JP3341539B2 - Cleaning method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a BGA (ball gri
d array) or PGA (pin grid array) or a method for cleaning these components, and a method for cleaning a system board on which a BGA is mounted. Specifically, BGA or PGA can be produced by a specific cleaning device using an industrial cleaning agent.
The present invention relates to a method for effectively and precisely cleaning various kinds of dirt adhering to BGA or PGA or a component thereof, and various kinds of dirt adhering to a system board on which a BGA is mounted, in a GA manufacturing process.

[0002]

2. Description of the Related Art An ASIC (Application Specific Int.) Has been increased in scale and speed with the increase in the multimedia market.
BGA or PGA has begun to be used in earnest as a package that can fully exploit the capabilities of egrated circuits. These BGAs or PGAs are conventionally known as QFP
(Quad flat package), which fundamentally improves the inductance that causes noise during high-speed operation, which is a problem, and enables multi-function, large capacity, high speed, small size and thin type. . Such BGA or P
Since GA is applied to mounting technology that requires high density and high quality, precision is required for BGA or PGA itself. Must be removed by washing.
In addition, when the BGA is mounted on the system board, various stains adhere to the system board. Therefore, various stains attached to the system board on which the BGA is mounted must be removed by precision cleaning.

Hitherto, a high-pressure shower system, a submerged jet system, and the like have been employed as a method for precision cleaning of various kinds of dirt adhering in the process of manufacturing BGA or PGA. However, in high pressure shower system, BGA
In addition, PGA tends to be small and thin, so there is a risk that BGA or PGA itself may be damaged by high-pressure cleaning, mist countermeasures are required, liquid management is required, and the equipment is large. However, the submerged jet method has a problem that an operation for determining the position of the nozzle is required. Further, in the conventional method, in order to prevent damage due to mutual contact of BGA or PGA, a BGA
Alternatively, the PGA is loaded on a package pallet every ten or more pieces, and the pallet is cleaned, so that the cleaning capacity is insufficient. Furthermore, in the above-mentioned conventional method, in order to dry without water stain so as to satisfy the precision, drying is performed by a spin dry method after washing (rinsing). Only one of them could be processed, and the cleaning efficiency was very poor. Similarly, when the system board on which the BGA is mounted is precision cleaned, the cleaning efficiency is also extremely low.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a method for precisely cleaning a large amount of BGA or PGA on which dirt is adhered, a component thereof, or a system board on which BGA is mounted in a short time. The purpose is to do.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, when cleaning is performed by the following specific method, BGA or the like can be removed in a short time and in a large amount. The present invention was found to be capable of precision cleaning and completed the present invention.

That is, according to the present invention, there is provided a washing tower which is provided in a cleaning tower circulating line and has only a liquid passage hole at the bottom without a body passage hole accommodated and installed in a loosely inserted state. When the BGA or PGA with dirt, which is the object to be washed, or these components are stacked in a vertical container for storing the object to be washed without the objects to be washed contacting each other, and can be stacked in multiple stages. After being stored in a state in which it is loaded in a cleaning basket through which the cleaning agent can be passed in the vertical direction, industrial cleaning agent is forcibly circulated into the container to remove BGA or PGA or dirt attached to these components. For cleaning BGA or PGA or a component thereof, and a trunk housed in a cleaning tower incorporated in a circulation line of a cleaning agent in a loosely inserted state. No liquid passage hole After storing a system board on which dirt-adhered BGA is mounted in a vertical container for storing an object to be cleaned having a liquid passage hole only in a portion, with the plane of the system board being in a vertical direction, The present invention relates to a method of cleaning a BGA-mounted system board, which comprises forcibly circulating an industrial cleaning agent into the inside of the system board to remove dirt attached to the BGA-mounted system board.

BGA or PG to be cleaned according to the present invention
A is used as a package that can fully exploit the ability of ASICs to speed up.
A component such as A is a component in a manufacturing process such as BGA.
It refers to a GA substrate or the like that has been subjected to router processing, plating, or the like. The system board on which the BGA is mounted refers to a board on which the BGA is finally mounted. The BGA includes a ceramic BGA (CBGA) using a ceramic substrate, a plastic BGA (PBGA) using a PCB substrate, a film BGA (TBGA) using a polyimide film, and a BGA (FC-BGA) using a flip chip. And P
GA also has the same thing as BGA.

