JPH06155954A - Metal mask - Google Patents
Metal maskInfo
- Publication number
- JPH06155954A JPH06155954A JP33218492A JP33218492A JPH06155954A JP H06155954 A JPH06155954 A JP H06155954A JP 33218492 A JP33218492 A JP 33218492A JP 33218492 A JP33218492 A JP 33218492A JP H06155954 A JPH06155954 A JP H06155954A
- Authority
- JP
- Japan
- Prior art keywords
- pads
- adjacent
- pad
- small openings
- metal mask
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
- H05K3/12—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns
- H05K3/1216—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns by screen printing or stencil printing
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
- H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
- H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
- H05K3/341—Surface mounted components
- H05K3/3421—Leaded components
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
- H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
- H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
- H05K3/3457—Solder materials or compositions; Methods of application thereof
Landscapes
- Electric Connection Of Electric Components To Printed Circuits (AREA)
- Manufacturing Of Printed Wiring (AREA)
- Printing Plates And Materials Therefor (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、プリント配線板のパッ
ドにステンシル法によりクリームはんだを供給する際に
用いるメタルマスクに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal mask used when cream solder is supplied to a pad of a printed wiring board by a stencil method.
【0002】[0002]
【従来の技術】プリント配線板に表面実装型ICなどの
電子部品をはんだ付けする方法として、リフローソルダ
リング法がある。この方法はプリント配線板に形成した
パッドにクリームはんだを供給し、ICのリードなどを
このクリームはんだに仮止めし、リフロー炉で加熱する
ことによりクリームはんだを溶融し、はんだ付けするも
のである。2. Description of the Related Art A reflow soldering method is known as a method for soldering an electronic component such as a surface mount IC to a printed wiring board. In this method, cream solder is supplied to a pad formed on a printed wiring board, IC leads and the like are temporarily fixed to this cream solder, and the cream solder is melted by heating in a reflow furnace and soldered.
【0003】ここにクリームはんだをパッドに供給する
1つの方法としてステンシル法が広く知られている。こ
のステンシル法では、ステンレス板あるいはニッケル板
にクリームはんだを供給するパッドに対応する開口をエ
ッチング法などで加工して、メタルマスク(ステンシル
板ともいう)をまず作る。そしてこのメタルマスクをプ
リント配線板に密着させ、メタルマスクの上からこのメ
タルマスクの厚さにより決まる量のクリームはんだを塗
布してからメタルマスクを剥すことにより、メタルマス
クの開口に入ったクリームはんだをパッドに供給するも
のである。The stencil method is widely known as one method of supplying cream solder to the pad. In this stencil method, an opening corresponding to a pad for supplying cream solder to a stainless plate or a nickel plate is processed by an etching method or the like to first make a metal mask (also called a stencil plate). Then, the metal mask is brought into close contact with the printed wiring board, and the amount of cream solder determined by the thickness of the metal mask is applied onto the metal mask, and then the metal mask is peeled off. Is supplied to the pad.
【0004】図7は従来のメタルマスクの一例を一部省
略して示す平面図、図8はその開口の配置を示す一部拡
大図、図9は開口の他の配置例を示す図である。図7に
示されたメタルマスク10は4辺にリードを持つフラッ
トパッケージ型のLSIをリフローはんだ付けする場合
に用いられる。FIG. 7 is a plan view showing an example of a conventional metal mask with a part thereof omitted, FIG. 8 is a partially enlarged view showing the layout of the openings, and FIG. 9 is a view showing another layout example of the openings. . The metal mask 10 shown in FIG. 7 is used when reflow soldering a flat package type LSI having leads on four sides.
【0005】メタルマスク10の開口群12は、図8の
ように4角型の各辺に沿って並んだ多数の長方形の開口
14で形成される。この図8のメタルマスク10を用い
た場合のクリームはんだ供給状況は図10に、またリー
ドのはんだ付け状況は図11に示されている。The group of openings 12 of the metal mask 10 is formed by a large number of rectangular openings 14 arranged along each side of a square as shown in FIG. FIG. 10 shows the cream solder supply situation and the lead soldering situation when the metal mask 10 shown in FIG. 8 is used.
