JPH0360093A - Cream solder local printer - Google Patents

Abstract

PURPOSE:To print a cream solder at a local position even if part of an electronic component is already mounted on the board by moving a squeegee between two solder standby parts through a solder passing part in a state that a printing screen formed by inclining the standby parts substantially in an inverted flared shape as observed from side is brought into contact with a printing position. CONSTITUTION:A screen 14 is formed of a horizontal solder passing part 15 and solder standby parts 16, 16' of an oblique plate state formed substantially in an inverted flared shape as directed obliquely upward from both ends of the part 15. When a printing head 11 is accessed onto a printed circuit board 2, cream solder 27 is supplied from the end 29a of a solder supply pipe 29 between two squeegees 24 and 24', and held. Then, one squeegee 24 is first moved obliquely downward to slide on the part 16, then moved horizontally while rubbing on the upper face of the part 15, the solder 27 is sequentially moved on the upper parts of the parts 16, 15, passed through the parts 15a, 15a,..., and supplied onto connecting lands 4a, 4a,....

Description

DETAILED DESCRIPTION OF THE INVENTION The cream solder local printing apparatus of the present invention will be described in detail according to the following items.

A. Industrial field of application B6 Overview of the invention C1 Prior art 1 Problem to be solved by the invention E1 Means for solving the problem F. Example a Printed circuit board [Figs. 1, 2, 4 Figure, No. S
Figure] b Cream solder local printing device [￥S1 to Figure 4] b-1, Guide rail, robot [Figure 2, Figure 4] b-2, To stamp 1/Sodo “Kanbo 1 stroke Kano 4 Figure 1b-2-
a, Screen housing [Figure 1 to Figure 4] b-2-b, Squeegee [Figure 1, Figure 3, Figure 4 b-2-c, Dispenser [Figure 2 to Figure 4] ] b-3, Printing [Fig. 1, Fig. 5 (B)]] b-3-a,
Access of the printing head onto the printed circuit board b-3-b, squeegee operation G0 Effects of the invention (A. Field of industrial application) The present invention comprises a novel ream solder local printing device. Specifically, it relates to a device that prints cream solder on local parts of a circuit board, and even if some electronic components are already mounted on the circuit board, printing on these parts can be performed using a so-called printing screen. It is an object of the present invention to provide a new ream solder local printing device that is capable of printing.

(B. Summary of the Invention) The cream solder local printing device of the present invention has solder standby areas located at C on both sides of a solder transmission area on which a printed pattern is formed so that they form a substantially inverted V-shape with respect to each other when viewed from the side. With the tilted printing screen in contact with the printed area on the circuit board, the squeegee is moved from one of the two solder waiting areas to the other solder waiting area through the solder transmission area, thereby removing the electronic components. Even if a part of the circuit board is already mounted, cream solder can be printed locally using a printing screen.

(C, Prior Art) For example, when mounting a so-called surface-mounted electronic component such as a chip component on a printed circuit board, the terminal portion located on the outer surface is usually coated in advance on the connection land of the conductor on the printed circuit board. This is done by adhering to the cream solder.

Conventionally, there are two main methods for applying the cream solder onto a printed circuit board: a screen printing method and a dispenser one-way method. This is done by superimposing a printed screen in which solder permeation holes are formed in the same pattern as the pattern on the printed circuit board, supplying cream solder onto the printed screen, and moving it by rubbing it with a squeegee.

Further, application using a single dispenser is performed by pushing cream solder stored in a cylindrical container onto each connecting land using high-pressure air.

(D. Problem to be Solved by the Invention) By the way, most printed circuit boards are equipped with a plurality of electronic components, and the order in which these electronic components are mounted on the printed circuit board depends on the individual electronic components. 1pa) π Kuu ＾
--b Sea r Dan 4b ↓ 1 Noshi hf ↓ Usu, f4, or intermediate measures such as inspecting a partially assembled circuit before the entire circuit is completed are required. It is common to make decisions by taking into account the procedures for such treatment, and when conducting such tests,
Normally, it is necessary to solder the mounted electronic components to the connection lands in the process up to that point.

In other words, some electronic components may have to be mounted after the already mounted electronic components have been soldered.

