JPH10326845A - Resin package, semiconductor device and manufacture of resin package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise the moisture resistance of a resin package and to reduce the production cost of the package by a method, wherein the intermediate part of each lead member with one end part electrically connected with a semiconductor chip is embedded in a package main body, and an oxide layer formed in the surface of one part of the intermediate part is formed thicker than other oxide layer. SOLUTION: One end part of each lead 3 is extruded within a resin package main body and is connected with a semiconductor chip. At the same time, the other end part of the lead 3 connected with the outside is extruded to the outside of the main body and is exposed. In such a state, the intermediate parts 11 between inner and outer leads 3a and 3b of these leads 3 are embedded in the main body, that is, a resin constituting the main body. These leads 3 are electrically connected with the chip via the leads 3a. An oxide layer 11a is formed on at least one part of the surface of the part 11 of each lead 3 and has a thickness which is 1.5 to 500 times thicker than that of a natural oxide layer formed on other surfaces of the chip.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin package for accommodating a semiconductor chip such as an IC or a CCD (solid-state image sensor), and more particularly to a resin package having excellent moisture resistance.

[0002]

2. Description of the Related Art A resin package is for housing a semiconductor chip in a semiconductor device. The hollow package is made by insert-molding a lead into a box-shaped molded product made of resin, a semiconductor chip is bonded to the bottom inside this molded product, and the upper opening of the molded product is a transparent or opaque lid called a lid. This is a type of the resin package used as a semiconductor device by being closed.

A semiconductor device is used by being incorporated in an electronic product such as a video camera. Therefore, such a semiconductor device is required to have strict moisture resistance so that a semiconductor chip housed in an electronic product always operates normally. Therefore, a hollow package corresponding to a container in a semiconductor device needs to have durability capable of maintaining excellent moisture resistance that can withstand a severe test called a pressure cooker test for a long period of time.

Hitherto, in order to increase the moisture resistance of the hollow package, the resin composition constituting the resin package body has been improved. For example, it has been attempted to change the chemical structure of an epoxy resin from a basic structure such as a novolak type or a bisphenol A type to various improved structures.
Moisture resistance did not always improve to a satisfactory degree. In addition, other components constituting the resin composition, for example, a release agent for improving the releasability from a mold, or various fillers added for adjusting a coefficient of thermal expansion or thermal conductivity. However, it was not possible to sufficiently improve the moisture resistance of the hollow package even if the kind and the amount were adjusted.

As an attempt to solve these problems, according to Japanese Patent Application Laid-Open No. Hei 8-55927, "As a result of various studies to improve the moisture resistance of a hollow package, the factors that influence the moisture resistance of a hollow package are mainly the lead. In other words, it was found that the stronger the adhesion between the lead and the resin layer, the more moisture resistance that can be used for a long time was obtained. " ing. That is, a resin package body having a concave portion for accommodating a semiconductor element, and an intermediate portion having the one end portion extending into the concave portion and the other end portion extending outside the package main body, wherein the intermediate portion is formed. A hollow package having a lead frame embedded in the lead frame and electrically connected to the semiconductor element via the one end portion, wherein an intermediate portion of the lead frame is formed on a rough surface. With the structure, a relatively long time of 14 hours in the pressure cooker test was obtained.

[0006] Such a rough surface formation on the intermediate portion of the lead is performed by a sand blast method. That is,
A rough surface is formed on the lead by subjecting the intermediate portion of the lead to air blasting of fine alumina powder.

[0007]

However, the formation of a rough surface on a lead by such a sand blasting method requires time and effort to sufficiently remove alumina fine powder from the surface of the lead, and polishing powder is generated on a metal mask for a lead frame. There is a problem such as unevenness of the rough surface formation state due to deposition. Furthermore, there are problems related to costs such as high cost of consumables such as consumption of lead frame metal masks and consumption of alumina polishing powder, and high maintenance costs such as failure due to polishing powder of the sand blasting device itself or a compressor or the like. .

[0008] On the other hand, the demand for moisture resistance of hollow packages of semiconductor devices such as CCDs has been increasing strictly year by year, and it has been necessary to realize a further longer durability of the pressure cooker test. . Further, since the demand for lowering the cost of the hollow package is severe, a new process development for manufacturing an inexpensive hollow package having excellent moisture resistance has been required.

