JP3340726B2 - Flexible printed circuit board plating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible printed circuit board (hereinafter referred to as FPC (FPC)) which is thin and has excellent flexibility and is very useful for wiring such as connection between rigid printed circuit boards.
flexible Printed Circuit))
More particularly, the present invention relates to a plating apparatus for plating an inner wall portion of a through hole which is a through hole in an FPC.

[0002]

2. Description of the Related Art FPC is made of polyester, polyimide,
Polyamide paper-based epoxy resin, glass cloth-based epoxy resin, glass cloth-based BT resin, etc. are used as the base film, and one or both sides of the base film are copper foils, especially highly flexible rolled copper foils, special examples. As a conductor laminated such as aluminum foil, stainless steel foil, the surface of which is covered with an insulating film or liquid resist,
It is a thin layer having a thickness of several tens to several hundreds of micrometers. Therefore, FP
C has excellent flexibility and is used for wiring in movable parts and narrow spaces regardless of consumer equipment and industrial equipment including calculators, cameras and printers.

In the manufacturing process of an FPC having a copper foil conductor layer on both sides, a through hole is drilled at a required portion of a substrate having a copper foil laminated on a base film of the insulating material by a drilling machine or the like. There is a step of performing through-hole plating for plating the inner wall portion with only copper or a double structure with solder to enable conduction between the inner and outer layer circuits. The plating on the inner wall of the blind via hole, which is a non-through hole, is also performed in the same plating step.

Conventionally, the through-hole plating is performed by fixing screws and nuts 72 to a metal frame 71 such as copper shown in FIG.
A metal frame jig 70 having a substrate mounting portion 73 provided with a metal frame jig and the like, in which the flaky substrate 21 is stretched and fixed like a paper having a size of about 30 cm × 50 cm, and the substrate 21 is fixed. This is achieved by continuously performing electroless copper plating and electrolytic copper plating while moving the entire 70.
At this time, the line of 10,000 m ² B / month requires 10 to 15 workers per line.

[0005] In the electroless copper plating step, the entire metal frame jig 70 to which the substrate 21 is fixed, for example, a leveling and surface cleaning solution, a soft etching solution, an acid cleaning solution, a pretreatment solution, a catalyst, an accelerator, an electroless copper The liquid is sequentially immersed in each liquid tank, and copper is deposited by a chemical reduction reaction to a thickness of about 0.5 μm on the inner wall surface of the base film which is a non-conductor in the through hole which is a through hole of the substrate 21. At this time, the copper deposited on the surface of the base film contacts the inner walls of the copper foil on both sides of the base film, and the inner walls of the through holes are given conductivity.

[0006] Thereafter, the electrolytic copper plating process, for example, copper sulfate, sulfuric acid, using a copper plate to the copper plating solution and an anode made of such as chlorine ion and brighteners traces of copper sulfate as a copper ion source (CuSO 4 _· 5H ₂ Copper is deposited on the inner wall of the through hole provided with conductivity by copper sulfate plating of an acidic bath using O), and the thickness which can guarantee the function as an electric circuit over the entire inner wall of the through hole, for example, 15
By growing copper of 銅 20 μm, the copper foil on both sides of the substrate is brought into a sufficiently conductive state. After cleaning after the electrolytic copper plating, the substrate 21 is dried.

If a plating solution is selected, a film thickness of 15 to 20 μm is formed on the base film surface only by electroless copper plating.
Although it is possible to form a copper film having a thickness of m, it has hardly been put to practical use because of the poor physical properties of the deposited copper, high cost, and poor productivity.

As described above, the conventional plating apparatus used in the through-hole plating step in the production of the FPC uses the metal frame jig 70 as shown in FIG. 7 and the electroless copper plating step and the electrolytic copper plating step. Each liquid tank is provided.

[0009]

However, in the plating apparatus used in the conventional through-hole plating process,
Electroless copper plating and electrolytic copper plating are performed while the substrate 21 is mounted on the metal frame jig 70. In the electrolytic copper plating, the substrate 21 together with the metal frame jig 70 becomes a cathode. Each time the process is performed, copper is deposited on the metal frame portion 71 of the metal frame jig 70, the substrate mounting portion 73, and the like, and the thickness of the deposited copper gradually increases. Therefore, the current flowing through the substrate 21 fixed to the substrate mounting portion 73 of the metal frame jig 70 with the screw and the nut 72 changes, so that the thickness of the copper plated on the substrate 21 changes or Screws and nuts 7 for fixing in the board mounting portion 73 may be uneven.
The metal frame jig 70 is used for about 30 times in the plating process, and it is necessary to replace the metal frame jig with a new metal frame jig.

