage 2 by die bonding, each of the plurality of elements on the element 11 is A wire 14 is automatically connected between the bump electrode and each corresponding lead 13 formed around the stage using a wire bonding machine.

Thereafter, the area including the element 11 up to a predetermined position of the lead 13 is sealed with epoxy resin so as to bury the stage together, thereby forming a flat package IC.

In a package IC with such a configuration, ■ Stage 12
Since moisture easily enters the element 11 from the back surface of the stage 12 through the contact surface with the resin of the stage 12, it is necessary to cover the back surface of the stage 12 with a resin having a thickness that does not cause poor moisture resistance.

(2) In the case of connection using a wire bonding machine, since the wire 14 is connected with extra length, it is necessary to make the package IC thicker than the surface of the element 11 by three dimensions shown in the figure.

For these reasons, there are restrictions on reducing the thickness of a packaged IC, which is at least about 1 mm, which has the disadvantage that it cannot be applied to fields that require particularly thin ICs.

[Problem to be solved by the invention]

Conventional flat package type ICs have restrictions on their thinness, which limits their applicability, and there is a problem in that they cannot be used for high-density mounting printed boards, IC cards, etc., which require a particularly thin thickness.

(Means for Solving the Problems) The above problem is that the device is mounted in a recess formed in the center of the substrate surface, and the external leads are arranged on the substrate around the recess. The lead-out lead is connected by the connection lead, the element on the front side of the board, the connection lead, and the external lead-out lead are covered with resin, and the back side of the board where the recess is formed is not covered with resin. The problem is solved by a thin package device that is sealed.

If the insulating resin layer on the back side of the element mounting stage can be removed, the thickness of the resin can be reduced by one minute.

Furthermore, if the connection between the bump electrode of the element and the peripheral lead wire is changed from the conventional wire bonding wire to the connection lead by tape lead bonding, the extra length, that is, the bending, is no longer necessary, and the thickness of the resin on the surface side can be reduced.

In the present invention, a recess is formed in the element mounting portion.

By using the substrate on which the leads are arranged around the recess as a base, it is possible to remove the insulating resin layer on the back side of the stage, and furthermore, by using a combination of lead connection using tape automated bonding means, etc. The aim is to achieve a thinner IC with good moisture resistance.

Therefore, it can be made compact as an IC without degrading its characteristics.
It is possible to realize moldization.

1. Function] Used in conventional flat package type IC [Example] Fig. 1 is a process diagram showing a manufacturing method of a thin package device according to the present invention, and Fig. 2 is a diagram showing another embodiment. It is.

The explanation will be given below according to the figures.

In Figure 1 (8), 1 is Chichi (Fe), Kiri (Cu),
The substrate is made of aluminum or an alloy thereof, and has a thickness of, for example, about 100 μm, and the central portion of the stage 18, which is at least slightly larger than the element area, is an open plane with a step d (100 μm) that is approximately equal to the thickness of the plate. If the substrate on which the element is mounted and the adhesive for leading to the outside is arranged is formed of the metal material f'' in this way, it can be formed thin and with high strength, and the heat from the element can be dissipated well. .

Therefore, a bonding fixing material 11Ulb such as solder or adhesive with a thickness of about 10 μm is formed on the substrate 1 in an area approximately the same as the mounting element in the center of the stage 1a, and the substrate 1 is removed from the area. After coating almost the entire surface of the front and back surfaces of the insulating film 1c, such as enamel, having the same helix, the insulating film 1 is placed on the convex surface along the entire periphery of the stage 1a to a thickness of about 10 μm in this predetermined width region. An insulating adhesive layer 1d made of a low melting point glass such as lead glass or a heat resistant resin such as polyimide is formed by coating in the same manner as described above.

Figure (B) shows this state.

On the other hand, the outer lead 2 in figure (C) is made of iron (Fe), 'A
(Cu).

A metal plate with a thickness of 50 μm made of aluminum (Affi) or an alloy thereof is formed by means such as etching, and a plurality of bump electrodes with a width of about 40 μm are formed in correspondence with a plurality of bump electrodes on a predetermined mounted element. External lead lead 2
The extranuclear lead 2
External leads 2a, 2b, 2c, 2d...
The lead base 3 shown in Figure (C) is formed by adhering and fixing each tip of . There is.