Accordingly, it is an object of the present invention to provide a resin package with further improved moisture resistance and low manufacturing cost.

[0010]

Means for Solving the Problems The present inventor has taken the following means in order to solve the above points. That is, a first aspect of the resin package of the present invention is a resin package main body for accommodating a semiconductor chip, one end of which extends into the resin package main body, and the other end of which extends outside the resin package main body. A lead member whose middle part is embedded in the package body, and whose one end is electrically connected to the semiconductor chip;
An oxide layer formed on a surface of one portion of the intermediate portion of the lead member, the oxide layer being thicker than an oxide layer formed on a portion other than the intermediate portion. .

By using the resin package having such a structure, the adhesiveness between the lead member and the resin package body can be improved, so that a resin package having more excellent moisture resistance than before can be provided. .

According to a second aspect of the present invention, there is provided a resin package body for accommodating a semiconductor chip, one end of which extends into the resin package body and the other end of which is provided with the resin package body. A lead member extending to the outside, an intermediate portion of which is embedded in the package body, and one end of which is electrically connected to the semiconductor chip; A periodic uneven portion having a pitch of 10 to 100 µm.

Since the unevenness is formed on the surface of the intermediate portion of the lead member, the adhesion between the lead member and the resin package body can be improved.
It is possible to provide a resin package having more excellent moisture resistance than before.

Further, a semiconductor device according to the present invention is characterized by including the resin package of each of the above-described embodiments and a semiconductor chip housed in the resin package. By employing such a structure, a semiconductor device having higher moisture resistance than a conventional semiconductor device can be provided. Here, the semiconductor chip is preferably a solid-state imaging device, and among them, a CCD is preferable.

Further, according to the method of manufacturing a resin package of the present invention, a laser beam is irradiated in a pulsed manner onto a middle portion of a lead member for electrically connecting one end of the semiconductor chip to the semiconductor chip. Forming an oxide layer on an intermediate portion of the lead member, and integrally molding the resin and the lead member so as to extend the other end of the lead member to the outside and embed the intermediate portion in the resin. And a step.

When a resin package is manufactured by using such a manufacturing method, unlike a sand blast method or the like, it is possible to selectively process only a necessary portion without subjecting an object to be processed to masking or the like. The manufacturing process can be simplified as compared with the first embodiment.

[0017]

Embodiments of the present invention will be specifically described below with reference to the drawings. The resin package of the present invention includes a resin package body for housing a semiconductor chip and leads electrically connected to each electrode of the semiconductor chip. (1) Structure of Resin Package The resin package may have a structure of a lead mounting method or a surface mounting method. However, a structure called a hollow package in which a resin package body having a concave portion and leads are integrally formed. In contrast, the effects of the present invention are best exhibited.

FIG. 1 is a schematic sectional view of the resin package according to the present embodiment. The resin package 9 includes a box-shaped resin package body 1 and leads 3 (lead members). A semiconductor device in which the semiconductor chip is sealed in the resin package is formed by placing the semiconductor chip in the resin package and covering with a lid. That is, as shown in FIG. 1, a concave portion 5 for accommodating the semiconductor chip 2 is provided at the center of the resin package main body 1.
Is fixed by the adhesive 6. Each electrode (not shown) of the semiconductor chip 2 is electrically connected to the lead 3 via a bonding wire 7. In addition, resin package 1
A lid 4 is adhesively fixed to an upper end surface 1a of the resin package 1 with an adhesive 8, whereby an upper opening 1b of the resin package 1 is closed. The molded body in which the lead 3 and the resin package body 1 are integrated is the resin package of the present invention.

The method for manufacturing such a resin package is not particularly limited. As an example, the resin package body 1 can be manufactured by transfer molding or injection molding. At this time, prior to molding the resin, the lead frame 3 is inserted into a mold in advance, and then the resin is injected and cured or solidified to manufacture a resin package.