[0010] Further, as a plating apparatus for solving the above-mentioned problems, in the electrolytic copper plating step after the electroless copper plating step using the metal frame jig 70, electrical contact with the substrate is made. In addition to small metal contacts provided at a plurality of locations for fixing and electrodes connected to an external power supply, a resin frame jig in which a metal portion is not exposed in a synthetic resin frame is used, and the contacts of the resin frame jig are used. Since almost no copper is precipitated, it is conceivable to use a plating apparatus that can be used until the resin frame jig is physically broken.

However, even if the resin frame jig is used in the electrolytic copper plating step, the metal frame jig 70 used in the preceding electroless copper plating step uses the Since it is fixed by the mounting portion 73, the worker holds the wet substrate 21 after electroless copper plating with a metal frame jig 70 by hand wearing rubber gloves or vinyl gloves.
It takes time and effort to remove it from, and workability is poor.

Therefore, if the substrate 21 is dried after the electroless copper plating while the substrate 21 is attached to the metal frame jig 70, it is necessary to use rubber gloves or the like to remove the substrate 21 from the metal frame jig 70. Since the work of removing the substrate 21 can be performed with nylon or cotton gloves, the workability is improved. However, after the electroless copper plating, the metal frame jig 7
When the substrate 21 is dried with the substrate 21 attached thereto, the trace of the substrate attaching portion 73 of the metal frame jig 70 remains on the substrate 21 as a stain, resulting in poor appearance.

If the electroless copper plating and the electrolytic copper plating are performed while the substrate is fixed to the resin frame jig, the problem of poor workability as described above can be avoided. Since it is a non-conductor, copper is deposited on the synthetic resin portion of the resin frame jig by electroless copper plating, so that the same problem occurs when the metal frame jig 70 is used in the subsequent electrolytic copper plating. Therefore, electroless copper plating cannot be performed using a resin frame jig.

In order to increase the productivity of through-hole plating, a plurality of the substrates are put in a basket capable of accommodating a plurality of the substrates, and the substrates are separated by a horizontal bar so that the substrates do not come into contact with each other. A method of performing a plating process is considered. However, since the substrates are flaky like paper, it is difficult to accommodate the substrates in a basket so that the substrates do not come into contact with each other.Therefore, a plurality of substrates cannot be processed at the same time. The frame jig 70 must be used.

The present invention has been made in order to solve the above-mentioned problems, and a large number of substrates can be processed at a time in electroless plating. It is an object of the present invention to provide a plating apparatus for a flexible printed circuit board, which can reduce the number of times the jig needs to be replaced to greatly reduce the cost of the jig and has good workability.

[0016]

SUMMARY OF THE INVENTION The present invention relates to an apparatus used for plating a flexible printed circuit board, comprising: a conductor jig having a frame portion having a mounting member for holding, extending and fixing the board; A basket for accommodating the conductor jig;
A processing tank for performing electroless plating of the substrate together with the basket,
A drying oven having a mechanism for suspending the basket and applying an impact to the jig of the conductor housed in the basket, a jig in which a main part for fixing the substrate is non-conductive, and a jig in which the main part is non-conductive And a treatment tank for performing electroplating of the substrate together with the jig.

Further, the mechanism for applying an impact to the jig of the conductor is a mechanism for supporting a suspension member for suspending the cage, and alternately raising and lowering both ends of the suspension member by natural fall. It may be something.

[0018]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an embodiment of a plating apparatus for a flexible printed board according to the present invention. 2A and 2B show a conductor jig in FIG. 1, wherein FIG. 2A is a front view and FIG. 2B is a side view. FIG.
It is a schematic perspective view which shows the basket which accommodated the jig of the conductor in FIG. FIG. 4 is a schematic cross-sectional view showing a state where the left end of the suspension member is raised in the drying furnace in FIG. 1. 5A and 5B show a jig in which the main part in FIG. 1 is a non-conductor. FIG. 5A is a front view in which the jig is developed, and FIG. 5B is a side view.

