JPH04249349A - Semiconductor device and manufacture there - Google Patents

Abstract

PURPOSE:To improve a resin sealed semiconductor device and a manufacturing method thereof concerning the reliability. CONSTITUTION:A single film layer of a silane coupling agent is deposited, at the covering ratio of 1exp-5 through 1, over the surface of components 10, 14 and 12 of a plastic seal semiconductor device. In the manufacturing method for this semiconductor device, the amount of the silane coupling agent sufficient to coat the surface of the components 10, 14, 12 is dispersed in vapor phase, or in liquid phase, and the elements are subjected to a coupling process in the liquid or the vapor phase. The deposition, or the formation, of a monomolecular layer of the silane coupling film leads to an improvement in the strength of joint between the plastic seal and the components, whereby the semiconductor device and the manufacturing method thereof can be enhanced with respect to the reliability.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor devices, and particularly to a technique that is effective when applied to resin-sealed semiconductor devices.

0002

[Prior Art] A semiconductor device in which a semiconductor pellet and an inner lead are electrically connected and each of the semiconductor pellet and the inner lead is sealed with a resin, a so-called resin-sealed semiconductor device, is used. .

In recent years, as semiconductor integrated circuit devices have become more highly integrated, the size of semiconductor pellets has tended to increase. As a result, distortion due to thermal cycling increases. That is,
As the stress increases, cracks occur in the resin sealing part.
There is a problem that occurs.

[0004] Therefore, the surface of each component constituting a semiconductor device, such as a semiconductor pellet or an inner lead, is treated with a silane coupling agent to combine the resin and the semiconductor pellet,
A method has been proposed to reduce the occurrence of cracks by strengthening the adhesive force with the inner lead. This type of technology is described in, for example, Japanese Patent Laid-Open No. 63-288050. Regarding silane coupling agents, for example, see the Japan Adhesive Association Journal Vol. 21 N
o. 6 pp 252-260 (1985).

[0005] In the technique described in the above publication, the step of treating each component with a silane coupling agent is performed immediately before the resin sealing step, for example, by connecting the semiconductor pellet to a die pad and connecting the external terminals of the semiconductor pellet to the die pad. This is done in the process after connecting the inner leads with bonding wires. Further, the treatment is performed by applying a silane coupling agent by potting.

[0006]

[Problems to be Solved by the Invention] However, as a result of studying the above-mentioned prior art, the present inventor found the following problems.

First, the bonding mechanism between metal or inorganic material and resin will be explained in detail.

FIG. 2 (conceptual diagram for explaining the bonding mechanism between metal or inorganic material and resin) is a conceptual diagram showing the most typical bonding state when resin is bonded to metal or inorganic material.

As shown in FIG. 2, polarized water (H2O) is usually adsorbed on the surface of a metal or inorganic material, and when the adsorption of this water becomes stable, one hydrogen (H) is removed. It becomes a hydroxyl group (OH). The hydroxyl groups cover the entire surface of the metal or inorganic material. In this way, when the resin component comes with the entire surface of the metal or inorganic material covered with hydroxyl groups, the functional groups of the resin component react with the hydroxyl groups. Generally, hydroxyl groups and alkoxy groups (OR) in the resin act to form typical hydrogen bonds as shown in the bonding layer of FIG. 2 above. Most common resins such as epoxy resins, polyurethane resins, and acrylic resins are bonded to metal or inorganic material surfaces through hydrogen bonds. The bond energy of such hydrogen bonds is 1/5 to 1/10 that of covalent bonds, ionic bonds, metal bonds, coordinate bonds, etc.
It has a relatively weak bonding energy.

On the other hand, since metals or inorganic materials and resins have different coefficients of thermal expansion, temperature changes can cause a difference in displacement, or strain, at the bonding interface, as shown in FIG.
Stress based on the difference in their respective elastic moduli is applied to the bonding interface. As a result, if the metal or inorganic material and the resin are bonded by hydrogen bonding, the stress reduces the bonding force. This can be expressed as Eb=Ech-σ...1. Here, Eb
represents (effective bond strength)/(one hydrogen bond group). Ech represents (hydrogen bonding force)/(one hydrogen bonding group). σ indicates (stress applied to one hydrogen bond).

At normal temperatures, all solid atoms are in thermal vibration. The amplitude of this thermal oscillation is distributed according to the Boltzmann low energy distribution. When the amplitude is expressed in terms of energy, it becomes as shown in FIG. 3 (a diagram in which the amplitude of solid molecules is expressed in terms of energy).

As shown in FIG. 3, bonds are broken in regions where solid molecules having energy higher than the bond energy exist (areas indicated by diagonal lines in FIG. 3). This phenomenon is the so-called joint surface deterioration phenomenon. Furthermore, the bonding surface exposed to the surface is attacked by gas molecules from the outside, as shown in FIG. 2 above. In particular, polarized water molecules
Easily approach the bonding layer from the outside. As shown in FIG. 4 (a diagram showing the amplitude of gas molecules in terms of energy), the energy distribution of these gas molecules is also distributed according to the Boltzmann low energy distribution, similar to the solid molecules. Therefore, when a molecule with energy greater than Eb collides with the bonding group from the outside, the bond is broken.

