JPH05166861A - Honing machine - Google Patents

Abstract

(57) [Summary] [Object] It is an object of the present invention to provide a honing processing device which has a long life, is easy to maintain and manage, and is capable of efficiently mass-producing semiconductor products without defects or defects. .. A honing device according to the present invention comprises a semiconductor element 9 and a sealing resin 1 which are resin-sealed on a lead frame 2.
IC having marking 6 displayed on the surface of the
With the mask jig 7a that shields the marking 6 arranged on the surface of the sealing resin 1 of FIG.
In a honing machine for removing the foreign matter 3 adhered to the substrate by a honing process, the mask jig 7a is formed by a ceramic material such as silicon nitride or sialon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a honing machine, and more particularly, by improving the wear resistance of constituent parts to prolong the service life thereof, maintenance of the honing machine is facilitated and semiconductor product manufacturing efficiency is improved. The present invention relates to a honing processing device that can be greatly improved.

[0002]

2. Description of the Related Art In the manufacturing process of semiconductor products such as LSIs, ICs, transistors, diodes, etc., semiconductor elements are sequentially mounted in a longitudinal direction on a lead frame which is punched and formed into a predetermined shape, and each semiconductor element is mounted. A product intermediate is formed by sealing with an epoxy resin or the like containing silica.
Markings such as the product model number, name, and manufacturer name are printed or engraved on the surface of the resin-sealed portion of the product intermediate. The formed product intermediate is divided into individual parts by dipping the lead frame part and stacking the solder layers, and then cutting the lead wires led out from the resin sealing part to a predetermined length, and further separating the protruding lead wires. A semiconductor product is finally finished by bending it into a predetermined shape.

However, in the intermediate product which is still sealed with the resin, as shown in FIG. 3, the lead frame 2 led out from the sealing resin 1 is covered with the slag of the sealing resin and the lead frame 2.
Foreign matter 3 such as flash is sealed, and even if the lead frame 2 is dipped in the solder solution as it is, the leaking property to the solder is reduced, so that the solder is less sealed and soldering of the product semiconductor IC or the like is performed. Easy to be incomplete.

Therefore, the product intermediate obtained by sealing with a resin is subjected to a step of previously removing the foreign matter 3 by a honing device (shot blasting device) as shown in FIG. The honing device is generally provided with a plurality of honing nozzles 4 facing each other so as to sandwich the lead frame 2, and for example, honing is performed by using abrasive grains 5 such as glass beads having a small diameter or green carborundum (GC) as an abrasive. The surface of the lead frame 2 is ground and swept by projecting from the nozzle 4 onto the side surfaces of the lead frame 2 and the sealing resin 1 at a high speed. When carrying out such honing processing,
In order to prevent the marking 6 displayed on the surface of the sealing resin 1 from being scraped by the abrasive grains 5 and disappearing, a mask jig 7 is preliminarily provided on the surface of the sealing resin 1 so as to shield the marking 6 portion. It is arranged. The mask jig 7 is generally formed of cemented carbide, and the mask jig 7 prevents projection of the abrasive grains 5 onto the marking portion 6, so that the disappearance of the marking 6 is effectively prevented.

[0005]

However, the conventional mask jig formed mainly of cemented carbide has a drawback that the abrasion resistance against abrasive grains such as glass beads used as an abrasive is low, and the conventional mask jig has a drawback. There is a problem that wear is rapidly progressed by a short-term operation. That is, when the mask jig 7 having a sharp squareness at the start of use of the mask jig is about 15 to 20 days after the start of operation,
As shown in FIG. 3, the abrasive grains 5 significantly abrade the abrasive grains 5 to the central portion of the surface of the sealing resin 1, and the percentage of the abrasive grains 5 wraps around, and the marking 6 partially disappears.

Further, since the thickness of the conventional mask jig is formed to be the same as the width of the sealing resin, the abrasive grains 5 are largely projected onto the side surface of the sealing resin which is the lead-out portion of the lead frame 2. .. Therefore, there is a drawback that cracks 8 and peeling are likely to occur on the side surface of the resin, which lowers the product yield.

Therefore, it has been necessary to stop the honing device frequently at intervals of about 15 to 20 days and replace the mask jig, which is a complicated work. As a result, it is difficult to perform efficient continuous operation of the honing device over a long period of time, the labor required for maintenance and management of the device is high, and the operating rate of the device is low, resulting in low productivity of semiconductor ICs. It was

On the other hand, since the cemented carbide that constitutes the conventional mask jig contains a large amount of high-density tungsten material, the weight of the mask jig becomes large, and when it is placed on the sealing resin 1, the There is also a problem that the sealing resin 1 and the lead frame 2 are easily deformed by the weight.

The present invention has been made to solve the above problems, and has a long life, is easy to maintain and manage, and is a honing machine capable of efficiently mass-producing semiconductor products without defects or defects. The purpose is to provide.

[0010]

In order to achieve the above object, a honing apparatus according to the present invention is a semiconductor having a semiconductor element resin-sealed on a lead frame and a marking displayed on the surface of the sealing resin. In a honing device that removes foreign matter sealed on the lead frame by a honing process while a mask jig that shields the marking is arranged on the surface of a sealing resin such as an IC, the mask jig is a ceramic material. It is characterized by being formed in.