FIG. 2 shows that the resin package 9 is connected to the upper opening 1.
The top view seen from b side is shown. Leads 3 are embedded in the resin package body 1, and one end (inner lead 3 a) extends into the resin package body and is connected to the semiconductor chip 2, and the other end ( The outer leads 3b) extend outside the resin package body 1 and are exposed. In such a state, an intermediate portion 11 of the lead 3 between the inner lead 3a and the outer lead 3b is embedded in the resin package body 1, that is, the resin 10 constituting the resin package body 1.

Therefore, the intermediate portion 11 of the lead 3 is fixed in the resin 10, whereby the lead 3 is fixed in a positioned state. The leads 3 are electrically connected to the semiconductor chip 2 via the inner leads 3a. (2) Resin package body The constituent material of the resin package body 1 is a thermosetting resin such as an epoxy resin, a polyimide resin, a phenol resin, an unsaturated polyester resin, or a silicone resin, or a liquid crystal polymer, polyphenylene oxide, or polyphenylene sulfide (PPS). Heat-resistant thermoplastic resins such as resin, polysulfone, polyamide-imide, and polyallyl sulfone resin. Among them, epoxy resin, polyimide resin, PPS and the like are preferable.

Further, inorganic fillers such as alumina powder, silica powder, silicon nitride powder, boron nitride powder, titanium oxide powder, silicon carbide powder, glass fiber and alumina fiber may be added to these heat resistant resins. . Further, in addition to the inorganic filler, if necessary, additives such as a curing agent, a curing accelerator, and a coupling agent may be contained. (3) Lead The material of the lead 3 is iron-nickel based alloy such as 42 alloy, iron-based alloy such as iron-nickel-chromium based, iron-nickel-cobalt based or magnesium, silicon, phosphorus, titanium, chromium, nickel. A copper-based alloy to which several kinds of metals are added from the group consisting of zinc, tin, and zirconium is used. In addition, metals and alloys commonly used as lead materials can also be used.

Here, a feature of the present invention is that the lead 3 has an oxide layer or a periodic uneven portion having a pitch of 10 to 100 μm on at least a part of the portion in close contact with the resin package body 1. Hereinafter, oxides and uneven portions, and methods for forming them will be described.

FIG. 3 is a plan view of the lead 3. In FIG. 3, an oxide layer 11a is formed on the surface of the intermediate portion 11 of the lead 3, that is, on a portion in close contact with the resin layer. The oxide layer 11a needs to be formed on at least a part of the surface of the intermediate portion 11 of the lead 3. As shown in FIG. 3, a box-shaped resin is formed so as to cross the intermediate portion 11 of each lead. Preferably, it is formed along the long side direction of the package body 1. When the oxide layer 11a is formed on the intermediate portion 11 of the lead 3 in this manner, the lead 3 and the resin are firmly adhered to each other, so that the water inflow path at the interface between the lead and the resin can be completely closed. .

It is necessary that the oxide layer is formed on at least one surface of the intermediate portion 11 of the lead 3. The oxide layer may be formed on only one surface of the lead surface or on both surfaces. However, if the oxide layer is formed on both surfaces of the lead surface, the effect of moisture resistance becomes more excellent.

Except for the intermediate portion 11 of the lead 3, that is, the inner lead 3a that is wire-bonded to the semiconductor chip 2 and the outer lead 3b that is connected to an external circuit are formed with an intentionally formed oxide layer. ,
When molding the resin package body 1, the inner leads 3a
Resin burrs firmly adhere to the surface and the surface of the outer lead 3b. Then, it is difficult to completely remove these resin burrs even in a cleaning operation in a later step, and the bonding force with the bonding wire 7 and other wiring may be weakened. Therefore, it is preferable that the oxide layer is formed only on the intermediate portion 11 of the lead 3.

Here, the oxide layer is a layer made of a metal or nonmetal oxide and having a certain thickness or more, and is not particularly limited as long as it is a layer obtained by processing the lead surface. However, the oxide layer formed on the surface of a part of the intermediate portion in the present invention does not include a surface oxide layer formed by naturally oxidizing a metal constituting a lead (hereinafter, this surface layer is referred to as a surface oxide layer). The oxide layer is referred to as “native oxide layer”).

