JP2010135807A - Adhesive for semiconductor, and semiconductor device manufactured using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive for semiconductor capable of being continuously dispensed in a stable applied amount even with a delivery in a small amount by removing thoroughly involved minuscule bubbles, and a semiconductor device excellent in productivity and reliability by using the adhesive for semiconductor. <P>SOLUTION: This adhesive for semiconductor is an adhesive for semiconductor comprising (A) a thermocurable resin and (B) a filler and is characterized in that the adhesive is manufactured by subjecting the adhesive to a vibration treatment under a reduced pressure. A semiconductor device manufactured using the adhesive for semiconductor is also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a semiconductor adhesive and a semiconductor device manufactured using the semiconductor adhesive.

As lightness, thinness and miniaturization in the field of electronics and electric machinery are reduced, miniaturization of members typified by semiconductor devices is also required. For this reason, a small amount and a stable discharge are required for the adhesive used in the assembly process of the semiconductor device. However, in the case of using a highly viscous adhesive containing a filler (filler), the adhesive is used. It is difficult to sufficiently remove the encapsulated microbubbles. For this reason, as the nozzle diameter becomes smaller in dispensing using nozzles, the problem of blanking due to the discharge of microbubbles contained during dispensing becomes more prominent, and improvement is desired from the viewpoint of lowering productivity and lowering reliability. ing. Here, idle shot refers to a phenomenon in which encapsulated bubbles are discharged at the time of dispensing and the adhesive is not discharged or the discharge amount of the adhesive becomes unstable. Conventionally, there is a method in which each component of a semiconductor adhesive is premixed in order to remove encapsulated air bubbles, then kneaded using three rolls, and then subjected to vacuum decompression after kneading (for example, see Patent Document 1).
In addition to vacuum depressurization, dispensing with adhesives for semiconductors that has been defoamed by rotation treatment, treatment using a rotating / revolving stirring defoaming mixer, etc. has been studied, and the effect is still high, but there are still microbubbles. There was a problem with the discharge, which was not fully satisfactory.

JP 2000-273326 A

  The present invention provides a semiconductor adhesive having excellent coating amount stability with less blanking in dispensing using a nozzle, and provides a semiconductor device having excellent productivity and reliability by using the semiconductor adhesive. is there.

Such an object is achieved by the present invention described in the following [1] to [6].
[1] A semiconductor adhesive comprising (A) a thermosetting resin and (B) a filler, which is produced by performing vibration treatment under reduced pressure.
[2] In a continuous dispense using a single needle having an inner diameter of 0.1 mm or more and 0.3 mm or less, the application amount per point is 0.1 mg or more and 20 mg or less, and the blanking is 100 ppm or less. The adhesive for semiconductors as described in item 1].
[3] The adhesive for semiconductors according to [1] or [2], wherein the filler (B) is silver powder.
[4] The viscosity at 25 ° C. and 2.5 rpm measured with an E-type viscometer at 5 rpm is 5 Pa · s to 50 Pa · s, and the viscosity ratio between 0.5 rpm and 2.5 rpm is The adhesive for semiconductors according to any one of [1] to [3], which is 2.5 or more.
[5] The semiconductor adhesive according to any one of [1] to [4], wherein the (A) thermosetting resin is an epoxy resin.
[6] A semiconductor device manufactured using the semiconductor adhesive according to any one of items [1] to [5].

  According to the present invention, by sufficiently removing the microbubbles contained in the semiconductor adhesive, continuous dispensing can be performed with a stable coating amount even with a small amount of discharge, and a semiconductor device with excellent productivity and reliability can be provided. It becomes.

The present invention is an adhesive for semiconductors including a thermosetting resin and a filler, and by removing microbubbles contained in the adhesive for semiconductors, there is little space in dispensing a small amount of dispense using a nozzle. A highly reliable semiconductor device capable of stable coating can be obtained.
This will be described in detail below.

  The present invention is a semiconductor adhesive in which fine bubbles contained by vibration treatment are removed under reduced pressure in dispensing dispensing semiconductor adhesive. The microbubbles contained in the adhesive for semiconductors cause empty shots during continuous dispensing, so it is necessary to remove them sufficiently, such as vacuum decompression processing, rotation processing, processing using a rotating / revolving stirring deaerator mixer, etc. The defoaming treatment by is not sufficient, and it is possible to effectively remove the encapsulated microbubbles by applying vibration under reduced pressure. In order to carry out more effectively, it is preferable to carry out after filling the semiconductor adhesive composition into a dispensing syringe.

