JPH06350238A - Circuit board - Google Patents

Abstract

(57) [Summary] [Purpose] To facilitate positioning and soldering of terminals and terminals of conductors to lands. [Structure] A solder layer 20 is formed on a land portion 4a formed of a copper foil on a circuit board 10, and the solder layer 20 has V
A letter-shaped recess 20a is formed. The end 6a of the conducting wire winding 6 such as the winding of the head chip is inserted and positioned in the recess 20a. Then, the solder paste 20 is melted by placing it in a heating furnace or pressing a heating body. As a result, the terminal 6a is accurately positioned and soldered on the land 4a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board provided with a solder layer for positioning and soldering the ends of conductors and terminals of electronic parts.

[0002]

2. Description of the Related Art FIG. 10 is a perspective view showing the structure of a magnetic head unit mounted on a rotary drum of a rotary drum device mounted on a VTR or the like from the back side. The magnetic head unit 1 includes a metal head base 2, a head chip 3 attached to one end of the head base 2, and a film-like circuit attached to the front surface 2a of the head base 2 in the figure. And a substrate 4. One end of the head base 2 is formed to project in a bifurcated shape, and the head chips 3 and 3 are attached to the tips of the bifurcated projections. A mounting hole 2b is formed in the head base 2 and is fixed to the rotary drum by a mounting screw 5 inserted in the mounting hole 2b.

Four circuit patterns A to D are formed on the illustrated surface of the circuit board 4. Four land portions 4 to which the windings 6 and 6 wound around the head chip 3 are soldered at one end of each circuit pattern A to D.
a to 4d are formed. In addition, each circuit pattern A
Four lands 4e to 4h are formed at the other ends of the lead wires D to D for pressure contact with the lead portion on the rotary drum side. The circuit patterns A to D are formed by etching a copper foil, and the copper foil other than each land portion is covered with a resist film R (shown by diagonal lines in the figure). Electrolytic solder plating is applied to the land portions 4a to 4d to facilitate soldering of the winding wire 6, and gold is applied to the other land portions 4e to 4h to reduce the pressure resistance with the lead on the rotary drum side. It has been subjected.

[0004]

In the manufacturing process of the magnetic head unit 1, the head chips 3 and 3 are attached to the head base 2 and the film-shaped circuit board 4 is adhered to the head base 2 and then the head chip is obtained. It is necessary to solder the ends 6a of the windings 6 wound around 3, 3 to the lands 4a to 4d. Conventionally, the terminal 6a of each winding 6 is manually attached to the lands 4a to 4d, and the soldering work is performed with a thread solder and a soldering iron.

In this case, first, skilled work is required to accurately position the terminal 6a of the winding 6 on the land portion and quickly complete the soldering work.
Since a cannot be accurately positioned on the land portion, defective soldering easily occurs. Further, in the soldering work using the thread solder, the flux in the thread solder scatters and is easily attached to the gold-plated lands 4e to 4h. If the flux adheres to the lands 4e to 4h, the contact between the lands 4e to 4h and the lead of the rotary drum becomes poor when the flux is attached to the rotary drum. Further, a problem related to this type of soldering work similarly occurs when the terminals of various electronic components are positioned on the lands and soldered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a circuit board in which the ends and terminals of conductors can be accurately positioned on lands for soldering work. .

[0007]

In the circuit board according to the present invention, a solder portion is formed on a land portion formed on the circuit substrate, and a conductive member to be soldered to the land portion is provided on the solder portion. It is characterized in that a recess for positioning is formed.

[0008]

In the above means, the solder deposit is previously formed on the land portion of the circuit board, and the recess is formed on the solder deposit. Therefore, a conductive member such as a terminal of a conductive wire or a terminal of an electronic component is inserted into the concave portion to be positioned on the land portion. By melting the solder deposit in this positioning state, the conductive member is reliably soldered to the land portion.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a film-shaped circuit board attached to a head base of a magnetic head unit, and FIG.
4 is an enlarged perspective view of a portion indicated by N. FIG. This circuit board 1
Circuit patterns A to D made of copper foil similar to those shown in FIG. 10 are formed on the surface of 0, and land portions 4a to 4d and land portions 4e are formed at the ends of the circuit patterns A to D.
Through 4h are formed. The copper foil other than the land portion is covered with the resist film R. Also land part 4
Gold plating is applied to e to 4h as described above.