Due to the mechanism described above, peeling occurs at the bonding interface. The probability that this separation will occur is

[0014]

[Math 1]

It is expressed as: Here, C represents a constant related to the bonding force of the lattice and the mass of the constituent atoms. k represents Boltzmann's constant. T indicates temperature. NA indicates Avogadro's number. 22.4 (l/mol) indicates the volume of gas when the outside air is 1 atm. n indicates the linear density (pieces/cm) of bonding groups. Here, the first term on the right side is the probability of breakage due to lattice vibration. This breakage corresponds to the shaded area in FIG. 3 above. In addition, the second term on the right side is for the linear density of the bonding group when it breaks from the surface due to attack by gas molecules.
The linear density of gas molecules facing these bonding groups, that is, the probability of the hatched area in FIG. 4 is shown. The first term on the right side is a phenomenon that occurs over the entire joint surface, but since the Eb value changes depending on the stress distribution, it becomes a phenomenon that occurs more intensely at the point of maximum stress. That is, lowering the probability of failure P occurring at the interface exposed on the surface will reduce the interfacial peeling rate. In other words, by increasing Eb, the failure probability P
It is clear from Equation 1 above that the bonding strength can be increased and the reliability of the bonding can be improved because the bonding strength is reduced.

Improving the bonding group density has an effect only on the second term on the right-hand side, and also only in a proportional manner. For example, regarding the improvement of reliability by strengthening the coupling proposed by Hirayama, Totsuka, Nambu et al., see Nikkei Micro Devices, 1989, No. 4, pp. 97 to 103 (
1989). The technique described in this document is an improvement by creating a large number of hydrogen bonding groups in an epoxy resin containing a large number of hydroxyl groups. This method has the effect of improving n (linear density of bonding groups) in Formula 2 above. However, when resin sealing is performed using a mold, a release agent is mixed into the epoxy resin in order to facilitate separation of the sealing resin from the mold. For this reason, Fig. 5 (conceptual diagram for explaining the bonding mechanism between metal or inorganic material and resin mixed with mold release agent)
As shown in , the mold release agent is interposed between the epoxy resin and the semiconductor pellet surface or lead frame surface, which is originally desired to be strongly bonded, and thus inhibits hydrogen bonding. . For this reason, even if the number of hydroxyl groups mixed into the epoxy resin is increased, the value of n that can be increased is limited. Therefore, there was a problem that the strength of the joint could not be made sufficiently strong.

[0017] Furthermore, in the case of resin sealing using a mold, since a silane coupling agent is mixed into the epoxy resin, there is a possibility that covalent bonds stronger than hydrogen bonds may be formed. However, when the amount of the silane coupling agent mixed in is increased, the mold type and the silane coupling agent react, and a covalent bond is formed between the two. For this reason,
There is a problem in that the mold and the sealing resin are not easily separated from each other. Therefore, the amount of silane coupling agent that can be mixed into the sealing resin is limited in order to ensure separation between the sealing resin and the mold, so the bonding strength due to the effect of the silane coupling agent is reduced. The problem was that it was impossible to improve.

[0018] Furthermore, in the techniques described in JP-A-63-288050 and JP-A-63-237423, the coupling process is performed in the assembled state, but the mechanical Its strength is extremely weak, so care must be taken when handling it. Furthermore, since the outer surface of the assembled device has a complicated shape, there is a problem in that it is difficult to adsorb the silane coupling agent with a uniform film thickness.

FIG. 6 (chemical structure diagram for explaining the activity of silicon) shows a chemical structure showing the activity of silicon. In contrast to the bonds of oxygen (O) and hydrogen (H) to silicon (Si), silicon has a large spread of d orbitals (electron clouds), so it also has the property of easily reacting with other substances {carbon (
C) has no spread of this d orbit}. For example, Figure 6
As shown in , when an oxygen atom approaches silicon, electron clouds overlap covalently, and the oxygen atom becomes constrained. Accordingly, the bonding force between silicon and hydrogen and carbon weakens,
Beyond the activation region of thermal vibration energy, etc., the covalent bond of the oxygen atoms alone is completed. Silane containing silicon atoms is
This action forms strong covalent bonds directly with oxygen atoms on inorganic substances and metals. This is explained in FIG. 7 (a conceptual diagram for explaining the reaction mechanism of silane). As shown in FIG. 7, hydroxyl groups and alkoxy groups, which are functional groups attached to silicon, approach hydroxyl groups on the solid surface through hydrogen bonds. Then, by applying heat treatment, dehydration condensation occurs to form a covalent bond. The bonding force in this case is 5 to 10 times that of hydrogen bonding. The symbol Y in FIG. 7 indicates a functional group that has high reaction activity with the sealing resin. This functional group Y is also designed to cause a reaction to generate a coordinate bond or a covalent bond. Therefore, a strong bond is completed as a whole. As shown in FIG. 7, a state in which silane is coated with a monomolecular layer is ideal.

However, as in the prior art, for example,
When the silane coupling agent is applied by potting, it is difficult to form a monomolecular layer of the silane coupling agent, and a two or more molecular layer of the silane coupling agent is formed. When two or more molecules of silane overlap, the functional group Y, hydroxyl group, and alkoxy group are often set so that they do not bond with each other.
In the molecular layers of the second or higher molecular layers, each molecular layer is bonded by intermolecular attraction (van der Waals force). This intermolecular attraction is an extremely weak bond compared to other chemical bonds, so there is a problem that the bond between the sealing resin and metal bonded via these silane coupling agents becomes weak. Ta.