On the other hand, 5 shown in the plan view (D) is formed on one side of a resin film 6 made of polyimide or the like having a square hole 6a of approximately the same size as the substrate 1, from the square hole 6a to the inside of the square hole 6a. The inner end that protrudes toward [! 1 corresponds to a plurality of electrode positions on a predetermined element, and the end E2 of the square hole 6a corresponds to each external lead 2 of the lead base 3 shown in FIG.
A, 2b, 2c, 2d, etc. A plurality of connection leads 5a, 5b, 5c made of copper (Cu) or an alloy thereof are patterned to correspond to the tips of the leads 5a, 2b, 2c, 2d, .

5d... shows a circuit board with...

Therefore, after placing the element 7 in a predetermined area indicated by the broken line L1, each hump electrode on the element 7 and the inner end E1 of each connection lead of the circuit board 5 are bonded by soldering or other means. Then, a finished chip 8 shown in FIG. 8(E) can be obtained.

In the case of a completed chip 8 using such a circuit board 5, tape-shaped connection leads 5a, 5b, 5c, 5d,
Since the wires are formed planarly, there is no need to provide extra length during bonding unlike the wires used in wire bonding means, and as a result, an effective connection can be realized for thinning.

Next, the back side of the element 7 of the completed chip body 8 is placed on the surface of the bonding fixing film 1b of the lead base 3 to perform dicing, and each connection lead 5a of the completed chip body 8 is
, 5b, 5c, 5d... Figure (D) and Figure (
The E2 portion in E) is connected to each external lead-out lead 2a, 2b, 2c, 2d, etc. of the corresponding outer lead 2.
When bonding is made to the inner end of . . , and each connection lead is cut along the line shown by the dashed-dotted line L2 in FIGS. (D) and (E), a state as shown in FIG. (F) can be obtained.

Here, in a state where the back surface side of the substrate 1 is exposed, at least the above-mentioned completed chip body 8 is buried under the dotted chain line L3 in the figure.
The area indicated by is sealed with epoxy resin or the like by a normal low-pressure transfer molding method and packaged, and the area indicated by the two-dot chain line L4 in Figure (C) is c''-c,
By cutting and removing the peripheral connecting portion 2z of the outer lead 2 with the lines , it is possible to construct the required thin package device 9 as shown in Figure (G).

In addition, it has been experimentally confirmed that when using elements similar to the conventional one, the overall thickness of the package device can be configured to be approximately 0.5 mm or less.

FIG. 2 shows an example in which the method is applied particularly when the amount of heat generated by the element is large.

In this case, in the process shown in FIG. 1(B), solder IJi 1f is formed on a predetermined area of the lower side of the paper surface of the substrate 1, that is, the back surface, through an insulating adhesive film 1e such as epoxy resin, and other parts are It is formed as explained in FIG. 1 to obtain the state shown in FIG. 1(a).

Next, after configuring the required thin package device through the steps explained in FIG. 1, a normal heat dissipation fin IQ is attached to the surface of the solder 1191f, and a heat dissipation fin as shown in FIG. 1B is attached. A thin package device can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a thin package device that is small and thin without sacrificing the characteristics of an IC and expands the field of application.

FIG. 2 is a diagram showing another embodiment, and FIG. 3 is a sectional view showing the configuration of a conventional flat package IC.

It is. In the figure, 1 is a substrate, 1a is a recess (stage), 1b is a bonding fixing film, 1c is an insulating layer, 1d is an adhesive layer,
1e is an insulating adhesive film, if is a solder film, 2
2a, 2b... are external leads, 2
z is the connection part, 3 is the lead base, 5 is the circuit board, 5
a, 5b... are connection leads, 6 is a resin film, 7
[C] represents a chip (element), 8 represents a completed chip, 9 represents a thin package device, and 10 represents a heat dissipation fin.

[Brief explanation of drawings]

Figure 1 shows how the thin package device of the present invention is manufactured.
Figure (G) LOL Figure 1 (Part 3) Figure

Claims (1)

[Claims] An element (7) is mounted in a recess (1a) formed in the center of the surface of the substrate (1), and external leads (2a) are mounted on the substrate (1) around the recess (1a). , 2b, 2c, 2d) are arranged, and the element (7
) and external lead-out leads (2a, 2b, 2c, 2d) are connected by connection leads (5a, 5b), and the board (1
) The surface side element (7), the connection leads (5a, 5b), and the external lead-out leads (2a, 2b, 2c, 2d) are covered with resin and the part of the substrate in which the recess (1a) is formed ( 1) A thin package device characterized in that the back surface is sealed without being covered with resin.