Such a vibration treatment under reduced pressure is not particularly limited as long as it is a device capable of obtaining vibration using compressed air as power because there is a safety problem when an electrically driven vibrator is used under reduced pressure. The compressed air obtained by the compressor is supplied to an air-driven vibrator to generate vibration. The supplied compressed air needs to be adjusted according to the capacity of the compressor and the amount of semiconductor adhesive to be processed, but when the supplied compressed air is low, the vibrator does not start due to static frictional force, etc. When compressed air is high, the pressure resistance of the vibrator is exceeded, which is not preferable. The vibration obtained from this vibrator is 100 Hz or more and 500 Hz or less in frequency. The vibrator is fixed to the diaphragm, and a syringe stand for setting a syringe filled with the semiconductor adhesive composition is also fixed to the diaphragm. When the vibration treatment is performed under reduced pressure, each syringe may be fixed to a syringe stand, or can be moved freely up, down, left and right without being fixed. At the time of vibration addition, each syringe is vibrated to promote the rise of microbubbles remaining in the adhesive composition for semiconductor and the bubble breakage. When applying vibration while reducing pressure, bubble breakage is observed from a vacuum degree of about 20 mmHg, but in order to obtain a stronger defoaming effect in a shorter time, 10 mmHg or less is preferable, and the treatment time is 1 minute or more, It is preferable to process for 60 minutes or less. The processing time here is the time after the degree of vacuum becomes 20 mmHg or less. Further, when the degree of vacuum is 10 mmHg or more, the effect of removing the encapsulated microbubbles is insufficient, and the encapsulated microbubbles cannot be effectively removed when the applied vibration frequency is outside the above range. Furthermore, depending on the amount of encapsulated microbubbles, the effect of removing the encapsulated microbubbles is insufficient even when the treatment time is shorter than the lower limit, and if it is longer than the upper limit, the productivity deteriorates, In some cases, the viscosity of the semiconductor adhesive is increased, which is not preferable. More preferable conditions are a vacuum degree of 10 mmHg or less, 100 Hz or more and 250 Hz or less, and 5 minutes or more and 30 minutes or less.

If the adhesive for semiconductors from which the encapsulated microbubbles are sufficiently removed, it can be used favorably without causing blank shots, but considering the workability during dispensing, the viscosity of the adhesive for semiconductors is an E-type viscometer. Use a semiconductor adhesive with a value measured at 25 ° C. and 2.5 rpm measured using a 3 ° cone of 5 Pa · s to 50 Pa · s and a viscosity ratio of 0.5 rpm to 2.5 rpm of 2.5 or more. It is preferable to do. If the viscosity is lower than this, it is not preferable because the adhesive for semiconductor drops (hereinafter referred to as dripping) from the tip of the nozzle, and if it is higher than this, the cut after dispensing is poor and the yarn is pulled (hereinafter referred to as yarn drawing). Since the amount is not stable, it is not preferable. More preferably, those of 8 Pa · s or more and 25 Pa · s or less are used. When the viscosity ratio is lower than this, it is not preferable because it is easy to cause problems such as stringing and the coating amount becomes unstable. A more preferable viscosity ratio is 3.2 or more. If such a semiconductor adhesive is used, a small amount of ink is discharged, so that even if a single needle having an inner diameter of 0.1 mm or more and 0.3 mm or less is used, no blank shot is observed, and good continuous coating properties are exhibited. The coating amount per point at this time is 0.1 mg or more and 20 mg or less.

  Examples of such an adhesive for semiconductor include an adhesive for semiconductor in which (A) a thermosetting resin has (B) a filler dispersed therein. (A) As a thermosetting resin, an epoxy resin, an acrylic resin, a maleimide resin, a phenol resin, etc. are mentioned, These can use 1 type or multiple types together, and are not specifically limited. Preferred examples include epoxy resins, such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, glycidylamine type liquid epoxy resin, phenol novolac. Polyglycidyl ether, biphenyl type epoxy resin, stilbene type epoxy resin, hydroquinone type epoxy resin, triphenolmethane type epoxy resin, phenol aralkyl type (including phenylene and diphenylene skeletons) epoxy obtained by reaction of cresol novolaks with epichlorohydrin Examples thereof include a resin, an epoxy resin containing a naphthalene skeleton, and a dicyclopentadiene type epoxy resin.