[0008] The dirt adhering to the BGA and the like is as follows.
It adheres in each process of manufacturing BGA, etc.
Dirt to be washed and removed differs in each step. For example, B
After router processing of a glass epoxy substrate, a ceramic substrate, or the like serving as a substrate of GA or the like, polishing powder, fingerprints, and adhesives are attached as dirt. Next, after plating a substrate such as a BGA (for example, gold plating, tin plating, nickel plating, etc.), a plating solution (typically sodium cyanide) adheres as dirt. further,
After bonding and joining a heat sink, a die, a ring, a radiator, and the like to a plated substrate such as a BGA with a solder, an epoxy resin, or the like, flux or the like adheres as dirt. Further, after mounting the BGA on a system board made of a glass epoxy substrate, a selanmic substrate, a metal substrate (eg, aluminum), or the like, flux or the like adheres as dirt. As described above, since various stains adhere to the BGA and the like in the manufacturing process, it is necessary to perform precision cleaning in each process.

Hereinafter, the cleaning method of the present invention will be described with reference to the accompanying drawings.

As is clear from the overall flow diagram schematically shown in FIG. 1, the cleaning apparatus used in the cleaning method of the present invention uses the cleaning agent 2 stored in the liquid tank 1 to return the liquid 2a to the liquid outlet 1a. A liquid circulating line 3 for circulating with the port 1b is provided. A washing tower 4 and a liquid sending pump 5 for forced liquid circulation are installed in the middle of the line 3, and the object to be cleaned a (BGA Or PGA or a system board on which these components and BGA are mounted, the same applies to the following).
A blower 13 and a heater 14 are provided in the wind or hot air supply line 11 branching from the middle of the forward path 3a of the liquid circulation line 3 and the waste line 12 branching in the middle of the return path 3b. I have.

In the liquid circulation line 3, the forward path 3a is connected to the upper chamber 4a of the washing tower 4 starting from the liquid outlet 1a, and the return path 3b is started from the upper end of the lower chamber 4b as the liquid return port 1b. Connected to On the other hand, only the blower 13 is used in the case of liquid removal performed after the washing, and the blower 13 and the heater 14 are used in drying. The blower 13 uses a heater 14 as shown in FIG. The blower 13 is provided with a heater 1 as shown in FIG.
It may be provided in the line 11 before the line 4, or after the line 12 or the gas-liquid separation device 15.

Valves V _{1 to} V ₄ are provided on the reciprocating paths 3 a and 3 b between the lines 11 and 12 and the liquid circulation line 3.
For switching between the liquid circulation line drying line by opening and closing of these valves V ₁ ~V _4.

In the example shown in the figure, the washing tower 4 is installed above the liquid tank 1 in order to return the remaining washing liquid in the tower 4 to the inside of the liquid tank 1 through the return line 6 using the head difference. However, if they are returned using a pump, there is no particular need to install them above. Valve V ₅ is provided in the return line 6. Further, in the illustrated example, a circulation line that enables washing and drying in the same washing tower 4 and a switchable wind or hot air supply line and a discharge line are provided, but separately from the washing tower 4. A drying tower similar to the washing tower 4 may be provided so that washing and drying can be performed in separate towers. In this case, when washing and drying are performed in separate towers, a circulating line and a switchable wind Alternatively, a hot air supply line and a discharge line are not particularly required.

Further, in the washing tower 4 of the washing apparatus used in the washing method of the present invention, there is no body passage hole and only a bottom body passage hole for accommodating the article a to be cleaned. A vertical container 7 for accommodating a washing object is accommodated and installed in a loosely inserted state.

As shown in detail in FIGS. 2 and 3, the vertical container 7 is a cylindrical type having a bottom without a cover, and the bottom 7a is formed of a porous member such as a punched metal or a wire mesh. The liquid can pass through, and the body 7b is made of a non-porous member, and the liquid does not flow out from the body 7b. The cross-sectional shape of the tube is not particularly limited, and may be circular or polygonal. Generally, the circular shape shown in FIG. 2 is preferable. Moreover, the inside of the vertical cylinder may be divided into a plurality of parts by a partition plate or the like.

