JPH07283253A - Method for manufacturing semiconductor device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a method for manufacturing a semiconductor device, which does not require a frame mounting step and can improve productivity. [Structure] A semiconductor element is mounted on a substrate, and a screen having an opening is placed on the substrate with the semiconductor element accommodated in the opening, and then a predetermined amount of a resin sealing material is squeegeeed from the substrate. A method of manufacturing a semiconductor device in which a substrate and a semiconductor element are integrally sealed by being embedded in the opening by removing the screen, wherein the resin encapsulant has optical transparency and the screen is removed. After that, it is made of a material that hardens while maintaining a shape substantially the same as the opening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical semiconductor device in which a semiconductor element such as a light emitting element or a light receiving element is integrally resin-sealed on a substrate.

[0002]

2. Description of the Related Art Generally, when manufacturing an optical semiconductor device including a substrate and a semiconductor element such as a light receiving element mounted on the substrate, a resin sealing material for integrally sealing the substrate and the semiconductor element is used. A thermosetting resin having good light transmittance is used.

However, the conventional thermosetting resin used has a low viscosity. Moreover, when the filler is highly filled to increase the viscosity or to impart thixotropic property which is a flow property suitable for screen printing, there is a drawback that the required properties such as satisfactory light transmittance are impaired.
Therefore, in order to conventionally manufacture an optical semiconductor device, a frame or the like for preventing the flow of resin is required,
In addition, a step of attaching them on the substrate is required separately.

For example, as shown in FIGS. 4 (a) and 4 (b), first, a substantially rectangular frame 2 is attached to a substrate 1 with an adhesive,
Next, the semiconductor element 3 such as the IC 3a and the photodiode 3b is die-bonded onto the substrate 1 in the frame 2. Then, after the IC 3a and the photodiode 3b are wire-bonded to a bonding pad (not shown) on the substrate 1, the thermosetting resin 4 is applied to the inside of the frame 2 with a dispenser or the like for resin sealing.

[0005]

However, in the above method, if the frame 2 is not adhered well to the substrate 1, the thermosetting resin 4 having a low viscosity applied to the frame 2 may leak out of the frame 2. there were. Further, the adhesive itself used for mounting the frame 2 spreads on the bonding pad and the wire bonding property is deteriorated.

Further, the work is carried out on a one-to-one basis with the object to be processed such as mounting the frame 2 and applying the thermosetting adhesive 4 into the frame 2, so that there is a problem that the tact time is limited and the productivity is poor. It was The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a semiconductor device that does not require a frame attaching step and can improve productivity.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is a state in which a semiconductor element is mounted on a substrate, and a screen having an opening is accommodated in the opening. A method for manufacturing a semiconductor device in which a predetermined amount of resin sealing material is embedded in the opening with a squeegee from the substrate after the substrate is arranged, and the screen and the semiconductor element are integrally sealed by removing the screen. The resin encapsulant is made of a material that is light-transmissive and hardens while removing the screen and maintaining a shape substantially the same as the opening.

According to a second aspect of the present invention, as the resin encapsulating material in the first aspect of the invention, a resin sealing material containing a thermosetting resin, a curing agent and a thixotropic agent is used. It is a thing. Furthermore, the invention according to claim 3 is such that an epoxy resin is used as the thermosetting resin in the invention according to claim 2. Further, the invention according to claim 4 is such that, as the curing agent in the invention according to claim 2 or 3, a material having a small change in viscosity when left standing is used.

[0009]

According to the present invention, when the resin encapsulating material is embedded in the opening of the screen and then the screen is removed, the resin encapsulating material cures while maintaining a shape substantially the same as the opening. The resin sealing material is applied to a predetermined area.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a semiconductor device according to the present invention will be described below with reference to the drawings. FIG. 1 is a process diagram showing an example of a method for manufacturing a semiconductor device of the present invention, and FIG. 2 is a sectional view of an example of a semiconductor device manufactured by this embodiment. The present invention is a method for manufacturing an optical semiconductor device in which a substrate and a semiconductor element mounted on the substrate are integrally sealed. The feature is that a light-transmissive resin encapsulant having excellent flow characteristics suitable for screen printing, that is, thixotropic property is used, and encapsulation is performed by screen printing.

