JPS60182729A - Sheathing treatment functioning as deburring in combination in assembly process for semiconductor package - Google Patents

Abstract

PURPOSE:To execute deburring and sheathing treatment at a time by a method wherein a semiconductor chip is bonded with a lead frame, a film material for laminating is stuck to a molding unnecessary section, a resin is molded to a molding necessary section, and the film material for laminating is peeled off as a thin-film as a sheathing material is left as it is. CONSTITUTION:IC chips 4 are fixed to island sections 2 in a lead frame 1 with the island sections 2, inner leads 3 and outer leads 7 and 8, and films 5 and films 6 in Al, etc. on which thin-films 6 as sheathing materials are laminated are stuck on both surfaces of molding unnecessary sections in the frame 1 while being inward directed. The films 6 are fast stuck mutually among the leads 8 through pressing by a section with projecting sections corresponding to sections among the leads 8, and the lead frame is molded centering around the chips 4. The burrs 10 of a resin flowing out of a molding section 9 are removed together with the Al films 5, and deburring and sheathing treatment are executed at a stroke.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing deburrs and treating the exterior in a package assembly process, and more particularly, to a method that can perform the deburring and exterior treatment simultaneously, with precision, and self-control. It is.

1. of semi-η body of near one plant. “Increase in energy and high quality 11?
Along with this, efforts have been made to control and improve the accuracy of the JFT W1 analysis of the original package, and the progress has been remarkable. The currently widely used manufacturing method is to mount a semi-specialized chip on a partially plated lead frame, mold it with epoxy on the side for airtight sealing, and then apply a multiplier to the part that does not need to be molded.・Remove the inflowing wood υIJ flash, then plate it with tin or the like and immerse it to give the lead an exterior treatment, and then apply markings, etc.

In the future, further miniaturization and higher performance will be sought for semi-finished parts and parts, as well as improvements in quality stability, productivity, and economic efficiency. Therefore, as mentioned above, the assembly process is becoming more precise and automated, and the process up to the bonding process is reaching a technological level that can meet future requirements. However, the removal of the Paris along with the molding and the subsequent exterior treatment-18! Unfortunately, the level of technology is still inadequate, and this is a serious barrier to moving the semiconductor package assembly process to a fully automated single line.

In other words, when it comes to removing paris, if this remains on the lead frame, that part will remain insulated even after the next exterior treatment, which will impair the performance of the semiconductor and result in it being rejected. .

Therefore, it is 100% sure that there is no dust on the frame.
required with completeness. To date, various methods have been proposed to remove paris, including a chemical method in which the lead frame is immersed in the product.

There are electrical methods using demolition shadows, and mechanical (physical) methods such as blowing high-pressure air or e-granules. However, these methods have problems such as insufficient separation of paris and the risk of damaging lead frames and semiconductor chips. On the other hand, it was possible to eliminate the outbreak of Paris, but
If the lead frame is simple and standard, it may be 1 function, but if you are dealing with a complex and wide variety of products, do you think it's 2+1? It is impossible to do so. Therefore, at present, in order to remove the particles attached to the lead frame, some of the above-mentioned methods are used in combination, or the particles are removed manually with a brush.

However, as long as such means are used, it is not possible to completely automate the entire assembly process line, even if the initial and subsequent processes are more precise and self-controlled. Moreover, in the future, as semimetals become finer and lead frames become finer, mold resins with more fluidity will be used. Therefore, resin flows, leaks, and scatters more frequently during molding, which increases the amount of debris, so removing debris is expected to become an even bigger problem in the future.

Regarding the one-sided device 1, as described above, the solder (tin Σ plating method and the half-white (tin) bath immersion method have been conventionally used. However, if a uniform plating film is obtained, However, due to the plating process Kt/-1 half-body backge manufacturing and the special work speculum that is different from Vi, it cannot be put into the assembly line, so it must be ordered to an outside plating specialist or plated in a separate building. This must be done at the factory.This would result in incomplete product processing and quality control.Also, the latter solder (tin) bath immersion method was designed to enable production lines, but 1. Difficult to adjust the thickness of the pattern [There is a button, so the film tends to be thicker than necessary.As a result, the pattern may stick to the bridge between the leads, or the leads may not enter the charging hole when machining the printed circuit board. Furthermore, it cannot be guaranteed that the high-temperature atmosphere of the bath will not have a negative effect on the semi-solid circuit, and may even cause damage to the circuit.

