JPH08132588A - Squeegee - Google Patents

Abstract

PURPOSE: To provide a squeegee which can regulate the coating amount of a coating agent such as solder, etc., and coat to print the agent of a suitable coating amount. CONSTITUTION: A squeegee is used for a screen printer which coats to print a coating material by using a screen and the squeegee formed of an elastic member, and comprises a main squeegee 15 provided forward with respect to the advancing direction of the squeegee, and an auxiliary squeegee 20 provided at a predetermined interval rearward of the main squeegee 15, wherein the coating amount of the material can be regulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a squeegee used in a screen printing machine for printing a coating material or the like on an electronic circuit board.

[0002]

2. Description of the Related Art When an electronic component (hereinafter abbreviated as a substrate) is surface-mounted on an electronic circuit substrate (hereinafter abbreviated as a substrate), a metal mask having an opening formed at a position corresponding to a component mounting portion of the substrate is mounted on the substrate. And apply cream solder (hereinafter abbreviated as solder) by printing using a squeegee. A method is widely used in which a component is mechanically mounted on the printed and applied solder, the solder is melted in a high temperature furnace, and the component is soldered to an electronic circuit pattern (hereinafter abbreviated as a pattern) formed on the substrate. There is.

Conventional screen printing will be described with reference to FIG. 2A and 2B are views showing a screen printing machine, FIG. 2A is a side sectional view showing a printed state, FIG. 2B is a sectional view showing a component mounted state, and FIG. 2C is a sectional view showing a soldered state. 6
Reference numeral 0 denotes a squeegee holder (hereinafter abbreviated as a holder), which has a plate-like shape and is formed with a groove 61 for holding the squeegee 65 from the lower surface to the upper surface of the holder in the longitudinal direction. The holder 60 is held at both ends in parallel with the upper surface of the mask 70, and is held by a moving mechanism (not shown) that moves in the left-right direction (arrow J or K direction). Also, the holder 60
Is also held by a vertical movement mechanism (not shown) that moves in the vertical direction (arrow H or I direction), and is movable in the vertical and horizontal directions. The holder is generally a holder 60 squeezing in the direction of arrow J and a holder squeezing in the direction of arrow K (the inclination of the holder 60 is opposite, not shown).
2 are configured in parallel, and depending on the squeegeeing direction, 2
One of the pieces rises and stands by.

The squeegee 65 makes elastic contact with the upper surface 72 of a metal mask (hereinafter abbreviated as mask) 70, and the upper surface 7 of the mask 70 is covered.
Squeegee the solder 80 supplied to the mask 2
It is a member for printing and applying the solder 80 on the pattern of the substrate 75 which is filled in the holes 71 of 0 and is in close contact with the lower surface of the mask 70. The upper portion of the squeegee 65 is tilted in the squeegeeing direction so that the tip edge portion 66 of the squeegee 65 is elastically contacted with the upper surface 72 of the mask 70 when the squeegee 65 is attached to the holder 60. A hard urethane resin is used for the material of the squeegee 65.

The mask 70 is placed at the component mounting position on the substrate 75.
Opening holes (hereinafter abbreviated as holes) 71 for printing and applying the solder 81 are formed, and are installed on the upper portion of the substrate 75. The amount of solder applied is approximately equal to the area of the holes and the plate thickness of the mask 70. Mask 7
A thin stainless steel plate or the like is used as the material of No. 0, and the hole is formed by etching or laser processing.

A conductor pattern 76 is formed on the substrate 75, and solder is printed and applied to the component mounting portion, and the component is mechanically mounted on the portion and soldered in a high temperature furnace. Next, the operation will be described. First, the substrate 75 sent below the mask 70 is positioned and raised, and the upper surface 77 of the pattern 76 is brought into close contact with the lower surface 73 of the mask 70.

Next, the holder 60 is lowered and the squeegee 65 is moved.
The tip edge portion 66 of the above is elastically contacted with the upper surface 72 of the mask 70. When the squeegee 65 is moved in the direction of the arrow J in this state, the solder 80 supplied to the upper surface 72 of the mask 70 is filled in the hole 71 of the mask 70 by the squeegee 65.
Then, when the substrate 75 is lowered back to its original position, the mask 7
The solder 81 filled in the holes 71 of No. 0 escapes from the holes 71 and is printed and applied on the upper surface of the pattern 76.