Furthermore, due to the deterioration of cream solder over time and the necessity of processing, cream solder for electronic components mounted after soldering other electronic components may have to be applied after the above soldering. be. That is, it may be necessary to apply cream solder to a printed circuit board on which some electronic components are already mounted.

In the conventional cream solder printing device using the Sufurin printing method, it is almost impossible to overlay the printing screen on the solder-coated surface of the entire circuit board of the printing screen. When applying cream solder, there was no choice but to use the one-type dispenser described above.

However, with this dispenser type, the cream solder is applied to each connection land, which takes time, and it is difficult to adjust the amount of cream solder applied.Furthermore, it is necessary to apply a small amount of cream solder by scraping. In this case, since a thin needle-like pipe is used at the supply end, the pipe often becomes clogged with solder, resulting in problems such as a lot of time being spent on maintenance work.

(E. Means for Solving the Problems) Therefore, in order to solve the above problems, the cream solder local printing device of the present invention has a substantially horizontal solder transmission area having a printed pattern and both ends of the solder transmission area in the squeegee direction. a printing screen having two solder waiting portions protruding diagonally upward from the screen in a substantially inverted V-shape, a squeegee, a solder supply means for supplying cream solder onto the printing screen, and the squeegee. A squeegee moving means for moving the printing screen from one solder waiting part to the other solder waiting part via the solder transmission part, and a squeegee moving means for moving the printing screen so that the solder transmission part contacts the printed part of the circuit board at the printing position. A screen moving means for moving the screen is provided.

Therefore, in the cream solder local printing device of the present invention,
Since the solder waiting area of the printing screen is tilted, the size of the horizontal part of the printing screen can be made the same size as the printed area on the circuit board, which makes it possible to place the printing screen on the circuit board. Even if the printed screen is placed on the circuit board, the printed screen will not come into contact with the electronic components already mounted on the circuit board, so cream solder can be applied by screen printing even to the circuit board on which some electronic components are already mounted. .

(F. Example) The details of the cream solder local printing apparatus of the present invention will be described below according to the illustrated example.

First, an example of a circuit board on which cream solder is printed by the cream solder local printing device 1 will be explained, and then each part of the cream solder local printing device 1 will be explained.

(a, printed circuit board) [Fig. 1, Fig. 2, Fig. 4,
FIG.
printed conductor 4.4 having a predetermined wiring pattern,
. . are formed, electronic components 5.5, . . . and other electronic components not shown are mounted, and the terminal portions of these electronic components are soldered to printed conductors 4.4, . As a result, an electronic circuit having a predetermined function is formed.

4a, 4a, . . . are connection lands to which, for example, leads of an IC (not shown) are soldered, and these connection lands 4a, 4a, . arranged in columns.

And such connection lands 4a, 4a.

. . . Cream solder is printed by the C cream solder local printing device 1, and moreover, the printing is performed on the electronic component 5.
5, . . are mounted on the printed circuit board 2 and soldered to the printed conductors 4, 4, .

That is, the printed circuit board 2 is transferred to the cream solder local printing apparatus 1 with some of the electronic components already soldered.

(b, cream solder local printing device) [Figures 1 to 4 (b-1, guide rail, robot) [Figures 2, 4] 6 is the opportunity of the cream solder local printing device 1; A substrate transfer section 8 having two guide rails 7.7 extending parallel to each other is arranged at a position offset toward one end of the upper surface 6a.

9 is a three-dimensional orthogonal robot, and the upper surface 6a of the machine base 6
The moving unit 9a of the other side passenger n and the second moving unit 9a of the kotoreki trading basket 1 and the second moving unit 9a that is moved in the same direction as the direction in which the guide rail 7.7 extends. The third moving unit 9C is moved by the moving unit 9b and the second moving unit 9b in a direction perpendicular to the extending direction of the guide rail 7.7, and the third moving unit 9C is moved vertically by the third moving unit 9C. The third moving unit 9C is disposed at a higher position than the guide rail 7.7.

Then, the printed circuit board 2 is transported with its surface 3a facing upward while its both side edges are slidably supported by guide rails 7.7, and the positioning in the board transfer section 8 is carried out by a positioning unit 10 ( (Only a part of it is shown in FIG. 2.)