As shown in FIGS. 1 to 5, a plating apparatus 10 for a flexible printed circuit board (hereinafter, referred to as an FPC) according to an embodiment of the present invention employs a base film 61 made of a non-conductive polyimide shown in FIG. Plating of a substrate 21 having a metal foil, in this case, copper foils 62a, 62b laminated on both sides,
In particular, it is an apparatus used for through-hole plating,
Attachment members 22a, 22b, 22c, and 22d which hold and hold 1 at a plurality of locations, for example, four locations, and extend and fix with springs 24.
Frame jig 20 which is a conductor jig provided with a frame portion 23 having: a stainless steel cage 30 for accommodating a plurality of, for example, ten stainless frame jigs 20, and a cage 3
A treatment tank 11 for performing electroless plating of the substrate 21 for every 0; a drying furnace 40 provided with a vertical movement mechanism 41 which is a mechanism for suspending the basket 30 and shocking the stainless steel frame jig 20 accommodated in the basket 30; A resin frame jig 50 whose main part to fix the substrate 21 is a nonconductive jig, and a processing tank 13 for electrolytic plating of the substrate 21 together with the resin frame jig 50.

The FPC plating apparatus 10 has a storage 12 for temporarily storing the substrate 21 after the drying process after the electroless plating and a storage 14 for storing the substrate after the drying process after the electroplating. And Note that the storage 12 and / or the storage 14 may not be provided. In addition, the post-treatment liquid tank and the drying furnace 13c may be in a form without a drying furnace.
The substrate 21 is removed from 0 and the substrate 21 is dried naturally. Alternatively, only the substrate 21 is separately dried by a dryer.

In the FPC plating apparatus 10, the basket 30 is transported onto a treatment tank 11 for performing electroless plating and a drying furnace 40, and the treatment tank 11 for performing electroless plating and a drying furnace 40.
There is provided a processing tank 11 for lowering the inside and electroless plating, and a transfer device 15 for raising the processing tank 11 from the drying furnace 40. For example, the transport device 15 suspends and suspends a suspension member 46a in which three cages 30 are suspended.

Further, a resin frame jig 50 to which the substrate 21 is fixed
Is transported onto a processing tank 13 for performing electrolytic plating, lowered into the processing tank 13 for performing electrolytic plating, and a processing tank 1 for performing electrolytic plating.
A transport device 16 is provided for ascending from 3.

The transfer devices 15 and 16 need only be installed in a form having functions as required, and the transfer device 15 and / or the transfer device 16 may not be provided. Alternatively, the stainless steel frame jig 20 may be directly attached to the transfer device 15 without the cage 30, or an electrolytic plating cage capable of accommodating a plurality of resin frame jigs 50 may be used. In FIG. 1, 15a, 15b and 15c denote the ascending direction, descending direction and transport direction of the basket 30, respectively.
Reference numerals a, 16b, and 16c denote an ascending direction, a descending direction, and a transport direction of the resin frame jig 50, respectively.

As shown in FIG. 2, the stainless steel frame jig 20 has a mounting member 22a,
The auxiliary frame 27 is fixed to a guide 26 movable by being guided by a side frame of the frame 23. The auxiliary frame 27 is provided with mounting members 22c and 22d. 24 is attached. The spring 24 may be any member that can extend the substrate 21.
The number of attachments is preferably two, but other numbers may be used, and the spring 24 may be fixed to the auxiliary frame 27 and / or the lower frame of the frame 23.

Mounting members 22a, 22b, 22c, 22d
Has a holding portion for holding the substrate 21 with a short linear contact area, and the holding portion is biased by a spring to hold the substrate 21. Therefore, the mounting portions 22a, 22b, 22c, 22
Although the board 21 attached to d does not easily come off, the board 21 can be easily taken off by operating a lever or the like for removal.

Further, the mounting members 22a,
The substrate 21 fixed to 2b, 22c, 22d is pulled and extended. The guide portion 26 is provided with a fixing member, and after the substrate 21 is extended by the spring 24, the guide portion 26 can be fixed to the frame portion 23 by the fixing member. The substrate 21 is not displaced or slackened even if is swung. As the fixing member, for example, a guide portion 26 is provided with a screw, and a frame portion 23 for guiding the guide portion 26 is provided with a screw hole into which the screw is screwed.
Can be fixed to the frame portion 23.

Since the stainless steel frame jig 20 sandwiches the substrate 21 with a small contact area, only a small amount of liquid such as cleaning which is post-treatment after electroless copper plating remains in that portion. The substrate 21 is completely dried in the drying furnace 40, and the appearance defect due to the stain on the substrate 21 does not occur. In addition, stainless steel frame jig 2
0 has a mounting member for the substrate 21 as described above,
1 can be used as long as it is a structure that can be extended and fixed, and it is sufficient that at least a portion that is in contact with the processing liquid is formed of a conductor that is resistant to various processing liquids other than stainless steel. The part may be formed of the conductor.

