JP2005235849A - Thin substrate fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin substrate fixture capable of eliminating the cause of incomplete mounting by securing the entire surface of a thin substrate stably. <P>SOLUTION: The thin substrate fixture has a weak adhesive layer formed on one side of a plate wherein a region of different thickness is formed in the weak adhesive layer. The region of different thickness is formed by laying a different weak adhesive layer, by die molding, or by removing a part of the weak adhesive layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a thin substrate fixing jig used when a thin flexible printed wiring board is placed and fixed, and storage / transfer / electronic parts are mounted.

Recently, printed wiring boards have been used in many electronic devices due to improved productivity and high reliability. In recent years, a flexible printed wiring board (hereinafter referred to as a thin board) having a conductor pattern on the surface of a film-like insulating board has been widely used in order to cope with the reduction in size and weight of electronic devices. In this thin substrate, a so-called surface mounting method in which an electronic component is mounted on the surface of the conductor pattern is widely adopted.
A thin substrate is usually subjected to a cream solder application process, etc., depending on the position of the electronic component to be mounted, etc., and then the electronic component is mounted on this cream solder application part, and then these are heated to remove the cream solder. It melts and hardens, and the electronic component is joined to a thin substrate (see Patent Document 1).

JP-A 63-204695

Because thin substrates are flexible, and due to recent progress in miniaturization, it is complicated and unstable to handle each of the above processes, storage, and transfer individually. A weak adhesive layer is formed on the surface of a rigid plate (plate), and a thin substrate is attached to the weak adhesive layer.
In a thin substrate, a high rigidity sheet “backing reinforcing plate” is bonded to the opposite surface of the circuit surface for a portion requiring rigidity such as an insertion / extraction type connector insertion portion. The backing reinforcing plate portion has a step of about 0.2 mm with respect to other portions. Further, when the surface on which a component such as an IC chip is mounted on a thin substrate is fixed to a jig, a step corresponding to the component dimension is generated.

When a thin substrate having such a step is fixed to a flat weak pressure-sensitive adhesive layer formed on the surface of a plate (plate), as shown in FIG. Becomes floating from the weak adhesive layer 24 on the plate material (plate) 23 and becomes unstable when the cream solder 25 or the like is printed / applied to the portion, causing the solder application position shift or the solder application amount variation. Such inconveniences are likely to occur.
Also, in order to absorb the steps of the backing reinforcement plate or mounted parts, the required part of the fixture for thin substrates may be counterbored, but conventional sacrificial machining is performed after forming a weak adhesive layer Therefore, it is difficult to leave a weak pressure-sensitive adhesive layer on the bottom, and as shown in FIG. 5, the counterbore processing is performed until the surface of the plate (plate) is reached, and the bottom of the counterbore processing portion is weak. Usually, the pressure-sensitive adhesive layer is not formed.

Therefore, when the step portion is inserted into the counterbored portion and the thin substrate is fixed to the fixing jig, the step portion is not substantially fixed. Also in this case, if it is necessary to print and apply the cream solder 25 to the portion, the plate separation state becomes unstable at the time of applying the cream solder, and the amount of applied solder may vary, which may cause mounting failure.
In addition to printing and applying cream solder, stability of fixing a thin substrate is desired not only in the mounting process, reflow process, and transfer process of electronic components.

  In view of the above points, an object of the present invention is to provide a thin substrate fixing jig that can stably fix the entire surface of a thin substrate and eliminate the cause of mounting defects.

  The thin substrate fixing jig of the present invention is a thin substrate fixing jig in which a weak adhesive layer is formed on one side of a flat plate, wherein regions having different thicknesses are formed in the weak adhesive layer.

  According to the thin substrate fixing jig of the present invention, by forming regions with different thicknesses on the weak adhesive layer, the thin substrate having a step is also fixed on the entire surface. Further, there is an advantage that it can stably cope with various processing / operations on a thin substrate. In addition, when the weak adhesive layer is formed in two steps, the adhesiveness and hardness of the bottom surface and the top surface can be arbitrarily changed.