Furthermore, Japanese Patent Laid-Open No. 63-288051 proposes a method in which silicone oil is applied to a lead frame, and then a semiconductor pellet is attached and sealed. However, when coated with a material having a large molecular weight such as silicone oil, there is a problem in that a subsequent metal-to-metal bond (for example, a metal bond between a bonding wire and a bonding pad) cannot be formed.

An object of the present invention is to provide a technique that can improve reliability in a resin-sealed semiconductor device.

Another object of the present invention is to provide a technique that can improve reliability in the method for manufacturing the semiconductor device.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0025]

[Means for Solving the Problems] Among the inventions disclosed in this application, a brief overview of typical inventions will be as follows.
It is as follows.

(1) In a semiconductor device in which a semiconductor pellet and an inner lead are electrically connected and each of the semiconductor pellet and the inner lead is sealed with a resin, the surface of the semiconductor pellet and the inner lead is , a monomolecular layer of silane coupling film with a coverage of 1ex
Provided in the range of p-5 to 1.

(2) The semiconductor pellet and the multilayer wiring board or the multilayer TAB are electrically connected, and the multilayer wiring board or the multilayer TAB is electrically connected to the inner leads, and the semiconductor pellet and the multilayer wiring are connected electrically. In a semiconductor device in which a substrate or a multilayer TAB and an inner lead are each sealed with a resin, on the surfaces of the semiconductor pellet, the multilayer wiring board or the multilayer TAB and the inner lead,
A monomolecular layer silane coupling film with a coverage of 1exp
-5 to 1.

(3) Determine the surface area of each component constituting the semiconductor device, and calculate the amount of silane coupling agent necessary to cover each component with a coverage rate of 1 or less. the determined amount of the silane coupling agent is dispersed in the gas phase or liquid phase, and the surfaces of the respective components are coupled in the gas phase or liquid phase. The silane coupling agent is applied to the surface of each component at a coverage rate of 1exp-
It is adsorbed in the range of 5 to 1.

(4) By dispersing the silane coupling agent in an amount such that the coverage ratio is 1 or more with respect to the surface area of each component in the gas phase or liquid phase and controlling the time, A silane coupling agent is adsorbed onto the surface of the component at a coverage of 1exp-5 to 1exp-1.

(5) A step of subjecting each component constituting the semiconductor device to silane coupling, a step of assembling these silane-coupled components, and a step of metal-to-metal bonding between each component. The method includes a step of electrically connecting and a step of sealing each component with resin.

[0031]

[Operation] According to the above-mentioned means (1) or (2), the silane is present between each component such as the semiconductor pellet, the inner lead, the multilayer wiring board or the multilayer TAB, and the resin sealing part. Because there is a coupling membrane,
At least a portion of the bond between the two is a covalent bond. Therefore, a region is formed where the sealing resin and each component are bonded by covalent bonds, which have a stronger bonding force than hydrogen bonds, improving the bonding strength between the resin sealing part and each component. Therefore, the reliability of the semiconductor device can be improved.

According to the above-mentioned means (3), only an amount of the sila coupling agent is dispersed in the liquid phase or gas phase to cover each component with a coverage of 1 or less.
The silane coupling film formed on the surface of each component finally becomes a monomolecular layer. Therefore, a decrease in bonding strength, which is a problem when a silane coupling film of two or more molecular layers is formed, does not occur. In other words, since the bonding strength between each component and the sealing resin portion is improved, reliability in the method of manufacturing a semiconductor device can be improved.

At the same time, since the bonding strength between each component and the sealing resin is improved, mold release is possible regardless of the limit on the amount of silane coupling agent that can be mixed into the sealing resin. Since the bonding strength between each component and the sealing resin can be improved, the reliability of the semiconductor device manufactured using the mold can be improved.

According to the above-mentioned means (4), the coverage is controlled by using the silane coupling agent in an amount that gives a coverage of 1 or more and controlling the time, so that the above-mentioned means (3) It is possible to achieve the same effect as,
The time required for the coupling process can be shortened compared to the above-mentioned means (3).

According to the above-mentioned means (5), since the coupling treatment is performed for each component whose outer surface shape is simpler than that of the assembled product, the film thickness is uniform, that is, the silane coupling A monolayer of the agent can be formed. Thereby, the bonding strength between each component and the sealing resin can be improved, so reliability can be improved in the method of manufacturing a semiconductor device.

[0036] At the same time, since the coupling process is performed at the stage of each component, which has stronger mechanical strength than the assembled product, handling becomes easier. Therefore, deformation that occurs during handling can be reduced.
In a method for manufacturing a semiconductor device, reliability can be improved.

At the same time, since the silane coupling film formed on the surface of each component is a monomolecular layer, when forming a metal-to-metal bond between each component, the monomolecular layer of the silane coupling film is is easily destroyed. Therefore, metal-to-metal bonding can be easily formed, and the reliability of metal-to-metal bonding can be improved. Thereby, reliability can be improved in the method of manufacturing a semiconductor device.

[0038]

Embodiments Hereinafter, embodiments of the present invention will be explained in detail with reference to the drawings.

In all the figures for explaining the embodiment, parts having the same functions are given the same reference numerals, and repeated explanations thereof will be omitted.

First, the physical principle for making the coverage of the coupling agent 1 or less will be explained.