Further, ceramic materials for forming the mask jig are silicon nitride (Si ₃ N ₄ ) and sialon (S).
i-Al-O-N). The above silicon nitride and sialon exhibit excellent wear resistance characteristics in the honing treatment using glass beads as abrasive grains, as compared with other ceramic materials such as zirconia (ZrO ₂ ) and alumina (Al ₂ O ₃ ). ..

Further, it is natural that the thickness of the mask jig is set to be at least equal to or larger than the width of the sealing resin.
By setting the width of the sealing resin to be 0.05 to 0.1 mm larger than the width of the sealing resin, it is possible to effectively prevent the occurrence of cracking or peeling at the lead-out portion of the lead frame from the sealing resin. When the above dimension value is less than 0.05 mm, the above effect is insufficient, while when it exceeds 0.1 mm, it becomes difficult to polish foreign matter adhered to the lead-out portion of the lead frame, and solder of the lead frame is not cleaned. The adhesion rate will decrease.

The above-mentioned mask jig is manufactured in accordance with a usual method for manufacturing a ceramic sintered body. That is, a sintering aid such as yttria (Y ₂ O ₃ ) is added to the ceramic raw material powder to prepare a raw material mixture, and the obtained raw material mixture is molded into a predetermined strip shape by die molding or casting. It is manufactured as a body, after which a sintered body obtained by degreasing and sintering the molded body is ground and subjected to a final dimensional inspection.

[0014]

According to the honing machine having the above-mentioned structure,
Since the mask jig is made of a hard, lightweight and wear-resistant ceramic material, product deformation can be prevented compared to a honing device equipped with a conventional mask jig made of cemented carbide. Effectively prevent wear of the mask jig,
The life can be greatly extended.

Therefore, it is possible to continue the stable honing process for a long period of time with little stoppage of the device due to replacement of the mask jig, simplifying the maintenance management of the device and processing the semiconductor product. The manufacturing efficiency can be greatly improved.

Further, by setting the thickness of the mask jig to be 0.05 to 0.1 mm larger than the width of the sealing resin, the side surface of the sealing resin can be formed without impairing the polishing and cleaning effect of foreign matters by the abrasive grains. The ratio of the abrasive grains projected can be reduced, and the occurrence of cracks or the like on the side surface of the sealing resin can be effectively prevented.

[0017]

An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing an embodiment of a honing machine according to the present invention. The same elements as those in the conventional example shown in FIG. 3 are designated by the same reference numerals.

That is, the honing processing apparatus according to this embodiment is a sealing resin such as a semiconductor IC having a semiconductor element 9 resin-sealed on the lead frame 2 and a marking 6 displayed on the surface of the sealing resin 1. In a honing processing device for removing foreign matter 3 sealed on the lead frame 2 by honing treatment with a mask jig 7a for shielding the marking 6 arranged on the surface 1, the mask jig 7a is made of a ceramic material. Formed and configured.

Further, in FIG. 2, the width W _m of the mask jig 7a is smaller than the width W _IC of the sealing resin 1 such as a semiconductor _IC by 0.
It is formed to be 1 mm larger, and on both side surfaces of the mask jig 7a, a steady rest pin 10 for positioning the jig 7a at a predetermined position and preventing shake is formed of the same material as the jig body. It is arranged so as to press and fix the jig body. Further, the contact corner portion of the mask jig 7a with the sealing resin 1 is
It is formed to have a sharp squareness without chamfering.

According to the honing device according to this embodiment,
The mask jig 7a, which receives intense abrasive grain projections, is set to Si ₃ N
_{4. Since} it is made of a hard and wear-resistant ceramics sintered body such as Sialon, it is possible to effectively prevent the mask jig 7a from being worn and to extend the life of the honing machine. In addition, the frequency of replacement of the mask jig 7a can be reduced, and maintenance of the inspection device becomes extremely easy.

Further, the weight of the mask jig 7a made of the ceramics sintered body is less than half the weight of the conventional mask jig 7 made of cemented carbide, so that the weight of the mask jig is small. It is possible to effectively prevent the deformation of the sealing resin and the lead frame due to the above.

Further, the thickness W _m of the mask jig 7a is set to be 0.1 mm larger than the W _IC of the sealing resin 1 so that both end portions of the lower end of the mask jig 7a are the side surfaces of the sealing resin on the honing nozzle 4. On the other hand, since the protrusion is formed so as to slightly cover, the proportion of the abrasive grains directly projected onto the side surface portion of the sealing resin 1 is suppressed. Therefore, it is possible to prevent cracks and peeling that are likely to occur at the lead-out portion of the lead frame 2.

Next, the effect of the honing machine according to this embodiment will be described more specifically.