As shown in FIG. 3, the basket 30 is formed of stainless steel, and the upper and lower ends of the stainless steel frame jig 20 to which the substrate 21 is fixed are fixed to fixtures 31a, 31b, 32a,
It is received and fixed by the cut formed in 32b. The fixtures 31a and 31b are fixed to the bottom of the basket 30, and the fixtures 32a and 32b are detachable. When the stainless steel frame jig 20 is fixed, it is fixed to the horizontal frame 33 of the basket 30. The fixtures 31a, 31b, 32a, and 32b allow the ten stainless steel frame jigs 20 to be fixedly accommodated in the basket 30 without bringing the adjacent substrates 21 into contact with each other. The distance between the adjacent stainless steel frame jigs 20 is the fixture 31a,
Adjustable by 31b, 32a, 32b, 20m
m is preferable, and there is no problem in the electroless plating treatment at this distance.

A handle 34 is attached to the upper part of the basket 30, and the basket 30 is suspended on the suspension portion 46a by the handle 34. Note that the handle 34 may have a structure that can be easily attached to and detached from the suspension portion 46a and that does not easily come off the suspension portion 46a during the drying process in the drying furnace 40. Further, the handle 34 and / or the suspension portion 46a may be provided with a non-slip member so that the handle 34 does not slide left and right on the suspension portion 46a in FIG.

The material of the basket 30 is not limited to stainless steel, but may be any conductor that is resistant to various treatment liquids, and the cage 30 may have any structure that can provide sufficient strength. The method for fixing the stainless steel frame jig 20 is not limited to the method using the fixing tools 31a, 31b, 32a, and 32b, but may be any method that can fix a plurality of stainless steel frame jigs 20 at desired intervals. . The basket 30 can accommodate a plurality of stainless steel frame jigs 20 and may have an appropriate size, but preferably has a size capable of fixedly accommodating ten stainless steel frame jigs 20.

The pretreatment liquid tank 11a is composed of, for example, a leveling and surface cleaning tank, a soft etching tank, an acid cleaning tank, a pretreatment tank, a catalyst tank, an accelerator tank, and the like. Note that the pretreatment liquid tank 11a may be constituted by a treatment tank capable of performing necessary pretreatment.

The electroless plating tank 11b is a plating tank for performing electroless copper plating. A liquid tank formed of a resin such as a vinyl chloride resin contains copper sulfate as a copper ion source and sodium hydroxide as an alkali source. An electroless copper plating solution having a liquid composition in which formaldehyde is added as a reducing agent, Rochelle salt or EDTA (ethylenediaminetetraacetic acid) is added as a chelating agent, and a trace amount of a compound is added as a stabilizer and a malleable agent. The electroless plating tank 11b includes a plating tank cleaning device, a plating solution stirring device, a plating solution filtering device, and a control mechanism for controlling the temperature, concentration, and pH of the plating solution.

When a metal other than copper, for example, nickel or tin is electrolessly plated, a necessary plating solution may be used, and the material, size, plating solution and the like of the electroless plating tank 11b may be changed. Just use what you need, and
The electroless plating tank 11b is not limited to the above as long as it has a necessary function.

The post-treatment liquid tank 11c is constituted by a cleaning tank for cleaning the substrate 21 plated with electroless copper.

As shown in FIG. 4, for example, the drying furnace 40 has a vertical movement mechanism 41 for applying an impact to the stainless steel frame jig 20 while moving the main body 42, the cover 43, and the basket 30 up and down, Hot air circulator 4 with air volume control system
4. A ventilation path 45 for sending warm air from the warm air circulator 44 to the inside of the main body 42 and a filter attached in front of the air inlet of the warm air circulator 44 are provided.

The warm air is exhausted from the bottom of the main body 42,
The air is sucked into the hot air circulator 44 through the filter and sent to the air passage 45 at a constant temperature and air volume by the hot air circulator 44.
The paper is sent into the main body 42 from the upper side surface of the main body 42. In this way, the hot air flows in the flow direction 47 of the hot air. The outlet for the hot air into the main body 42 and the outlet for the hot air from the main body 42 to the hot air circulator 44 may be provided in a place where a flow of the hot air is obtained so that the substrate 21 can be completely dried. The opening area may be appropriately selected. Further, instead of circulating hot air with the hot air circulator 44, a heater may be provided in the main body 42 to heat the air and circulate the air.