Solder plating is applied to the surfaces of the four lands 4a to 4d, and solder swells 20 to 23 having a predetermined thickness are provided on the solder plating.
V-shaped recesses 20a to 23a are formed on the solder deposits 20 to 23, respectively. When this circuit board 10 is attached to the head base 2 of the magnetic head unit 1 shown in FIG. 10, as shown in FIG. 2, the terminal 6a of the winding wire 6 wound around the head chips 3 and 3 is soldered. It can be positioned by inserting it into the recesses 20a to 23a of 20 to 23. At this time, flux is applied to the end 6a of the winding wire 6 or flux is applied to the recesses 20a to 23a as required. Then, the entire magnetic head unit 1 shown in FIG. 10 is put into a heating furnace and heated, or all the solder piles 20 to 2 are heated.
The heating elements are pressed against the three individually or simultaneously to melt the solder piles 20 to 23. As a result, the end 6a of the winding 6 is accurately positioned and soldered on the lands 4a to 4d.

Next, the process of forming the solder deposits 20 to 23 having the concave portions on the circuit board 10 will be described with reference to FIGS. FIG. 3 is a perspective view of a continuous body 30 in which a plurality of the circuit boards 10 are continuously arranged, and FIG. 4 is an enlarged sectional view showing the continuous body 30. As shown in FIG. 4, the continuous body 30 includes a strip-shaped film substrate material 31, a copper foil layer 32 formed on the front surface of the substrate material 31, and an adhesive layer 33 formed on the back surface of the substrate material 31. And a release paper 34 attached to the adhesive layer 33.

First, by etching the copper foil layer 32,
A plurality of sets of circuit patterns A to D are formed at predetermined intervals. The land portions 4a to 4d and the land portions 4e to 4h of the circuit patterns A to D of the respective sets are masked, and the resist film R is applied to the surface of the patterned copper foil other than the land portions. The land portions 4a to 4d of the circuit patterns A to D of each set are plated with solder, and the land portions 4e to 4h are plated with gold. Before or after this plating operation, a cut is made in the board material 31 and trimming is performed for each circuit board 10 so that the board material 31 can be separated from the release paper 34.

Next, the land portions 4a and 4b of each trimmed circuit board 10 are left, the other portions are masked, and cream solder is applied to the land portions 4a to 4d exposed from the masking sheet. After removing the masking, the continuous body 30 is put into a heating furnace to melt the cream solder applied to the lands 4a to 4d. When this is cooled, the land portion 4a of each circuit board 10 is
To 4d on the surface of the solder paste 20 to 23 of a predetermined thickness
Is formed.

Next, as shown in FIGS. 5 and 6, the press die 5 is used.
Press work by 0. The press die 50 is provided with a plurality of V-shaped press blades 51 facing the central portions of the solder deposits 20 to 23 formed on the plurality of sets of lands 4a to 4d shown in FIG. . When the press die 50 is lifted by pressurizing the continuous body 30 by the press die 50, as shown in FIG. 7, the land portions 4a to 4d are
V-shaped recesses 20a to 23a are formed on the solder heaps 20 to 23 formed on the substrate. As a method other than the above, when cream solder is applied to each land portion 4a to 4d, a molding plate having the same shape as the press die 50 shown in FIGS. 5 and 6 is placed on the cream solder to form a V-shape. The V-shaped concave portion is formed in the cream solder layer by the blade 51 having a circular shape. Then, the molding plate is placed on the cream solder layer and supplied to the heating path to melt the cream solder, and after cooling, the molding plate is removed. By this method, the solder deposits 20 to 23 each having a V-shaped recess can be formed.
In this case, it is preferable to use a molded plate made of a material such as aluminum which is unlikely to have solder attached thereto.