First, when a unit component is immersed in a liquid phase in which a silane coupling agent is dispersed, silane molecules enter the solid surface and are supplemented, causing adsorption. Molecules adsorbed on the surface are dissolved into the liquid phase again by thermal vibrational energy. The average residence time τ of the adsorbed molecules is given by the following equation, assuming that the detachment energy of the adsorbed molecules is -Ea (this matches the binding energy, -Eb).

[0042]

[Math 2]

[0043] Here, ν is the thermal vibration factor,
In the case of high temperature, it becomes large and τ becomes small. Furthermore, as the temperature T increases, τ decreases. Furthermore, it can be seen that as Ea increases, τ increases exponentially. It is clear that when the incident energy of molecules is R and the concentration of silane molecules adsorbed on the substrate is n, dn/dt=R-n/τ...4. Furthermore, when this equation 4 is integrated, n=Rτ{1-exp(-t/τ)}...5. If there are sufficient silane molecules in the liquid phase, this substrate adsorption concentration n is independent of the concentration of silane molecules in the liquid phase. The above is a case where only the case of a single layer is considered.

[0044] Letting the detachment energy of the second layer be Ea',

[0045]

[Math 3]

##EQU1## The increase in the adsorbed molecule concentration n' is also
This progresses simultaneously with the substrate adsorption concentration n of molecules in the first layer. Therefore, it becomes multilayered as shown in FIG. 8 (a diagram showing the relationship between the amount of silane adsorption and the immersion time from the first layer to the nth layer). Therefore, processing of less than a monolayer is essentially impossible. Furthermore, in methods such as spraying and coating, since the adsorption concentration n of the molecules on the substrate is the same as the amount of silane attached, it is essentially impossible to control the silane coupling film to be less than a monomolecular layer.

Next, the silane coupling treatment method of this embodiment will be explained using FIG. 9 (a diagram for explaining the silane coupling treatment method of the embodiment of the present invention).

As shown in FIG. 9, a unit component 5 such as a multi-lead frame having a surface area Scm2 is immersed in a tank 1 containing a diluent 3 (Wg) in which a silane coupling agent wg is dispersed. The diluent 3 is, for example, a silane coupling agent dispersed in an organic solvent. Here, the amount wg of the silane coupling agent is the minimum weight necessary to adsorb the surface area Scm2 of the unit component in a monomolecular layer. The amount wg of this silane coupling agent is determined by calculating from the minimum coverage area c (m2/g) calculated from the molecular radius of silane. That is, the amount wg of the silane coupling agent is w=S/C...7. Also, determine the size of tank 1 that is convenient for dipping, and determine the amount of diluted liquid Wg.
Determine. If the amount Wg of the diluent is too large, diffusion and convection will be the rate limiting factor when the silane molecules reach the unit component 5, so determine an appropriate amount. As described above, the adsorption energy (detachment energy) of each layer has the following relationship with Eb (first layer) and Eb' (second layer).

[0049]Eb>Eb'>Eb''>...8
Therefore, the average residence time of each layer is τ>τ'>τ''...9. Adsorption (immersion)
As time passes, as shown in Figure 10 (a diagram showing the relationship between the amount of silane adsorbed and the immersion time in the example of the present invention), the adsorption of multiple layers increases due to the difference in adsorption energy and average residence time for each layer. This will result in settling on the first layer. That is, by the above method, the coverage can be controlled to 1 or less.

Next, another method of silane coupling treatment according to an embodiment of the present invention is shown in FIGS. 11 and 12 (diagrams for explaining another method of silane coupling treatment according to an embodiment of the present invention). I will explain using This silane coupling treatment method is a method in which a concentration difference is provided in silane in a liquid phase, a unit component is moved in the liquid phase, and the coverage rate is controlled by dynamic diffusion control. Note that FIG. 11 shows a view seen from a direction perpendicular to the moving direction of the unit component, and FIG.
Here, a view as seen from a direction parallel to the moving direction of the unit component is shown.

As shown in FIGS. 11 and 12, diluent 3
A plurality of shielding plates (inner tank with holes) 7 are provided in the tank 1 to prevent convection as much as possible and to achieve homogeneous diffusion. Then, the amount wg of the silane coupling agent in the shielding plate 7 of the innermost tank is set to a value that satisfies a coverage of 1 or less with respect to the surface area Scm2 of the unit component 5 treated in the tank 1. Diffusion of silane molecules in the liquid phase has zero convection (no convection)
Then, D=D0exp(-E/RT)...10

[
0052

[Math 4]

It is expressed by Equations 10 and 11. Here, D represents the rate-limiting diffusion of silane molecules in the diluted solution 3. E indicates the activation energy of diffusion. x indicates the diffusion distance. t indicates time. T indicates temperature. R represents a gas constant. D0 indicates the frequency coefficient. The diffusion coefficient of organic molecules in an organic solvent is 10exp-5cm2/s (
10exp-9m2/s), which is extremely large. That is, from the above formula 11, 0.4 mm per minute
It can be seen that it progresses to some degree. If the temperature T is increased, it is also possible to increase D by one order of magnitude according to equation 10 above. Here, the diffusion is in the x-axis direction (direction of movement of the unit component 5)
If the amount of substance that diffuses per unit time per unit cross-sectional area is J, it is expressed as J=-D・dC/dx...12. C indicates concentration. dC/dx indicates the concentration gradient in a minute portion. Here, if the amount of silane that satisfies the coverage rate of 1 or less for the unit component 5 is w0g, the consumption amount of silane per unit time w(t)g is expressed as w(t)=w0・v...13 . here,
As shown in FIG. 12, v is the speed at which the unit component 5 advances per unit time, and the unit is pieces/s. That is, by determining the conditions that satisfy J<w(t)...14, a coverage of 1 or less can be achieved. Further, by sequentially supplying an amount of silane that satisfies this condition into the layer 1 from the silane inlet 9 shown in FIGS. 11 and 12, the unit components 5 can be continuously processed. In this case, from the relationship between the silane adsorption amount and the diluent concentration, as shown in FIG. Supply silane.