Although the plurality of baskets 30 can be accommodated in the main body 42, the size of the main body 42 is as shown in FIG.
It is preferable that the size is such that three cages 30 can be accommodated. Basket 3 that can accommodate 10 stainless steel frame jigs 20
If three 0s can be accommodated, 30 substrates can be dried at a time, and the main body 42 is not too large.

The vertical movement mechanism 41 supports the left and right ends of a rod-shaped suspension member 46a on which the basket 30 is suspended, alternately raises each of the left and right ends by several centimeters, and lowers them by natural fall. By applying an impact to the substrate 20 and the substrate 21, the mounting members 22 a, 22 b, 22
This is a mechanism for facilitating the removal of a liquid such as a cleaning liquid remaining in a gap between c and 22d. The vertical movement mechanism 41
The cam which has a six-character outer shape for vertically moving the left and right ends so that the left and right ends of the suspension member 46a fall naturally from the highest point is used for each of the left and right ends.

FIG. 4 shows a state in which the left end of the suspension member 46a has reached the highest point, and the suspension member 46b in which the right end has reached the highest point is indicated by a two-dot chain line. In this manner, the left and right ends of the suspension member 46a are alternately moved up and down to apply an impact, thereby completely removing the liquid remaining from the stainless steel frame jig 20 and the substrate 21 in a shorter time than when no impact is applied. be able to. Therefore, in the drying furnace 40, since the drying is performed by heating as weakly as possible, the copper foil of the substrate 21 is less likely to be modified, and no abnormality occurs in the substrate even after the electrolytic copper plating. The suspension member 46a may have a shape other than a rod shape as long as the cage 30 can be suspended.

The suspension member 46a may be provided in the vertical movement mechanism 41 of the drying furnace 40. In this case, after the post-processing in the post-treatment liquid tank 11c, the basket 30 containing the stainless steel frame jig 20 to which the substrate 21 is fixed is removed from the transport device 15, and the suspension member 46a provided in the drying furnace 40 is moved to the suspension member 46a. The basket 30 may be suspended.

The mechanism for lowering the vertical movement mechanism 41, which is a mechanism for applying an impact, may be a mechanism for dropping naturally using a mechanism other than the cam. A mechanism for forcibly lowering by the method described above may be used. In addition, the mechanism for giving an impact is the basket 3
A mechanism that applies an impact by hitting the suspension member 46a or zero or the like may be used, and a mechanism that applies an impact when the left and right ends of the suspension member 46a are alternately raised, for example, by lowering with the 6-shaped cam, A mechanism for giving an impact by raising the tension of the spring may be used. Further, both ends of the suspension member 46a may be raised at the same time, and may be simultaneously dropped naturally or urged by a spring to be lowered at the same time, or an impact may be applied when the both ends are simultaneously raised.

In order to store the basket 30 in the drying oven 40, first, the lid 43 is opened, and the three baskets 40 suspended on the suspension members 46a suspended by the transport device 15 are lowered to form the main body 42 together with the suspension members 46a. And the left and right ends of the suspension member 46 a are installed on the vertical movement mechanism 41. After removing the suspension member 46a from the transport device 15, the lid 43 is closed. After the drying process is completed, the lid 43 is opened, and the three baskets 39 are lifted together with the suspension members 46a by the transport device 15, and the drying furnace 40 is opened.
Get out of

After the substrate 21 is taken out of the drying furnace 40 after the drying process, the stainless steel frame jig 20 is removed from the basket 30 and
The substrate 21 is removed from the stainless steel frame jig 20 and the storage 1
2 and temporarily store the substrate 21 thereon. The work at this time is
Workability is good because it can be done with gloves such as cotton and nylon.

The resin frame jig 50 may be a conventional product as shown in FIG. 5, and includes synthetic resin frames 51a, 51b, and 51c.
Leader line 52 embedded in frames 51a, 51b, 51c
a, 52b, 52c, and 52d, and lead lines 52a and 52
exposed contacts 53 connected to b, 52c, 52d;
A pressing member 54 formed of an elastic body such as synthetic rubber provided opposite to the contact point, exposed terminals 54a and 54b for connecting to an external power supply (not shown), and lead wires 52a and 52d are formed. Wiring 5 connected to terminals 54a, 54b
5 a and 55 b and a fixing member 57 are provided. Frame 51
b, 51c are hinged to the frame 51a,
When closed, c is held in a closed state by the fixing member 57.