(b-2, Ell printing head) [Figures 1 to 4] 11
is the print head, which includes a roughly box-shaped screen housing,
It consists of two squeegees movably arranged inside the screen casing, and a dispenser that supplies cream solder to the inside of the screen casing in a timely manner.

(b-2-a, screen housing) [Figures 1 to 4] 12 is a screen housing.

The screen housing 12 is formed into a box shape having a substantially rectangular outer shape when viewed from above, and the center portion of the top plate portion 13 is fixed to the lower end of the vertical movement shaft 9d.

The bottom plate portion 14 of such a screen housing 12 serves as a screen portion for printing cream solder, and the screen portion 14 has a horizontal solder transmission portion 15 forming the center portion in the longitudinal direction, and The solder transmission part 15
Slanted plate-shaped solder standby parts 16 and 16' that protrude diagonally upward from each end so as to form a substantially inverted V shape with respect to each other.
It consists of Further, the solder transmission portions 15 are the connection lands 4a, 4a, . . . on the surface 3a of the printed circuit board 2.
It is formed slightly larger than the minimum rectangular area 17 (hereinafter referred to as the "printed area") containing the solder transmission area 15, and the connecting lands 4a, 4a, . . .
Solder penetration holes 15a, 15a arranged in the same pattern as the arrangement pattern of.

... is formed. That is, these solder penetration holes 15
a, 15a, . . . are formed in two rows, and each row is separately arranged at the end of the solder transmission section 15 closer to the solder standby section 16, 16'.

(b-2-b, squeegee) [Figures 1, 3, 4] 18 is an air cylinder for a squeegee that is supported so as to move integrally with the screen housing 12, and its piston rod 19 is inside the screen housing 12, and the axial direction is the arrangement direction (
Hereinafter, this will be referred to as the "squeegee direction." ), the tip of the piston rod 19 has a thick plate-shaped f-pressing base 2 with a Taku pattern on it, and a squeegee puller on the top surface of the movable base 20. Two air cylinders 21, 21' are fixed, the axial direction of these air cylinders 21, 21' extends in the vertical direction, and
They are arranged apart from each other in the squeegee direction.

22.22' is a piston rod that is moved in the vertical direction by the air cylinder 21.21', and a squeegee support member 23.23' that is long in the direction horizontally orthogonal to the squeegee direction is fixed to the lower end of the piston rod. , a rectangular plate-shaped squeegee 2 is attached to these squeegee support members 23 and 23'.
4.24' upper end is attached.

Therefore, the squeegees 24, 24' are positioned so as to be spaced apart from each other and to face each other in parallel in the squeegee direction.

25.25' is a coil spring, which is externally fitted onto the piston rod 22.22' and is connected to the arb base 2.
0 and the squeegee support member 23, 23'.

LA) L te bi 71- + noro seasonal bari ri ri ri'^<
1-7 When an upward moving force is applied by the cylinder 21.21', the piston rod 22.22', the squeegee support member 23.23', and the squeegee 24.24' compress the coil spring 25.25'. Figure 1 (
It is moved to the position shown in B) (hereinafter referred to as the "pull-up position") and held at this height, and from that state the upward moving force on the piston rod 22, 22' is released. When the piston rod 22.22', the squeegee support member 23.23', and the squeegee 24.24' are moved downward together by the elastic force of the coil spring 25.25', the squeegee 24.24' is moved downward. The lower edge of 24' is brought into contact with the upper surface of the screen portion 14.

Furthermore, when the piston rod 19 of the squeegee air cylinder 18 moves, the moving base 20 and the squeegee lifting air cylinder 21.21' are moved toward the squeegee, so that the two squeegees 24.24' At the same time, it is moved in the direction of the squeegee.

(b-2-c, dispenser) [Figures 2 to 4] 26 is a dispenser for supplying cream solder 27 onto the screen part 14, and a solder tank 28 and one end thereof are connected to the solder tank 26. 28 nozzle-shaped lower end portion 28a
An air hose 30 (see FIG. 2) has one end connected to a high-pressure air generator (not shown) and the other end connected to an air nozzle 28b that communicates with the upper end inside the solder tank 28 (see FIG. 2). ) etc., solder tank 2
8 is supported by a support means (not shown) in the screen housing 12 so as to move integrally with the screen housing 12, and the tip 29a of the solder supplying vibe 29 projects into the screen housing 12 and faces the solder transmission portion 15 from above. It is arranged like this.