The vertical cylinder 7 is preferably as long as possible in order to accommodate a large number of objects to be cleaned a with a relatively small cross-sectional area. Therefore, the ratio between the diameter and the height is set in the range of about 1 to 10, preferably about 2 to 5 with respect to the former. The diameter of the vertical container 7 is not particularly limited, and may be appropriately determined depending on the type and the size of a cleaning object a such as a cleaning basket loaded with a BGA or the like or a system board mounted with the BGA. It is about 1 cm to 1 m. Preferably it is 5 cm to 50 cm, more preferably 10 cm to 30 cm. Further, the number of the vertical cylinders 7 inserted and installed in the washing tower 4 is arbitrary, and may be one as shown in FIG. 1 or plural as shown in FIG.

In order to accommodate such a vertical barrel 7 in a loosely inserted and suspended state, the upper end of the vertical barrel 7 is usually provided at the upper end thereof.
A flange portion 8 is provided, and the flange portion 8 is suspended on an annular member 9 projecting inward from the upper end of the inner peripheral surface of the tower 4. The overlapping portion of the flange portion 8 and the annular member 9 forms a surface contact seal portion 10 without a gap over the entire range of 360 °, and the upper portion 4a and the lower portion of the cleaning tower 4 are separated from the seal portion 10 in the washing tower 4. 4b.

In the present invention, the object to be cleaned a is cleaned using such a cleaning apparatus. When the cleaning target a is a stained BGA or PGA or a component thereof, the cleaning target does not contact the cleaning target with each other,
After being loaded in a washing basket which can be stacked in multiple stages and in which a cleaning agent can be passed vertically in the case of being stacked in multiple stages, it is stored in a vertical container 7 for storing an object to be cleaned. As such a washing basket, a package pallet capable of storing BGA or the like in the horizontal direction with respect to the vertical container 7 or a container generally capable of storing BGA or the like in the vertical direction with respect to the vertical container 7 is generally referred to as a magazine. can give. The size of the washing basket is not particularly limited as long as it can be accommodated in the vertical container 7. Usually, the size of the washing basket can be about 4 to 16 without being in contact with each other. preferable. The number of multi-tiered baskets is not particularly limited as long as the height of the multi-tiered basket does not exceed the vertical barrel 7. The cleaning effect is reduced by the height of the multi-tiered basket. I will not do it. In the cleaning method of the present invention, it is preferable to stack the cleaning baskets containing the objects to be cleaned without gaps, since the flow rate of the cleaning liquid in the gaps between the objects to be cleaned is increased, and the cleaning property is improved. Is suitable for washing in large quantities. In addition, FIG.
FIG. 5 is a top view and a vertical cross-sectional view of a vertical container in which a package using a package pallet capable of loading 16 BGAs or the like as a cleaning basket is stacked in 30 stages and stored.
Cleaning and drying of 480 BGAs or the like can be performed at a time.

The object a to be cleaned is made of BG with dirt.
In the case of a system board on which A is mounted, the system board is stored in a state where the plane of the system board is in the vertical direction. When the system board is stored, the system board can be loaded into a general magazine and stored.
FIG. 6 is a longitudinal sectional view of the vertical cylinder when the system board is loaded in a magazine and stored in the vertical cylinder 7, and as shown in FIG. A plurality of objects can be stored in the vertical direction as long as they are in the same direction as the vertical direction.

Hereinafter, the cleaning method of the present invention will be specifically described. That is, after the object to be cleaned a is stored in the vertical container 7 as described above, the cleaning agent 2 in the liquid tank 1 is operated in the state shown in FIG. Is forcedly circulated so that the cleaning agent 2 flows from the outgoing path 3a to the cleaning tower 4
The cleaning object a is cleaned while being forced into the vertical cylinder 7 via the upper chamber 4a and forcedly flowing in the cylinder 7 in the axial direction. The cleaning agent 2 that has washed the object to be cleaned a enters the lower part of the lower chamber 4a of the washing tower 4 from the lower end of the vertical container 7, and further rises in the lower chamber 4a, passes through the return path 3b, and enters the liquid tank 1 through the return path 3b. Return to and be used cyclically. Incidentally, this during the washing operation is valve V ₁ ~V ₂ open state, V ₃ ~V ₅ is held in the closed state.