Next, the substrate 75 coated with the solder 81 is sent to the next step, and the component is mechanically mounted on the coated portion of the solder 81. At this time, as shown in FIG. 2B, the solder 81 is pressed against the component and spreads laterally like the solder 82.
Then, when the solder is melted and soldered in the high temperature furnace of the next step, a solder fillet 83 is formed. However, if the space between the adjacent patterns 76 is narrow, as shown in FIG. The solder bridge 84 may occur. Therefore, it is desirable to change the print coating amount of solder according to the conditions of components mounted on the substrate.

[0009]

However, in the above-mentioned screen printing, the print application amount on the substrate is constant, but it is difficult to adjust the print application amount of solder with the conventional squeegee. Therefore, depending on the type of component, if the amount of solder is too large, the proportion of the solder bridge 84 between the adjacent pattern or the adjacent component is high, and, on the contrary, if the amount of solder is too small, the adhesive strength of the solder becomes weak. Easier to do.

Therefore, the present invention solves the above-mentioned problems, and an object of the present invention is to provide a squeegee in which the coating amount of a coating agent such as solder can be adjusted and an appropriate coating amount of the coating agent can be applied by printing. And

[0011]

Means for Solving the Problems The present invention achieves the above-mentioned object, in a squeegee used in a screen printing machine for printing and applying a coating material using a screen and a squeegee formed of an elastic member, A main squeegee provided in front of the direction of travel of the squeegee and an auxiliary squeegee provided behind the main squeegee at a predetermined interval so that the amount of printing material applied can be adjusted. Is characterized by.

Further, the hardness of the auxiliary squeegee is softer than the hardness of the main squeegee so that the auxiliary squeegee is easily adapted to the opening hole formed in the screen.

[0013]

According to the present invention, when the main squeegee and the auxiliary squeegee having different hardnesses pass through the holes formed in the screen while elastically contacting with the screen, first, the main squeegee having the higher hardness is used. The coating agent on the screen is filled in the holes formed in the screen in substantially the same plane as the surface. Then, when the auxiliary squeegee having a softer hardness than the main squeegee passes, a part of the elastic contact part of the squeegee fits into the hole of the screen and scrapes a part of the coating agent filled in the hole, Adjust the coating amount of the coating agent.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a view showing a screen printing machine, (a) is a side sectional view showing a printing state, (b) is a sectional view showing a component mounting state,
(C) is a sectional view showing a soldering state. Reference numeral 10 denotes a holder, which is plate-shaped and has a groove 11 for holding the main squeegee 15 and the auxiliary squeegee 20 formed in the length direction from the lower surface to the upper surface of the holder 10. Holder 10
Is held at both ends in parallel with the upper surface of the mask 25, and is held by a moving mechanism (not shown) that moves in the left-right direction (arrow D or E direction). The holder 10 is also held by a vertical movement mechanism (not shown) that moves in the vertical direction (direction of arrow B or C), and can move vertically and horizontally (the vertical movement mechanism is fixed to the movement mechanism, Holder 10
Is held by the vertical movement mechanism. Alternatively, the moving mechanism is fixed to the vertical movement mechanism, and the holder 10 is held by the moving mechanism. ). Incidentally, the holder is generally constituted by two holders 10 squeegeeing in the direction of arrow D and two holders squeezing in the direction of arrow E (inclination of the holder 10 is in the opposite direction, not shown) facing each other in parallel. Depending on the direction, one of the two goes up and stands by.

The main squeegee 15 and the auxiliary squeegee 20 are in elastic contact with the upper surface 27 of the mask 25, and
Squeegee the solder 40 supplied to the mask 25
Is a member for printing and applying the solder 40 on the pattern 31 of the substrate 30 which is filled in the holes 26 of the substrate 25 and adheres to the lower surface 28 of the mask 25. The main squeegee 15 and the auxiliary squeegee 20 are attached to the holder 10 so that the leading edge portions 11 and 16 of the main squeegee 15 and the auxiliary squeegee 20 make elastic contact with the upper surface 27 of the mask 25. The upper part of 20 is inclined in the direction of squeezing. In addition, the upper surface 27 of the mask 25 and the edge portion 1
The positional relationship between Nos. 1 and 16 can be finely adjusted by an adjuster installed above the holder 10. A hard urethane resin is used for the material of the main squeegee 15, and a soft urethane resin is used for the material of the auxiliary squeegee 20 so that the auxiliary squeegee 20 can easily fit in the holes 26 of the mask 25.