The material of the oxide layer is preferably a metal oxide obtained from at least one metal among the metal materials constituting the leads 3 used. Specifically, such a metal oxide is obtained by oxidizing the surface of the lead 3 to be used. As a specific example of such a metal oxide, when a 42 alloy is used as the material of the lead, the oxide is iron oxide and / or nickel oxide. Other metal or nonmetal oxides having good properties may be used. As such an oxide layer, an oxide of iron is particularly preferably used.

The thickness of the oxide layer does not need to be uniform, and at least a part of the thickness is preferably from 5 to 500 nm, more preferably from 10 to 500 nm. The effect of the present invention is best exhibited when the thickness of the oxide layer is 50 to 500 nm. In addition, the oxide layer is formed in at least one place by 1.5 to 500 times the natural oxide layer formed on the surface other than the middle part of the lead.
It is desirable to have twice the thickness. The oxide layer is desirably formed from one end to the other end of the lead at the intermediate portion, and the width of the oxide layer is desirably 0.1 mm or more in the longitudinal direction of the lead. However, it does not need to be formed all over this range. As described above, it is considered that the presence of the oxide layer having the above-described thickness on at least a part of the lead surface improves the adhesion between the lead and the resin, but the reason is not clear.

When the oxide layer further has metal oxide fine particles having a particle size of 10 nm to 2 μm on the surface thereof, the oxide fine particles serve as an anchor to further improve the adhesion between the lead and the resin. Can be improved. The particle diameter of the oxide fine particles is more preferably 50 nm to 1 μm.

As a method for forming an oxide layer on the lead, thermal methods such as laser irradiation, electron beam irradiation, plasma processing, high-frequency induction heating, electric discharge machining, and flame treatment can be used. PVD (Physical Vapor Depositio)
An oxide layer may be formed on the lead surface using n), CVD (Chemical Vapor Deposition), or the like. However, considering the simplicity of the resin package manufacturing process, the above-described thermal method is suitable. In addition, the lead is in the form of an ultra-thin plate having a thickness of 0.1 to 0.3 mm. Since the material is mainly the above-mentioned iron-based alloy or copper alloy, heat input by heat treatment is reduced, and warpage of the lead is reduced. It is most important to make it smaller. That is, it is more effective to use a high-density heat source such as laser irradiation. When an oxide layer is formed on the lead surface by laser irradiation, the metal material constituting the lead evaporates in the laser-irradiated portion of the lead,
It is also considered that fine particles of metal oxide formed by scattering are deposited and adhered.

The intermediate portion 11 of the lead 3 shown in FIG. 3 has a pitch of 10 to 100 μm instead of an oxide layer.
Periodic uneven portions may be formed in one direction. The uneven portion is obtained by roughening the lead surface into a periodic shape. When such an uneven portion is formed in the middle portion of the lead, the adhesion between the lead and the resin is improved by the anchor effect. It is considered that the pitch and the surface roughness ( _Rmax ) of the uneven portion contribute to the adhesion between the lead and the resin.

The pitch of such uneven portions is 25 to 10
More preferably, it is 0 μm. R _max is
It is preferably from 1 to 100 μm. As the shape of such an uneven portion, the pitch is 30 to 50 μm, and R
_{The maximum} effect is exhibited when _max is 3 to 20 μm. In addition, it is necessary that the uneven portion is formed on one side of the surface of the intermediate portion 11 of the lead 3 so as to cross the intermediate portion 11 over a length of 0.1 mm or more in the longitudinal direction of the lead 3, It is preferable that the lead 3 is formed from one end to the other end in a direction crossing the intermediate portion. If the uneven portions are formed on both surfaces of the lead 3, the effect of the present invention is further exhibited.

As a method of forming the concave and convex portions on the lead 3, a method of irradiating the lead 3 with a laser or etching may be mentioned. However, considering the simplicity of resin package production, the laser irradiation on the lead 3 is suitable. I have.

The above-described surface oxide layer and the uneven portion may both be formed in the intermediate portion 11 of the lead 3. For example, an oxide layer having a thickness of 5 to 500 nm may be further formed on the surface of the uneven portion formed in the lead intermediate portion 11.