The present invention is based on the fact that regions having different thicknesses are formed in the weak adhesive layer, and the weak adhesive layer is also formed at the bottom thereof.
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram for explaining a process of forming regions having different thicknesses by forming a plurality of weak adhesive layers (weak adhesive layers) according to the first embodiment of the present invention.
FIG. 2 shows a second embodiment of the present invention, in which regions having different thicknesses are formed in a weak adhesive layer (weak adhesive layer), and transferred or pasted on a plate (plate). It is a figure explaining the process of forming the area | region from which thickness differs according to.
FIG. 3 shows a third embodiment of the present invention, in which a flat weak adhesive layer (weak adhesive layer) is formed on a plate (plate) and then a weak adhesive layer (weak adhesive layer). It is a figure explaining the process of forming the area | region from which thickness differs by deleting the desired part.

In FIG. 1 showing the first embodiment of the present invention, 1 is a flat plate, 2 is a weak pressure-sensitive adhesive layer, and 5 is a second weak pressure-sensitive adhesive layer 3 and a second weak pressure-sensitive adhesive layer 3. It is a laminated sheet comprising the support sheet 4. 6 is a punched hole formed in the laminated sheet, and 7 is a weak adhesive layer.
A flat plate 1 is prepared (A), and a weak adhesive layer 2 is formed on the surface of the flat plate 1 (B). Separately, the second weak pressure-sensitive adhesive layer 3 is formed on the support sheet 4, and a laminated sheet 5 in which a punched hole 6 having a desired size and shape is formed at a desired position is prepared (C). On the agent layer 2, the second weak adhesive layer 3 side of the laminated sheet 5 is opposed and overlapped (d).
After performing the adhesive heat treatment between the weak pressure-sensitive adhesive layer 2 and the second weak pressure-sensitive adhesive layer 3, the support sheet 4 is peeled off (e).
After the support sheet 4 is peeled off, post-heat treatment is performed to form a weak adhesive layer 7.

In FIG. 2 which shows the 2nd Embodiment of this invention, 8 is the weak adhesive sheet which formed the thin part 9 of the desired magnitude | size and shape in the desired position by shaping | molding etc. FIG.
A weak pressure-sensitive adhesive sheet 8 in which a thin-walled portion 9 having a desired size and shape is formed at a desired position by molding a weak pressure-sensitive adhesive resin, roll forming with unevenness, or the like is prepared. Place and integrate (b). The cured weak adhesive sheet 8 may be integrated with the flat plate 1 by the adhesive layer 10 (C).

In FIG. 3 which shows the 3rd Embodiment of this invention, 11 is a flat weak adhesive sheet, 12 is the recessed part formed in the weak adhesive sheet 11 surface joined to the flat plate 1. FIG. .
A weak pressure-sensitive adhesive sheet 11 is prepared (A) and placed on the flat plate 1 (B). After the adhesive heat treatment between the weak pressure-sensitive adhesive sheet 11 and the flat plate 1, a recess 12 having a desired size and shape is formed at a desired position on the surface of the weak pressure-sensitive adhesive sheet 11. As a method for forming the recesses 12, an appropriate method such as heat evaporation removal with a laser beam or embossing before curing can be employed.
In addition, after forming a weak adhesive layer on a flat plate and forming a counterbore that is thicker than the weak adhesive layer as in the past, the bottom of the counterbore part or the entire surface including the weak adhesive layer, It is also possible to form a weak adhesive layer.

The material which comprises the fixing jig for thin substrates of this invention is demonstrated.
The material of the flat plate is not particularly limited as long as it is a rigid body having heat resistance capable of withstanding heating for mounting electronic components by cream solder. For example, aluminum alloy, glass epoxy composite plate, magnesium alloy, etc. It is mentioned as a suitable thing.
As the material for forming the weak pressure-sensitive adhesive layer, it is desirable to have heat resistance, cold resistance, electrical insulation, self-adhesion, and capable of repeatedly adhering, for example, silicone, polyimide silicone, Examples thereof include elastomer materials having high heat resistance such as those obtained by curing a fluorinated elastomer having a fluorinated polyether skeleton having a curable functional group.
When the weak adhesive layer is substantially composed of a plurality of layers, the adhesive strength of the weak adhesive layer in the portion where the thin substrate, the backing reinforcing plate constituting the step, and the mounted electronic component are in contact with each other is made different. Or, the material of the weak adhesive layer may be changed, or the like may be appropriately modified.
The surface of the weak pressure-sensitive adhesive layer 4 is preferably finished to a mirror surface.

