JPH07106501A - Semiconductor package and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Object] To provide a highly reliable and highly productive semiconductor package and a method for manufacturing the same. A semiconductor element 1, a resin lead 3 in which a conductive metal layer 8 formed on the surface is connected to an Al electrode 5 of the semiconductor element 1 by an Au wire 6, and a seal for covering the semiconductor element 1 and the resin lead 3 It consists of a stop resin 2. [Effect] Resin lead 3 and resin die pad 4
Since the amount of thermal expansion is substantially equal to that of the sealing resin 2, the internal stress generated by the temperature change is small, and package cracks and the like are less likely to occur, resulting in high reliability. Further, since the external terminals 3a are molded with a relatively low stress while the resin leads 3 are heated and softened, peeling at the adhesive interface between the sealing resin 2 and the resin leads 3 can be prevented, and the production Good nature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor package such as a plastic mold package and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable trend toward miniaturization, thinness and high performance of electronic equipment, and along with this trend, electronic parts are rapidly becoming highly functional. This tendency is particularly strong in the field of semiconductor devices such as memories, and there is a demand for semiconductor packages that are smaller, thinner, low cost, highly reliable, and suitable for high-density mounting. In the past, ceramic packages were the mainstream semiconductor package, but now the demand for surface-mount plastic mold packages, which is more advantageous for high-density mounting than insertion, is increasing. There are many types of surface mount type plastic mold packages such as QFP type, SOP type and SOJ type depending on the mounting form.

An SOJ type plastic mold package will be described with reference to FIG. In this SOJ type plastic mold package, the leads 33 are arranged on the back surface side of the semiconductor element 31, and the semiconductor element 31 and the leads 33 are covered with the sealing resin 32. The semiconductor element 31 is bonded to the die pad 34 of the lead 33 with Ag paste 37. The Al electrode 35 of the semiconductor element 31 is connected to the lead 33 by an Au wire 36. The lead 33 is made of a metal material such as copper or 42 alloy, and leads the J-shaped external terminal 33 a to the outside of the sealing resin 32.

[0004]

However, since the lead 33 is bonded to one surface of the semiconductor element 31, the amount of thermal expansion between the main surface side and the back surface side of the semiconductor element 31 due to temperature change is different, and internal stress is reduced. Warpage due to occurrence of was likely to occur. Therefore, a large stress stress is applied to the semiconductor element 31, which causes package cracks and peeling at the bonding interface of the sealing resin 32. Further, when the package becomes hot after absorbing moisture, the absorbed moisture expands as water vapor at the bonding interface between the back surface of the die pad 34 and the sealing resin 32, which causes a package crack especially during the soldering process. .

Further, the plastic mold package is cut off from the lead frame (not shown), and the external terminal 33a of the lead 33 is formed into a J shape by metal working. For this reason, since a large load is applied to the lead 33, the lead 33 is likely to come off due to peeling at the adhesive interface between the lead 33 and the sealing resin 32.

The above problems reduce productivity and hinder thinning and high density of the package,
Furthermore, the reliability of the semiconductor element 32 is impaired. An object of the present invention is to provide a semiconductor package having high productivity and high reliability, and a manufacturing method thereof.

[0007]

According to another aspect of the present invention, there is provided a semiconductor package including a semiconductor element, leads electrically connected to electrodes of the semiconductor element, and a sealing resin covering the semiconductor element and the leads. The lead is made of a resin material having a conductive metal layer formed on its surface. In the semiconductor package according to the second aspect, the back surface of the semiconductor element is fused to the die pad surface of the resin lead having a conductive metal layer formed on the surface other than the die pad. The electrodes of the semiconductor element and the conductive metal layers of the resin leads are electrically connected. The semiconductor element and the resin lead are covered with a sealing resin. In the semiconductor package according to the third aspect, the main surface of the semiconductor element is directly fused to the back surface of the internal terminal of the resin lead having the conductive metal layer formed on the front surface. The conductive metal layer of the resinous lead is electrically connected to the electrode of the semiconductor element. The semiconductor element and the leads are covered with a sealing resin.

According to a fourth aspect of the semiconductor package, the resin forming the lead according to the first, second or third aspect is composed of a thermoplastic resin. According to a fifth aspect of the semiconductor package, the leads and the sealing resin according to the first, second, third or fourth aspect are formed of the same resin or a resin having the same thermal expansion coefficient.