As shown in FIG. 5A, the substrate 21 is placed on the contact 53 and the holding member 54, and the frame 51b,
When closing 51c, opposing contacts 53 provided on frames 51a, 51b, 51c, holding member 54 and frame 51
a, 51b, 51c, the side surface of the substrate 21 is 5 to 10 mm
The degree is pinched. By sandwiching the substrate 21 in this manner, the substrate 21 does not deviate from the resin frame jig 50 even when the plating solution is stirred or the resin frame jig 50 is swung in electrolytic copper plating. FIG.
In (a), the fixing member 57 is omitted, and the frames 51b and 51c are omitted.
Is shown in an open state.

When the frames 51b and 51c are closed, the plating solution is supplied to the substrate 21 so that the plating solution is sufficiently supplied to the substrate 21.
Many holes 58 and large openings are formed in a, 51b, and 51c. Also, the area of the exposed portion of the contact 53 is small, and each contact 53 contacts the substrate 21 with a small contact area.

As described above, the frame 51 made of synthetic resin
a, 51b, and 51c and the contact 53 having a small exposed area are used, so that the resin frame jig 50 is immersed in the electrolytic plating tank 13b so that the terminals 55a and 55b are not immersed in the plating solution. Since there is almost no plating on an extra portion of the resin frame jig 50, no trouble occurs, and the resin frame jig 50 can be used until it is broken. Note that no current flows through the fixing member 57 and the conductors such as hinges that are not connected to the terminals 55a and 55b, and therefore no plating is performed.

The resin frame jig 50 is not limited to the above-described one, but may be made of the material, shape and size of the non-conductive frames 51a, 51b and 51c, the size and number of the holes 58, the contacts 53 and the holding members 54. The number and arrangement of the fixing members 57 and the number and the fixing method of the fixing members 57 are required. When the electrolytic plating is performed, the substrate 21 is plated and the resin frame jig 5
What is necessary is that the plating is hardly plated on the extra portions of 0.

In the case where a basket for electrolytic plating containing a plurality of resin frame jigs 50 is used, the basket for electrolytic plating is made of a resin frame jig so that the basket for electrolytic plating is not plated by electrolytic plating. 50 terminals 55a, 55b
For example, if there is a portion that contacts a portion where current flows, at least that portion may be made of a nonconductor. Therefore, the basket for electrolytic plating is formed entirely of a non-conductive material such as a synthetic resin, and only a portion in contact with a portion where the current flows is formed of a non-conductive material, and the remaining portion is formed of a conductive material such as stainless steel or a non-conductive material. If there is no portion that contacts the portion where the current flows, or a portion made of a conductor such as stainless steel may be used.

The basket for electrolytic plating may have the same shape as that of the basket 30 and may have a structure capable of fixedly accommodating a plurality of resin frame jigs 50 at intervals. A terminal portion to which the terminals 55a and 55b of the resin frame jig 50 are connected is installed on the basket for electrolytic plating, and the terminal portion may be connected to an external power supply, and the terminal portion is installed. It may not be.

After the substrate 21 is fixed to the resin frame jig 50, the resin frame jig 50 is suspended and transported by the transport device 16.
On each liquid tank of the processing tank 13 for performing the electrolytic plating, the substrate 21 is immersed together with the resin frame jig 50 into each liquid tank to perform the electrolytic plating. The pretreatment liquid tank 13a is
This is a liquid tank for cleaning and the like.

The electrolytic plating tank 13b is formed of, for example, a synthetic resin such as a vinyl chloride resin, and the terminals 55a and 55b of the resin frame jig 50, that is, the substrate 21, are connected to the cathode at the center of the electrolytic plating tank 13b. A copper plate or a copper ball is provided, and a copper plating solution of an acidic bath or an alkaline bath is put in the electrolytic plating tank 13b. Copper plating solution is, for example, copper sulfate, sulfuric acid,
Made such as chlorine ion and brighteners traces of copper sulfate _(CuSO 4 · _5H 2 O) as a source of copper ions.

In addition, the electrolytic plating tank 13b is provided with a substrate 21, ie, a rocking device for the resin frame jig 50, a stirring device for the copper plating solution, a temperature control device, a current density control device, an impurity management device, and the like. Have been. Further, various organic compounds as brighteners and malleable agents are added to the copper plating solution.

The material, depth, width and capacity of the electrolytic plating tank 13b, arrangement of the cathode, shape and arrangement of the anode, copper plating solution,
And stirring condition of copper plating solution, temperature of copper plating solution, substrate 2
Regarding the swing condition 1, the current density, the impurity management, and the like, the conditions and conditions under which the necessary copper can be plated in the through holes may be used. When plating a metal other than copper, for example, nickel or tin, a necessary plating solution or the like may be used.