For example, as shown in FIG. 2, a semiconductor device in which a substrate 1 and a semiconductor element 3 composed of an IC 3a and a photodiode 3b mounted on the substrate 1 are integrally sealed with the resin sealing material 6 described above. In the case of manufacturing, the IC 3a and the photodiode 3b are first arranged on the substrate 1 and die-bonded. After that, the IC mounted on the substrate 1
3a and the photodiode 3b are wire-bonded to a bonding pad (not shown) on the substrate 1.
Then, a light-transmissive resin encapsulant 6 having thixotropic properties is screen-printed on the substrate 1.

The resin sealing material 6 used here is mainly composed of a thermosetting resin, a curing agent, and a thixotropic agent. As the thermosetting resin, for example, an epoxy resin having good light transmittance and moisture resistance is used.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, glycidyl ester type epoxy resin, glycidyl ether of aliphatic alcohol, polyglycidyl ether of novolac type phenol resin, polyglycidyl polyfunctional phenol type epoxy. Examples thereof include resins, polyglycidyl amine type epoxy resins, and epoxy resins having a chelate structure. These epoxy resins may be used alone or in combination of two or more. In addition, a flexible epoxy resin is blended with the epoxy resin in order to improve heat cycle resistance.

As the above-mentioned curing agent, a material whose viscosity changes little when left standing is used. That is, a material that is stable at room temperature for a long time and that is rapidly cured by receiving heat is used.

For example, an acid anhydride system whose viscosity changes little with time and whose moisture absorption is low is used. Alternatively, amine-based curing agents such as tertiary amines, quaternary ammonium salts, and aromatic amines, which have little moisture absorption before curing and are unlikely to cause curing defects due to bonding with water in the air or carbon dioxide, are also used. It is possible. In addition, a urea compound, an epoxy group polymerization catalyst type curing agent, a boron trifluoride complex compound and the like can be used. The compounding ratio of this curing agent and the above-mentioned thermosetting resin can be the same as in the case of a general thermosetting resin, for example.

On the other hand, as a thixotropic agent for imparting thixotropy to the resin encapsulant 6, inorganic materials such as quartz, calcium carbonate, titanium oxide and boron nitride,
Aromatic polyamide cotton products, salts of lauric acid or stearic acid, polybenzylidene sorbitol and its derivatives, and the like. The thixotropy imparting agent is blended to such an extent that the light transmittance of the above-mentioned thermosetting resin is not impaired.

In addition, the resin encapsulant 6 is further provided with amines which can be stored at room temperature for a short period of time, curing accelerators such as imidazoles, and for facilitating defoaming of air blown during printing. Antifoaming agents and the like can be added. The addition of the curing accelerator has the effect that there is less restriction on leaving it during printing. If you add an antifoaming agent,
When an acid anhydride type curing agent is used, it is difficult for the air to be saturated by vacuum deaeration, and it becomes remarkable especially when the thixotropy is increased. Further, when the photodiode 3b is for receiving infrared rays, visible light and near-infrared cut dyes can be added to the resin sealing material 6.

The resin encapsulant 6 is made light-transmissive by mixing these thermosetting resins, curing agents, thixotropy imparting agents and other additives in one liquid or two liquids at the time of use. It has thixotropic properties. That is, in addition to having optical transparency, it exhibits viscosity suitable for printing during printing, has high shape retention after printing, and has a flow characteristic that does not flow even when left for a long time. It also has the characteristics that it exhibits good curing characteristics with good moisture resistance and has a long pot life.

Therefore, by using the light-transmissive resin encapsulating material 6 having the thixotropy property, it is possible to achieve good encapsulation by screen printing. When screen-printing the resin sealing material 6 having such excellent characteristics, the IC 3a and the photodiode 3b are wire-bonded as described above, and then the screen is first placed on the substrate 1.

FIG. 3 is a schematic view showing a state in which the screen is arranged on the substrate 1. Screen 5 as shown
Has an opening 5a corresponding to the sealing pattern, and when the screen 5 is placed on the substrate 1, the opening 5a is formed.
The semiconductor element 3 including the IC 3a and the photodiode 3b is formed so as to be housed therein.

Further, for example, a concave resin reservoir 5b is formed on the surface side facing the substrate 1 and in the vicinity of the opening 5a, whereby the substrate 1 of the resin encapsulant 6 that wraps around the opening 5a during printing. It is designed to be prevented from adhering to. Further, the screen 5 is formed so that its thickness t is substantially equal to the height d of the resin encapsulant 6 for encapsulating the substrate 1 and the semiconductor device 3, and is formed to a thickness t of 0.5 mm or more, for example. Has been done.