On the other hand, since the adsorbed silane is only adsorbed on the surface of the unit component 5 through hydrogen bonding, the heat treatment utilizes the reactive species (functional groups) of silicon to bond it to the unit component 5. It is dehydrated and condensed with silane to form a covalent bond as shown in FIG. 7 above. It is an important step to carry out this treatment almost completely to withstand subsequent treatments, and the conditions are 110 to 150°C, 5 to 60°C.
It is appropriate to carry out a heat treatment for 30 minutes. By performing this heat treatment, a structure is formed on the surface of the unit component 5, as shown in FIG. Coverage rate 1 shown in FIG. 7 above
To confirm whether the following structure exists, it is possible to make a determination using a dynamic wettability tester using the Wilhelmy method. FIG. 14 (diagram showing the sequence of the dynamic wettability test) shows the sequence of the dynamic wettability test. In FIG. 14, the horizontal axis shows elapsed time and the vertical axis shows force.

Test pieces without silane treatment, water-repellent and hydrophilic silane treatments were prepared and tested in water. The test results are shown in Figure 15 (a diagram showing the results of the dynamic wettability test without silane treatment) and Figure 16 (a diagram showing the results of the dynamic wettability test with water-repellent silane treatment). ) and FIG. 17 (a diagram showing the results of a dynamic wettability test when hydrophilic silane treatment was applied). In FIGS. 15 to 17, the horizontal axis represents elapsed time and the vertical axis represents force. The functional group Y shown in FIG. 7 is a typical example of a case where it is water repellent (FIG. 16) and a case where it is hydrophilic (FIG. 17). A coverage ratio of 0 to 1 is between no silane treatment and complete treatment. In this case, it is quantified using the three elements Tw, Wb, and Fw shown in FIG. 14. In particular, Tw is the rate of wetting with water, and since the rate of wetting is different from that of hydroxyl groups and other hydrophilic groups,
If the activation energy is obtained from the Arrhenius plot based on Tw under several temperature conditions and managed, more clear quantification becomes possible. The manufacturer of this tester is, for example, Resca WET6000 (1 Takamatsu-cho, Tachikawa-shi, Tokyo).
-100).

Note that when the coverage exceeds 1, the wetting curve is close to the curve after the treatment shown in FIG. 16 or 17, but Tw tends to further increase, and Tw, Wb
The content will be clarified by examining the difference in activation energy between and Fw.

When the treated film thickness when the coverage of the silane coupling agent is 1 is d, it is expressed as d=1/{(minimum coverage area)·(density)}...15. A typical silane cup agent has a minimum coverage area of 300 to 4000 m2/g. The density is ~1×
10exp6g/m3. Therefore, the thickness d is 2 to 3 nm.

The thickness of the natural oxide film formed on the aluminum wiring of the semiconductor substrate is said to be 3 to 10 nm. This thickness is destroyed during subsequent bonding of gold wire or aluminum wire, so metal-to-metal bonding can be easily formed. On the other hand, the thickness of the silane coupling film formed by the method of this example is 2 to 3
It is nm. Therefore, when forming a metal-metal bond, the silane coupling film is easily destroyed. Furthermore, since the coverage ratio of the silane coupling film is less than 1, there remains an area where the metal surface is exposed, so that the metal
Metallic joints can be easily formed. In other words, it is possible to process the film to a thickness that does not cause any problems in subsequent processing.

[Example 1] The configuration of a semiconductor device according to Example 1 of the present invention is shown in FIG. I will explain using

As shown in FIG. 1, the semiconductor device of the first embodiment electrically connects an external terminal (bonding pad) (not shown) of a semiconductor pellet 10 and an inner lead 12 with a bonding wire 16, and connects these semiconductors. Pellet 10, inner lead 12 and bonding wire 1
6 are each sealed with a resin sealing portion 17. The inner lead 12 is constructed integrally with the outer lead 13. The semiconductor pellet 10
is made of, for example, single crystal silicon. This semiconductor pellet 10 is fixed to a die pad 14 via an epoxy resin 11 containing silver. Each of the inner leads 12, outer leads 13, and die pad 14 is made of, for example, Fe-Ni (iron-nickel) alloy (so-called 42 alloy). Further, the outer lead 13 is connected to the mounting wiring board 20 through the solder 18.
It is electrically connected to the terminal 21 of.

The surfaces of the semiconductor pellet 10, inner leads 12, and outer leads 13 are as shown in FIG.
As shown by the dotted line, the monolayer film 2 of the silane coupling agent
5 is formed. The coverage rate of the silane coupling film 25 on the surfaces of the semiconductor pellet 10, the inner leads 12, and the outer leads 13 is 10exp-5.
It is 1 to 1. By providing this silane coupling film 18, the adhesive strength between each of the semiconductor pellet 10 and the inner lead 12 and the resin sealing portion 17 can be improved. Thereby, the reliability of the semiconductor device can be improved.