In the washing method of the present invention, the vertical container 7 is vertically elongated and has a relatively small cross-sectional area. In addition, since there is no liquid passage hole in the body portion 7b, liquid cannot be passed, and only the bottom portion 7a has liquid passage. With the holes, the entire amount of the cleaning agent 2 passes from the upper end to the lower end, and the cleaning agent 2 has a relatively high flow rate and effectively contacts the gap between the objects to be cleaned a with the object to be cleaned a. Pass without loss. In other words, the flow rate of the cleaning agent 2 in the vertical container 7 is substantially constant from the upper end to the lower end, and the whole of the cleaning target a can be uniformly cleaned. A cleaning process can be performed. Moreover, the cleaning efficiency is good because the intense turbulence generated by the contact of the cleaning liquid 2 causes the cleaning liquid to enter the gap between the objects to be cleaned a and the back portion of the object to be cleaned a having a small gap.

The flow rate of the cleaning agent forcibly flowing through the vertical cylinder 7 is substantially constant from the upper end to the lower end, and the cleaning efficiency can be improved by increasing the flow rate. It may be appropriately adjusted depending on the type and amount of storage, the type of attached dirt, and the like. Usually, the flow rate of the cleaning agent is preferably about 3 to 200 cm / sec.
The cleaning time is about 30 seconds to 120 minutes. Also,
The washing temperature is about 10 to 90 ° C.

When the bottom 7a and the body 7b of the vertical cylinder 7 are provided with a liquid passage hole, a part of the cleaning agent 2 flows through the body of the vertical cylinder while passing through the inside of the vertical cylinder. Since the cleaning agent 2 flows out of the cylinder through the hole, the flow rate of the cleaning agent 2 in the vertical cylinder gradually decreases as it goes downward, and the average flow velocity in the vertical cylinder is the Although it depends on the opening / closing ratio, it is considerably reduced as compared with the present invention. Further, since the cleaning agent 2 flowing out through the liquid passage hole in the body of the vertical cylinder does not come into contact with the object a again, the amount of the cleaning agent 2 in contact with the object a also decreases. As a result, the contact efficiency decreases as compared with the present invention in which the entire amount of the cleaning agent 2 comes into contact with the object to be cleaned a.

After the predetermined cleaning, the operation of the pump 5 is stopped, the circulation of the cleaning agent 2 is stopped, and V ₁ and V ₂ are closed, and the valves V _{3 to} V ₅ are opened. Valve V ₃ ~V
By opening _5, the remaining washing liquid in the washing tower 4 and the vertical cylinder 7 is returned into the liquid tank 1 through the return line 6. On the other hand, the outside air is introduced into the vertical container 7 and the washing tower 4 through the lines 11 and 12 on the draining and drying side, and after collecting the remaining washing liquid, the valve 5 is closed.

Next, the blower 13 is operated to drain and dry the liquid by supplying wind or hot air. At the time of drying, the outside air is heated by the heater 14,
From the upper chamber 4a to the inside of the vertical container 7, where the liquid to be cleaned a is drained and dried, and the attached cleaning agent is removed. Further, by providing a vacuum device after the exhaust line 12 or the gas-liquid separation device 15, the liquid removal and drying may be performed under reduced pressure. Since such a drying step is performed in the washing tower 4, a high-speed air stream becomes a turbulent vortex and blows off water droplets.
Drying can be completed in a short time. Therefore, there is no occurrence of water stain, which has been a problem in the drying step of condensing or evaporating water droplets as in the related art.