After arranging such a screen 5 on the substrate 1, the resin sealing material 6 is subsequently supplied onto the screen 5 and embedded in the opening 5a by a squeegee. That is,
The resin sealing material 6 is applied onto the substrate 1 through the opening 5a.
At this time, the resin sealing material 6 is rotated by the squeegee to lower its viscosity and increase its fluidity, so that it is applied on the substrate 1 in a pattern corresponding to the openings 5a.

After coating, the screen 5 is removed from the substrate 1. Since the fluidity of the applied resin sealing material 6 is lowered and the viscosity thereof is increased, even if the screen 5 is removed, the shape of the opening 5a is kept substantially the same. Finally, the resin encapsulant 6 is heated to a predetermined temperature and cured to manufacture a semiconductor device having good moisture resistance in which the substrate 1 and the semiconductor element 3 are integrally encapsulated by the resin encapsulant 6. .

As described above, in this embodiment, by using the light-transmissive resin encapsulating material 6 having the thixotropy property, it is possible to control the area to be coated without mounting the frame on the substrate 1. You can Therefore, it is possible to reduce the frame mounting process and avoid occurrence of defects due to the frame mounting.

Further, since the application is carried out by screen printing, the application amount of the resin encapsulating material 6 can be controlled by the thickness t of the screen, and the variation in the application amount can be reduced as compared with the application by the conventional dispenser. Moreover, in the screen printing, the resin encapsulating material 6 having a long pot life remaining on the screen 5 can be repeatedly used. Therefore, the resin encapsulating material 6 including the resin residue in the conventional dispenser is included.
It is possible to save about 30% of the usage amount. Further, since the coating position can be set by the positioning accuracy of the screen printing machine, it is possible to perform sealing in a narrower area and a lower resin height d as compared with the conventional case.

Therefore, a high quality semiconductor device can be stably obtained, and the degree of freedom in designing the semiconductor device is also improved. Furthermore, since sealing is performed by screen printing, a large number of semiconductor devices can be manufactured by printing once, and it is possible to greatly reduce the takt time and improve productivity. Thus, according to this embodiment,
Light-transmissive resin encapsulant 6 with thixotropic properties 6
Since encapsulation is performed by screen printing using, it is possible to stably manufacture a semiconductor device with good quality and with high productivity.

[0027]

As described above, in the method of manufacturing a semiconductor device according to the present invention, after the screen is removed, the light-transmissive resin encapsulant that cures while maintaining a shape substantially the same as the opening of the screen. Therefore, it is possible to reduce the number of steps for mounting the frame, and it is possible to avoid the occurrence of defects due to the mounting of the frame. Moreover, since the application is performed by screen printing, sealing can be performed in a narrow area and a low resin height. Further, the screen printing encapsulation enables a large number of semiconductor devices to be manufactured by one printing, which can significantly reduce the takt time and improve the productivity. Therefore, according to the present invention,
A high-quality semiconductor device can be manufactured stably and with high productivity, and further, the degree of freedom in design can be improved.

[Brief description of drawings]

FIG. 1 is a process drawing of an example of the method of the present invention.

FIG. 2 is a sectional view of an example of a manufactured semiconductor device.

FIG. 3 is a schematic view of a state in which a screen is arranged.

FIG. 4 is an explanatory diagram showing an example of a conventional semiconductor device.

[Explanation of symbols]

 1 substrate 3 semiconductor element 5 screen 5a opening 6 resin sealing material

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 25/04 25/18 31/10 33/00 N

Claims (4)

[Claims] 1. A semiconductor element is mounted on a substrate, and a screen having an opening is arranged on the substrate with the semiconductor element accommodated in the opening, and then a predetermined amount of resin sealing material is applied from the substrate. Embedded in the opening with a squeegee and removing the screen to integrally seal the substrate and the semiconductor element, wherein the resin encapsulant has a light-transmitting property. And a method of manufacturing a semiconductor device, which is made of a material that cures while maintaining a shape substantially the same as the opening after removing the screen. 2. The method of manufacturing a semiconductor device according to claim 1, wherein the resin encapsulant contains a thermosetting resin, a curing agent, and a thixotropic agent. 3. The method of manufacturing a semiconductor device according to claim 2, wherein the thermosetting resin is an epoxy resin. 4. The method of manufacturing a semiconductor device according to claim 2, wherein the curing agent is made of a material that has a small change in viscosity when left standing.