Next, the method for manufacturing the semiconductor device of Example 1 will be described in FIGS. 18 (flowchart showing the method for manufacturing the semiconductor device of Example 1) and FIGS. The method will be explained using a cross-sectional view of main parts to explain the method.

First, a silane coupling treatment is applied to a multi-lead frame which is a component of a semiconductor device. In this silane coupling treatment, as an aminosilane-containing coupling agent, for example, Sila Ace S310, manufactured by Chisso Corporation (2-7-3 Marunouchi, Chiyoda-ku, Tokyo), i.e., N-(2-aminoethyl)3- Aminopropyl・
Methyldimethoxysilane was used. The minimum coverage of this S310 is C=380 m2/g. An organic solvent such as toluene is placed as a dispersion medium (solvent) in a tank containing one multi-lead frame, and S31 is added to the toluene.
0 was dispersed by wg (see FIG. 11 above). The silane amount wg is determined by the method described above to be an amount that will cover the surface of the multi-lead frame at a coverage rate of 10exp-5 to 10exp-1. Further, the amount of toluene is an amount that can sufficiently immerse the multi-lead frame. Then, after pouring S310 into the diluent, it was sufficiently stirred and the multiple lead frame was immersed for 1 minute <1A>. Various treatments were performed for other times ranging from 10 seconds to 1 hour, and treatment effects were observed.

Next, the multi-lead frame was pulled out of the tank, air-dried, and then heat-treated at 130° C. for 10 minutes. By performing this heat treatment, as described above, the silane coupling agent and the multi-lead frame 16
The bond between can be made into a covalent bond. In other words, a silane coupling film that is firmly bonded to the surface of the multiple lead frame 16 can be formed.

On the other hand, the semiconductor wafer (before dicing) was similarly subjected to the silane coupling treatment <1B>, and then was subjected to the same heat treatment.

The amount of the silane coupling agent dispersed in the diluted liquid is such that each component (semiconductor pellet 10 and multiple lead frame 15) is coated with a coverage ratio of 1 or less. The silane coupling film (25) formed on the surface finally becomes a monomolecular layer. Unit component parts (semiconductor pellet 10 or multi-lead frame 1) with a simpler outer surface shape than assembled products
By applying silane coupling treatment to 5), a uniform film thickness, that is, a monomolecular film of silane coupling agent 2
5 can be formed. At the same time, since the silane coupling treatment is performed on each component (semiconductor pellet 10 and multi-lead frame 15) which has stronger mechanical strength than the assembled product, handling becomes easier. Therefore, deformation and the like that occur when handling the assembled finished product can be reduced. Thereby, reliability can be improved in the method of manufacturing a semiconductor device.

Next, as shown in FIG. 19, the semiconductor pellet 10 is placed on the die pad 14 of the multiple lead frame 15.
<2> was fixed with silver-containing epoxy resin 11. Thereafter, this epoxy resin 11 was cured at 150° C. for 5 minutes. Semiconductor pellets 10 are made of this epoxy resin 11.
When mounting with a die bond, the semiconductor pellet 1
Since silane coupling films 25 are formed on the surfaces of the die pads 14 of the zero and multi-lead frames 15, the bond between them can be strengthened.

Next, while heated to 150° C., the external terminals (not shown) of the semiconductor pellet 10 and the inner leads 12 of the multiple lead frame 15 are bonded using ultrasonic gold wire ball bonding as shown in FIG. <3> which was electrically connected to. At this time, a silane coupling film 25 is formed on the entire surface of the semiconductor pellet 10 except for the cut surface, and on the entire surface of the multiple lead frame 14. However, as described above, the thickness of this silane coupling film 25 is such that it is easily destroyed when forming a metal-to-metal bond (bonding), and the coverage ratio is 1 or less. Therefore, a reliable metal-to-metal bond can be formed during bonding, and the external terminal of the semiconductor pellet 10 and the inner lead 12 can be electrically connected.

Next, as shown in FIG. 21, it was resin-sealed with a molded epoxy resin of epoxy novolac/phenol novolac silica type <4>. In this molding process, the semiconductor pellet 10 and the inner lead 1 are
Since a monomolecular layer of silane coupling film 25 is formed on the surface of 2 with a coverage in the range of 10exp-5 to 1, a problem will arise if a silane coupling film of two or more molecular layers is formed. No reduction in bonding force occurs. Therefore,
The bonding strength between the semiconductor pellet 10 and the inner lead 12 and the sealing resin 17 can be improved. In addition, the semiconductor pellet 10, the inner lead 12, and the sealing resin 17
Since the bonding strength between the semiconductor pellet 10 and the inner lead 12 is improved, mold releasability is ensured regardless of the limit on the amount of silane coupling agent that can be mixed into the sealing resin 17. The bonding strength between each and the sealing resin 17 can be improved.

By performing the above steps, the semiconductor device of Example 1 is completed. Next, the outer leads 13 were plated with solder. At this time, a good plating coating was formed by the usual degreasing treatment and pre-cleaning process. In other words, the silane coupling film 25 is formed on the surface of the outer lead 13, but this silane coupling film 25 is easily destroyed in the degreasing and cleaning process, forming a good plating film. be able to.