Examples of the curing agent in the case of using an epoxy resin include a phenol resin, an aliphatic amine, an aromatic amine, dicyandiamide, a dicarboxylic acid dihydrazide compound, and a carboxylic acid anhydride.
Furthermore, as an accelerator / curing agent in the case of using an epoxy resin, for example, as various imidazole compounds, 2-methylimidazole, 2-ethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2 General imidazole such as -C11H23-imidazole, 2,4-diamino-6- {2-methylimidazole- (1)}-ethyl-S-triazine added with triazine or isocyanuric acid, and its isocyanate adduct Yes, any of these can be used alone or in combination.

(B) As filler, metal powder such as silver powder, gold powder, copper powder, aluminum powder, platinum, palladium, rhodium, ruthenium, iridium, osmium, tungsten, nickel, tantalum, bismuth, indium, tin, zinc, titanium, etc. And metal particles such as alloys thereof, inorganic particles such as silica, boron nitride, alumina, aluminum nitride, silicon nitride, organic particles such as acrylic polymer, divinylbenzene polymer, polyethylene, polypropylene, and phenol resin are used. There is no particular limitation. Silver powder is particularly preferable because it is a metal powder used for imparting electrical conductivity and thermal conductivity, and has many types such as particle size and shape and is easily available. If necessary, a silane coupling agent, a titanium coupling agent, a surfactant, a stress reducing agent, a pigment, a dye, an antifoaming agent, a solvent, and the like can be added.

The adhesive for semiconductor of the present invention preferably has a hot water extraction chlorine ion concentration of 100 ppm or less. The hot water extraction chlorine ion concentration is measured by ion chromatography using 2 g of crushed semiconductor adhesive cured at 200 ° C. for 60 minutes and treated with 40 ml of pure water at 125 ° C. for 20 hours. Etc. The value of the chlorine ion concentration is a value obtained by converting the solution concentration obtained by the measurement into the sample concentration. Chloride ion concentration = solution concentration / sample weight (2 g) × pure water weight (40 g): However, the specific gravity of pure water was calculated as 1.

The adhesive for semiconductors of the present invention can be produced, for example, by premixing the respective components, kneading using three rolls and vacuum degassing, and further subjecting to vibration treatment under reduced pressure.
A known method can be used as a method of manufacturing a semiconductor device using the semiconductor adhesive of the present invention. For example, using a commercially available die bonder, a semiconductor adhesive is dispensed on a predetermined portion of the lead frame, and then the chip is mounted and heated and cured on a pot plate. Then, a semiconductor device is manufactured by wire bonding and transfer molding using an epoxy resin.

EXAMPLES Examples will be shown below to describe the present invention in more detail, but the present invention is not limited to these examples.
[Examples 1, 2, 3]
Diglycidyl bisphenol A (epoxy equivalent 180, liquid at room temperature, total chlorine content 500 ppm, hereinafter bis A epoxy) obtained by reaction of bisphenol A and epichlorohydrin, cresyl glycidyl ether (epoxy equivalent 185, hereinafter CGE), phenol novolac resin (Hydroxyl equivalent 104, softening point 85 ° C., hereinafter PN), dicyandiamide, cureazole 2MZ-A (manufactured by Shikoku Chemicals Co., Ltd., hereinafter 2MZ-A), silane coupling agent having glycidyl group (Shin-Etsu Chemical Co., Ltd.) Manufactured, KBM-403E, hereinafter referred to as epoxy silane), flaky silver powder (hereinafter referred to as silver powder) having an average particle diameter of 5 μm and a maximum particle diameter of 30 μm as shown in Table 1, kneaded using three rolls, and entrained during kneading. In order to remove bubbles, vacuum degassing was performed at 5 mmHg for 30 minutes. Thereafter, it was filtered through 100 mesh, filled with a syringe, and subjected to vibration treatment under reduced pressure under the conditions described in Table 1 to obtain an adhesive for semiconductor, and evaluated by the following methods. The blending ratio is parts by weight.

In Examples 1, 2, and 3, only the vibration treatment was performed under reduced pressure. In the embodiment, the supplied compressed air pressure was 0.2 MPa, and the frequency obtained from the air-driven vibrator was about 160 Hz.
Further, when the vibration obtained on the diaphragm was measured with a general-purpose vibrometer (Rion Corporation, VM-82), the amplitude was 0.15 mm and the acceleration was 50 m / s2. The decompression condition was 5 mmHg.