In the case where an oxide layer and / or an uneven portion is formed on the surface of a lead 3 made of an iron-based alloy or the like having an extremely thin plate shape by laser irradiation, it is desirable to use laser light in a near-infrared wavelength region. As the near-infrared laser light, a solid-state laser such as alexandrite or YAG can be used as one that maintains the shape of the lead during irradiation and can form an oxide layer on the lead.

The wavelength of the near-infrared laser light is 1 μm at which the reflectivity of energy by metal is low and the absorbance is high.
It is particularly desirable to be near. When a pulse laser is used as such a laser beam, a periodic uneven portion is easily formed in one direction. Q switch type N
The laser light of 1.06 μm emitted from the d: YAG laser is optimal as satisfying these conditions. When a Q-switched Nd: YAG laser is used, the output range for forming an oxide layer on the surface of the lead without deforming the lead is preferably 15 W to 50 W at the processing point. The Q switch frequency for stably irradiating the laser and improving the adhesion between the lead and the resin is 2 to 20 kHz, more preferably 2 to 8 kHz.
z, more preferably in the range of 4 to 7 kHz. By performing laser irradiation on the lead surface under such conditions, an oxide layer can be formed on the lead surface together with the uneven portions, so that a further effect can be obtained.

At the time of laser irradiation, if a galvanomirror scanning method using an f-θ lens system is used as a beam positioning method, a surface oxide layer and / or an uneven portion can be easily formed only at a necessary portion of a lead surface. Can be.

For example, a pulsed laser beam having a spot diameter of 80 μm on the irradiation surface is irradiated on the surface to be processed of the lead frame at the above-described frequency, and is scanned in a direction crossing the intermediate portion 11. Next, scanning is performed again while irradiating the laser beam to the surface of the lead frame 0.1 mm to 0.5 mm away from the scanned position. By repeating this several times, a plurality of linear laser light irradiation marks can be left on the processing surface of the lead frame. The number of laser beam scans may be one or more, but the greater the number, the greater the effect of the present invention. This laser beam
It is sufficient to scan until the entire area of the lead frame covered with the resin is irradiated.

Therefore, there is no need for any pre-treatment such as masking in advance the portions (inner lead portions 3a and outer lead portions 3b) which are not subjected to surface roughening as in the conventional sandblasting method, and no jigs are required. Product cost can be reduced.

[0041]

EXAMPLE A preliminary test was conducted in advance by the following method, and the effects of the oxide layer formed on the lead and the irregularities were examined.

(Experiment 1) First, as shown in FIG. 4, a narrow extension piece 14b is extended from one end of a rectangular base 14a, and is made of a 42 alloy made of 0.25 mm thick. By using the metal plate 14 and changing the surface treatment method, four types of metal plates were prepared. The surface treatment was performed on almost the entire surfaces of both surfaces of the extension piece 14b by the method described below.

Surface treatment A method: Q of rated 50 W output
Wavelength 1.06 by switch type YAG laser irradiator
μm, Q switch frequency 6 kHz, beam scanning speed 20
0mm / sec, aperture fully open, 100m from processing point
The laser beam is irradiated under the conditions of a laser output of 22.2 W below m and a spot diameter of 80 μm on the irradiation surface. The laser beam is irradiated on the entire surface of the extension piece 14b by scanning the extension piece 14b a plurality of times at intervals of 0.15 mm.

Surface treatment B method: Alumina powder having an average particle diameter of 14 μm was subjected to a sand blasting process with a diameter of 3.
Air blast is performed from a 0 mm nozzle under the conditions of an air pressure of 5 kg / cm ² G and a feed speed of 18 mm / sec.

Surface treatment C method: Q of rated 50 W output
Wavelength 1.06 by switch type YAG laser irradiator
μm, Q switch frequency 12 kHz, beam scanning speed 2
00mm / sec, aperture fully open, 100 from processing point
The laser beam is irradiated under the conditions of a laser output of 22.2 W below mm and a spot diameter of 80 μm on the irradiation surface.
This laser beam is scanned a plurality of times on the extension piece 14b at intervals of 0.15 mm, so that the extension piece 14b
Irradiate the entire surface of

Surface treatment D method: Nothing is done. next,
An extension piece 1 of each metal plate 14 that has been subjected to the surface treatments A to D above in a die 12 for producing a drawing test piece indicated by a solid line in FIG.
4b, insert epoxy resin at 165 ° C, 120Kg / c using a transfer molding machine.
The molding was performed under the conditions of m ² and 2 minutes. These molded articles were used as test pieces.