Next, the outer lead 13 was shaped and cut <5>. After this, electrical characteristics were inspected and burn-in (quenching) was performed. Thereafter, the semiconductor device is mounted on a printed circuit board (PCB).
<6>. At this time, since the outer leads 13 are plated with good solder, the electrical connection between the outer leads 13 and the mounting wiring board 20 can be ensured. Furthermore, in the reflow process, cracks occur due to temperature changes, but according to the manufacturing method of Example 1, no cracks were observed, and the resin sealing part 17 and the semiconductor pellet 10 It can be seen that they are firmly joined to the inner lead 12.

Furthermore, productivity can be improved by using multiple silane dilution tanks as shown in FIG. In addition, the amount of residual silane corresponding to the processing time w for the solution after processing one sheet
´ in advance, and determine the amount of silane replenishment w2 from next time onwards.
By replenishing as =w-w', the silane diluted solution can be used repeatedly. It goes without saying that the solvent should be added at an appropriate number of times depending on the amount of solvent pumped out. Since a dipping time of 10 seconds to 1 hour is effective, it can be seen that even if the number of bonding groups is small, the effect of the bonding strength Eb is large.

[Embodiment 2] Next, a method for manufacturing a semiconductor device according to Embodiment 2 of the present invention will be described. In the method of manufacturing a semiconductor device according to the second embodiment, in the method of manufacturing a semiconductor device according to the first embodiment, the silane coupling treatment is performed by the method shown in FIGS. 11 and 12.

In the manufacturing method of Example 2 of the present invention, for example, Sila Ace S510 manufactured by Chisso Corporation, ie, 3-glycidoxypropyltrimethoxylane, was used as the epoxy silane coupling agent. This S510wg is charged into the silane inlet of the tank shown in FIGS. 11 and 12 each time a multiple lead frame or semiconductor wafer passes through a predetermined section, and the bonding gold wire is also reeled in the same manner.
The silane treatment was performed by supplying the material on a reel (in this case, the required amount wg of silane per unit length was determined). The above three unit components (lead frame, semiconductor chip, gold wire) were assembled in the same manner as in Example 1 above. As a result, good results were obtained.

The shielding plate of the tank of Example 2 has, for example, an opening area of 30 to 70%, a direct diameter of the opening of 0.5 to 1 mm, and a plate thickness of 0.5 mm. The distance between this shielding plate and the inner tank is
For example, it was set to around 5 mm. This shielding plate was provided in the inner tank of the two layers. Alternatively, if it is a sponge-like material with a thickness of about 0.5 mm, only one shielding plate is sufficient. It goes without saying that the supply amount w2=w-w' depending on the coverage rate.

[Example 3] Next, the configuration of a semiconductor device according to Example 3 of the present invention is shown in FIG. This will be explained using Figure).

As shown in FIG. 22, the semiconductor device of Example 3 is the same as that of Example 1, except that the semiconductor pellet 10 is placed on a multilayer wiring board or a multilayer TAB 30.
This multilayer wiring board or multilayer TAB 30 and the inner leads 12 are electrically connected via solder 31, and each of these semiconductor pellets 10, the multilayer wiring board or multilayer TAB 30, and the inner leads 12 is , and is sealed with a resin sealing part 17.

In the method for manufacturing a semiconductor device according to the third embodiment,
It goes without saying that the silane coupling treatment of Example 1 or Example 2 is applied to the surface of the multilayer wiring board or multilayer TAB 30.

[Example 4] Next, the configuration of a semiconductor device according to Example 4 of the present invention is shown in FIG. This will be explained using Figure).

As shown in FIG. 23, the semiconductor device of Example 3 is the same as the semiconductor device of Example 1, in which external terminals (not shown) of the semiconductor pellet 10 are connected to bump electrodes 3.
3, the semiconductor pellet 10 and the inner lead 12 are partially sealed by potting. It is a device.

In the method for manufacturing a semiconductor device according to the third embodiment,
It goes without saying that the silane coupling treatment of Example 1 or Example 2 is performed before cutting the polyimide film 34 to which the inner leads 12 are fixed.

[0082] The present invention has been specifically explained above based on examples, but it goes without saying that the present invention is not limited to the above-mentioned examples and can be modified in various ways without departing from the gist thereof. .

For example, in Examples 1 and 2, N-(2-aminoethyl) was used as the silane coupling agent.
Although examples using 3-aminopropyl methyldimethoxysilane and 3-glycidoxypropyltrimethoxyrane have been shown, the present invention is also applicable to other silane coupling agents, such as
N-(2-aminoethyl)3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane,
2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane and the like can be used. In other words, a functional group that couples to each component of a semiconductor device or an electronic device includes an alkoxy group such as a hydroxyl group, a methoxy group, or an ethoxy group, and a functional group that couples to an epoxy resin as a sealing resin. Y may be any silane containing an amino group, an epoxy group, a mercapto group, a glycidyl group, a carbonyl group, or the like.

Further, in Examples 1 to 4, a semiconductor device in which a semiconductor pellet and an inner lead, or a semiconductor pellet and a mounting wiring board or a multilayer TAB are sealed with resin is shown, but the present invention is not limited to other embodiments. It is also possible to perform coupling treatment on the surface of each unit component of a semiconductor device or an electronic device, for example, a multi-chip (module) type electronic device, a hybrid type integrated circuit device, or the like.