【0006】すなわち図10の(A)に示すように、プ
リント配線板16の各パッド18にクリームはんだ20
が盛り上がるように供給される。なお図10の(A)お
よび(B)はLSI22のリード24がクリームはんだ
20から離れた状態を示す断面図と平面図である。That is, as shown in FIG. 10A, cream solder 20 is applied to each pad 18 of the printed wiring board 16.
Is supplied so that it will rise. 10A and 10B are a cross-sectional view and a plan view showing a state where the leads 24 of the LSI 22 are separated from the cream solder 20.
【0007】従ってこの図10の状態からLSI22の
リード24をクリームはんだ20に押圧すれば、図11
に示すようにクリームはんだ20がパッド18から周囲
に溢れ出る。ここに図11の(A)は断面図、図11の
(B)は平面図である。Therefore, if the leads 24 of the LSI 22 are pressed against the cream solder 20 from the state shown in FIG.
The cream solder 20 overflows from the pad 18 to the surroundings as shown in FIG. Here, FIG. 11A is a cross-sectional view and FIG. 11B is a plan view.
【0008】このようにクリームはんだ20がパッド1
8の外側へ溢れると、隣接するパッド18の間隙が小さ
い場合には図11(B)に示すように隣接するパッド同
志がクリームはんだ20で接続される。このためクリー
ムはんだ20を溶融し凝固させた時に隣接するパッド間
にはんだブリッジが形成される。In this way, the cream solder 20 is applied to the pad 1
If the gap between adjacent pads 18 is small when they overflow to the outside of 8, the adjacent pads are connected by cream solder 20 as shown in FIG. 11B. Therefore, when the cream solder 20 is melted and solidified, a solder bridge is formed between the adjacent pads.
【0009】また図9のメタルマスク10Aはパッド群
12Aを構成する隣接する開口14Aを、その隣接方向
に対して直角に互いに偏位させたものである。この場合
のクリームはんだ供給状況とはんだ付け状況が図12、
13、14に示されている。In the metal mask 10A of FIG. 9, the adjacent openings 14A forming the pad group 12A are offset from each other at right angles to the adjacent direction. The cream solder supply situation and soldering situation in this case are shown in FIG.
13 and 14 are shown.
【0010】すなわち図12の(A)はクリームはんだ
供給状況を示す平面図、図13の(A1)はそのA1−
A1断面図、図14のB1は同じくB1−B1断面図で
ある。また図12の(B)ははんだ付け状況を示す平面
図、図13の(A2)はそのA2−A2断面図、図14
の(B2)はそのB2−B2断面図である。That is, FIG. 12A is a plan view showing the cream solder supply state, and FIG. 13A1 is its A1-.
A1 sectional view, B1 of FIG. 14 is a B1-B1 sectional view similarly. 12B is a plan view showing the soldering condition, FIG. 13A2 is a sectional view taken along line A2-A2, and FIG.
(B2) is a B2-B2 sectional view thereof.
【0011】これらの図から明らかなように、クリーム
はんだ20はパッド18の端部に片寄って供給されるた
め、はんだはリード24とパッド18の対向面間に均一
に広がらず、パッド18の端に玉状に固まってしまう。As is apparent from these figures, the cream solder 20 is supplied to the end portion of the pad 18 while being offset, so that the solder does not spread evenly between the opposing surfaces of the lead 24 and the pad 18, and the end portion of the pad 18 is not spread. It solidifies into a ball.
【0012】[0012]
【従来技術の問題点】図8のように開口14を配置した
メタルマスク10を用いた場合には、隣接パッド18間
にはんだブリッジが形成され易く、接続不良による製品
不止まりが悪くなる問題が生じる。このためパッド18
の間隔を十分に大きくする必要が生じ、リード間隔を小
さくして高密度実装を行う場合の大きな障害となってい
た。2. Description of the Related Art When the metal mask 10 having the openings 14 as shown in FIG. 8 is used, a solder bridge is likely to be formed between the adjacent pads 18, resulting in a problem that the product unstoppability is deteriorated due to a connection failure. Occurs. Therefore, the pad 18
It becomes necessary to sufficiently increase the distance between the two, which is a major obstacle to high-density mounting by reducing the lead distance.