As mentioned above, in the semiconductor package assembly process, the parity removal and exterior treatment processes are technically less mature than other processes, and these also hinder the high precision of the entire semiconductor package assembly process and the complete automation of the entire line. There are two major factors contributing to this.

The present invention is directed to solving the above-mentioned problems of conventional means regarding parity removal and exterior treatment in the semiconductor package assembly process. 1111. The purpose of this is, first, to eliminate the attachment of paris to the leads or to flow between the leads, which occurs during molding, and to ensure the removal of paris. Second, it is possible to form a uniform YJ coating in the next process of coating the leads with solder (tin), and to perform this process during the assembly process of the semiconductor package. Thirdly,
The goal is to make the above two processes (i-tube precision and complete automation) as simple as possible.As a result, the entire assembly process of semiconductor package manufacturing can be performed with high precision and complete cut-off. 1 line, quality stability, productivity (yield), and lΔ characteristics II-II
The aim is to achieve J2.

The present invention will be described below, and the steps which are the main parts of the present invention are summarized in Examples as shown in FIG.

That is, after bonding a semiconductor chip to a lead frame, a laminated membrane material with a thin film of an exterior material formed on one side is attached to the Lq location of the lead frame where molding is not required, from both sides of the frame so that the thin film of the exterior material is in contact with the lead frame. do. next,
Pressure is applied between each lead of the lead frame from both sides,
Molding with resin in the required areas. Thereafter, the laminate film material is peeled off while leaving the exterior material thin film on the frame. Subsequently, a reroller is used to increase the wettability and gloss of the exterior material's film, and form a uniform exterior material coating using each Accooled Ktm. All that is left to do is to perform processing such as marking and cutting.

1, in the present invention, the paris removal process and the exterior treatment process are closely related and are carried out all at once. An example thereof will be explained based on FIG. tl+jK.

[+1 is a lead frame, as shown in Fig. 3, which has an island part (2) for medium heat, and a large number of inner leads (3) in its cylindrical part]. An IC chip (4) as a semiconducting chip on which a circuit is formed is bonded to the island portion (2), that is, chip bonding and wire bonding are performed. The above steps may be performed by means that are currently widely used.

(5) is a film material for lamination, and as shown in FIG. 2, a % II film (6) of an exterior material is formed on the back side. For example, a metal foil such as aluminum foil or a fd 1lit plastic film is used as the laminating film material (6).
Use a material that adheres closely to the t) side and can be peeled off from the +m material (5) side. Solder or tin is used as the exterior material, but the method for forming the binding film (6) may be, for example, a solder plating method or a solder cladding method, or if paste-like solder is applied with a roller type caulk, the device can be easily formed. is simple and has #membrane,
1 can be formed uniformly. In this case, frame (1)
However, if the frame is made of copper, the adhesion and wettability of the exterior material is sufficient (#+i).・For 210a), +J['] was found to be insufficient in terms of strength and wearability, so gfJ treatment was applied to the necessary areas of frame (1) for exterior treatment using a fluxing agent that is compatible with the alloy. The laminating membrane material (6) may be cut into the required dimensions in advance, but in order to make the line self-supporting, it was decided to cut it after lamination and make it into a coil shape. It is desirable to use things.

Then, as shown in FIG. 4, the laminating film material (5) is attached to the parts of the lead frame +11 where molding is not required from both sides so that the thin film of the exterior material (6) comes into contact with the parts. After that, each lead i￥J (see Fig. 5.
As shown in Figure 6, pressurize from both sides of the frame +1),
Exterior material 'tID tlQ between each actor and lead (8)
+61s are in close contact with each other. As a result, the valley actor lead (7) is closely surrounded by the first laminate material (5) and the inward facing exterior material shift (6), and each lead direction (8) is It is closed by the material (5) and the steam 91 model (6). In this state, when molding is performed centering around the semi-conducting chip (4), the resin that is multiplied by l:l', 17'fi, flows from the mold part (9), i.e., 71/1.
01 does not adhere to the lead (7) or flow into the lead 1MJt8+, but instead splatters on the surface of the laminating substitute material (5) on both sides, as shown in FIGS. 7 and 8.

During this molding, the working atmosphere is usually one in which heating is continued at 170° C. for 2 minutes, so the thin sheathing material film (6) inside the laminating film material (5) becomes a molten cancer. The exterior material is a laminating film material (5
) is transferred (transferred) onto the lead (7) surface of the frame (1), which is a material that is easier to layer. At this time, if the reflow step is assisted, the melting resistance and transfer will be made easier.