According to a sixth aspect of the method of manufacturing a semiconductor package, a semiconductor element is fixed to a resin lead frame having a surface on which a conductive metal layer is formed. A resin lead frame is electrically connected to the electrodes of the semiconductor element. The semiconductor element and the resin lead frame are covered with a sealing resin. The resin lead frame is heated to soften the resin lead frame. The external terminals of the lead of the resin lead frame in the softened state are separated from the resin lead frame and molded.

[0010]

In the semiconductor package of the present invention, since the leads are made of a resin material having a conductive metal layer formed on the surface, the thermal expansion amounts of the leads and the sealing resin can be made substantially equal, and the internal stress caused by the temperature change can be reduced. be able to. According to the semiconductor package manufacturing method of the present invention, when the plastic mold package is separated from the lead frame and molded, and the external terminals of the leads are molded and processed, the leads are heated and softened so that the stress is relatively low. It is possible to mold the external terminals of leads.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The semiconductor package of the first embodiment of the present invention is of the SOJ type as shown in FIG.
And a lead 3 made of resin electrically connected to the Al electrode 5 of the semiconductor element 1, and a sealing resin 2 covering the semiconductor element 1 and the lead 3 made of resin.

Resin lead 3 and resin die pad 4
Each have a conductive metal layer 8 formed on the surface thereof. The conductive metal layer 8 is a Cu layer formed by plating. At the tip of the internal terminal of the resin lead 3, a Ni / Au layer is further formed on the Cu layer. On the back surface of the semiconductor element 1, the conductive metal layer 8 of the resin die pad 4 is bonded with the Ag paste 7. Al electrode 5 of semiconductor element 1
Is connected to the conductive metal layer 8 at the tip of the internal terminal of the resin lead 3 by the Au wire 6. Resin lead 3
Guides the external terminal 3a to the outside of the sealing resin 2.

Resin lead 3 and resin die pad 4
The resin-made lead frame made of is a resin material in which a high heat resistant thermosetting resin such as epoxy or a high heat resistant thermoplastic resin such as thermoplastic polyimide or polyether amide imide is reinforced with glass fiber. These resin materials can be easily molded by die molding, punching, etching or the like, and the surface plating layer such as Cu, Ni or Au of the conductive metal layer 8 on the surface can be easily formed by a technique such as photolithography or etching. It can be formed selectively. In the resin lead frame, the mixing ratio of glass fibers is adjusted so that the thermal expansion coefficient becomes equal to that of the sealing resin 2.

In manufacturing, first, the semiconductor element 1 is fixed to a resin-made lead frame having a conductive metal layer 3 formed on the surface thereof, and the resin-made lead frame is attached to the Al electrode 5 of the semiconductor element 1 by an Au wire. Connecting. The resin lead frame and the semiconductor element 1 are covered with the sealing resin 2. In this state, set the resin lead frame to the Tg of the resin lead 3.
Alternatively, the resin is softened by heating to near Tm, and the external terminals of the leads of the resin lead frame are separated from the resin lead frame and molded.

As described above, by heating the resin lead 3 and the resin die pad 4, the external terminals 3a of the resin lead 3 can be processed with a relatively low stress, so that the sealing resin 2 and the resin lead 3 are formed. Can be prevented from peeling at the adhesive interface, and productivity can be improved. Further, since the resin lead 3 and the resin die pad 4 and the sealing resin 2 are made of resins having the same thermal expansion coefficient, the thermal expansion amounts of the two become substantially equal to each other even if the temperature changes. Generation of internal stress is small. Furthermore, since the resin lead 3 and the resin die pad 4 and the sealing resin 2 have excellent adhesiveness to each other, peeling, cracking, or the like is unlikely to occur at the adhesive interface between them, and the reliability of the package is improved.

Therefore, the resin leads 3, the resin die pad 4, and the sealing resin 2 can be made relatively thin, and the package as a whole can be made thin and highly densified. Moreover, the reliability of the package with respect to heat history can be improved. Next, a semiconductor package according to the second embodiment of the present invention will be described with reference to FIG. The resin lead 13 and the resin die pad 14 are formed of a thermoplastic resin. The conductive metal layer 18 is formed only on the surface of the resin lead 13 and is not formed on the surface of the resin die pad 14.