In this way, a continuous body 30 having a plurality of circuit boards 10 having solder lands 20 to 23 formed on the respective land portions 4a to 4d is formed. When the respective circuit boards 10 are peeled off from the continuous body 30, the adhesive layer 33 on the back surface of the circuit board 10 is peeled off from the release paper 34, and the single circuit board 10 as shown in FIG. 1 is obtained.
The circuit board 10 is attached to the head base 2 shown in FIG. 10 with the adhesive layer 33. Further, although the film-shaped circuit board adhered to the head base 2 of the magnetic head unit 1 has been described in the above embodiment, the present invention can be implemented in other circuit boards.

FIG. 8 shows a hard circuit board 72 on which the discrete component 70 is mounted. Solder deposits 73, 73 are formed on the land portions 72a, 72b of the circuit board 72.
Then, a V-shaped recess or a recess 73a corresponding to the shape of the terminal 71 of the discrete component 70 as shown in FIG. 8 is formed on the upper surface of each solder heap 73. When mounting the discrete component 70 on this circuit board, the terminal 71 is inserted into the recess 73a, and thereby the discrete component 70 is positioned. After the mounting of the plurality of components is completed, the circuit board 72 is put into a heating furnace and the solder deposit 73 is melted, so that the soldering of the terminals 71 is completed while the components 70 are accurately positioned.

An IC package 80 as shown in FIG.
Also in the case of mounting, the concave portion 8 corresponding to the shape of the terminal 81 is formed on the solder deposit 83 formed on each land portion on the circuit board 82.
3a is formed. When the IC package 80 is mounted, the terminals 81 are fitted into the recesses 83a so that the IC package 80 is installed without displacement. At this time, the lower surface of the IC package 80 is attached to the adhesive 8
Alternatively, it may be adhered to the surface of the circuit board 82 by means of 5. When the IC package 80 thus mounted is sent to a heating furnace, the solder deposit 83 is melted and each terminal 81
Are soldered while they are positioned.

8 and 9, flux is applied to the terminals 71 or 81 in advance, or the recesses 73a,
Flux may be applied to the inside of 83a. 8 and 9, the heating element may be pressed against the solder heap 73 or 83 to melt the solder.

[0019]

As described above, according to the present invention, the soldering can be completed in a state where the end of the conductive wire and the terminal of the electronic component are positioned on the land. Therefore, the deterioration of soldering quality can be prevented, and the automation of the work becomes easy. Further, unlike the case of using the thread solder, the flux does not scatter during the soldering work.

[Brief description of drawings]

FIG. 1 is a perspective view showing a film-shaped circuit board attached to a head base of a magnetic head unit as an example of a circuit board.

FIG. 2 is an enlarged perspective view of a portion indicated by N in FIG.

FIG. 3 is a perspective view of a circuit board manufacturing process, showing the circuit board continuous body shown in FIG. 1;

FIG. 4 is an enlarged cross-sectional view of a continuous body.

FIG. 5 is a front view showing a solder pile and a press die formed on a continuous body.

FIG. 6 is a front view showing a pressing operation on the solder deposit.

FIG. 7 is a front view of the continuous body showing a state in which a concave portion is formed on the solder pile.

FIG. 8 is an enlarged perspective view of a circuit board on which discrete components are mounted.

FIG. 9 is an enlarged perspective view of a circuit board on which an IC package is mounted.

FIG. 10 is a perspective view showing a magnetic head unit in which a film-shaped circuit board is attached to a head base.

[Explanation of symbols]

1 Magnetic Head Unit 2 Head Base 3 Head Chip A to D Circuit Pattern 4a to 4d Land Part 4e to 4h Land Part 6 Winding 6a Terminal 10 Circuit Board 20 to 23, 73, 83 Solder Plate 20a, 21a, 22a, 23a, 73a, 83a Recessed portion 30 Continuous body 31 Substrate material 50 Press type 70 Discrete parts 71 Terminals 80 IC package 81 terminals

Claims (1)

[Claims] 1. A solder deposit is formed on a land portion formed on a circuit board, and a recess for positioning a conductive member to be soldered to the land portion is formed on an upper portion of the solder deposit. And a circuit board.