The article to be cleaned peeled adhered liquid from a accumulates in the bottom of the lower chamber 4b of the wash column 4 flows down through dropwise to, returned by the opening and closing of the valve V ₅ adhered liquid accumulated in the bottom after completion of the drying operation line It is returned to the liquid tank 1 through 6. On the other hand, wind or hot air enters the lower part of the lower chamber 4b of the washing tower 4 from the lower end of the vertical container 7 and passes through the exhaust line 12 while facing the upper part of the lower chamber 4b while leaving the detergent 2 at the bottom of the lower chamber 4b. Release to atmosphere. Further, a gas-liquid separator 15 is connected to the exhaust line 12.
The provided, separated liquid through the return line 16, may be returned to the liquid tank 1 by opening and closing the valves V _6. Further, if necessary, the cleaned object a is rinsed and then dried. In addition, water etc. are mentioned as a rinsing agent. After the draining and drying of the cleaning target a are completed, the operation of the blower 13 is stopped, and V ₃ and V ₄ are closed.

According to the cleaning method of the present invention, the object to be cleaned a is washed and dried, and the dirt adhering to the object to be cleaned a can be efficiently removed in a short time. When a series of washing and drying operations is completed, the upper lid 17 of the washing tower 4 is opened, the vertical cylinder 7 is replaced with the next vertical cylinder 7, and the next operation can be performed sequentially. .

Although the above has been described with reference to FIG. 1, in the present invention, the return path 3b of the liquid circulation line 3 is connected to the bottom of the lower chamber 4b of the washing tower 4 and the liquid in the liquid tank 1 as shown in FIG. You may make it provide between the return ports 1b. In this case, the return path 3b can also serve as the return line 6 for the residual cleaning solution.

Further, as shown in FIG.
At the bottom of the lower chamber 4b of the washing tower 4 and at the return path 3
b may be connected to the upper chamber 4a. In this case, the cleaning agent 2 passes through the inside of the vertical container 7 upward from the lower end.
Since the article to be washed a is made to flow, the washing property is improved. In this case, a net member 18 can be provided at the upper end of the vertical container 7 for the purpose of preventing the outflow of the cleaning target a.

Further, as shown in FIG. 9, the washing tower 4 can be provided with a plurality of sets, for example, three sets of circulating systems for the washing liquid. The three circulation systems are individually provided with liquid tanks 1A, 1B, 1C and circulation lines 3A, 3B, 3C, and can be sequentially switched to be used for cleaning. In addition, such a plurality of circulatory systems can be used for cleaning,
It is also convenient when performing preliminary rinsing, main rinsing and the like sequentially.

The cleaning agent used in the cleaning method of the present invention is BG
There is no particular limitation as long as it is used as an industrial cleaning agent such as A. However, chlorine and other halogen-containing hydrocarbon solvents themselves are nonflammable and have excellent drying properties, but cannot be used due to environmental pollution problems such as destruction of the ozone layer.
In addition, isopropyl alcohol, alcohols such as ethyl alcohol, xylene, petroleum solvents such as benzene,
There is a problem in odor and flammability, and it is difficult to use an alkaline cleaning agent because it has defects such as corroding metals such as aluminum and copper and roughening the surface of the member.

Under such circumstances, in the cleaning method of the present invention,
It is preferable to use an industrial cleaning agent which can satisfy required performances such as environmental characteristics, odor and flammability to some extent. Examples of such an industrial detergent include an industrial detergent containing at least one selected from a nonionic surfactant, an ionic surfactant and a glycol ether compound, and water. In particular, it is not affected by dirt such as polishing powder, fingerprints, adhesives and the like adhered after router processing of a glass epoxy substrate or the like which becomes a substrate of BGA or the like, or stains such as plating solution adhered after plating. Industrial detergents containing ionic surfactants and glycol ether compounds are preferred, and non-ionic surfactants, glycol ether compounds and ionic Industrial detergents containing a neutral surfactant are preferred. From the viewpoint of flammability, it is preferable that these industrial detergents contain at least 5% by weight of water.