Therefore, when high pressure air is supplied into the solder tank 28,
The cream solder 27 in the solder tank 28 is pushed out through the solder supply vibe 29 and dripped onto the solder permeation section 15.

The ream solder 27 is supplied in this manner with the tip 29a of the solder supplying vibrator 29 positioned between the two squeegees 24 and 24' when viewed from above.

(b-3, Printing) [Figures 1 and 5 (B)] Therefore, printing of the cream solder 27 on the printed circuit board 2 by the ream solder local printing device 1 as described above is performed as follows, for example.
It is done as follows.

(b-3-a, out of access of the print head onto the printed circuit board) When the printed circuit board 2 is positioned at a predetermined printing position of the board transfer section 8, the print head 11 is moved by the robot 9 to the printed circuit board. The robot 9 is moved to a position directly above and opposite the print head 17 of the substrate 2, and then the vertical movement axis 9d of the robot 9 is moved downward to allow the print head 11 to access the printed circuit board 2.

As a result, the lower surface of the solder permeable portion 15 of the screen portion 14 of the screen housing 12 is brought into surface contact with the printed portion 17, and the solder permeable holes 15a, 15a, . . .
4a, . . . are located correspondingly to each other.

At this time, the solder standby section 16, 16' of the screen section 14
As shown in FIG. 1, the electronic components 5.5, . . . are opposed to the electronic components 5.5, . It is located like this.

In the initial state, the squeegee 24, 24' is
As shown in FIG. 1(A), when only one squeegee 24, that is, the left squeegee 24 as viewed in the figure, is pulled up to the pulled-up position, the other squeegee 24'
The squeegee 24 is placed in standby at a position in contact with one end, that is, the left end as viewed in the figure, and in this state, one squeegee 24 is in contact with a portion approximately in the middle of one solder standby portion 16 in the squeegee direction. It is located in

Note that the cream solder 27 supplied on the screen portion 14
When the squeegee 24, 24' moves to the above-mentioned position, it is pushed by the other squeegee 24' and is moved so as to ride on the lower half of one solder standby section 16',
It is located between two squeegees 24 and 24'.

(b-3-b, squeegee operation) Therefore, when the print head 11 is accessed onto the printed circuit board 2 as described above, first, the other squeegee 2
4' is pulled up to the raised position as shown in FIG. 1(B), and the air cylinder 21 for one squeegee 24 is
The upward movement force exerted on the piston rod 22 by the squeegee 24 is released, and one of the squeegee 24 is brought into elastic contact with the upper surface of the solder standby section 16 with an appropriate elastic force.

From this state, the piston rod 19 of the squeegee air cylinder 18 is moved to the right in the figure.

Therefore, one squeegee 24 first moves obliquely downward so as to cross over the - side solder standby section 16, and then,
As shown in FIG. 1(C), from the point where the squeegee 24 comes into contact with one end of the solder transmitting section 15, it moves horizontally while rubbing the upper surface of the solder transmitting section 15. As a result, the cream solder 27 is sequentially moved over the upper surfaces of the solder standby section 16 and the solder transmitting section 15, and when it is moved over the solder transmitting section 15, a part of the cream solder 27 passes through the solder transmitting holes 15a, 15a. , . . , and onto the connecting lands 4a, 4a, . . . .

When the piston rod 19 is moved to the right, at least one squeegee 24 is moved to a place where the solder permeable part 15 and the other solder waiting part 16' are continuous, as shown in FIG. 1(D). It will be stopped after coming.

As a result, the cream solder 27 is supplied to the connection lands 4a, 4a, . . . without leaking, and in this state,
The other squeegee 24' is positioned so as to be in contact with the intermediate portion of the other solder standby section 16'.

Therefore, as shown in FIG. 5(B), the connection land 4a
, 4a, ... Cream solder on top 27.27, ...
・is printed.