[0024] Al ₂ O ₃ and 4 wt% Example 1 Example 1, an AlN 3 wt%, the Y ₂ O ₃ 5 wt%, Si and the balance Si ₃ N _4
3 N ₄ raw material mixture is molded into a plate shape by a die press,
The obtained molded body is further heated at 700 ° C. for 3 hours to be degreased, and then fired at a temperature of 1750 ° C. for 4 hours, and the obtained sintered body is ground to have a strip plate shape shown in FIG. Five mask jigs were prepared.

Example 2 A mask jig made of sialon having the same dimensions was processed by the same manufacturing method as in Example 1 except that α + β type Si—Al—O—N powder was used as the ceramic material in Example 2. Five sheets were prepared.

Example 3 Also, as Example 3, a partially stabilized zirconia raw material powder containing 3% by weight of Y ₂ O ₃ was used, and the same process as in Example 1 was carried out, and the same size as in Example 1 was applied. 5 mask jigs made of ZrO _{2 were} manufactured.

[0027] using Al ₂ O ₃ raw material powder as Example 4 The Example 4 was treated in a similar to Example 1 Preparation, Al of the same dimensions as in Example 1
Five mask jigs made of ₂ O _{3 were} manufactured.

Comparative Example 1 On the other hand, as Comparative Example 1, a cemented carbide (JIS) which is a conventional material is used.
Using D type 2), 5 mask jigs having the same dimensions as in Example 1 were prepared.

Next, the mask jigs prepared in Examples 1 to 4 and Comparative Example 1 were mounted on the same honing machine shown in FIGS. 1 and 2, and resin molding was completed for a predetermined period. The product intermediate was continuously subjected to honing treatment, and the average life of each mask jig was measured and evaluated.

The honing conditions were set as follows. That is, as the abrasive (abrasive grain), the grain size is 70 to 75.
The abrasive grains were prepared by dispersing glass particles (# 400) of μm in water as a dispersion medium, and the injection pressure at the honing nozzle 4 was set to 1.5 kgf / cm ² .

Here, the life of each mask jig is determined by marking the surface of the sealing resin 1 (mask contact side) from the starting point of the continuous wet honing of the product intermediate under the above processing conditions. It was measured as the number of months until (imprinted characters) began to disappear, and the average value of 5 test bodies was calculated.

The measurement results are shown in Table 1 below.

[0033]

[Table 1]

As is clear from the results shown in Table 1, in the honing apparatus according to Examples 1 to 4 equipped with the mask jig formed of the ceramic material (sintered body) having excellent wear resistance, the conventional material was used. The average life of the mask jig is longer than that of the formed apparatus of Comparative Example 1. Especially, in the apparatus using the mask jig formed of Si ₃ N ₄ and Sialon, the mask jig has a long life. However, almost no wear was generated in the contact portion with the sealing resin, and the average life could be dramatically improved to about 4 to 12 times.

When the side surfaces of the sealing resin of the honing-processed product intermediates of Examples 1 to 3 were inspected, no cracking or peeling was observed.

In the above embodiments, the mask jig of the honing device is made of a ceramic material. However, abrasive grains such as a metal member supporting the lead frame 2 and a honing nozzle are directly projected. When the peripheral equipment was made of a ceramic material, the same excellent wear resistance effect appeared, and the maintenance management of the honing device was further simplified, and the durability of the device could be greatly improved.

[0037]

As described above, in the honing apparatus according to the present invention, the mask jig is made of a hard and lightweight ceramic material having abrasion resistance. Compared with a honing device equipped with a tool, the product can be prevented from being deformed, the mask jig can be effectively prevented from being worn, and the life can be significantly extended.

Therefore, it is possible to continue the stable honing process for a long period of time with little stoppage of the device due to replacement of the mask jig, simplifying the maintenance management of the device and processing the semiconductor product. The manufacturing efficiency can be greatly improved.

Further, by setting the thickness of the mask jig to be 0.05 to 0.1 mm larger than the width of the sealing resin, the side surface of the sealing resin can be covered without impairing the polishing and cleaning effect of foreign matters by the abrasive grains. The ratio of the abrasive grains projected can be reduced, and the occurrence of cracks or the like on the side surface of the sealing resin can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part showing an embodiment of a honing device according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a cross-sectional view showing an operating state of a conventional honing device.

[Explanation of symbols]

 1 Sealing Resin 2 Lead Frame 3 Foreign Material (Burning) 4 Honing Nozzle 5 Abrasive Grain 6 Marking 7, 7a Mask Jig 8 Crack 9 Semiconductor Element 10 Steady Pin

Claims (3)

[Claims] 1. A mask jig for shielding the above-mentioned marking is arranged on the surface of a sealing resin such as a semiconductor IC having a semiconductor element resin-sealed on a lead frame and a marking displayed on the surface of the sealing resin. A honing processing device for removing foreign matter sealed in the lead frame portion by a honing process in a state, wherein the mask jig is formed of a ceramic material. 2. The ceramic material forming the mask jig is silicon nitride (Si ₃ N ₄ ) or sialon (Si-).
The honing machine according to claim 1, which is made of at least one of Al-O-N). 3. The honing device according to claim 1, wherein the thickness of the mask jig is set to be 0.05 to 0.1 mm larger than the width of the sealing resin.