When forming a weak adhesive layer on a flat plate, it is preferable to form an undercoat with a weak adhesive including a coupling agent, for example, a silane coupling agent, on the flat plate to form a weak adhesive layer.
When forming a base film with the liquid silicone resin adhesive containing a silane coupling, it is preferable that the thickness of a base film shall be 10-20 micrometers.
Although the thickness of a weak adhesive layer can be set suitably, generally it is 50-250 micrometers, Preferably it is 75-150 micrometers.
Although there is no special restriction | limiting as a support sheet, PET, PE, PP, etc. are used from intensity | strength and ease of handling.
The rubber hardness of the weak adhesive layer forming the step is preferably 20 to 70 ° Hs, and particularly preferably 40 to 60 ° Hs. The depth of the step is preferably the same depth as the step between the reinforcing plate, the mounting component, etc. and the thin substrate.
The difference in different thicknesses provided in the weak adhesive layer of the thin substrate fixing jig is preferably the same depth as the step difference between the backing reinforcing plate, the mounted component and the thin substrate.

A liquid silicone resin adhesive TSE3221 (manufactured by Toshiba Silicone Co., Ltd.) containing a silane coupling agent on one side of an aluminum flat plate was applied by screen printing at a thickness of 10 μm and heat-cured, and then uncured as a weak adhesive layer. A millable type silicone rubber KE-9510U (manufactured by Shin-Etsu Chemical Co., Ltd.), which was formed into a sheet shape with a thickness of 100 μm by a calendar roll, was attached and heat cured at 130 ° C. for 30 minutes. Separately, KE-9510U is formed into a sheet shape with a thickness of 200 μm on a support sheet made of PET by a calender roll, and this sheet-like product is punched into a shape corresponding to a predetermined region, and the aluminum flat plate previously produced Affixed on the weak adhesive layer, heat-cured at 130 ° C. for 3 minutes, peeled off the support sheet, and further heat treated at 270 ° C. for 30 minutes with a hot air dryer to prepare a thin substrate fixing jig (FIG. 1). .
The fixing of the thin substrate having a step to the fixing jig for the thin plate substrate was performed on the entire surface, and there was no problem of the position misalignment of the cream solder even when printing or applying the cream solder.

  According to the present invention, the printing, application and other operations of the cream solder on the stepped portion of the thin board can be stably performed. The tolerance in the operation process is more reliably improved than before, and can be suitably used as a thin substrate fixing jig which is very desirable in the field of electronic equipment manufacturing.

It is 1st Embodiment of this invention, Comprising: It is a figure explaining the process of forming the area | region where thickness differs by making a weak adhesive layer (weak adhesive layer) into multiple steps. In the second embodiment of the present invention, regions having different thicknesses are formed in the weak adhesive layer (weak adhesive layer), and the thicknesses are different by transferring or pasting on the plate (plate). It is a figure explaining the process of forming a field. In the third embodiment of the present invention, after forming a flat weak adhesive layer (weak adhesive layer) on a plate (plate), a desired part of the weak adhesive layer (weak adhesive layer) is formed. It is a figure explaining the process of forming the area | region from which thickness differs by deleting. It is a figure explaining the state in which the thin board | substrate has lifted from the weak adhesive layer in a prior art. It is a figure explaining that fixation of the level | step-difference part of a thin substrate is unstable when the counterbore process is performed in a prior art.

Explanation of symbols

1: flat plate 2: weak adhesive layer 3: second weak adhesive layer 4: support sheet 5: laminated sheet 6: punched hole 7: weak adhesive layer 8: weak adhesive sheet 9: thin-walled portion 10: adhesive Layer 11: Weak adhesive sheet 12: Recess 21: Thin substrate 22: Step (of thin substrate) 23: Plate material (plate)
24: Weak adhesive layer 25: Cream solder 26: Counterbored part

Claims (1)

  A thin substrate fixing jig in which a weak adhesive layer is formed on one side of a flat plate, wherein regions having different thicknesses are formed in the weak adhesive layer.

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