【0013】また図9のように開口14Aを交互にづら
したメタルマスク10Aを用いた場合にはリード24と
パッド18との対向面間にはんだが広がらずはんだ付け
不良を発生し易いという問題が生じる。Further, when the metal mask 10A having the openings 14A alternately arranged as shown in FIG. 9 is used, there is a problem that the solder does not spread between the facing surfaces of the leads 24 and the pads 18 and a soldering failure is likely to occur. Occurs.
【0014】[0014]
【発明の目的】本発明はこのような事情に鑑みなされた
ものであり、隣接するパッド間のはんだブリッジが生成
されにくくし、パッド間隔を狭くして高密度実装を可能
にすると共に、はんだ付け不良も発生しにくくすること
ができるメタルマスクを提供することを目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and makes it difficult for solder bridges between adjacent pads to be formed, and makes the pad interval narrower to enable high-density mounting and to perform soldering. It is an object of the present invention to provide a metal mask that can prevent defects from occurring.
【0015】[0015]
【発明の構成】本発明によればこの目的は、プリント配
線板のパッドにステンシル法によりクリームはんだを供
給するために用いるメタルマスクにおいて、1つのパッ
ドに対して複数の小開口が形成され、隣接するパッドに
対向する各小開口がこれらパッドの隣接方向に直角な方
向に互いに偏位していることを特徴とするメタルマスク
により達成される。According to the present invention, an object of the present invention is to provide a plurality of small openings for one pad in a metal mask used for supplying cream solder to a pad of a printed wiring board by a stencil method. It is achieved by a metal mask characterized in that the small openings facing each other are offset from each other in a direction perpendicular to the direction in which the pads are adjacent.
【0016】[0016]
【実施例】図1は本発明の一実施例であるメタルマスク
の一部を示す平面図、図2はその一部である領域IIの
拡大図、図3はこのメタルマスク10Bを使った場合の
クリームはんだ供給状況を示す図である。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view showing a part of a metal mask which is an embodiment of the present invention, FIG. 2 is an enlarged view of a region II which is a part thereof, and FIG. 3 is a case where this metal mask 10B is used. It is a figure which shows the cream solder supply situation of.
【0017】このメタルマスク10Bには、プリント配
線板16の長方形のパッド18の形状内に入る3つの小
開口14Bが形成されている。すなわち各パッド18の
長手方向に3つの小開口14Bが一列に並んでいる。ま
た隣接するパッド18、18に対する各小開口14B
は、その隣接方向に直交する方向に互いに偏位してい
る。The metal mask 10B is formed with three small openings 14B which fit within the shape of the rectangular pad 18 of the printed wiring board 16. That is, three small openings 14B are arranged in a line in the longitudinal direction of each pad 18. Also, each small opening 14B for the adjacent pads 18 and 18
Are offset from each other in a direction orthogonal to their adjacent directions.
【0018】例えばLSI22のリード24のピッチが
0.5mm、プリント配線板16のパッド寸法が0.2
5mm×1.3mmの場合には、各小開口14Bの直径
は0.25mmとされ、そのパッド18の長手方向のピ
ッチは0.4mmに設定される。また図2に示すよう
に、隣接するパッド18、18の小開口14B、14B
は、パッド18の長手方向に互いに0.2mm偏位して
いる。For example, the pitch of the leads 24 of the LSI 22 is 0.5 mm, and the pad size of the printed wiring board 16 is 0.2.
In the case of 5 mm × 1.3 mm, the diameter of each small opening 14B is 0.25 mm, and the pitch of the pads 18 in the longitudinal direction is set to 0.4 mm. Further, as shown in FIG. 2, the small openings 14B, 14B of the adjacent pads 18, 18 are formed.
Are offset from each other by 0.2 mm in the longitudinal direction of the pad 18.
【0019】従ってこのメタルマスク10Bを用いれば
図3に示すように、プリント配線板16の各パッド18
上に点状に3つのクリームはんだ20Bが供給される。
なお図3の(A)はプリント配線板16の平面図、同図
の(B)はそのB−B線断面図である。Therefore, if this metal mask 10B is used, as shown in FIG. 3, each pad 18 of the printed wiring board 16 is used.