Specific examples of the nonionic surfactant include:
Polyoxyalkylene alkyl (alkyl group having 6 carbon atoms)
Polyalkylene glycol ether type nonionic surfactants such as ether, polyoxyalkylene phenol ether and polyoxyalkylene alkyl phenol ether; polyalkylene glycol ester nonionic surfactants such as polyalkylene glycol monoester and polyalkylene glycol diester Activator;
Alkylene oxide adducts of fatty acid amides; polyhydric alcohol type nonionic surfactants such as sorbitan fatty acid esters and sucrose fatty acid esters; fatty acid alkanolamides and polyoxyalkylene alkylamines. One of these nonionic surfactants can be used alone, or two or more can be appropriately selected and used in combination. Here, the alkylene refers to ethylene, propylene or butylene, and the polyoxyalkylene refers to polyoxyethylene, polyoxypropylene, polyoxybutylene or a copolymer thereof.
Among these nonionic surfactants, a polyethylene glycol ether type nonionic surfactant is preferred from the viewpoint of detergency. More preferred are those represented by the general formula (1):
R ¹ —O— (CH ₂ CH ₂ O) _m —H (wherein, R ¹ is a linear or branched alkyl group having 6 to 20 carbon atoms, a phenyl group, or a linear or branched chain having 7 to 12 carbon atoms) And m represents an integer of 2 to 20), wherein the phenyl group is substituted with a branched alkyl group. In particular, R ¹ is an alkyl group having 8 to 16 carbon atoms, and m is preferably a polyoxyethylene alkyl ether having an integer of 3 to 16.

Examples of the ionic surfactant include various known sulfate-based anionic surfactants such as sulfates of higher alcohols, alkyl sulfates, and polyoxyethylene alkyl sulfates; alkyl sulfonates; Various known sulfonate anionic surfactants such as alkylbenzene sulfonates; phosphate anions such as alkyl phosphates, polyoxyethylene alkyl phosphates, and polyoxyethylene alkylphenyl phosphates Cationic surfactants such as alkylated ammonium salts and quaternary ammonium salts; and amphoteric surfactants such as amino acid type and betaine type amphoteric surfactants.

The glycol ether compound is represented by the general formula (2): R ² O— (CH ₂ (R ⁴ ) CHO)
_n -R ³ (wherein, a linear or branched alkyl group of R ² is 1 to 5 hydrogen atoms or carbon, R ³ is 1 to carbon atoms
5 is a linear or branched alkyl group, R ⁴ is a hydrogen atom or a methyl group, and n is an integer of 2 to 4). Specific examples of glycol ether compounds include diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol monopropyl ether, diethylene glycol dipropyl ether, diethylene glycol methyl propyl ether, and diethylene glycol ethyl propyl ether. , Diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl butyl ether, diethylene glycol ethyl butyl ether, diethylene glycol propyl butyl ether, diethylene glycol monopentyl ether, diethyl Glycol dipentyl ether, diethylene glycol methyl pentyl ether, diethylene glycol ethyl pentyl ether, diethylene glycol propyl pentyl ether, diethylene glycol butyl pentyl ether; tri- or tetraethylene glycol ethers corresponding thereto; di-, tri- or tetrapropylene corresponding thereto Glycol ethers can be exemplified. These glycol ether compounds can be used alone or in combination of two or more.

[0036]

According to the cleaning method of the present invention, dirt-adhered BGA or PGA or their components, a system board on which a BGA is mounted, etc. can be removed in a short time.
It is capable of precision cleaning in large quantities and has very good cleaning efficiency.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the cleaning method of a BGA or the like of the present invention is carried out using a cleaning apparatus of the type shown in FIG. 1 or 9 will be described below.

Production Example 1 Water was further added to a mixture consisting of 60 parts by weight of diethylene glycol monobutyl ether and 40 parts by weight of polyoxyethylene (additional number of moles 7) nonyl ether, and the content of the mixture (active ingredient) was 0.1%. A 5% by weight industrial cleaning agent was prepared.

Production Example 2 85 parts by weight of diethylene glycol monobutyl ether
Polyoxyethylene (additional mole number 7) nonyl ether 7
An industrial detergent consisting of 3 parts by weight of dodecyl phosphate / triethanolamine salt and 5 parts by weight of water was prepared.