Using a tensile tester (Tensilon UCT-5T), the pull-out adhesive strength (K) between the metal plate and the epoxy resin layer was measured.
g) was measured under the conditions of a tensile speed of 5 mm / min. The number of samples was set to 5, and the average value was defined as the pull-out adhesive strength. The results are shown in Table 1. At this time, the size of the bonding surface between the extension piece 14b of the metal plate 14 and the epoxy resin is 4 mm in width on one side of the extension piece 14b and 5 mm in the pulling direction.

As shown in Table 1, the test pieces to which the surface treatment A was applied (hereinafter referred to simply as "test pieces A";
D). The same result was obtained with the highest pull-out adhesive strength. With respect to the test piece C, the same pull-out adhesive strength as that of the test piece B was obtained, and it was found that the surface treatment of the lead by laser irradiation was effective.

[0049]

[Table 1] (Experiment 2) A lead frame plate having twelve leads 3 shown in FIG. 3 was prepared, and the same surface treatments A to D as in Experiment 1 were applied to both surfaces of the intermediate portion 11 of each lead 3. In the surface treatment B method, the inner lead portion 3a and the outer lead portion 3
b) is masked using a jig or a seal tape,
The exposed intermediate portion 11 was subjected to sandblasting. In the surface treatment methods A and C, laser was applied only to the intermediate portion 11 by laser beam scanning. Then, surface treatment A,
Each of the lead frames processed by the methods B, C and D was used to obtain a hollow resin package made of epoxy resin as shown in FIG. 2 by using a transfer molding machine. A glass lid was put on the resin package using an epoxy resin adhesive and sealed, and a pressure cooker test was performed. The test conditions are as follows: leave in a steam of 121 ° C. and 100% for a predetermined time, and then place in a constant temperature room of 25 ° C. for 30 minutes;
Fogging was observed on the glass lid. The number of samples was set to 10, the average time until fogging was defined as the endurance time, and the results are shown in Table 2. The longer the durability time, the better the moisture resistance.

As in Experiment 1, the result of the surface treatment A was the best, and the result of the surface treatment C was almost the same as that of the sandblast (surface treatment B).

[0051]

[Table 2] (Experiment 3) Next, the test piece of Experiment 1 (see FIG. 5)
Surface treatment A was performed while changing the switch frequency, and the Q-switch frequency dependence of the pull-out adhesive force was examined. The number of samples was set to 5, and the average value was defined as the pull-out adhesive strength. The results are shown in FIG. The Q-switch frequency changes significantly between 6-8 kHz, both the pull-out adhesive strength and the endurance time change to 7 kHz.
It was determined that the durability time was the best below.

(Experiment 4) Further, the relationship between the presence / absence of oxide attachment by laser irradiation and the pull-out adhesive strength was examined. In order to create a state without oxide deposition, the Q switch frequency is 6 kHz.
The test piece prepared in z was sufficiently washed with an ultrasonic cleaner to remove oxide fine powder. The number of samples was set to 5, and the average value was defined as the pull-out adhesive strength. Table 3 shows the results. It was determined that the presence or absence of the oxide greatly contributed to the improvement of the pull-out adhesive strength.

[0053]

[Table 3] (Experiment 5) For each of the test pieces (see FIG. 5) subjected to the surface treatments A, B, and C, the thickness of the oxide layer formed on the treated portion (extended piece 14b) and the natural nature of the portions other than the treated portion The thickness of the oxide layer was measured. The method for measuring the thickness of these oxide layers and natural oxide layers is as follows. First, a laser beam was irradiated until a relatively thick oxide layer was formed on the surface of the extension piece 14b that had not been subjected to the surface treatment.
Then, the extended piece on which the oxide layer was formed was cut, and the cross section was observed with a scanning electron microscope (SEM). When the cross section of the extension piece is observed by SEM, the oxide layer looks different in contrast from the metal part. Therefore, the thickness of this oxide layer was measured using the difference in contrast observed from a micrograph by SEM.