When the semiconductor element 1 is mounted on the resin die pad 14, the back surface of the semiconductor element 1 is directly fused with the thermoplastic resin forming the resin die pad 4 by thermocompression bonding without using Ag paste. You can Therefore, the step of applying the Ag paste is unnecessary, and the cost can be suppressed. Further, by omitting the Ag paste, the thermal stress can be easily balanced, and the reliability against the thermal stress becomes higher than in the first embodiment. Other configurations and effects are similar to those of the first embodiment.

Next, a semiconductor package according to the third embodiment of the present invention will be described with reference to FIG. The resin lead 23 is made of a thermoplastic resin. Al electrode 25
Is arranged in the center of the semiconductor element 21. The resin lead 23 extends to near the center of the main surface of the semiconductor element 21. The conductive metal layer 28 is formed only on the surface of the resin lead 23.

The semiconductor package having the above structure is
Since the main surface of the semiconductor element 21 and the thermoplastic resin forming the resin leads 23 are directly fused by thermocompression bonding, a resin die pad is not required, and as in the second embodiment, A
Since the g paste is unnecessary, cost reduction and high reliability can be achieved. Further, the resin lead 23 can be easily routed, and the resin lead 23 adhered to the semiconductor element 21 does not fall off. Therefore, the package size can be made relatively smaller than the chip size. Other configurations and effects are similar to those of the first embodiment.

In the second and third embodiments,
The lead and the sealing resin were made of the same resin or resins having the same coefficient of thermal expansion.

[0021]

According to the semiconductor package of the present invention, since the leads are made of a resin material having a conductive metal layer formed on the surface, the thermal expansion amounts of the leads and the sealing resin can be made substantially equal,
Internal stress caused by temperature change can be reduced. Therefore, the leads and the sealing resin can be made relatively thin, and the package as a whole can be made thin and highly densified. Moreover, the reliability of the package with respect to heat history can be improved.

According to the method of manufacturing the semiconductor package of the present invention, when the plastic mold package is separated from the lead frame and molded, and the external terminals of the leads are molded and processed, the leads are heated and softened relatively. The external terminals of leads can be molded with low stress. Therefore, it is possible to prevent the lead from falling off due to peeling at the adhesive interface between the lead and the sealing resin, and it is excellent in productivity.

[Brief description of drawings]

FIG. 1 is a sectional view of a semiconductor package according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a semiconductor package according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a semiconductor package according to a third embodiment of the present invention.

FIG. 4 is a sectional view of a conventional semiconductor package.

[Explanation of symbols]

 1 Semiconductor Element 2 Sealing Resin 3 Resin Lead 4 Resin Die Pad 5 Al Electrode 8 Conductive Metal Layer

Claims (6)

[Claims] 1. A semiconductor element, a lead electrically connected to an electrode of the semiconductor element, and a sealing resin for covering the semiconductor element and the lead, wherein the lead has a conductive metal layer on a surface thereof. A semiconductor package made of the formed resin material. 2. The back surface of the semiconductor element is fused to the die pad surface of the resin lead having a conductive metal layer formed on the surface other than the die pad, and the electrode of the semiconductor element and the conductive metal layer of the resin lead are electrically connected. Package in which the semiconductor elements and the resin leads are covered with a sealing resin. 3. The main surface of a semiconductor element is directly fused to the back surface of an internal terminal of a resin lead having a conductive metal layer formed on the surface thereof, and the conductive metal layer of the resin lead is attached to the electrode of the semiconductor element. A semiconductor package in which the semiconductor element and the leads are electrically connected and covered with a sealing resin. 4. The semiconductor package according to claim 1, wherein the resin forming the leads is a thermoplastic resin. 5. The semiconductor package according to claim 1, claim 2, claim 3 or claim 4, wherein the lead and the sealing resin are made of the same resin or a resin having the same thermal expansion coefficient. 6. A step of fixing a semiconductor element to a resin lead frame having a surface on which a conductive metal layer is formed, a step of electrically connecting the resin lead frame to an electrode of the semiconductor element, and the semiconductor element. And a step of coating the resin-made lead frame with a sealing resin, a step of heating the resin-made lead frame to soften the resin-made lead frame, and the outside of the lead of the resin-made lead frame in the softened state. And a step of separating the terminals from the resin lead frame and molding the semiconductor lead frame.