[Comparative Examples 1 and 2]
After blending in the proportions shown in Table 1 and kneading in the same manner as in the Examples, vacuum degassing was carried out, followed by filtration through 100 mesh and filling with a syringe, and defoaming was performed under the conditions shown in Table 1. In Comparative Example 1, no vibration treatment was performed under reduced pressure after syringe filling. In Comparative Example 2, rotation 600 rpm, revolution 2000 rpm, and treatment time 1 minute were carried out using a rotation / revolution stirring deaerator mixer (manufactured by EME Co., Ltd., Awatori Kantaro VMX-360).

Evaluation method Viscosity: Using an E-type viscometer (3 ° cone), values at 25 ° C., 0.5 rpm and 2.5 rpm were measured. The unit of viscosity is Pa · s. The viscosity ratio of 0.5 rpm to 2.5 rpm was used as the viscosity ratio.
Hot water extraction chlorine content: The above-mentioned adhesive for semiconductor was cured at 200 ° C. for 60 minutes, and 2 g of crushed cured product of adhesive for semiconductor and 40 ml of pure water were placed in an extraction kettle and extracted at 125 ° C. for 20 hours.
The supernatant after cooling and centrifugation was used as a specimen, and the chloride ion concentration was measured by ion chromatography. The obtained extract concentration was converted to the sample concentration by the following formula. However, the specific gravity of pure water was calculated as 1.
Chlorine ion concentration (vs. sample)
= Chlorine ion concentration (extract) / cured material weight (2g) x pure water weight (40g)
Dotting test: 70,000 points of the above-mentioned syringe-filled semiconductor adhesive using a metal needle 25G single nozzle (inner diameter 0.26 mm, length 15 mm) with a hitting tester (manufactured by Musashi Engineering, SHOTMASTER-300) Application (coating amount 20 mg / 1 point) was performed, and idle shot was measured. A case where the blank shot was 7 points or less (100 ppm or less) was regarded as acceptable.
Reflow resistance: Dispense to the following frame using the above-mentioned adhesive for semiconductor, mount the chip, cure and bond at 150 ° C. for 60 minutes, and further seal the material (Sumicon EME-6300SL, manufactured by Sumitomo Bakelite Co., Ltd.) The package was manufactured by sealing using. This package was subjected to a moisture absorption treatment at 30 ° C. and a relative humidity of 60% for 168 hours, followed by an IR reflow treatment (260 ° C., 10 seconds, 3 times reflow). It was confirmed that the package after processing was ultrasonic cracking equipment (reflection type) on the chip and the peeled area on the back of the die pad was 10% or less, and no package crack was generated. The case where the peeled area was 10% or less and there was no package crack was rated as ◯, and the case where the peeled area was 10% or less and where there was a package crack was marked as x.
Package: SOT23 (2 x 1.5 x 1 mm)
Frame: Copper frame Chip size: 0.5 x 0.5 mm

  According to the present invention, it is possible to provide an adhesive for a semiconductor that is excellent in coating amount stability with less blanking, and it is possible to provide a semiconductor device that is excellent in productivity and reliability.

Claims (5)

Applying a semiconductor adhesive by dispensing on a support;
Placing a semiconductor element on a metal frame via the semiconductor adhesive, and a method for manufacturing a semiconductor device,
A manufacturing method of a semiconductor device, wherein the semiconductor adhesive is one in which blanking is 100 ppm or less in the following spot test.
[Spotting test: Applying 70,000 points (application amount 20 mg / 1 point) of a semiconductor adhesive filled in a syringe using a metal needle 25G single nozzle (inner diameter 0.26 mm, length 15 mm) with a spotting tester As a result, the rate of occurrence of blank shots was measured. ] 2. The semiconductor device manufacturing according to claim 1, wherein the adhesive for semiconductor includes (A) a thermosetting resin and (B) a filler, and is obtained by performing pressure reduction or vibration treatment. Method. The method for manufacturing a semiconductor device according to claim 2, wherein the filler (B) is silver powder. The viscosity at 25 ° C. and 2.5 rpm measured at 3 ° C. with an E-type viscometer of the semiconductor adhesive is 5 Pa · s to 50 Pa · s, and 0.5 rpm to 2.5 rpm 4. The method for manufacturing a semiconductor device according to claim 1, wherein the viscosity ratio is 2.5 or more. The method for manufacturing a semiconductor device according to claim 2, wherein the (A) thermosetting resin is an epoxy resin.