Further, in Examples 1 to 4, the silane coupling treatment was performed in the liquid phase, but the present invention can also perform the silane coupling treatment in the gas phase.

[0086]

Effects of the Invention A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

[0087] Reliability can be improved in a resin-sealed semiconductor device.

[0088] In the method for manufacturing a semiconductor device, reliability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a main part showing a state in which a semiconductor device according to a first embodiment of the present invention is mounted on a mounting wiring board.

FIG. 2 is a conceptual diagram for explaining a bonding mechanism between metal or inorganic material and resin.

FIG. 3 is a diagram showing the amplitude of solid molecules in terms of energy.

FIG. 4 is a diagram showing the amplitude of gas molecules in terms of energy.

FIG. 5 is a conceptual diagram for explaining a bonding mechanism between a metal or an inorganic material and a resin mixed with a mold release agent.

FIG. 6 is a chemical structure diagram for explaining the activity of silicon.

FIG. 7 is a conceptual diagram for explaining the reaction mechanism of silane.

FIG. 8 is a diagram showing the relationship between silane adsorption amount and immersion time from the first layer to the nth layer.

FIG. 9 is a diagram for explaining a silane coupling treatment method according to an embodiment of the present invention.

FIG. 10 is a diagram showing the relationship between silane adsorption amount and immersion time in an example of the present invention.

FIG. 11 is a diagram for explaining another method of silane coupling treatment according to an embodiment of the present invention.

FIG. 12 is a diagram for explaining another method of silane coupling treatment according to the embodiment of the present invention.

FIG. 13 is a diagram showing the amount of silane adsorbed and the concentration of the diluted solution versus the treatment time, and the time point at which silane is supplied versus the concentration of the diluted solution.

FIG. 14 is a diagram showing the sequence of a dynamic wettability test.

FIG. 15 is a diagram showing the results of a dynamic wettability test without silane treatment.

FIG. 16 is a diagram showing the results of a dynamic wettability test when water-repellent silane treatment was applied.

FIG. 17 is a diagram showing the results of a dynamic wettability test when hydrophilic silane treatment is applied.

FIG. 18 is a flowchart showing a method for manufacturing a semiconductor device according to Example 1 of the present invention.

FIG. 19 is a cross-sectional view of a main part for explaining a method for manufacturing a semiconductor device according to Example 1 of the present invention.

FIG. 20 is a sectional view of a main part for explaining a method for manufacturing a semiconductor device according to Example 1 of the present invention.

FIG. 21 is a sectional view of a main part for explaining a method for manufacturing a semiconductor device according to Example 1 of the present invention.

FIG. 22 is a sectional view of a main part showing a state in which a semiconductor device according to a second embodiment of the present invention is mounted on a mounting wiring board.

FIG. 23 is a sectional view of a main part showing a state in which a semiconductor device according to a third embodiment of the present invention is mounted on a mounting wiring board.

[Explanation of symbols]

10 Semiconductor pellets 12 Inner lead 13 Outer lead 14 Die pad 16 Bonding wire 17 Resin sealing part 18 Solder 20 Mounted wiring board 21 Terminal 25 Silane coupling film

Claims (5)

[Claims] 1. A semiconductor device in which a semiconductor pellet and an inner lead are electrically connected and each of the semiconductor pellet and the inner lead is sealed with a resin, in which a single layer is provided on the surfaces of the semiconductor pellet and the inner lead. 1. A semiconductor device comprising a molecular layer silane coupling film with a coverage in the range of 1exp-5 to 1. Claim 2: Semiconductor pellet and multilayer wiring board or multilayer T
AB and electrically connect the multilayer wiring board or multilayer TAB to the inner lead, and seal each of the semiconductor pellet, the multilayer wiring board or multilayer TAB, and the inner lead with resin. In the semiconductor device formed by the semiconductor pellet, the multilayer wiring board or the multilayer T.
1. A semiconductor device characterized in that a monomolecular layer of silane coupling film is provided on the surfaces of AB and inner leads with a coverage in the range of 1exp-5 to 1. 3. Determine the surface area of each component constituting the semiconductor device, and calculate the amount of silane coupling agent necessary to cover each component with a coverage rate of 1 or less as the surface coverage rate of the silane coupling agent. and determined from the surface area of each component,
The determined amount of the silane coupling agent is dispersed in a gas phase or liquid phase, and the surface of each component is subjected to a coupling treatment in the gas or liquid phase, and a silane cup is placed on the surface of each component. 1. A method for manufacturing a semiconductor device, comprising adsorbing a ring agent at a coverage of 1exp-5 to 1. 4. By dispersing a silane coupling agent in the gas phase or liquid phase in an amount such that the coverage ratio is 1 or more with respect to the surface area of each component, and controlling the time, each of the components Coverage rate of silane coupling agent on the surface of parts is 1
4. The method for manufacturing a semiconductor device according to claim 3, wherein the adsorption is performed in a range of exp-5 to 1. 5. A step of subjecting each component constituting the semiconductor device to a silane coupling treatment, a step of assembling each of the components subjected to the silane coupling treatment, and an electrical connection between each component by metal-to-metal bonding. 5. The method of manufacturing a semiconductor device according to claim 3, further comprising a step of connecting each component to a semiconductor device, and a step of sealing each component with a resin.