Note that such a squeegee operation is performed as a reciprocating operation as necessary. That is, when one squeegee 24 is pulled up from the state shown in FIG. 1(D), and the upward moving force applied to the other squeegee 24' is released, the movable base 20 is moved to the left. This time, since the other squeegee 24' moves the cream solder 27,
Connection lands 4a, 4a of cream solder 27.

... will be performed twice, thereby making it possible to perform printing more reliably and to make the amount of cream solder applied uniform.

When such printing on the connection lands 4a, 4a, . . . is completed, the print head 11 is pulled upward and the printed circuit board 2 is transferred to the next process.

(G. Effects of the Invention) As is clear from the above description, the cream solder local printing device of the present invention is a device that locally prints cream solder on a circuit board on which some necessary electronic components are already mounted. It has a substantially horizontal solder transmitting part having a printed pattern and two solder waiting parts protruding obliquely upward from both ends of the solder transmitting part in the squeegee direction so as to form a substantially inverted V-shape with each other. a printing screen, a squeegee, a solder supplying means for supplying cream solder onto the printing screen, and a squeegee moving means for moving the squeegee from one solder standby part of the print screen to the other solder standby part via the solder transmission part. The present invention is characterized by comprising screen moving means for moving the printing screen so that the solder-transmitting portion thereof comes into contact with the printed portion of the circuit board that has come to the printing position.

Therefore, in the cream solder local printing device of the present invention,
Since the solder waiting area of the printing screen is tilted, the size of the horizontal part of the printing screen can be made the same size as the printed area on the circuit board concerned, so that the printing screen can be placed on the circuit board. Even when placed, the printed screen does not come into contact with the electronic components already mounted on the circuit board, so cream solder can be applied by screen printing even to the circuit board on which some electronic components are already mounted. can.

In the above embodiment, the solder transmitting part and the solder waiting part are formed integrally, but depending on the case, the solder transmitting part and the solder waiting part may be formed separately and then assembled. .

The cream solder local printing apparatus of the present invention may also be used to print cream solder on a circuit board on which no electronic components are mounted. For example, when printing cream solder on a large circuit board or a so-called aggregated board that has a plurality of the same printed patterns, the entire printed pattern is divided into several blocks, and each block is printed with the cream solder local printing of the present invention. If the printing apparatus is used for printing, this type of printing apparatus can be downsized, and it can be made easier to keep pace with other processes.

[Brief explanation of drawings]

The drawings show an example of the implementation of the cream solder local printing apparatus of the present invention, and FIG. 1 shows the printing operation from (A) to (D).
2 is a perspective view showing the entire device, FIG. 3 is an enlarged perspective view showing a part of the print head cut away, and FIG. 4 is an enlarged sectional view showing the print head in sequence. ) IV-
FIG. 5 is a sectional view taken along line IV, and FIG. 5 shows an example of the circuit board, in which (A) is a perspective view showing the state before printing, and (B) is a perspective view showing the state after printing. Explanation of symbols 1...Cream solder local printing device, 2...Circuit board, 5...Electronic component, 9...Screen moving means, 14...Printing screen, 15/16. 17 ・ 18. 24. 26 ・ 27 ・ ...Solder transmission part, 16'...Solder waiting part, ...Printing part, 19.20...Squeegee moving means, 24'...Squeegee, ...Solder supply means, ...Cream Enlarged sectional view of the solder print head (A) Enlarged sectional view of the print head (CB) Enlarged sectional view of the print head (C) Enlarged sectional view of the print head (D) Part of the print head Enlarged perspective view of notch

Claims (1)

[Claims] An apparatus for locally printing cream solder on a circuit board on which some necessary electronic components are already mounted, comprising: a substantially horizontal solder transmission area having a printed pattern; and a squeegee for the solder transmission area. a printing screen having two solder waiting portions protruding diagonally upward from both ends in the direction so as to form a substantially inverted V-shape; a squeegee; a solder supply means for supplying cream solder onto the printing screen; a squeegee moving means for moving the squeegee from one solder waiting area of the printing screen to the other solder waiting area via the solder transparent area; and a squeegee moving means for moving the squeegee from one solder waiting area of the printing screen to the other solder waiting area; A cream solder local printing device characterized by comprising a screen moving means for moving the screen in a manner that