Further, in this extended piece, the same location where the thickness of the oxide layer was measured by the SEM image was measured by Auger spectroscopy. That is, the oxygen peak was traced while etching the lead surface with Ar ions, and the point where the peak was saturated to a low value was defined as the boundary between the oxide layer and the metal. The conditions of Auger spectroscopy at this time are as follows. While etching the lead surface with Ar ions at an acceleration voltage of 2 kV, an acceleration voltage of 5 kV,
An electron beam was irradiated at a current of 100 nA, an incident angle of 30 °, and a spot diameter of several μm, and the etching time and the peak intensity of oxygen were determined. The thickness of the oxide layer corresponding to the unit etching time was determined by calibrating the etching time up to the boundary with the value obtained from the SEM.

Extension piece 1 of each test piece subjected to each of the above treatments
Auger spectroscopy is performed on the surface of 4b under the above conditions, the oxygen peak is traced while performing etching, and the point where the oxygen peak is saturated to a low value is defined as the boundary of the oxide layer, and the etching time up to that point I asked. By calibrating the etching time, the thickness of the oxide layer formed on each of the extended pieces was determined. In each extension piece, the portion embedded in the resin was exposed to the surface by mechanically peeling off the resin and the extension piece, and the Auger spectroscopy was performed as described above.

The surface roughness (R _max ) of the treated part of each test piece
Is a surface roughness meter (SURFCOM, manufactured by Tokyo Seimitsu Co., Ltd.)
It measured using. Further, the pitch of the concave and convex portions is such that the resin and the extension piece are mechanically peeled off at the portion of the extension piece embedded in the resin to expose the surface of the extension piece, and the surface is exposed to an acceleration voltage of 15 kV. It was determined by SEM observation.

As is clear from Table 4, in the treated portions of the test pieces A and C that were subjected to the laser irradiation, an oxide layer thicker than the oxidized substance formed on the other portions of the leads was formed. In addition, irregularities were formed on the surfaces of these treated parts. On the other hand, with respect to the test piece B subjected to the sandblast treatment, although the surface of the extended piece was roughened, the pitch was not measurable, so that it was determined that the periodic uneven portion was not formed. From this, it is considered that the oxide layer and the uneven portion due to the laser irradiation contribute to the moisture resistance of the lead (the durability time of the pressure cooker test).

The pitch of the irregularities on the surface of the test pieces A and C obtained by laser irradiation is equal to the spot interval on the surface of each test piece calculated from the frequency and scanning speed of the pulse laser. Was. Therefore, it is considered that the uneven portion formed by melting the metal of the portion irradiated with the pulse laser is effective for improving the moisture resistance of the lead.

[0059]

[Table 4] Next, with respect to each test piece, the resin and the extension piece were mechanically peeled off to expose the surface of the portion where each of the above-mentioned treatments was performed. The surface of the surface is traced using an Auger spectroscopic analysis while etching it with Ar ions under the above conditions, and the point where the oxygen peak is saturated at a low value is defined as the boundary between the oxide layer and the metal. The ratio of the thickness of the oxide layer between the treated part and the untreated part of each test piece was determined by using the ratio of the etching times of the test pieces.

As a result of Auger spectroscopy, the test piece A having the best results in the pull-out adhesive strength, the oxide layer formed in the treated portion, and the durability time in the pressure cooker test was the surface of the treated portion. The thickness ratio between the oxide layer and the native oxide layer was 1.5 to 500 times.

Further, oxide fine particles further adhered on the surface oxide layers of the test pieces A and C. The particle size of these oxide fine particles was determined by mechanically peeling off each test piece and extended piece, exposing the surface of the treated portion, and observing the surface with an SEM at an accelerating voltage of 15 kV. . The particle size of the oxide fine particles formed on the surface of the test piece A is 50
nm to 1 μm.

[0062]

According to the present invention, it is possible to provide a resin package for housing a semiconductor element, which is inexpensive and excellent in moisture resistance, can have a longer durable time than before even in a severe pressure cooker test.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a hollow package shown in an embodiment of the present invention.