Next, after processing such as washing is performed in the post-treatment liquid tank and the post-treatment liquid tank of the drying furnace 13c, the resin frame jig 50 is removed from the transfer device 16, and the substrate 21 is taken out from the resin frame jig 50. After the plurality of substrates 21 are stored in a drying furnace and the substrates 21 are dried, the substrates 21 are stored in the storage 14. When taking out the substrate 21 from the resin frame jig 50, the substrate 21 is wet, so work is performed with rubber gloves or the like.
It is easy to remove the substrate 21 from 0, and the workability is good.

Next, F using the FPC plating apparatus 10
The through hole plating of the PC will be briefly described with reference to FIG. The substrate 21 has a thickness of 25 to
Copper foils 62a and 62 having a thickness of about 18 μm are formed on both sides of a base film 61 made of polyimide having a thickness of about 100 μm.
b is a thin layer. The substrate 21 has a plurality of through holes 63 formed at required locations.

The substrate 21 is fixed to the stainless steel frame jig 20, and the substrate 21 is placed in the pretreatment liquid tank 11a as described above.
And then the substrate 21 in the electroless plating tank 11b.
Is subjected to electroless copper plating. In the electroless copper plating process, copper 64 is precipitated by a chemical reduction reaction on the inner wall of the base film 61 which is a non-conductor on the inner wall of the through hole 63 of the substrate 21, and copper foils 62 a on both surfaces of the base film 61 are formed.
The copper 64 comes into contact with 62 b, and conductivity is given to the entire inner wall of the through hole 63. The thickness of the copper 64 to be deposited is 0.
It is about 5 μm.

After cleaning in the post-treatment liquid tank 11c, the drying furnace 4
At 0, the substrate 21 is dried. With the drying furnace 40, the temperature of the hot air is 80 ° C., the drying time is 2 minutes, and 30 substrates 21 can be completely dried at a time. After the substrate 21 is dried, the substrates 21 are stacked and stored in a temporary storage.

Next, the dried substrate 21 is placed on a resin frame jig 50.
After fixing the substrate 21 in the pretreatment liquid tank 13a as described above, the substrate 21 is immersed in the electrolytic plating tank 13b to perform electrolytic copper plating, and the entire inner wall portion of the through hole 63 has a thickness of 15 mm. A copper 65 of about 20 μm is grown.
By this electrolytic copper plating, the entire inner wall portion of the through hole 63 is covered with the copper 65 having a thickness that can guarantee the function as an electric circuit, and the copper foils 62a and 62b on both surfaces of the substrate 21 are brought into a sufficiently conductive state. The copper foils 62a, 6 on both sides of the substrate 21
Copper of the same thickness grows on 2b.

After the electrolytic copper plating treatment, the substrate 21 is washed in the post-treatment liquid tank and the post-treatment liquid tank in the drying furnace 13c. After drying the substrate 21, the substrate 21 is stored in the storage 14.

The FPC plating apparatus 10 according to the embodiment of the present invention is used not only for plating on the inner wall of a through-hole which is a through-hole of a substrate, but also for plating the inner wall of a blind via-hole which is a non-through-hole. It may be used for forming a copper film on a part of a substrate having no copper foil, or for forming a copper film on a substrate having no copper foil.

Further, not only copper plating but also other metals may be plated by using a necessary plating solution for electroless plating and electrolytic plating. The substrate on which the plating treatment is performed is not limited to the one having the structure shown in FIG. 6, but may be a non-conductive base film having a conductor foil laminated on one or both sides of a non-conductive base film.

As described above, the FPC plating apparatus 1
If 0 is used, electroless copper plating can be performed using a cage 30 capable of accommodating 30 substrates 21 at a time at intervals of about 20 mm, so that the capacity of various processing liquid tanks can be reduced. Can be reduced in size. Further, the substrate 21 is sandwiched by the stainless steel frame jig 20 with a small contact area, and is accommodated in the basket 30 so that the stainless steel frame jig 20 and the substrate 21 are held together.
Since the drying furnace 40 capable of efficiently drying the substrate 21 is used, the remaining processing solution remaining on the substrate 21 can be completely dried in a short time, and the substrate 21 after drying does not have poor appearance due to stains.