Three cream solders 20B are supplied in a dot shape on the top.
3A is a plan view of the printed wiring board 16 and FIG. 3B is a sectional view taken along line BB thereof.
【0020】図4の(A)、(B)はこのプリント配線
板16にLSI22を実装する直前の状態を示す側面図
と平面図、図5の(A)、(B)は同じくLSI22を
クリームはんだ20Bに接着し仮止めした状態を示す側
面図と平面図、図6の(A)、(B)はさらにクリーム
はんだを溶融後凝固させた状態を示す側面図と平面図で
ある。4A and 4B are a side view and a plan view showing a state immediately before the LSI 22 is mounted on the printed wiring board 16, and FIGS. 5A and 5B are the same as the LSI 22 cream. 6A and 6B are a side view and a plan view showing a state where the cream solder is adhered to and temporarily fixed to the solder 20B, and FIGS. 6A and 6B are a side view and a plan view showing a state in which the cream solder is further melted and then solidified.
【0021】クリームはんだ20Bにリード24を押圧
すれば、図5に示すように隣接するパッド18、18の
クリームはんだ20Bの分布はパッド18の長手方向に
不均一になる。しかしリフロー炉で加熱しクリームはん
だ20Bを溶融させれば、リード24とパッド18との
間隙に毛細管現象によって吸い込まれる。このため溶融
したクリームはんだ20Bは、図6に示すようにリード
24とパッド18との間に均一に流れ込み、リード24
とパッド18との間隙全体がはんだ付けされる。なお図
6の(A)において20Cはこのクリームはんだ20B
が溶融後に凝固した状態を示している。When the lead 24 is pressed against the cream solder 20B, the distribution of the cream solder 20B on the adjacent pads 18, 18 becomes uneven in the longitudinal direction of the pad 18, as shown in FIG. However, if the cream solder 20B is melted by heating in the reflow oven, it is sucked into the gap between the lead 24 and the pad 18 by the capillary phenomenon. Therefore, the melted cream solder 20B uniformly flows between the lead 24 and the pad 18 as shown in FIG.
The entire gap between the pad and the pad 18 is soldered. In FIG. 6A, 20C is the cream solder 20B.
Shows the state of solidification after melting.
【0022】以上の実施例はLSI22のリード24を
はんだ付けするためのパッド18について説明したが、
本発明はこれに限られず、チップ型抵抗器などの表面実
装型部品を高密度実装するプリント配線板に適用するも
のも含む。In the above embodiment, the pad 18 for soldering the lead 24 of the LSI 22 has been described.
The present invention is not limited to this, and also includes application to a printed wiring board on which surface-mounted components such as chip resistors are mounted at high density.
【0023】またパッド18の形状はこの実施例のよう
な長方形に限られるものではない。例えば円形のパッド
が隣接している場合には、両パッドに対向するメタルマ
スクの小開口を隣接方向に直角な方向へ偏位させればよ
い。要するに隣接するパッドに点状に供給するクリーム
はんだが互いに離隔するように小開口を配置すればよ
い。The shape of the pad 18 is not limited to the rectangular shape as in this embodiment. For example, when circular pads are adjacent to each other, the small openings of the metal mask facing both pads may be displaced in a direction perpendicular to the adjacent direction. In short, the small openings may be arranged so that the cream solders that are supplied to the adjacent pads in spots are separated from each other.
【0024】メタルマスクに形成する小開口14Bの形
状は円形とするのが望ましいが、パッド18の形状に対
応して楕円形や角型など他の形状としてもよい。The shape of the small opening 14B formed in the metal mask is preferably circular, but may be other shape such as elliptical or rectangular corresponding to the shape of the pad 18.
【0025】[0025]
【発明の効果】請求項1の発明は以上のように、1つの
パッドに対して複数の小開口が形成され、隣接するパッ
ドに対向する小開口はこの隣接方向に直角な方向に互い
に偏位されているから、隣接するパッドに小開口から点
状に供給されるクリームはんだの位置が離れることにな
る。As described above, according to the invention of claim 1, a plurality of small openings are formed for one pad, and the small openings facing the adjacent pads are displaced from each other in a direction perpendicular to the adjacent direction. Therefore, the positions of the cream solders, which are supplied in dots from the small openings to the adjacent pads, are separated from each other.