A hole 26 for printing and applying the solder 41 is formed in the mask 25 at a component mounting position on the substrate 30, and is installed on the substrate 30. The amount of solder applied is approximately equal to the area of the hole and the plate thickness of the mask 25. A thin stainless steel plate or the like is used as the material of the mask 25, and the holes are formed by etching or laser processing.

A conductor pattern 31 is formed on the substrate 30. Solder is printed and applied to the component mounting portion, the component is mechanically mounted on the portion, and the solder is melted and soldered in a high temperature furnace. Next, the operation will be described. First, the substrate 30 sent below the mask 25 is positioned and raised, and the upper surface 32 of the pattern 31 is brought into close contact with the lower surface 28 of the mask 25.

Next, the holder 10 is lowered and the main squeegee 1
5 and the tip edge portions 16 and 21 of the auxiliary squeegee 20 are elastically contacted with the upper surface 27 of the mask 25. When the main squeegee 15 and the auxiliary squeegee 20 are moved in the direction of arrow J in this state, the solder 40 supplied to the upper surface 27 of the mask 25
Are filled in the holes 26 of the mask 25 by the main squeegee 15. Then, when the auxiliary squeegee 20 is squeegeeed with the solder and the hole 26 is squeezed, a part of the edge portion 21 of the auxiliary squeegee 20 enters the hole 26 and is filled with the solder 4.
1 is made into a state in which the central portion is dented like the scraping solder 42. Then, when the substrate 30 is lowered to the original position below, the solder 42 filled in the holes 26 of the mask 25 escapes from the holes 26 and is printed and applied on the upper surface 32 of the pattern 31.

Next, the substrate 30 coated with the solder 42 is sent to the next step, and the component is mechanically mounted on the coated portion of the solder 42. At this time, as shown in FIG. 1B, the solder 42 is pressed against the component and does not protrude from the pattern 31, and has a shape close to the original state like the solder 44. Then, the component and the pattern 31 are soldered in the high temperature furnace of the next step to form the solder fillet 45 as shown in FIG.

As described above, according to this embodiment,
Since the same portion is squeezed twice by the main squeegee 15 and the auxiliary squeegee 20 having a different hardness, an appropriate amount of solder can be applied and the soldering quality is improved. It should be noted that if the auxiliary squeegee 20 is installed only on a portion of the substrate 30 where solder amount adjustment is required, the solder amount can be partially adjusted on the substrate 30. Further, in the present embodiment, the main squeegee 15 and the auxiliary squeegee 20 are attached to one holder 10, but by attaching them to different holders, finer pressure adjustment or the like becomes possible, and the solder print application amount is adjusted. Will be even easier.

In this embodiment, the printing application in the case of using solder as the coating agent has been described. However, the same effect as in the case of solder is also applied to other applications such as adhesives and paints. Can be obtained.

[0022]

As described above, according to the present invention, the coating amount of the coating agent can be accurately adjusted, and the optimum amount of the coating agent can be applied by printing, and high quality and highly reliable soldering can be achieved. It will be possible.

[Brief description of drawings]

FIG. 1 is a screen printing machine showing an embodiment of the present invention,
(A) is a side sectional view showing a printed state, (b) is a sectional view showing a component mounting state, and (c) is a sectional view showing a soldering state.

2A and 2B are views showing a conventional screen printing machine, in which FIG. 2A is a side sectional view showing a printing state, FIG. 2B is a sectional view showing a component mounting state, and FIG. 2C is a sectional view showing a soldering state. is there.

[Explanation of symbols]

 10 ... Holder 15 ... Main squeegee 20 ... Auxiliary squeegee 25 ... Mask 30 ... Substrate 31 ... Pattern 40 ... Solder 50 ... Parts

Claims (2)

[Claims] 1. A squeegee used in a screen printing machine for printing and applying a coating material using a screen and a squeegee formed of an elastic member, wherein a main squeegee provided in front of the squeegee traveling direction, A squeegee characterized by comprising an auxiliary squeegee provided behind the main squeegee at a predetermined interval so that the printing amount of the coating material can be adjusted. 2. The squeegee according to claim 1, wherein the hardness of the auxiliary squeegee is softer than that of the main squeegee so that the auxiliary squeegee can easily fit in the opening hole formed in the screen.