FIG. 2 is a schematic plan view of the hollow package shown in the embodiment of the present invention.

FIG. 3 is a schematic plan view of a lead frame constituting a part of the hollow package shown in the embodiment of the present invention.

FIG. 4 is a plan view of a metal plate used in a preliminary test of an example.

FIG. 5 is a plan view of a mold for preparing a test piece used in a preliminary test of an example.

FIG. 6 is a graph showing the result of the Q-switch frequency dependence of the pull-out adhesive force of the example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin package main body 2 Semiconductor chip 3 Lead frame 3a Inner lead part (one end part) 3b Outer lead part (other end part) 11 Intermediate part 11a Oxide layer

Claims (19)

[Claims] A resin package main body for accommodating a semiconductor chip; one end extending into the resin package main body and the other end extending outside the resin package main body; A lead member embedded in the main body and one end of which is electrically connected to the semiconductor chip; and an oxide layer formed on a surface of a part of the intermediate portion of the lead member, wherein the lead member And a thicker oxide layer than other oxide layers formed in other portions of the resin package. 2. The resin package according to claim 1, wherein said oxide layer is made of an oxide of at least one metal among a plurality or a single metal material constituting said lead member. 3. The resin package according to claim 1, wherein the oxide layer is an oxide layer having a thickness in at least a part in a range of 5 to 500 nm. 4. The oxide layer according to claim 1, wherein the thickness of at least a portion of the oxide layer is 1.5 to 500 times the thickness of an oxide layer formed in another portion of the lead member. Item 4. The resin package according to any one of Items 3. 5. The method according to claim 1, wherein fine particles of an oxide having a particle diameter of 10 nm to 2 μm are further arranged on the surface of the oxide layer. Resin package. 6. The resin package according to claim 1, wherein said oxide layer is formed by irradiating a part of said lead member with laser light. 7. The resin package according to claim 6, wherein said laser light is a laser light having a wavelength in a range of 0.8 to 1.5 μm. 8. The resin package according to claim 6, wherein the laser light is a pulse laser. 9. The laser beam is a Q-switch type Nd: YAG.
The resin package according to claim 6, which is a laser beam having a wavelength of 1.06 µm emitted from a laser. 10. A resin package main body for accommodating a semiconductor chip, one end of which extends into the resin package main body and the other end of which extends outside the resin package main body, and an intermediate part of which extends between the package main body and the package. A lead member embedded in the main body and having one end electrically connected to the semiconductor chip; 0.1 mm in a longitudinal direction on a surface of an intermediate portion of the lead member;
It is formed over the above length, and its pitch is 10 to 1
A resin package comprising: a periodic uneven portion having a thickness of 00 μm. 11. The uneven portion has a surface roughness of 1 at _Rmax .
The resin package according to claim 10, wherein the thickness is from 100 μm to 100 μm. 12. The thickness formed on the surface of the uneven portion is 5
The resin package according to claim 10, further comprising an oxide layer in a range of about 500 nm. 13. The resin package according to claim 10, wherein said uneven portion is formed by irradiating a part of said lead member with a laser beam. 14. The resin package according to claim 13, wherein said laser light is a laser light having a wavelength in a range of 0.8 to 1.5 μm. 15. The resin package according to claim 13, wherein the laser beam is a pulse laser. 16. The laser beam is a Q-switch type Nd: YA
14. The resin package according to claim 13, which is a laser beam having a wavelength of 1.06 [mu] m emitted from the G laser. 17. The resin package according to claim 1, wherein said resin package is a hollow package having a cavity for accommodating a semiconductor chip. 18. A semiconductor device comprising: the resin package according to claim 1; and a semiconductor chip housed in the resin package. 19. An intermediate portion of a lead member for electrically connecting one end of the semiconductor chip to the semiconductor chip is irradiated with a laser beam in a pulsed manner while scanning with a laser beam, so that an oxide portion is applied to the intermediate portion of the lead member. Forming a layer, and extending the other end of the lead member to the outside and embedding the intermediate portion in the resin so as to integrally mold the resin and the lead member. Package manufacturing method.