【0026】このため隣接するパッド間にはんだブリッ
ジが発生しにくくなり、製品の歩留まりが向上する。ま
たパッド間隔を狭くして高密度実装化を促進することが
できる。さらにはんだはパッドを実装部品のリードとの
間に均一に広がって供給されるから、はんだ付けの不良
が発生しにくくなり、信頼性が向上する。Therefore, a solder bridge is less likely to occur between adjacent pads, and the product yield is improved. In addition, the pad interval can be narrowed to facilitate high-density mounting. Further, the solder is supplied so that the pads are evenly spread between the pads and the leads of the mounted components, so that defective soldering is less likely to occur and reliability is improved.
【図1】本発明の一実施例の平面図FIG. 1 is a plan view of an embodiment of the present invention.
【図2】その一部領域IIの拡大図FIG. 2 is an enlarged view of a partial area II thereof.
【図3】このメタルマスクを用いた場合のクリームはん
だ供給状況を示す図FIG. 3 is a diagram showing a cream solder supply situation when this metal mask is used.
【図4】部品実装前を示す図FIG. 4 is a diagram showing a state before component mounting.
【図5】部品接着状態を示す図FIG. 5 is a diagram showing a state where components are bonded.
【図6】部品はんだ付け状態を示す図FIG. 6 is a diagram showing a soldered state of parts
【図7】従来のメタルマスクの一例を示す平面図FIG. 7 is a plan view showing an example of a conventional metal mask.
【図8】その一部拡大図[Figure 8] Partly enlarged view
【図9】開口の他の配置例を示す図FIG. 9 is a diagram showing another arrangement example of openings.
【図10】部品実装前を示す図FIG. 10 is a diagram showing a state before component mounting.
【図11】部品接着状態を示す図FIG. 11 is a view showing a bonded state of parts.
【図12】部品の接着状態およびはんだ付け状態を示す
平面図FIG. 12 is a plan view showing a bonded state and a soldered state of parts.
【図13】部品の接着状態およびはんだ付け状態を示す
側面図FIG. 13 is a side view showing a bonded state and a soldered state of components.
【図14】部品の接着状態およびはんだ付け状態を示す
側面図FIG. 14 is a side view showing a bonded state and a soldered state of components.
10B メタルマスク 14B 小開口 18 パッド 20B クリームはんだ 22 実装部品としてのLSI 24 リード 10B Metal mask 14B Small opening 18 Pad 20B Cream solder 22 LSI as a mounting component 24 Lead
Claims (1)
によりクリームはんだを供給するために用いるメタルマ
スクにおいて、 1つのパッドに対して複数の小開口が形成され、隣接す
るパッドに対向する各小開口がこれらパッドの隣接方向
に直角な方向に互いに偏位していることを特徴とするメ
タルマスク。1. A metal mask used for supplying cream solder to a pad of a printed wiring board by a stencil method, wherein a plurality of small openings are formed for one pad, and each small opening facing an adjacent pad. A metal mask which is deviated from each other in a direction perpendicular to the direction in which these pads are adjacent to each other.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP33218492A JPH06155954A (en) | 1992-11-19 | 1992-11-19 | Metal mask |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP33218492A JPH06155954A (en) | 1992-11-19 | 1992-11-19 | Metal mask |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH06155954A true JPH06155954A (en) | 1994-06-03 |
Family
ID=18252112
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP33218492A Pending JPH06155954A (en) | 1992-11-19 | 1992-11-19 | Metal mask |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH06155954A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5868070A (en) * | 1997-05-19 | 1999-02-09 | International Business Machines Corporation | Method and system for applying solder paste on tape carrier package component sites |
-
1992
- 1992-11-19 JP JP33218492A patent/JPH06155954A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5868070A (en) * | 1997-05-19 | 1999-02-09 | International Business Machines Corporation | Method and system for applying solder paste on tape carrier package component sites |
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