Example 1 Sixty glass epoxy substrates (40 mm × 40 mm × 2 mm in height) to which router-processed abrasive powder had adhered were loaded into a magazine (130 mm × 130 mm × 50 mm in height). In addition, the magazine was stacked in six stages,
It was stored in a 133 mm × 133 mm × 350 mm height vertical container (vertical container 7 in FIG. 1) having a gap hole only at the bottom. Next, the cylinder was placed in the washing tower of the washing apparatus shown in FIG. 1, and the washing was performed at a flow rate of 35 cm / sec into the cylinder using the industrial detergent prepared in Production Example 1.
After 1 minute at 0 ° C., the line was switched and hot air drying with a heater was performed at 80 ° C. for 5 minutes.

Example 2 A heat sink and a die were attached to the glass epoxy substrate cleaned in Example 1, and then subjected to gold plating to obtain a package. Sixteen packages to which the plating solution was attached were loaded on a package pallet (215 mm × 215 mm × 10 mm in height). Further, the package pallets stacked in 30 stages were stored in a vertical container (220 mm × 220 mm × 350 mm height) having a gap hole only at the bottom (vertical container 7 in FIG. 9). Next, the cylinder was placed in the washing tower of the washing apparatus shown in FIG. 9, and the washing was performed at a flow rate of 35 cm / sec into the cylinder using the industrial detergent prepared in Production Example 1. After 3 minutes at C, the line was switched and drainage was performed for 1 minute. Further, the line was switched, and rinsing treatment was performed at 50 ° C. for 3 minutes using pure water at the same inflow rate. Then, the line was switched again, and hot air drying by a heater was performed at 80 ° C.
The operation performed for 5 minutes with was repeated twice.

Example 3 In the package cleaned in Example 2 after plating,
After soldering the ball solder and chip capacitor, reflow was performed. The package to which the reflowed flux is attached is placed on a package pallet (215 m
m × 215 mm × height 10 mm). Furthermore, the package pallet was stacked in 30 stages, and was 220 mm × 220 mm having a gap hole only at the bottom.
And housed in a 350 mm high vertical container (vertical container 7 in FIG. 9). Next, the cylinder was placed in the washing tower of the washing apparatus shown in FIG. 9, and washing was performed at a flow rate of 35 cm / sec into the cylinder using the industrial detergent prepared in Production Example 2. After 3 minutes at C, the line was switched and drainage was performed for 1 minute. Further, the line was switched, and a pre-rinse treatment was performed at room temperature C for 3 minutes at the same inflow rate using pure water. Then, the line was switched again and draining was performed for 1 minute. The line was further switched, and a finish rinsing treatment was performed at 50 ° C. for 3 minutes using pure water at the same inflow rate. Then, the line was switched again, and hot air drying with a heater was performed at 80 ° C. for 5 minutes.

Example 4 Sixteen packages cleaned in Example 2 were combined with a glass epoxy system board (170 mm × 170 mm ×
(Height: 10 mm). The system board to which the flux on which the package is mounted is adhered to a magazine (180 mm × 180 mm × 17
5 mm), and the magazines were stacked in two stages, and a 185 mm × 185 having a gap hole only at the bottom was prepared.
As shown in FIG. 6, the system board was housed in a vertical container having a height of 380 mm and a height of 380 mm (vertical container 7 in FIG. 9) so that the plane of the system board was in the vertical direction. Next, the cylinder was set in the washing tower of the washing apparatus shown in FIG. 9, and the inflow velocity into the cylinder was 35 cm using the industrial detergent prepared in Production Example 2.
After washing for 3 minutes at 60 ° C./sec, the line was switched and draining was performed for 1 minute. Further, the line was switched, and a pre-rinse treatment was performed at room temperature C for 3 minutes at the same inflow rate using pure water. Then, the line was switched again and draining was performed for 1 minute. The line was further switched, and a finish rinsing treatment was performed at 50 ° C. for 3 minutes using pure water at the same inflow rate. Then, the line was switched again, and hot air drying with a heater was performed at 80 ° C. for 5 minutes.