Next, as shown in Fig. 9, by peeling the laminating material 1 (5) from the lead frame il+,
The particles adhering to n are effectively removed together with the film material (5). Also, the peeling 1lj1. ．． Sometimes,
The exterior material thin film (6) has already been applied to the frame (1) as shown in item 1.
) is transferred to the reed (7), so it is 11 momme material (6)
As shown in Figure 10, each lead (7)
There is even a surface that is attached to the surface. Subsequently, by reflowing the lead frame (1), the outer sheath 4; A thin film (6) attached to the circumference m1 of each lead (7) is
As shown in Figure 1, the wettability is increased and a thin and uniform coating (6a) is formed on the same track of each reed (7), and the gloss is also increased. After that, processes such as cleaning, cutting, bending, and backing may be performed.

Although the above embodiments have been described in terms of pars removal and exterior treatment in the IC package assembly process, they can also be widely used in the assembly process of half-41 packages.

Regardless of the shape of the package, we can process both individual-in-line packages, flat packages, and more. In the above example, frame + 11 songs)
For example, pressurize from the l+bJ side with Shosan air, or
It is also possible to use means such as suctioning air between the twisted ribs (5) to bring them into close contact.

As is clear from the following, the feature of the present invention is to form an exterior lυ/film on the surface of the laminating film material, and then apply it to the lead frame after bonding from both sides without the need for molding. Apply pressure from both sides of the laminating ribs to create a tight seal between the leads. Then, the dust produced during bonding is attached to the leads and the coating material is melted by the heat and transferred between the leads. Next, remove all the particles together with the laminating film material by stripping the film material for lamination, or leave the exterior abrasion thin film on each lead and reflow the lead frame to remove 17% of the exterior material. ff
This increases the resistance to formation.

Therefore, according to the present invention, firstly, the flashes generated during molding do not cross over to the lead surface or between the leads, and all the flashes are removed by peeling off the laminating film material (#f). Second, the sheathing material, which is pre-formed on the membrane material for lamination, is transferred between the leads using the flow of the molding jig, increasing the width of the tympanic membrane, resulting in a uniform and thin eardrum. In addition, since the process is not particularly different from the semiconductor package assembly process, it can be incorporated into the line.Thirdly, parity removal and exterior processing are related and performed in parallel. As a result, it is possible to achieve high precision and complete automation with a simple method.Moreover, as a result, the entire assembly process of semiconductor package manufacturing can be completed on one highly precise and fully automated line, resulting in stable quality and It has excellent effects such as improving raw N (productivity, yield, and economic efficiency).

[Brief explanation of the drawing]

The figures show an example of the present invention, in which Fig. 1 is a process diagram, Fig. 2 is an enlarged perspective view of a part of the glazed (glazed) laminate film material, and Fig. 3 is a plan view after bonding. Figure 4 is a partially enlarged longitudinal cross-sectional view after the gland shrine was installed, Figure 5 is a flat line view after pressing one piece of material, and Figure 6 is a partially enlarged view of section 8-A in Figure 5. (Figure 7 is a perspective view after molding, Figure 8 is a partially enlarged vertical side view of the section B-B in Figure 7, and Figure 9 is a vertical side view.)
Fig. 10 is a partially enlarged longitudinal sectional side view after the film material is removed; Fig. 11 is a partially enlarged longitudinal sectional side view after the beam is flowed. Figure mountain [mark (1)...lead frame, (5)...
Membrane material for lamination, (6)...Thin film of exterior material, (6a
)...Eardrum, (7)...Reed, (8)...Reed rL f+01-...Paris applicant Tetsuya Kitaen

Claims (1)

[Claims] ■The lead frame has an innate chip,
Molding with Yokozukiji, that i? This is a semi-finished product with a process of removing the hollows that occur on the reed and applying exterior treatment to the reed.
In the metal package assembly process, the lead frame fi
Laminating jr with a thin U*+6+ exterior material formed on one side in advance on both 1n of the mold-free slots of l, ;,!
Paste the material (5) with its thin film (6) side, and place the image (5) of both of the two parts in close contact between the leads (8) so that each lead' (7) is connected by &H. At the same time as molding, attach all of the Paris (1o) on the membrane material (5), copy the exterior (thin film +61) onto each lead (7) 1.fTl, and then apply the special film (6) to the entire frame. Leave it on (1) and release the Eigiri (5) with +0+ on it, then apply reflow treatment to increase the wettability of the exterior material, and apply a uniform fin exterior on the circumference of the valley reed (7). A method for removing pars and treating the exterior in a half-bar package assembly process in which a material cover 111 bar 6a) is formed.