The substrate 21 on the stainless steel frame jig 20
Since the work of attaching and detaching can be performed by using gloves such as cotton or nylon, the workability is good, and further, since the workability of the resin frame jig 50 is good, the work of attaching and detaching the substrate 21 is performed by using rubber gloves. It can be easily performed, so than when using a conventional metal frame jig,
When the above-mentioned jig for fixing a substrate is used, workability is better and work can be performed by a small number of people. Further, since the stainless steel frame jig 20 and the resin frame jig 50 used for the electroless plating process and the electrolytic plating process are hardly plated, the stainless steel frame jig 20 and the resin frame jig 50 are used until they are broken. be able to.

[0065]

According to the present invention, a large number of substrates can be subjected to electroless copper plating and drying at a time,
The drying time for drying the substrate together with the stainless steel frame jig after the electroless plating is short, and there is no defective appearance of the substrate after the drying, and the work of attaching and removing the substrate to and from the stainless steel frame jig and the resin frame jig. Workability is good, and the number of replacements of stainless steel frame jigs and resin frame jigs for fixing substrates used in electroless copper plating and electrolytic copper plating can be significantly reduced as compared with the case where conventional jigs are used. it can.
Therefore, it is possible to improve the productivity, reduce the size of the equipment, improve the workability, save labor, and reduce the cost of the jig for fixing the substrate.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a flexible printed circuit board plating apparatus according to the present invention.

2A and 2B show a conductor jig in FIG. 1, wherein FIG. 2A is a front view and FIG. 2B is a side view.

FIG. 3 is a schematic perspective view showing a basket accommodating a conductor jig in FIG. 1;

FIG. 4 is a schematic cross-sectional view showing a state where a left end of a suspension member is raised in the drying furnace in FIG. 1;

FIG. 5 shows a jig whose main part in FIG. 1 is a non-conductor,
(A) is an expanded front view, and (b) is a side view.

6A and 6B are cross-sectional views showing a state in which copper is deposited by electroless copper plating on an inner wall of a base film in an inner wall portion of a through hole, and FIG. FIG. 4 is a cross-sectional view showing a state where copper is deposited on the deposited copper by electrolytic copper plating and the inner wall of the through hole is covered with a copper film.

FIG. 7 is a view showing a conventional metal frame jig.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Plating apparatus of flexible printed circuit board 11 Treatment tank 11a, 13a Pretreatment liquid tank 11b Electroless plating tank 11c Post-treatment liquid tank 12, 14 Storage 13 Treatment tank 13c performing electroplating 13b Electrolytic plating tank 13c Treatment liquid tank and drying furnace 15, 16 Transfer device 15a, 16a Upward direction 15b, 16b Downward direction 15c, 16c Transport direction 20 Stainless steel frame jig 21 Substrate 22a, 22b, 22c, 22d Mounting member 23 Frame portion 24 Spring 25 Horizontal frame 26 Guide part 27 Auxiliary frame part 30 Basket 31a, 31b, 32a, 32b Fixture 33 Horizontal frame part 34 Handle 40 Drying furnace 41 Vertical movement mechanism 42 Main body 43 Lid part 44 Hot air circulator 45 Air passage 46a, 46b Suspension member 47 Hot air flow method 50 Resin frame jigs 51a, 51b, 51c Frame 52 a, 52b, 52c, 52d Lead wire 53 Contact 54 Pressing member 55a, 55b Terminal 56a, 56b Wiring 57 Fixing member 58 Hole 61 Base film 62a, 62b Copper foil 63 Through hole 64, 65 Copper 70 Metal frame jig 71 Metal frame Part 72 Screw and nut 73 Board mounting part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-10-145030 (JP, A) JP-A-8-23164 (JP, A) JP-A-4-173994 (JP, A) JP-A-58-1983 128792 (JP, A) JP-A 4-114564 (JP, U) JP-A 2-42065 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 18/31 C25D 17 / 00 H05K 3/18

Claims (2)

(57) [Claims] 1. An apparatus used for plating a flexible printed circuit board, comprising: a conductor jig provided with a frame having a mounting member for holding, extending and fixing the substrate; and a housing for accommodating the conductor jig. A basket for performing electroless plating of the substrate together with the basket; a drying furnace having a mechanism for suspending the basket and applying an impact to a jig of the conductor housed in the basket; and the substrate. A jig having a non-conductive main part for fixing the jig, and a treatment tank for performing electrolytic plating of the substrate together with the jig having the non-conductive main part, a plating apparatus for a flexible printed circuit board. 2. A mechanism for giving an impact to the conductor jig,
The plating apparatus for a flexible printed board according to claim 1, wherein the mechanism is a mechanism for supporting a suspension member for suspending the basket, and alternately raising and lowering both ends of the suspension member by natural fall. .