Cleaning Evaluation (1): One package subjected to the cleaning treatment in Example 3 was placed in a polypropylene bag, ultrapure water was further charged, and air was expelled, followed by heat sealing. On the other hand, only the same amount of ultrapure water was put in a similar polypropylene bag, and air was expelled, followed by heat sealing. Place these polypropylene bags in a water bath,
After boiling for 1 hour, it was taken out and cooled to room temperature, and the ion content in ultrapure water in the polypropylene bag was examined by ion chromatography. As a result, there was no difference between them, and it was confirmed that the package cleaned in Example 3 was subjected to precision cleaning.

Washing evaluation (2): The ion residue concentration of the system board washed in Example 4 was measured with an omega meter, and the result was 0.2 μg NaCl / in.
ch ² or less. According to the mill standard, 14 μg
NaCl / inch ² or less is preferred.

[Brief description of the drawings]

FIG. 1 is an overall flow chart of a cleaning apparatus for performing a cleaning method of the present invention.

FIG. 2 is a vertical sectional view of a vertical cylinder provided in a cleaning apparatus for performing the cleaning method of the present invention.

FIG. 3 is a plan view of the same.

FIG. 4 is a flowchart illustrating an example of a case where a plurality of vertical containers are provided.

5A and 5B are a top view and a vertical cross-sectional view of a vertical container in which cleaning baskets loaded with objects to be cleaned are stacked and stored in multiple stages.

FIG. 6 is a vertical cross-sectional view of a vertical cylinder housing a system board on which an object to be cleaned is mounted.

FIG. 7 is a flowchart showing a modification of the liquid circulation line.

FIG. 8 is a flowchart showing another modified example of the embodiment.

FIG. 9 is a flowchart showing an example in a case where a plurality of liquid circulation systems are provided.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid tank 2 Cleaning agent 3 Liquid circulation line 4 Washing tower 5 Liquid sending pump 6 Return line 7 Vertical type cylinder 8 Flange part 9 Ring member 10 Seal part 11 Wind or hot air supply line 12 Air exhaust line 13 Blower 14 Heater 15 Air Liquid separator 16 Return line 17 Top cover 18 Mesh member

Claims (7)

(57) [Claims] An object for storing an article to be washed, which has no body liquid passage hole accommodated and installed in a washing tower incorporated in a cleaning agent circulation line and has a liquid passage hole only at the bottom. The BGA or PGA to which the object to be cleaned is adhered or the components thereof are not in contact with each other, and can be stacked in multiple stages. After being stored in a state in which it is loaded in a cleaning basket through which the cleaning agent can pass, an industrial cleaning agent is forcibly circulated in the cylinder to wash and remove BGA or PGA or dirt attached to these components. BGA characterized by the following:
Alternatively, PGA or a method for cleaning these components. 2. An object for storing an object to be washed, which has no body liquid passage hole accommodated and installed in the washing tower incorporated in the cleaning agent circulation line and has a liquid passage hole only at the bottom. After storing a system board on which dirt-adhered BGA is mounted in a vertical cylinder, the industrial cleaning agent is forcibly circulated in the cylinder, and the BGA is placed in the cylinder. A method for cleaning a system board equipped with a BGA, characterized by washing and removing dirt adhering to a system board equipped with a BGA. 3. The method according to claim 1, further comprising a supply line and a discharge line for air or hot air which can be switched with a circulation line for the cleaning agent, and wherein the line is switched and dried after cleaning and removal. Cleaning method. 4. A vertical container is housed in a washing tower in a suspended state, and the washing tower is divided into an upper chamber and a lower chamber. The cleaning liquid communicates with the lower part of the chamber, and the cleaning liquid passes through the upper chamber, the vertical container, the lower part of the lower chamber, and the lower part of the lower chamber in this order. 4. The cleaning method according to claim 1, wherein the cleaning method is performed. 5. The cleaning tower according to claim 4, wherein a supply line for air or hot air is provided in an upper chamber of the washing tower, and a discharge line is provided in an upper part of the lower chamber so as to be switchable with a circulation line of a washing liquid. The cleaning method as described. 6. The cleaning according to claim 1, wherein the vertical container is vertically long, and the ratio of diameter to height is 1 to 10 with respect to the former. Method. 7. An industrial detergent comprising at least one selected from a nonionic surfactant, an ionic surfactant and a glycol ether compound, and water. The cleaning method according to claim 1.